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Singh V, Van Why SK. Monogenic Etiology of Hypertension. Med Clin North Am 2024; 108:157-172. [PMID: 37951648 DOI: 10.1016/j.mcna.2023.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2023]
Abstract
Monogenic hypertension encompasses a group of conditions wherein single gene mutations result in increased renal sodium reabsorption manifesting as low renin hypertension. As these diseases are rare, their contribution to hypertension in children and adolescents is often overlooked. Precise diagnosis is essential in those who have not been found to have more common identifiable causes of hypertension in adolescents, since treatment strategies for these rare conditions are specific and different from antihypertensive regimens for the other more common causes of hypertension in this age group. The objective of this review is to provide insight to the rare, monogenic forms of hypertension.
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Affiliation(s)
- Vaishali Singh
- Department of Pediatrics, Medical College of Wisconsin, Suite 510, 999 North 92nd Street, Milwaukee, WI 53226, USA.
| | - Scott K Van Why
- Department of Pediatrics, Medical College of Wisconsin, Suite 510, 999 North 92nd Street, Milwaukee, WI 53226, USA
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Park SJ, Shin JI. Diagnosis and Treatment of Monogenic Hypertension in Children. Yonsei Med J 2023; 64:77-86. [PMID: 36719014 PMCID: PMC9892546 DOI: 10.3349/ymj.2022.0316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 12/08/2022] [Accepted: 12/26/2022] [Indexed: 01/17/2023] Open
Abstract
Although the majority of individuals with hypertension (HTN) have primary and polygenic HTN, monogenic HTN is a secondary type that is widely thought to play a key role in pediatric HTN, which has the characteristics of early onset, refractory HTN with a positive family history, and electrolyte disorders. Monogenic HTN results from single genetic mutations that contribute to the dysregulation of blood pressure (BP) in the kidneys and adrenal glands. It is pathophysiologically associated with increased sodium reabsorption in the distal tubule, intravascular volume expansion, and HTN, as well as low renin and varying aldosterone levels. Simultaneously increased or decreased potassium levels also provide clues for the diagnosis of monogenic HTN. Discovering the genetic factors that cause an increase in BP has been shown to be related to the choice of and responses to antihypertensive medications. Therefore, early and precise diagnosis with genetic sequencing and effective treatment with accurate antihypertensive agents are critical in the management of monogenic HTN. In addition, understanding the genetic architecture of BP, causative molecular pathways perturbing BP regulation, and pharmacogenomics can help with the selection of precision and personalized medicine, as well as improve morbidity and mortality in adulthood.
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Affiliation(s)
- Se Jin Park
- Department of Pediatrics, Daejeon Eulji Medical Center, Eulji University School of Medicine, Daejeon, Korea
| | - Jae Il Shin
- Department of Pediatrics, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea.
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Khandelwal P, Deinum J. Monogenic forms of low-renin hypertension: clinical and molecular insights. Pediatr Nephrol 2022; 37:1495-1509. [PMID: 34414500 DOI: 10.1007/s00467-021-05246-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 07/16/2021] [Accepted: 07/19/2021] [Indexed: 11/25/2022]
Abstract
Monogenic disorders of hypertension are a distinct group of diseases causing dysregulation of the renin-angiotensin-aldosterone system and are characterized by low plasma renin activity. These can chiefly be classified as causing (i) excessive aldosterone synthesis (familial hyperaldosteronism), (ii) dysregulated adrenal steroid metabolism and action (apparent mineralocorticoid excess, congenital adrenal hyperplasia, activating mineralocorticoid receptor mutation, primary glucocorticoid resistance), and (iii) hyperactivity of sodium and chloride transporters in the distal tubule (Liddle syndrome and pseudohypoaldosteronism type 2). The final common pathway is plasma volume expansion and catecholamine/sympathetic excess that causes urinary potassium wasting; hypokalemia and early-onset refractory hypertension are characteristic. However, several single gene defects may show phenotypic heterogeneity, presenting with mild hypertension with normal electrolytes. Evaluation is based on careful attention to family history, physical examination, and measurement of blood levels of potassium, renin, and aldosterone. Genetic sequencing is essential for precise diagnosis and individualized therapy. Early recognition and specific management improves prognosis and prevents long-term sequelae of severe hypertension.
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Affiliation(s)
- Priyanka Khandelwal
- Division of Nephrology, Department of Pediatrics, All India Institute of Medical Sciences, New Delhi, 110029, India.
| | - Jaap Deinum
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
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Mashmoushi A, Wolf MTF. A narrative review of Hyporeninemic hypertension-an indicator for monogenic forms of hypertension. PEDIATRIC MEDICINE (HONG KONG, CHINA) 2022; 5:21. [PMID: 36325202 PMCID: PMC9624485 DOI: 10.21037/pm-21-48] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND OBJECTIVE While the role of the renin-angiotensin-aldosterone system (RAAS) in the development of hypertension is well known, the significance and contribution of low renin hypertension is often overlooked. RAAS stimulation results in more tubular absorption of sodium and water along the nephron, contributing to a higher circulating vascular volume. In addition, members of the RAAS system, such as angiotensin II, have direct effects on vascular vasoconstriction, the heart, aldosterone synthesis in the adrenal glands, the sympathetic nervous system, and the central nervous system. This has resulted in a line of antihypertensive therapeutics targeting RAAS with angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and renin inhibitors, which prevent conversion of angiotensinogen to angiotensin. While general practitioners and nephrologists are well aware of the causes and the long-term consequences of elevated renin and aldosterone levels, the opposite situation with low renin and/or low aldosterone levels is frequently underappreciated. The objective of this review is to provide insight to the less common forms of hyporeninemic hypertension. METHODS We searched the PubMed online library for keywords related to hyporeninemic hypertension and focused on the pediatric population. For pathophysiology we focused on literature of the last 5 years. KEY CONTENT AND FINDINGS The low renin and aldosterone levels may be indicators of inherited (especially when associated with hypokalemia), monogenic forms of hypertension stimulating excessive tubular sodium and water absorption which subsequently results in plasma volume expansion and hypertension. These forms of hypertension require frequently specific forms of therapy. This underlines the importance of the practitioner to be familiar with these rare diseases. CONCLUSIONS In this review article, we outline the different forms of hypertension characterized by low renin/low aldosterone and low renin/high aldosterone levels, how to diagnose these forms of hypertension, and how to treat them.
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Affiliation(s)
- Ahmad Mashmoushi
- Pediatric Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Matthias T F Wolf
- Pediatric Nephrology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Habeeb E, Aldosari S, Saghir SA, Cheema M, Momenah T, Husain K, Omidi Y, Rizvi SA, Akram M, Ansari RA. Role of Environmental Toxicants in the Development of Hypertensive and Cardiovascular Diseases. Toxicol Rep 2022; 9:521-533. [PMID: 35371924 PMCID: PMC8971584 DOI: 10.1016/j.toxrep.2022.03.019] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 03/17/2022] [Indexed: 12/12/2022] Open
Abstract
The incidence of hypertension with diabetes mellitus (DM) as a co-morbid condition is on the rise worldwide. In 2000, an estimated 972 million adults had hypertension, which is predicted to grow to 1.56 billion by 2025. Hypertension often leads to diabetes mellitus that strongly puts the patients at an increased risk of cardiovascular, kidney, and/or atherosclerotic diseases. Hypertension has been identified as a major risk factor for the development of diabetes; patients with hypertension are at two-to-three-fold higher risk of developing diabetes than patients with normal blood pressure (BP). Causes for the increase in hypertension and diabetes are not well understood, environmental factors (e.g., exposure to environmental toxicants like heavy metals, organic solvents, pesticides, alcohol, and urban lifestyle) have been postulated as one of the reasons contributing to hypertension and cardiovascular diseases (CVD). The mechanism of action(s) of these toxicants in developing hypertension and CVDs is not well defined. Research studies have linked hypertension with the chronic consumption of alcohol and exposure to metals like lead, mercury, and arsenic have also been linked to hypertension and CVD. Workers chronically exposed to styrene have a higher incidence of CVD. Recent studies have demonstrated that exposure to particulate matter (PM) in diesel exhaust and urban air contributes to increased CVD and mortality. In this review, we have imparted the role of environmental toxicants such as heavy metals, organic pollutants, PM, alcohol, and some drugs in hypertension and CVD along with possible mechanisms and limitations in extrapolating animal data to humans. Rising incidence of hypertension may be linked to chronic exposure with environmental toxicants. Urban lifestyle and alcohol intake may be responsible for increased incidence of hypertension among urbanites. Exposure with organic solvent, heavy metals and pesticides could also be contributing to the rise in blood pressure.
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Affiliation(s)
- Ehsan Habeeb
- Department of Pharmaceutical Sciences, College of Pharmacy, Health Professions Division, Nova Southeastern University, 3200S University Drive, Fort Lauderdale, FL 33200, USA
| | - Saad Aldosari
- Department of Pharmaceutical Sciences, College of Pharmacy, Health Professions Division, Nova Southeastern University, 3200S University Drive, Fort Lauderdale, FL 33200, USA
| | - Shakil A. Saghir
- The Scotts Company LLC, Marysville, OH 43041, USA
- Department of Biological and Biomedical Sciences, Aga Khan University, Karachi, Pakistan
| | - Mariam Cheema
- Department of Pharmaceutical Sciences, College of Pharmacy, Health Professions Division, Nova Southeastern University, 3200S University Drive, Fort Lauderdale, FL 33200, USA
| | - Tahani Momenah
- Department of Pharmaceutical Sciences, College of Pharmacy, Health Professions Division, Nova Southeastern University, 3200S University Drive, Fort Lauderdale, FL 33200, USA
| | - Kazim Husain
- Department of Gastrointestinal Oncology (FOB-2), Moffitt Cancer Center and Research Institute, Tampa, FL 33612, USA
| | - Yadollah Omidi
- Department of Pharmaceutical Sciences, College of Pharmacy, Health Professions Division, Nova Southeastern University, 3200S University Drive, Fort Lauderdale, FL 33200, USA
| | - Syed A.A. Rizvi
- Department of Pharmaceutical Sciences, School of Pharmacy, Hampton University, VA 23668, USA
| | - Muhammad Akram
- Department of Eastern Medicine and Surgery, Government College University Faisalabad, Faisalabad, Pakistan
| | - Rais A. Ansari
- Department of Pharmaceutical Sciences, College of Pharmacy, Health Professions Division, Nova Southeastern University, 3200S University Drive, Fort Lauderdale, FL 33200, USA
- Corresponding author.
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Fan P, Pan XC, Zhang D, Yang KQ, Zhang Y, Tian T, Luo F, Ma WJ, Liu YX, Wang LP, Zhang HM, Song L, Cai J, Zhou XL. Pediatric Liddle Syndrome Caused by a Novel SCNN1G Variant in a Chinese Family and Characterized by Early-Onset Hypertension. Am J Hypertens 2020; 33:670-675. [PMID: 32161960 PMCID: PMC7368168 DOI: 10.1093/ajh/hpaa037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 03/02/2020] [Accepted: 03/06/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Liddle syndrome (LS), an autosomal dominant disorder, is a common monogenic hypertension in pediatrics. In this study, we reported a novel SCNN1G variant in a Chinese family with pediatric LS, and conduct a systematic review of epithelial sodium channel (ENaC)-gene-positive LS cases to conclude the clinical genetic features of LS in childhood. METHODS Next-generation sequencing and in silico analysis were performed in the proband to discover candidate variants. Sanger sequencing was used to identify the predicted likely pathogenic variant. LS patients in this family were treated with amiloride. The Medline database was searched to summarize clinical features of pediatric LS cases whose age at genetic diagnosis was not more than 18 years. RESULTS Genetic analysis identified a novel SCNN1G missense variant (c.1874C>T, p.Pro625Leu) in the proband with LS in childhood. In silico analysis revealed this heterozygous variant was highly conserved and deleterious. A total of 38 publications described pediatric LS associated with 25 pathogenic variants in SCNN1B and SCNN1G in 54 children. Despite the phenotypic heterogeneity, early-onset hypertension is the most common feature. All LS patients in this family or the reviewed cases showed significantly improvements in hypertension and hypokalemia after treatment with ENaC inhibitors. CONCLUSIONS This study identified a novel SCNN1G missense variant in a patient with pediatric LS, expanding the genetic spectrum of SCNN1G and demonstrating the PY motif of γ-ENaC as a potential mutant region. Early identification and specific management of LS in children and adolescents are important to prevent the development of hypertensive end-organ disease.
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Affiliation(s)
- Peng Fan
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xiao-Cheng Pan
- Department of Graduate School, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, China
| | - Di Zhang
- Department of Emergency and Critical Care, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Kun-Qi Yang
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ying Zhang
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Tao Tian
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Fang Luo
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Wen-Jun Ma
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Ya-Xin Liu
- Department of Emergency and Critical Care, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lin-Ping Wang
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Hui-Min Zhang
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lei Song
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jun Cai
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Xian-Liang Zhou
- Department of Cardiology, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
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Raina R, Mahajan Z, Sharma A, Chakraborty R, Mahajan S, Sethi SK, Kapur G, Kaelber D. Hypertensive Crisis in Pediatric Patients: An Overview. Front Pediatr 2020; 8:588911. [PMID: 33194923 PMCID: PMC7606848 DOI: 10.3389/fped.2020.588911] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 09/08/2020] [Indexed: 01/17/2023] Open
Abstract
Hypertensive crisis can be a source of morbidity and mortality in the pediatric population. While the epidemiology has been difficult to pinpoint, it is well-known that secondary causes of pediatric hypertension contribute to a greater incidence of hypertensive crisis in pediatrics. Hypertensive crisis may manifest with non-specific symptoms as well as distinct and acute symptoms in the presence of end-organ damage. Hypertensive emergency, the form of hypertensive crisis with end-organ damage, may present with more severe symptoms and lead to permanent organ damage. Thus, it is crucial to evaluate any pediatric patient suspected of hypertensive emergency with a thorough workup while acutely treating the elevated blood pressure in a gradual manner. Management of hypertensive crisis is chosen based on the presence of end-organ damage and can range from fast-acting intravenous medication to oral medication for less severe cases. Treatment of such demands a careful balance between decreasing blood pressure in a gradual manner while preventing damage end-organ damage. In special situations, protocols have been established for treatment of hypertensive crisis, such as in the presence of endocrinologic neoplasms, monogenic causes of hypertension, renal diseases, and cardiac disease. With the advent of telehealth, clinicians are further able to extend their reach of care to emergency settings and aid emergency medical service (EMS) providers in real time. In addition, further updates on the evolving topic of hypertension in the pediatric population and novel drug development continues to improve outcomes and efficiency in diagnosis and management of hypertension and consequent hypertensive crisis.
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Affiliation(s)
- Rupesh Raina
- Department of Nephrology, Akron Children's Hospital, Akron, OH, United States.,Akron Nephrology Associates/Cleveland Clinic Akron General Medical Center, Akron, OH, United States
| | - Zubin Mahajan
- Akron Nephrology Associates/Cleveland Clinic Akron General Medical Center, Akron, OH, United States
| | - Aditya Sharma
- Department of Internal Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Ronith Chakraborty
- Akron Nephrology Associates/Cleveland Clinic Akron General Medical Center, Akron, OH, United States
| | - Sarisha Mahajan
- Cleveland Clinic Akron General Medical Center, Akron, OH, United States
| | - Sidharth K Sethi
- Pediatric Nephrology and Pediatric Kidney Transplantation, The Medicity Hospital, Kidney and Urology Institute, Medanta, Gurgaon, India
| | - Gaurav Kapur
- Division of Pediatric Nephrology and Hypertension, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, MI, United States
| | - David Kaelber
- Departments of Pediatrics, Internal Medicine, Population and Quantitative Health Sciences, Center for Clinical Informatics Research and Education, Case Western Reserve University and Metro Health System, Cleveland, OH, United States
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Enslow BT, Stockand JD, Berman JM. Liddle's syndrome mechanisms, diagnosis and management. Integr Blood Press Control 2019; 12:13-22. [PMID: 31564964 PMCID: PMC6731958 DOI: 10.2147/ibpc.s188869] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2019] [Accepted: 08/23/2019] [Indexed: 12/26/2022] Open
Abstract
Liddle's syndrome is a genetic disorder characterized by hypertension with hypokalemic metabolic alkalosis, hyporeninemia and suppressed aldosterone secretion that often appears early in life. It results from inappropriately elevated sodium reabsorption in the distal nephron. Liddle's syndrome is caused by mutations to subunits of the Epithelial Sodium Channel (ENaC). Among other mechanisms, such mutations typically prevent ubiquitination of these subunits, slowing the rate at which they are internalized from the membrane, resulting in an elevation of channel activity. A minority of Liddle's syndrome mutations, though, result in a complementary effect that also elevates activity by increasing the probability that ENaC channels within the membrane are open. Potassium-sparing diuretics such as amiloride and triamterene reduce ENaC activity, and in combination with a reduced sodium diet can restore normotension and electrolyte imbalance in Liddle's syndrome patients and animal models. Liddle's syndrome can be diagnosed clinically by phenotype and confirmed through genetic testing. This review examines the clinical features of Liddle's syndrome, the differential diagnosis of Liddle's syndrome and differentiation from other genetic diseases with similar phenotype, and what is currently known about the population-level prevalence of Liddle's syndrome. This review gives special focus to the molecular mechanisms of Liddle's syndrome.
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Affiliation(s)
| | | | - Jonathan M Berman
- New York Institute of Technology College of Osteopathic Medicine at Arkansas State University, Jonesboro, AR, USA
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O'Shea PM, Griffin TP, Denieffe S, Fitzgibbon MC. The aldosterone to renin ratio in the diagnosis of primary aldosteronism: Promises and challenges. Int J Clin Pract 2019; 73:e13353. [PMID: 31009143 DOI: 10.1111/ijcp.13353] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 03/16/2019] [Accepted: 04/18/2019] [Indexed: 12/20/2022] Open
Abstract
The complexity of evaluating patients for secondary treatable causes of hypertension is underappreciated. Primary aldosteronism (PA) is the most prevalent cause of secondary hypertension (3%-32% of hypertensive patients). The recent endocrine society clinical practice guideline (ESCPG), "The Management of Primary Aldosteronism: Case Detection, Diagnosis, and Treatment", differs from the previous version in the explicit recognition of PA as a major public health issue. Despite this, PA is underdiagnosed. The guidelines call on physicians to substantially ramp up the screening of hypertensive patients at risk of PA. Further, it recommends the plasma aldosterone to renin ratio (ARR), as the test of choice for screening for PA. However, the ARR is a highly variable test with reported diagnostic sensitivities and specificities ranging from 66% to 100% and 61% to 100%, respectively. Variability of the ARR can be attributed to the high degree of within-subject variation, differences in sampling protocols, laboratory assays, reporting units, the effect of medications and the population characteristics used to establish the decision thresholds. These factors render the possibility of false positive and false negative results-which have the potential to adversely impact patients. The limitations and caveats to the use of the ARR necessitate an effective clinic-laboratory interface, with specialist physician and clinical scientist collaboration for ARR result interpretation. Improvement in the diagnostic sensitivity and specificity of the ARR is predicated on harmonisation of pretesting patient preparation criteria, knowledge of the analytical methods used to derive the ratio and the method-specific threshold for PA.
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Affiliation(s)
- Paula M O'Shea
- Department of Clinical Biochemistry, Galway University Hospitals, Galway, Ireland
| | - Tomás P Griffin
- Centre for Diabetes, Endocrinology and Metabolism, Galway University Hospitals, Galway, Ireland
| | - Stephanie Denieffe
- University College Dublin and Department of Clinical Biochemistry & Diagnostic Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
| | - Maria C Fitzgibbon
- Department of Clinical Biochemistry & Diagnostic Endocrinology, Mater Misericordiae University Hospital, Dublin, Ireland
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Starr MC, Flynn JT. Neonatal hypertension: cases, causes, and clinical approach. Pediatr Nephrol 2019; 34:787-799. [PMID: 29808264 PMCID: PMC6261698 DOI: 10.1007/s00467-018-3977-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/12/2018] [Accepted: 05/01/2018] [Indexed: 12/24/2022]
Abstract
Neonatal hypertension is increasingly recognized as dramatic improvements in neonatal intensive care, advancements in our understanding of neonatal physiology, and implementation of new therapies have led to improved survival of premature infants. A variety of factors appear to be important in determining blood pressure in neonates, including gestational age, birth weight, and postmenstrual age. Normative data on neonatal blood pressure values remain limited. The cause of hypertension in an affected neonate is often identified with careful diagnostic evaluation, with the most common causes being umbilical catheter-associated thrombosis, renal parenchymal disease, and chronic lung disease. Clinical expertise may need to be relied upon to decide the best approach to treatment in such patients, as data on the use of antihypertensive medications in this age group are extremely limited. Available data suggest that long-term outcomes are usually good, with resolution of hypertension in most infants. In this review, we will take a case-based approach to illustrate these concepts and to point out important evidence gaps that need to be addressed so that management of neonatal hypertension may be improved.
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Affiliation(s)
- Michelle C. Starr
- Division of Nephrology, Department of Pediatrics, Seattle Children’s Hospital and University of Washington School of Medicine, Seattle, WA, USA
| | - Joseph T. Flynn
- Division of Nephrology, Department of Pediatrics, Seattle Children’s Hospital and University of Washington School of Medicine, Seattle, WA, USA
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11
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Fowokan A, Punthakee Z, Waddell C, Rosin M, Morrison KM, Gupta M, Rangarajan S, Teo K, Lear S. Multifactorial correlates of blood pressure in South Asian children in Canada: a cross-sectional study. BMJ Open 2019; 9:e027844. [PMID: 30962241 PMCID: PMC6500289 DOI: 10.1136/bmjopen-2018-027844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
OBJECTIVE We sought to explore various correlates of blood pressure (BP) and hypertension, and to identify the most important aggregate combination of correlates for BP in South Asian children. DESIGN Cross-sectional study SETTING: Community-based recruitment in two Canadian cities PARTICIPANTS: South Asian children (n=762) provided a range of physiological, lifestyle and social variables. BP was assessed using an automated device. Body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and BP were transformed to z-scores using published standards. OUTCOME MEASURES Linear and logistic regression analyses were used to explore associations between the range of variables with BP z-scores and hypertension while stepwise regression was used to identify aggregate factors that provided explanatory capacity for systolic BP (SBP) and diastolic BP (DBP) z-scores. RESULTS A range of variables were associated with BP z-score and hypertension in unadjusted analysis. On adjustment for confounders, the association between age (β=-0.054, 95% CI=-0.078 to 0.029), female sex (β=-0.208, 95% CI=-0.350 to -0.067), height (β=0.022, 95% CI=0.011 to 0.033), weight (β=0.047, 95% CI=0.040 to 0.055), BMI z-score (β=0.292, 95% CI=0.249 to 0.336), WC z-score (β=0.273, 95% CI=0.219 to 0.326), WHtR z-score (β=0.289, 95% CI=0.236 to 0.342), heart rate (β=0.016, 95% CI=0.010 to 0.022), child's perception of body image (β=0.183, 95% CI=0.128 to 0.239) and grip strength (β=0.025, 95% CI=0.007 to 0.043) with SBP z-score remained. In stepwise regression, age, sex, BMI z-score, heart rate and weight accounted for 30% of the variance of SBP z-score, while age, BMI z-score, heart rate and daily fast food intake accounted for 23% of the DBP z-score variance. CONCLUSION Our findings suggest that variables, such as age, sex, height, adiposity and heart rate, provide stronger explanatory capacity to BP variance and hypertension risk than other variables in South Asian children.
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Affiliation(s)
- Adeleke Fowokan
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Zubin Punthakee
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Charlotte Waddell
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
| | - Miriam Rosin
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - Milan Gupta
- Department of Medicine, McMaster University, Hamilton, Ontario, Canada
| | - Sumathy Rangarajan
- Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Koon Teo
- Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada
| | - Scott Lear
- Faculty of Health Sciences, Simon Fraser University, Vancouver, British Columbia, Canada
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Raina R, Krishnappa V, Das A, Amin H, Radhakrishnan Y, Nair NR, Kusumi K. Overview of Monogenic or Mendelian Forms of Hypertension. Front Pediatr 2019; 7:263. [PMID: 31312622 PMCID: PMC6613461 DOI: 10.3389/fped.2019.00263] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 06/10/2019] [Indexed: 12/16/2022] Open
Abstract
Monogenic or Mendelian forms of hypertension are described as a group of conditions characterized by insults to the normal regulation of blood pressure by the kidney and adrenal gland. These alterations stem from single mutations that lead to maladaptive overabsorption of electrolytes with fluid shift into the vasculature, and consequent hypertension. Knowledge of these various conditions is essential in diagnosing pediatric or early-onset adult hypertension as they directly affect treatment strategies. Precise diagnosis with specific treatment regimens aimed at the underlying physiologic derangement can restore normotension and prevent the severe sequelae of chronic hypertension.
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Affiliation(s)
- Rupesh Raina
- Department of Nephrology, Cleveland Clinic Akron General, Akron, OH, United States.,Akron Nephrology Associates, Cleveland Clinic Akron General, Akron, OH, United States.,Department of Pediatric Nephrology, Akron Children's Hospital, Akron, OH, United States
| | - Vinod Krishnappa
- Akron Nephrology Associates, Cleveland Clinic Akron General, Akron, OH, United States.,Department of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Abhijit Das
- Department of Medicine, Northeast Ohio Medical University, Rootstown, OH, United States
| | - Harshesh Amin
- Department of Internal Medicine, Carolinas Health Care System Blue Ridge, Morganton, NC, United States
| | | | - Nikhil R Nair
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States
| | - Kirsten Kusumi
- Department of Pediatric Nephrology, Akron Children's Hospital, Akron, OH, United States
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13
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Polfus LM, Boerwinkle E, Gibbs RA, Metcalf G, Muzny D, Veeraraghavan N, Grove M, Shete S, Wallace S, Milewicz D, Hanchard N, Lupski JR, Hashmi SS, Gupta-Malhotra M. Whole-exome sequencing reveals an inherited R566X mutation of the epithelial sodium channel β-subunit in a case of early-onset phenotype of Liddle syndrome. Cold Spring Harb Mol Case Stud 2017; 2:a001255. [PMID: 27900368 PMCID: PMC5111009 DOI: 10.1101/mcs.a001255] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
To comprehensively evaluate a European–American child with severe hypertension, whole-exome sequencing (WES) was performed on the child and parents, which identified causal variation of the proband's early-onset disease. The proband's hypertension was resistant to treatment, requiring a multiple drug regimen including amiloride, spironolactone, and hydrochlorothiazide. We suspected a monogenic form of hypertension because of the persistent hypokalemia with low plasma levels of renin and aldosterone. To address this, we focused on rare functional variants and indels, and performed gene-based tests incorporating linkage scores and allele frequency and filtered on deleterious functional mutations. Drawing upon clinical presentation, 27 genes were selected evidenced to cause monogenic hypertension and matched to the gene-based results. This resulted in the identification of a stop-gain mutation in an epithelial sodium channel (ENaC), SCNN1B, an established Liddle syndrome gene, shared by the child and her father. Interestingly, the father also harbored a missense mutation (p.Trp552Arg) in the α-subunit of the ENaC trimer, SCNN1A, possibly pointing to pseudohypoaldosteronism type I. This case is unique in that we present the early-onset disease and treatment response caused by a canonical stop-gain mutation (p.Arg566*) as well as ENaC digenic hits in the father, emphasizing the utility of WES informing precision medicine.
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Affiliation(s)
- Linda M Polfus
- Human Genetics Center, The University of Texas Health Science Center at Houston, Houston, Texas 70130, USA
| | - Eric Boerwinkle
- Human Genetics Center, The University of Texas Health Science Center at Houston, Houston, Texas 70130, USA;; Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 70130, USA
| | - Richard A Gibbs
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 70130, USA
| | - Ginger Metcalf
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 70130, USA
| | - Donna Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas 70130, USA
| | | | - Megan Grove
- Human Genetics Center, The University of Texas Health Science Center at Houston, Houston, Texas 70130, USA
| | - Sanjay Shete
- Department of Biostatistics, MD Anderson Cancer Center, The University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Stephanie Wallace
- Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Dianna Milewicz
- Division of Medical Genetics, Department of Internal Medicine, The University of Texas Health Science Center, Houston, Texas 77030, USA
| | - Neil Hanchard
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 70130, USA
| | - James R Lupski
- Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 70130, USA
| | - Syed Shahrukh Hashmi
- Department of Pediatrics, Children's Memorial Hermann Hospital, The University of Texas Health Science Center, Houston, Texas, Medical School, Texas 77030, USA
| | - Monesha Gupta-Malhotra
- Department of Pediatric Cardiology, Johns Hopkins All Children's Hospital, St. Petersburg, Florida 33701, USA
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14
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Potassium regulation in the neonate. Pediatr Nephrol 2017; 32:2037-2049. [PMID: 28378030 DOI: 10.1007/s00467-017-3635-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 02/13/2017] [Accepted: 02/21/2017] [Indexed: 10/19/2022]
Abstract
Potassium, the major cation in intracelluar fluids, is essential for vital biological functions. Neonates maintain a net positive potassium balance, which is fundamental to ensure somatic growth but places these infants, especially those born prematurely, at risk for life-threatening disturbances in potassium concentration [K+] in the extracellular fluid compartment. Potassium conservation is achieved by maximizing gastrointestinal absorption and minimizing renal losses. A markedly low glomerular filtration rate, plus adaptations in tubular transport along the nephron, result in low potassium excretion in the urine of neonates. Careful evaluation of clinical data using reference values that are normal for the neonate's postmenstrual age is critical to avoid over-treating infants with laboratory results that represent physiologic values for their developmental stage. The treatment should be aimed at correcting the primary cause when possible. Alterations in the levels or sensitivity to aldosterone are common in neonates. In symptomatic patients, the disturbances in [K+] should be corrected promptly, with close electrocardiographic monitoring. Plasma [K+] should be monitored during the first 72 h of life in all premature infants born before 30 weeks of postmenstrual age as these infants are prone to develop non-oliguric hyperkalemia with potential serious complications.
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15
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Characteristics of hypertension in premature infants with and without chronic lung disease: a long-term multi-center study. Pediatr Nephrol 2017; 32:2115-2124. [PMID: 28674750 DOI: 10.1007/s00467-017-3722-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 06/07/2017] [Accepted: 06/09/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND Many causes for neonatal hypertension in premature infants have been described; however in some cases no etiology can be attributed. Our objectives are to describe such cases of unexplained hypertension and to compare hypertensive infants with and without chronic lung disease (CLD). METHODS We reviewed all cases of hypertension in premature infants referred from 18 hospitals over 16 years. Inclusion criteria were hypertension occurring at <6 months of age and birth at <37 weeks gestation; the main exclusion criterion was known secondary hypertension. Continuous variables were compared using analysis of variance. Nominal variables were compared using chi-square tests. RESULTS A total of 97 infants met the inclusion criteria, of whom 37 had CLD. Among these infants, hypertension presented at a mean of 11.3 ± 3.2 chronological weeks of age and a postmenstrual age of 39.6 ± 3.6 weeks. Diagnostic testing was notable for plasma renin activity (PRA) being <11 ng/mL/h in 98% of hypertensive infants. Spironolactone was effective monotherapy in 51 of 56 cases of hypertension. Hypertension resolved in all infants, with an average treatment duration of 25 weeks. Significant differences between the two groups of infants were a 0.4 kg lower birthweight and a 2.5 weeks younger gestational age at birth in those with CLD (p < 0.01, p < 0.01, respectively). Hypertension presented in those with CLD 1.8 weeks later, but at the same postmenstrual age as those without CLD (p < 0.01, p = 0.45, respectively). CONCLUSION Premature infants with unexplained hypertension, with and without CLD, presented at a postmenstrual age of 40 weeks with low PRA, transient time course, and a favorable response to spironolactone treatment.
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16
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Flynn JT, Kaelber DC, Baker-Smith CM, Blowey D, Carroll AE, Daniels SR, de Ferranti SD, Dionne JM, Falkner B, Flinn SK, Gidding SS, Goodwin C, Leu MG, Powers ME, Rea C, Samuels J, Simasek M, Thaker VV, Urbina EM. Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents. Pediatrics 2017; 140:peds.2017-1904. [PMID: 28827377 DOI: 10.1542/peds.2017-1904] [Citation(s) in RCA: 1899] [Impact Index Per Article: 271.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
These pediatric hypertension guidelines are an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents." Significant changes in these guidelines include (1) the replacement of the term "prehypertension" with the term "elevated blood pressure," (2) new normative pediatric blood pressure (BP) tables based on normal-weight children, (3) a simplified screening table for identifying BPs needing further evaluation, (4) a simplified BP classification in adolescents ≥13 years of age that aligns with the forthcoming American Heart Association and American College of Cardiology adult BP guidelines, (5) a more limited recommendation to perform screening BP measurements only at preventive care visits, (6) streamlined recommendations on the initial evaluation and management of abnormal BPs, (7) an expanded role for ambulatory BP monitoring in the diagnosis and management of pediatric hypertension, and (8) revised recommendations on when to perform echocardiography in the evaluation of newly diagnosed hypertensive pediatric patients (generally only before medication initiation), along with a revised definition of left ventricular hypertrophy. These guidelines include 30 Key Action Statements and 27 additional recommendations derived from a comprehensive review of almost 15 000 published articles between January 2004 and July 2016. Each Key Action Statement includes level of evidence, benefit-harm relationship, and strength of recommendation. This clinical practice guideline, endorsed by the American Heart Association, is intended to foster a patient- and family-centered approach to care, reduce unnecessary and costly medical interventions, improve patient diagnoses and outcomes, support implementation, and provide direction for future research.
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Affiliation(s)
- Joseph T Flynn
- Dr. Robert O. Hickman Endowed Chair in Pediatric Nephrology, Division of Nephrology, Department of Pediatrics, University of Washington and Seattle Children's Hospital, Seattle, Washington;
| | - David C Kaelber
- Departments of Pediatrics, Internal Medicine, Population and Quantitative Health Sciences, Center for Clinical Informatics Research and Education, Case Western Reserve University and MetroHealth System, Cleveland, Ohio
| | - Carissa M Baker-Smith
- Division of Pediatric Cardiology, School of Medicine, University of Maryland, Baltimore, Maryland
| | - Douglas Blowey
- Children's Mercy Hospital, University of Missouri-Kansas City and Children's Mercy Integrated Care Solutions, Kansas City, Missouri
| | - Aaron E Carroll
- Department of Pediatrics, School of Medicine, Indiana University, Bloomington, Indiana
| | - Stephen R Daniels
- Department of Pediatrics, School of Medicine, University of Colorado-Denver and Pediatrician in Chief, Children's Hospital Colorado, Aurora, Colorado
| | - Sarah D de Ferranti
- Director, Preventive Cardiology Clinic, Boston Children's Hospital, Department of Pediatrics, Harvard Medical School, Boston, Massachusetts
| | - Janis M Dionne
- Division of Nephrology, Department of Pediatrics, University of British Columbia and British Columbia Children's Hospital, Vancouver, British Columbia, Canada
| | - Bonita Falkner
- Departments of Medicine and Pediatrics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
| | - Susan K Flinn
- Consultant, American Academy of Pediatrics, Washington, District of Columbia
| | - Samuel S Gidding
- Cardiology Division Head, Nemours Cardiac Center, Alfred I. duPont Hospital for Children, Wilmington, Delaware
| | - Celeste Goodwin
- National Pediatric Blood Pressure Awareness Foundation, Prairieville, Louisiana
| | - Michael G Leu
- Departments of Pediatrics and Biomedical Informatics and Medical Education, University of Washington, University of Washington Medicine and Information Technology Services, and Seattle Children's Hospital, Seattle, Washington
| | - Makia E Powers
- Department of Pediatrics, School of Medicine, Morehouse College, Atlanta, Georgia
| | - Corinna Rea
- Associate Director, General Academic Pediatric Fellowship, Staff Physician, Boston's Children's Hospital Primary Care at Longwood, Instructor, Harvard Medical School, Boston, Massachusetts
| | - Joshua Samuels
- Departments of Pediatrics and Internal Medicine, McGovern Medical School, University of Texas, Houston, Texas
| | - Madeline Simasek
- Pediatric Education, University of Pittsburgh Medical Center Shadyside Family Medicine Residency, Clinical Associate Professor of Pediatrics, Children's Hospital of Pittsburgh of University of Pittsburgh Medical Center, and School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Vidhu V Thaker
- Division of Molecular Genetics, Department of Pediatrics, Columbia University Medical Center, New York, New York; and
| | - Elaine M Urbina
- Preventive Cardiology, Cincinnati Children's Hospital Medical Center, Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio
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17
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Williams RB, Bishop GD, Haberstick BC, Smolen A, Brummett BH, Siegler IC, Babyak MA, Zhang X, Tai ES, Lee JJM, Tan M, Teo YY, Cai S, Chan E, Halpern CT, Whitsel EA, Bauldry S, Harris KM. Population differences in associations of serotonin transporter promoter polymorphism (5HTTLPR) di- and triallelic genotypes with blood pressure and hypertension prevalence. Am Heart J 2017; 185:110-122. [PMID: 28267464 PMCID: PMC5473420 DOI: 10.1016/j.ahj.2016.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 12/23/2016] [Indexed: 12/16/2022]
Abstract
Based on prior research finding the 5HTTLPR L allele associated with increased cardiovascular reactivity to laboratory stressors and increased risk of myocardial infarction, we hypothesized that the 5HTTLPR L allele will be associated with increased blood pressure (BP) and increased hypertension prevalence in 2 large nationally representative samples in the United States and Singapore. METHODS Logistic regression and linear models tested associations between triallelic (L'S', based on rs25531) 5HTTLPR genotypes and hypertension severity and mean systolic and diastolic blood pressure (SBP and DBP) collected during the Wave IV survey of the National Longitudinal Study of Adolescent to Adult Health (Add Health, N=11,815) in 2008-09 and during 2004-07 in 4196 Singaporeans. RESULTS In US Whites, L' allele carriers had higher SBP (0.9 mm Hg, 95% CI=0.26-1.56) and greater odds (OR=1.23, 95% CI=1.10-1.38) of more severe hypertension than those with S'S' genotypes. In African Americans, L' carriers had lower mean SBP (-1.27mm Hg, 95% CI=-2.53 to -0.01) and lower odds (OR = 0.78, 95% CI=0.65-0.94) of more severe hypertension than those with the S'S' genotype. In African Americans, those with L'L' genotypes had lower DBP (-1.13mm Hg, 95% CI=-2.09 to -0.16) than S' carriers. In Native Americans, L' carriers had lower SBP (-6.05mm Hg, 95% CI=-9.59 to -2.51) and lower odds of hypertension (OR = 0.34, 95% CI=0.13-0.89) than those with the S'S' genotype. In Asian/Pacific Islanders those carrying the L' allele had lower DBP (-1.77mm Hg, 95% CI=-3.16 to -0.38) and lower odds of hypertension (OR = 0.68, 95% CI=0.48-0.96) than those with S'S'. In the Singapore sample S' carriers had higher SBP (3.02mm Hg, 95% CI=0.54-5.51) and DBP (1.90mm Hg, 95% CI=0.49-3.31) than those with the L'L' genotype. CONCLUSIONS These findings suggest that Whites carrying the L' allele, African Americans and Native Americans with the S'S' genotype, and Asians carrying the S' allele will be found to be at higher risk of developing cardiovascular disease and may benefit from preventive measures.
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Affiliation(s)
- Redford B Williams
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA.
| | - George D Bishop
- Yale-NUS College, Singapore, Singapore; Department of Psychology, National University of Singapore, Singapore
| | - Brett C Haberstick
- Institute for Behavioral Genetics, University of Colorado Boulder, Boulder, CO, USA
| | - Andrew Smolen
- Institute for Behavioral Genetics, University of Colorado Boulder, Boulder, CO, USA
| | - Beverly H Brummett
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - Ilene C Siegler
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - Michael A Babyak
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - Xiaodong Zhang
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA; Neuroscience & Behavioral Disorders Program, Duke-NUS Graduate Medical School, Singapore, Singapore; Department of Physiology, National University of Singapore, Singapore
| | - E Shyong Tai
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore; Department of Medicine, National University of Singapore, Singapore
| | | | - Maudrene Tan
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Yik Ying Teo
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore; Department of Statistics and Applied Probability, National University of Singapore
| | - Shiwei Cai
- Neuroscience & Behavioral Disorders Program, Duke-NUS Graduate Medical School, Singapore, Singapore; Department of Physiology, National University of Singapore, Singapore
| | - Edmund Chan
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Carolyn Tucker Halpern
- Department of Maternal and Child Health, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, USA; Carolina Population Center, University of North Carolina at Chapel Hill, NC, USA
| | - Eric A Whitsel
- Department of Epidemiology, University of North Carolina, Gillings School of Global Public Health, Chapel Hill, USA; Department of Medicine, University of North Carolina, School of Medicine, Chapel Hill, NC, USA
| | - Shawn Bauldry
- Department of Sociology, University of Alabama, Birmingham, AL, USA
| | - Kathleen Mullan Harris
- Carolina Population Center, University of North Carolina at Chapel Hill, NC, USA; Department of Sociology, University of North Carolina, Chapel Hill, USA
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18
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Stowasser M, Gordon RD. Primary Aldosteronism: Changing Definitions and New Concepts of Physiology and Pathophysiology Both Inside and Outside the Kidney. Physiol Rev 2016; 96:1327-84. [DOI: 10.1152/physrev.00026.2015] [Citation(s) in RCA: 86] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In the 60 years that have passed since the discovery of the mineralocorticoid hormone aldosterone, much has been learned about its synthesis (both adrenal and extra-adrenal), regulation (by renin-angiotensin II, potassium, adrenocorticotrophin, and other factors), and effects (on both epithelial and nonepithelial tissues). Once thought to be rare, primary aldosteronism (PA, in which aldosterone secretion by the adrenal is excessive and autonomous of its principal regulator, angiotensin II) is now known to be the most common specifically treatable and potentially curable form of hypertension, with most patients lacking the clinical feature of hypokalemia, the presence of which was previously considered to be necessary to warrant further efforts towards confirming a diagnosis of PA. This, and the appreciation that aldosterone excess leads to adverse cardiovascular, renal, central nervous, and psychological effects, that are at least partly independent of its effects on blood pressure, have had a profound influence on raising clinical and research interest in PA. Such research on patients with PA has, in turn, furthered knowledge regarding aldosterone synthesis, regulation, and effects. This review summarizes current progress in our understanding of the physiology of aldosterone, and towards defining the causes (including genetic bases), epidemiology, outcomes, and clinical approaches to diagnostic workup (including screening, diagnostic confirmation, and subtype differentiation) and treatment of PA.
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Affiliation(s)
- Michael Stowasser
- Endocrine Hypertension Research Centre, University of Queensland School of Medicine, Greenslopes and Princess Alexandra Hospitals, Brisbane, Queensland, Australia
| | - Richard D. Gordon
- Endocrine Hypertension Research Centre, University of Queensland School of Medicine, Greenslopes and Princess Alexandra Hospitals, Brisbane, Queensland, Australia
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19
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Ray EC, Chen J, Kelly TN, He J, Hamm LL, Gu D, Shimmin LC, Hixson JE, Rao DC, Sheng S, Kleyman TR. Human epithelial Na+ channel missense variants identified in the GenSalt study alter channel activity. Am J Physiol Renal Physiol 2016; 311:F908-F914. [PMID: 27582106 PMCID: PMC5130461 DOI: 10.1152/ajprenal.00426.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 08/22/2016] [Indexed: 12/31/2022] Open
Abstract
Mutations in genes encoding subunits of the epithelial Na+ channel (ENaC) can cause early onset familial hypertension, demonstrating the importance of this channel in modulating blood pressure. It remains unclear whether other genetic variants resulting in subtler alterations of channel function result in hypertension or altered sensitivity of blood pressure to dietary salt. This study sought to identify functional human ENaC variants to examine how these variants alter channel activity and to explore whether these variants are associated with altered sensitivity of blood pressure to dietary salt. Six-hundred participants of the Genetic Epidemiology Network of Salt Sensitivity (GenSalt) study with salt-sensitive or salt-resistant blood pressure underwent sequencing of the genes encoding ENaC subunits. Functional effects of identified variants were examined in a Xenopus oocyte expression system. Variants that increased channel activity included three in the gene encoding the α-subunit (αS115N, αR476W, and αV481M), one in the β-subunit (βS635N), and one in the γ-subunit (γL438Q). One α-subunit variant (αA334T) and one γ-subunit variant (βD31N) decreased channel activity. Several α-subunit extracellular domain variants altered channel inhibition by extracellular Na+ (Na+ self-inhibition). One variant (αA334T) decreased and one (αV481M) increased cell surface expression. Association between these variants and salt sensitivity did not reach statistical significance. This study identifies novel functional human ENaC variants and demonstrates that some variants alter channel cell surface expression and/or Na+ self-inhibition.
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Affiliation(s)
- Evan C Ray
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jingxin Chen
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Tanika N Kelly
- Department of Epidemiology, Tulane University, New Orleans, Louisiana
| | - Jiang He
- Department of Epidemiology, Tulane University, New Orleans, Louisiana.,Department of Medicine, Tulane University, New Orleans, Louisiana
| | - L Lee Hamm
- Department of Medicine, Tulane University, New Orleans, Louisiana
| | - Dongfeng Gu
- State Key Laboratory of Cardiovascular Disease, Division of Population Genetics, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Lawrence C Shimmin
- Human Genetics Center, University of Texas School of Public Health, Houston, Texas
| | - James E Hixson
- Human Genetics Center, University of Texas School of Public Health, Houston, Texas
| | - Dabeeru C Rao
- Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri
| | - Shaohu Sheng
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania;
| | - Thomas R Kleyman
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.,Departments of Cell Biology and Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh, Pennsylvania
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20
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[Gordon syndrome: The importance of measuring blood pressure in children]. Arch Pediatr 2016; 23:827-31. [PMID: 27369102 DOI: 10.1016/j.arcped.2016.05.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Revised: 01/10/2016] [Accepted: 05/12/2016] [Indexed: 11/21/2022]
Abstract
Gordon's syndrome, or type II pseudo-hypoaldosteronism, is a rare cause of arterial hypertension in children. However, it is important to diagnose this syndrome because of the spectacular efficacy of thiazide diuretics. The typical clinical picture of Gordon syndrome includes, apart from arterial hypertension and dyskaliemia, hyperchloremia metabolic acidosis, hypercalciuria, a low rate of renin, and most frequently, a normal or high rate of aldosterone. Dental abnormalities and growth retardation can also be associated. In most cases, it is inherited in an autosomal dominant pattern. We report on a 7-year-old girl who was discovered with arterial hypertension during a consultation for chronic diarrhea. The association of growth retardation, hyperkaliemia, and metabolic acidosis oriented the diagnosis. Starting a thiazide diuretic helped control the arterial hypertension and the kaliemia in a spectacular manner. The genetic analysis proved the existence of a splice mutation on exon 9 of the CUL3 gene coding for cullin 3. This mutation is de novo.
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21
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A Case of Glucocorticoid Remediable Aldosteronism and Thoracoabdominal Aneurysms. Case Rep Endocrinol 2016; 2016:2017571. [PMID: 27366333 PMCID: PMC4912987 DOI: 10.1155/2016/2017571] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 05/15/2016] [Indexed: 11/19/2022] Open
Abstract
Glucocorticoid remediable aldosteronism (GRA) is rare familial form of primary aldosteronism characterized by a normalization of hypertension with the administration of glucocorticoids. We present a case of GRA and thoracoabdominal aneurysm complicated by multiple aortic dissections requiring complex surgical and endovascular repairs. Registry studies have shown a high rate of intracranial aneurysms in GRA patients with high case fatality rates. The association of thoracoabdominal aneurysms with GRA has not been described, thus far, in literature. Studies have shown that high tissue aldosterone levels concomitant with salt intake have a significant role in the pathogenesis of aneurysms and this may explain the formation of aneurysms in the intracranial vasculature and aorta. The association of GRA with thoracic aortic aneurysms needs to be further studied to develop screening recommendations for early identification and optimal treatment. Also, the early use of mineralocorticoid antagonists may have a significant preventive and attenuating effect in aneurysm formation, an association which needs to be confirmed in future studies.
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Abstract
Neonatal hypertension (HT) is a frequently under reported condition and is seen uncommonly in the intensive care unit. Neonatal HT has defined arbitrarily as blood pressure more than 2 standard deviations above the base as per the age or defined as systolic BP more than 95% for infants of similar size, gestational age and postnatal age. It has been diagnosed long back but still is the least studied field in neonatology. There is still lack of universally accepted normotensive data for neonates as per gestational age, weight and post-natal age. Neonatal HT is an important morbidity that needs timely detection and appropriate management, as it can lead to devastating short-term effect on various organs and also poor long-term adverse outcomes. There is no consensus yet about the treatment guidelines and majority of treatment protocols are based on the expert opinion. Neonate with HT should be evaluated in detail starting from antenatal, perinatal, post-natal history, and drug intake by neonate and mother. This review article covers multiple aspects of neonatal hypertension like definition, normotensive data, various etiologies and methods of BP measurement, clinical features, diagnosis and management.
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Affiliation(s)
- Deepak Sharma
- a Department of Pediatrics , Pt B.D. Sharma, PGIMS , Rohtak , Haryana , India
| | | | - Sweta Shastri
- c Department of Pathology , N.K.P Salve Medical College , Nagpur , Maharashtra , India , and
| | - Pradeep Sharma
- d Department of Medicine , Mahatma Gandhi Medical College & Hospital , Jaipur , Rajasthan , India
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23
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Abstract
Hypertension in children is common, and the prevalence of primary hypertension is increasing with the obesity epidemic and changing dietary choices. Careful measurement of blood pressure is important to correctly diagnose hypertension, as many factors can lead to inaccurate blood pressure measurement. Hypertension is diagnosed based on comparison of age-, sex-, and height-based norms with the average systolic and diastolic blood pressures on three separate occasions. In the absence of hypertensive target organ damage (TOD), stage I hypertension is managed first by diet and exercise, with the addition of drug therapy if this fails. First-line treatment of stage I hypertension with TOD and stage II hypertension includes both lifestyle changes and medications. First-line agents include angiotensin-converting enzyme (ACE) inhibitors, thiazide diuretics, and calcium-channel blockers. Hypertensive emergency with end-organ effects requires immediate modest blood pressure reduction to alleviate symptoms. This is usually accomplished with IV medications. Long-term reduction in blood pressure to normal levels is accomplished gradually. Specific medication choice for outpatient hypertension management is determined by the underlying cause of hypertension and the comparative adverse effect profiles, along with practical considerations such as cost and frequency of administration. Antihypertensive medication is initiated at a starting dose and can be gradually increased to effect. If ineffective at the recommended maximum dose, an additional medication with a complementary mechanism of action can be added.
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Affiliation(s)
- Jason Misurac
- Department of Pediatrics, Section of Pediatric Nephrology, Indiana University School of Medicine, 699 Riley Hospital Dr., Room 230, Indianapolis, IN, 46202, USA.
| | - Kristen R Nichols
- Department of Pharmacy Practice, College of Pharmacy and Health Sciences, Butler University, Indianapolis, IN, USA
- Department of Pharmacy, Riley Hospital for Children, Indiana University Health, Indianapolis, IN, USA
| | - Amy C Wilson
- Department of Pediatrics, Section of Pediatric Nephrology, Indiana University School of Medicine, 699 Riley Hospital Dr., Room 230, Indianapolis, IN, 46202, USA
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Gattineni J, Baum M. Developmental changes in renal tubular transport-an overview. Pediatr Nephrol 2015; 30:2085-98. [PMID: 24253590 PMCID: PMC4028442 DOI: 10.1007/s00467-013-2666-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 10/01/2013] [Accepted: 10/11/2013] [Indexed: 10/26/2022]
Abstract
The adult kidney maintains a constant volume and composition of extracellular fluid despite changes in water and salt intake. The neonate is born with a kidney that has a small fraction of the glomerular filtration rate of the adult and immature tubules that function at a lower capacity than that of the mature animal. Nonetheless, the neonate is also able to maintain a constant extracellular fluid volume and composition. Postnatal renal tubular development was once thought to be due to an increase in the transporter abundance to meet the developmental increase in glomerular filtration rate. However, postnatal renal development of each nephron segment is quite complex. There are isoform changes of several transporters as well as developmental changes in signal transduction that affect the capacity of renal tubules to reabsorb solutes and water. This review will discuss neonatal tubular function with an emphasis on the differences that have been found between the neonate and adult. We will also discuss some of the factors that are responsible for the maturational changes in tubular transport that occur during postnatal renal development.
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Affiliation(s)
- Jyothsna Gattineni
- Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9061, USA
| | - Michel Baum
- Department of Pediatrics, University of Texas Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9061, USA.
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, USA.
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Sampson MG. Actualizing the Benefits of Genomic Discovery in Pediatric Nephrology. J Pediatr Genet 2015; 5:69-75. [PMID: 27617144 DOI: 10.1055/s-0035-1557113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 01/19/2015] [Indexed: 01/13/2023]
Abstract
The discovery of genetic variation associated with pediatric kidney disease has shed light on the biology underlying these conditions and, in some cases, has improved our clinical management of patients. We are challenged to continue the momentum of the genomic era in pediatric nephrology by identifying novel disease-associated genetic variation and translating these discoveries into clinical applications. This article reviews the diverse forms of genetic architecture that have been found to be associated with kidney diseases and traits. These include rare, fully penetrant variants responsible for Mendelian forms of disease, copy number variants, and more common variants associated with increased risk of disease. These discoveries have provided us with a greater understanding of the molecular mechanisms underlying these conditions and highlighted key pathways for potential intervention. In a number of areas, the identification of rare, fully penetrant variants is immediately clinically relevant, whether in regard to diagnostic testing, prediction of outcomes, or choice of therapies and interventions. This article discusses limitations in the deterministic view of rare, putatively causal mutations, a challenge increasing in importance as sequencing expands to many more genes and patients. This article also focusses on common genetic variants, using those found to be associated with focal segmental glomerulosclerosis in African-Americans, IgA nephropathy, chronic kidney disease (CKD), and estimated glomerular filtration rate (eGFR) as examples. Identifying common genetic variants associated with disease will complement other areas of genomic inquiry, lead to a greater biological understanding of disease, and will benefit pediatric nephrology patients.
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Affiliation(s)
- Matthew G Sampson
- Division of Pediatric Nephrology, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, Ann Arbor, Michigan, United States
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Khosravi M, Walsh SB. The long-term complications of the inherited tubulopathies: an adult perspective. Pediatr Nephrol 2015; 30:385-95. [PMID: 24566812 DOI: 10.1007/s00467-014-2779-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2013] [Revised: 01/23/2014] [Accepted: 01/27/2014] [Indexed: 11/25/2022]
Abstract
The inherited tubulopathies are lifelong disorders and their clinical features and complications may present quite different challenges in adulthood from those in childhood. In this review we outline the pathophysiology and documented complications (including the late and unusual) of the monogenic tubulopathies from the perspective of the adult nephrologist.
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Affiliation(s)
- Maryam Khosravi
- UCL Centre for Nephrology, Royal Free Hospital, University College London, London, UK
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Abstract
The incidence of neonatal hypertension (HTN) remains low, at less than 2%, and its etiology is varied. Strict definitions of HTN in neonates are unavailable, and the decision to treat is based on opinion rather than evidence. More studies are needed to define normal blood pressure in neonates and to refine current reference values, thus permitting a better definition of HTN. Most causes of neonatal HTN, the most common of which seems to be renovascular disease, are determined by history and basic clinical investigations. Treatment is guided by clinical judgment and expert opinion, given the limited number of clinical trials.
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Affiliation(s)
- Donald L Batisky
- Pediatric Hypertension Program, Children's Healthcare of Atlanta, Emory - Children's Center, 2015 Uppergate Drive North East, Atlanta, GA 30322, USA.
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Rational use of antihypertensive medications in children. Pediatr Nephrol 2014; 29:979-88. [PMID: 23715784 DOI: 10.1007/s00467-013-2510-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 04/09/2013] [Accepted: 05/07/2013] [Indexed: 12/13/2022]
Abstract
Hypertension has traditionally been regarded as an uncommon diagnosis in childhood and adolescence; however, there is compelling evidence to suggest that its prevalence is on the rise, particularly in those with obesity. As a result, pediatricians increasingly are asked to evaluate and manage patients with elevated blood pressure. An increased emphasis on conducting drug trials in children over the last 15 years has yielded important advances with respect to evidence-based data regarding the efficacy and safety of antihypertensive medications in children and adolescents. Unfortunately, data to definitively guide selection of initial agents is lacking. This article will present guidelines for the appropriate use of antihypertensive medications in the pediatric population, including the rational approach to selecting an appropriate medication with respect to pathophysiology, putative benefit, and likelihood for side effects.
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Sodium surfeit and potassium deficit: Keys to the pathogenesis of hypertension. ACTA ACUST UNITED AC 2014; 8:203-13. [DOI: 10.1016/j.jash.2013.09.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 09/20/2013] [Accepted: 09/22/2013] [Indexed: 12/26/2022]
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Abstract
Arterial hypertension in childhood is less frequent as compared to adulthood but is more likely to be secondary to an underlying disorder. After ruling out more obvious causes, some patients still present with strongly suspected secondary hypertension of yet unknown etiology. A number of these children have hypertension due to single gene mutations inherited in an autosomal dominant or recessive fashion. The finding of abnormal potassium levels (low or high) in the presence of suppressed renin secretion, and metabolic alkalosis or acidosis should prompt consideration of these familial diseases. However, mild hypertension and the absence of electrolyte abnormalities do not exclude hereditary conditions. In monogenic hypertensive disorders, three distinct mechanisms leading to the common final pathway of increased sodium reabsorption, volume expansion, and low plasma renin activity are documented. The first mechanism relates to gain-of-function mutations with a subsequent hyperactivity of renal sodium and chloride reabsorption leading to plasma volume expansion (e.g., Liddle's syndrome, Gordon's syndrome). The second mechanism involves deficiencies of enzymes that regulate adrenal steroid hormone synthesis and deactivation (e.g., subtypes of congenital adrenal hyperplasia, apparent mineralocorticoid excess (AME)). The third mechanism is characterized by excessive aldosterone synthesis that escapes normal regulatory mechanisms and leading to volume-dependent hypertension in the presence of suppressed renin release (glucocorticoid remediable aldosteronism). Hormonal studies coupled with genetic testing can help in the early diagnosis of these disorders.
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Mongia A, Vecker R, George M, Pandey A, Tawadrous H, Schoeneman M, Muneyyirci-Delale O, Nacharaju V, Ten S, Bhangoo A. Role of 11βHSD type 2 enzyme activity in essential hypertension and children with chronic kidney disease (CKD). J Clin Endocrinol Metab 2012; 97:3622-9. [PMID: 22872687 DOI: 10.1210/jc.2012-1411] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND The mineralocorticoid receptor is protected from excess of glucocorticoids by conversion of active cortisol to inactive cortisone by enzyme 11β-hydroxysteroid dehydrogenase type 2 present in the kidney. The metabolites of cortisol and cortisone are excreted in the urine as tetrahydrocortisol (5αTHF+5βTHF) and tetrahydrocortisone (THE), respectively. HYPOTHESIS Patients with chronic kidney disease (CKD) and essential hypertension have a functional defect in their ability to convert cortisol to cortisone, thus leading to the activation of mineralocorticoid receptor. OBJECTIVE The objective of the investigation was to study the ratio of urinary steroids (5αTHF+5βTHF) to THE in patients with CKD, postrenal transplant, and essential hypertension and to compare the ratio with controls. DESIGN/METHODS We enrolled 44 patients (17 with CKD, eight postrenal transplant, 19 with essential hypertension) and 12 controls. We measured spot urinary 5α-THF, 5β-THF, THE, free active cortisol and inactive cortisone by gas chromatography/mass spectrometry. We collected data on age, sex, cause of kidney disease, height, weight, body mass index, blood pressure, serum electrolytes, aldosterone, and plasma renin activity. Blood pressure percentiles and z-scores were calculated. The glomerular filtration rate was calculated using the modified Schwartz formula. RESULTS The ratios of 5αTHF+5βTHF to THE were significantly higher in patients with CKD [mean±sd score (SDS)=1.31±1.07] as compared with essential hypertension (mean±SDS=0.59±0.23; P=0.02) and controls (mean±SDS=0.52±0.25; P=0.01). In the postrenal transplant group, the ratio was not significantly different (mean±SDS=0.71±0.55). The urinary free cortisol to free cortisone ratios were significantly higher in the hypertension and CKD groups as compared with the controls. The 5αTHF+5βTHF to THE ratio negatively correlated with the glomerular filtration rate and positively correlated with systolic and diastolic blood pressure z-scores. The correlation of the blood pressure z-scores with ratios was stronger in the CKD group than the essential hypertension and posttransplant groups. CONCLUSIONS We have elucidated a functional deficiency of 11β-hydroxysteroid dehydrogenase type 2 in children with CKD and a subset of essential hypertension. Urinary 5α-THF, 5β-THF, and THE analysis by gas chromatography/mass spectrometry should be a part of routine work-up of CKD and hypertensive patients.
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Affiliation(s)
- Anil Mongia
- Kings County Hospital and State University of New York Downstate Medical Center, 450 Clarkson Avenue, Box 49, Brooklyn, New York 11203, USA
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Abstract
PURPOSE OF REVIEW Continued interest in neonatal hypertension has led to generation of new data on normal blood pressure (BP) values in neonates, identification of new causes of hypertension in the neonatal period, and improved insights into therapy. RECENT FINDINGS Normal BP in neonates depends on a variety of factors, including gestational age, postnatal age, and birth weight, and may be influenced by other antenatal conditions. The incidence of neonatal hypertension is low, and it is most often seen in infants with concurrent conditions such as chronic lung disease (CLD) or renal disease, or in those that have undergone umbilical arterial catheterization. Although few data exist on efficacy and safety of antihypertensive medications in neonates, a wide variety of medications have been utilized in those who do require treatment. Hypertension resolves over time in most infants, although robust long-term outcome data are lacking. SUMMARY Our understanding of neonatal hypertension continues to evolve. Although better data are available on normal BP and the incidence of hypertension, we still need studies focused on appropriate treatment and long-term prognosis.
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Bogdanović R, Kuburović V, Stajić N, Mughal SS, Hilger A, Ninić S, Prijić S, Ludwig M. Liddle syndrome in a Serbian family and literature review of underlying mutations. Eur J Pediatr 2012; 171:471-8. [PMID: 21956615 DOI: 10.1007/s00431-011-1581-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 09/08/2011] [Indexed: 12/13/2022]
Abstract
UNLABELLED Severe and reproducible low-renin hypertension responsive to salt restriction and amiloride-thiazide therapy in a 13-year-old otherwise asymptomatic boy suggested Liddle syndrome. This assumption was strengthened by a positive family history of hypertension poorly responsive to conventional treatment or sudden deaths under 40 years of age in four generations. DNA analysis of the beta and gamma subunits of the epithelial sodium channel revealed a heterozygous mutation c.C1852T (p.Pro618Ser) in the SCNN1B gene in the patient and in both his hypertensive mother and uncle. A PubMed search revealed 21 different disease-causing mutations reported to date, all but two clustering in the cytoplasmic C-terminal regions of either beta (16 mutations) or gamma (5) subunit, leading to a three- to eightfold increase in the amiloride-sensitive sodium current. Inter- and intrafamilial variability in both hypertension and hypokalemia were disclosed, which may not be obligatory among the subjects carrying a Liddle mutation. CONCLUSION Liddle syndrome should be considered as a cause of hypertension in children or adolescents particularly with suppressed renin activity. Early diagnosis and appropriately tailored treatment avoid complications of long-term unrecognized or inappropriately managed hypertension.
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Dionne JM, Abitbol CL, Flynn JT. Hypertension in infancy: diagnosis, management and outcome. Pediatr Nephrol 2012; 27:17-32. [PMID: 21258818 DOI: 10.1007/s00467-010-1755-z] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2010] [Revised: 12/16/2010] [Accepted: 12/20/2010] [Indexed: 10/18/2022]
Abstract
Advances in the ability to identify, evaluate, and care for infants with hypertension, coupled with advances in the practice of Neonatology, have led to an increased awareness of hypertension in modern neonatal intensive care units. This review will present updated data on blood pressure values in neonates, with a focus on the changes that occur over the first days and weeks of life in both term and preterm infants. Optimal blood pressure measurement techniques as well as the differential diagnosis of hypertension in the neonate and older infants will be discussed. Recommendations for the optimal immediate and long-term evaluation and treatment, including potential treatment parameters, will be presented. We will also review additional information on outcome that has become available over the past decade.
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Affiliation(s)
- Janis M Dionne
- Division of Nephrology, Department of Pediatrics, University of British Columbia, BC Children's Hospital, Vancouver, BC, Canada
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37
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Mussa A, Camilla R, Monticone S, Porta F, Tessaris D, Verna F, Mulatero P, Einaudi S. Polyuric-polydipsic syndrome in a pediatric case of non-glucocorticoid remediable familial hyperaldosteronism. Endocr J 2012; 59:497-502. [PMID: 22447138 DOI: 10.1507/endocrj.ej11-0406] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Familial hyperaldosteronism (FH) encompasses 3 types of autosomal dominant hyperaldosteronisms leading to inheritable hypertension. FH type II (FH-II), undistinguishable from sporadic hyperaldosteronism, represents the most frequent cause of inheritable hypertension and is believed to only manifest in adults. FH-III is a severe variety of PA resistant to pharmacotherapy and recently demonstrated to be caused by mutations in the gene encoding the potassium channel KCNJ5. In this report, we describe a FH pediatric patient, remarkable both for age at onset and unusual presentation: a two-years old girl with polyuric-polydipsic syndrome and severe hypertension, successfully treated with canrenone and amiloride. The girl had severe hypertension, hypokalemia, hypercalciuria, suppressed renin activity, high aldosterone, and unremarkable adrenal imaging. FH type I was ruled out by glucocorticoid suppression test, PCR test for CYP11B1/CYP11B2 gene, and urinary 18-oxo-cortisol and 18-hydroxy-cortisol excretion, which was in FH-II range. In spite of a clear-cut FH-II phenotype, the girl and her mother were found to harbor a FH-III genotype with KCNJ5 mutation (c.452G>A). Treatment with canrenone was started, resulting in prompt normalization of electrolytes and remission of polyuric-polydypsic syndrome. The addition of amiloride led to a complete normalization of blood pressure. This report expands the phenotypic spectrum of FH-III to a milder end, mimiking FH-II phenotype demonstrating that pharmacotherapy may be effective. This also implies that FH-II/III should be considered in the differential diagnosis of hypertensive children and, perhaps, that the offspring of patients with hyperaldosteronism should be screened for hypertension.
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Affiliation(s)
- Alessandro Mussa
- Department of Pediatrics, Division of Pediatric Endocrinology and Diabetology, University of Torino, Italy.
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Taal HR, Verwoert GC, Demirkan A, Janssens ACJW, Rice K, Ehret G, Smith AV, Verhaaren BFJ, Witteman JCM, Hofman A, Vernooij MW, Uitterlinden AG, Rivadeneira F, Ikram MA, Levy D, van der Heijden AJ, Jaddoe VWV, van Duijn CM. Genome-wide profiling of blood pressure in adults and children. Hypertension 2011; 59:241-7. [PMID: 22203742 DOI: 10.1161/hypertensionaha.111.179481] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Hypertension is an important determinant of cardiovascular morbidity and mortality and has a substantial heritability, which is likely of polygenic origin. The aim of this study was to assess to what extent multiple common genetic variants contribute to blood pressure regulation in both adults and children and to assess overlap in variants between different age groups, using genome-wide profiling. Single nucleotide polymorphism sets were defined based on a meta-analysis of genome-wide association studies on systolic blood pressure and diastolic blood pressure performed by the Cohort for Heart and Aging Research in Genome Epidemiology (n=29 136), using different P value thresholds for selecting single nucleotide polymorphisms. Subsequently, genetic risk scores for systolic blood pressure and diastolic blood pressure were calculated in an independent adult population (n=2072) and a child population (n=1034). The explained variance of the genetic risk scores was evaluated using linear regression models, including sex, age, and body mass index. Genetic risk scores, including also many nongenome-wide significant single nucleotide polymorphisms, explained more of the variance than scores based only on very significant single nucleotide polymorphisms in adults and children. Genetic risk scores significantly explained ≤1.2% (P=9.6*10(-8)) of the variance in adult systolic blood pressure and 0.8% (P=0.004) in children. For diastolic blood pressure, the variance explained was similar in adults and children (1.7% [P=8.9*10(-10)] and 1.4% [P=3.3*10(-5)], respectively). These findings suggest the presence of many genetic loci with small effects on blood pressure regulation both in adults and children, indicating also a (partly) common polygenic regulation of blood pressure throughout different periods of life.
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Affiliation(s)
- Hendrik R Taal
- The Generation R Study Group (Ae-006), Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam, The Netherlands
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Wang X, Prins BP, Sõber S, Laan M, Snieder H. Beyond genome-wide association studies: new strategies for identifying genetic determinants of hypertension. Curr Hypertens Rep 2011; 13:442-51. [PMID: 21953487 PMCID: PMC3212682 DOI: 10.1007/s11906-011-0230-y] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Genetic linkage and association methods have long been the most important tools for gene identification in humans. These approaches can either be hypothesis-based (i.e., candidate-gene studies) or hypothesis-free (i.e., genome-wide studies). The first part of this review offers an overview of the latest successes in gene finding for blood pressure (BP) and essential hypertension using these DNA sequence-based discovery techniques. We further emphasize the importance of post-genome-wide association study (post-GWAS) analysis, which aims to prioritize genetic variants for functional follow-up. Whole-genome next-generation sequencing will eventually be necessary to provide a more comprehensive picture of all DNA variants affecting BP and hypertension. The second part of this review discusses promising novel approaches that move beyond the DNA sequence and aim to discover BP genes that are differentially regulated by epigenetic mechanisms, including microRNAs, histone modification, and methylation.
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Affiliation(s)
- Xiaoling Wang
- Georgia Prevention Institute, Department of Pediatrics, Medical College of Georgia, Augusta, GA USA
| | - Bram P. Prins
- Unit of Genetic Epidemiology & Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, PO Box 30.001, 9700 RB Groningen, The Netherlands
| | - Siim Sõber
- Human Molecular Genetics group, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Maris Laan
- Human Molecular Genetics group, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia
| | - Harold Snieder
- Unit of Genetic Epidemiology & Bioinformatics, Department of Epidemiology, University Medical Center Groningen, University of Groningen, Hanzeplein 1, PO Box 30.001, 9700 RB Groningen, The Netherlands
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Rolim ALR, Lindsey SC, Kunii IS, Fujikawa AM, Soares FA, Chiamolera MI, Maciel RMB, Silva MRDD. Ion channelopathies in endocrinology: recent genetic findings and pathophysiological insights. ACTA ACUST UNITED AC 2011; 54:673-81. [PMID: 21340151 DOI: 10.1590/s0004-27302010000800002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2010] [Accepted: 11/29/2010] [Indexed: 11/21/2022]
Abstract
Ion channels serve diverse cellular functions, mainly in cell signal transduction. In endocrine cells, these channels play a major role in hormonal secretion, Ca(2+)-mediated cell signaling, transepithelial transport, cell motility and growth, volume regulation and cellular ionic content and acidification of lysosomal compartments. Ion channel dysfunction can cause endocrine disorders or endocrine-related manifestations, such as pseudohypoaldosteronism type 1, Liddle syndrome, Bartter syndrome, persistent hyperinsulinemic hypoglycemia of infancy, neonatal diabetes mellitus, cystic fibrosis, Dent's disease, hypomagnesemia with secondary hypocalcemia, nephrogenic diabetes insipidus and, the most recently genetically identified channelopathy, thyrotoxic hypokalemic periodic paralysis. This review briefly recapitulates the membrane action potential in endocrine cells and offers a short overview of known endocrine channelopathies with focus on recent progress regarding the pathophysiological mechanisms and functional genetic defects.
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Affiliation(s)
- Ana Luiza R Rolim
- Laboratório de Endocrinologia Molecular e Translacional, Departamento de Medicina, Universidade Federal de São Paulo, Escola Paulista de Medicina, SP, Brazil
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41
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Putku M, Kepp K, Org E, Sõber S, Comas D, Viigimaa M, Veldre G, Juhanson P, Hallast P, Tõnisson N, Shaw-Hawkins S, Caulfield MJ, Khusnutdinova E, Kožich V, Munroe PB, Laan M. Novel polymorphic AluYb8 insertion in the WNK1 gene is associated with blood pressure variation in Europeans. Hum Mutat 2011; 32:806-14. [PMID: 21520334 PMCID: PMC3298642 DOI: 10.1002/humu.21508] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 03/28/2011] [Indexed: 01/16/2023]
Abstract
Mutations in WNK1 and WNK4 cause familial hypertension, the Gordon syndrome. WNK1 and WNK4 conserved noncoding regions were targeted to polymorphism screening using DHPLC and DGGE. The scan identified an undescribed polymorphic AluYb8 insertion in WNK1 intron 10. Screening in primates revealed that this Alu-insertion has probably occurred in human lineage. Genotyping in 18 populations from Europe, Asia, and Africa (n = 854) indicated an expansion of the WNK1 AluYb8 bearing chromosomes out of Africa. The allele frequency in Sub-Saharan Africa was ∼3.3 times lower than in other populations (4.8 vs. 15.8%; P = 9.7 × 10−9). Meta-analysis across three European sample sets (n = 3,494; HYPEST, Estonians; BRIGHT, the British; CADCZ, Czech) detected significant association of the WNK1 AluYb8 insertion with blood pressure (BP; systolic BP, P = 4.03 × 10−3, effect 1.12; diastolic BP, P = 1.21 × 10−2, effect 0.67). Gender-stratified analysis revealed that this effect might be female-specific (n = 2,088; SBP, P = 1.99 × 10−3, effect 1.59; DBP P = 3.64 × 10−4, effect 1.23; resistant to Bonferroni correction), whereas no statistical support was identified for the association with male BP (n = 1,406). In leucocytes, the expressional proportions of the full-length WNK1 transcript and the splice-form skipping exon 11 were significantly shifted in AluYb8 carriers compared to noncarriers. The WNK1 AluYb8 insertion might affect human BP via altering the profile of alternatively spliced transcripts. Hum Mutat 32:1–9, 2011. © 2011 Wiley-Liss, Inc.
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Affiliation(s)
- Margus Putku
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
| | - Katrin Kepp
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
| | - Elin Org
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
| | - Siim Sõber
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
| | - David Comas
- Institute of Evolutionary Biology (UPF-CSIC), CEXS-UPF-PRBB, Universitat Pompeu FabraBarcelona, Spain
| | - Margus Viigimaa
- Centre of Cardiology, North Estonia Medical CentreTallinn, Estonia
- Tallinn University of Technology, Department of Biomedical Engineering, Chair of Medical PhysicsTallinn, Estonia
| | - Gudrun Veldre
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
- Department of Cardiology, University of TartuTartu, Estonia
| | - Peeter Juhanson
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
| | - Pille Hallast
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
| | - Neeme Tõnisson
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
| | - Sue Shaw-Hawkins
- Clinical Pharmacology and The Genome Centre, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of LondonLondon EC1M 6BQ, United Kingdom
| | - Mark J Caulfield
- Clinical Pharmacology and The Genome Centre, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of LondonLondon EC1M 6BQ, United Kingdom
| | - Elza Khusnutdinova
- Institute of Biochemistry and Genetics, Ufa Science Center, Russian Academy of SciencesUfa, Bashkortostan, Russia
| | - Viktor Kožich
- Institute of Inherited Metabolic Diseases, Charles University—First Faculty of MedicinePrague, Czech Republic
| | - Patricia B Munroe
- Clinical Pharmacology and The Genome Centre, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of LondonLondon EC1M 6BQ, United Kingdom
| | - Maris Laan
- Human Molecular Genetics Research Group, Institute of Molecular and Cell Biology, University of TartuTartu, Estonia
- *Correspondence to: Maris Laan, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010 Tartu, Estonia. E-mail:
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Wasniewska M, Valenzise M, Aversa T, Mirabelli S, De Luca F, De Luca FL, Lombardo F. Early hypertension and prolonged mineralocorticoid therapy discontinuation in a child with salt-wasting 21-hydroxylase deficiency. J Endocrinol Invest 2011; 34:159-61. [PMID: 21502797 DOI: 10.1007/bf03347048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Current Opinion in Endocrinology, Diabetes & Obesity. Current world literature. Curr Opin Endocrinol Diabetes Obes 2010; 17:293-312. [PMID: 20418721 DOI: 10.1097/med.0b013e328339f31e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Stowasser M, Taylor PJ, Pimenta E, Ahmed AHAA, Gordon RD. Laboratory investigation of primary aldosteronism. Clin Biochem Rev 2010; 31:39-56. [PMID: 20498828 PMCID: PMC2874431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Availability and wider application of the plasma aldosterone/renin ratio (ARR) as a screening test for primary aldosteronism (PA) has led to the recognition that PA is the most common potentially curable and specifically treatable form of hypertension, possibly accounting for as many as 5-13% of patients. Aldosterone excess also has adverse cardiovascular consequences that go above and beyond hypertension development. These findings support the concept that PA plays an important role in cardiovascular disease states and should be systematically sought and specifically treated, and have led to the development of a US Endocrine Society clinical guideline for the detection, diagnosis and management of this condition. Reliable detection requires that interfering factors (including medications known to alter the ratio) are controlled before ARR measurement (or their effects taken into account), and reliable methods such as fludrocortisone suppression testing are used to confirm PA. Because computed tomography frequently misses aldosterone-producing adenomas yet demonstrates non-functioning nodules, adrenal venous sampling is the only dependable way to differentiate unilateral (surgically correctable) from bilateral (usually treated with aldosterone antagonist medications) forms of PA. For the glucocorticoid-remediable form of PA (familial hyperaldosteronism type I), genetic testing for the causative 'hybrid' 11beta-hydroxylase/aldosterone synthase gene has greatly facilitated detection. Laboratory assessment (including suppression testing post-operatively, and renin measurement during treatment with aldosterone antagonist medications) can assist in assessing therapeutic responses and in guiding ongoing management. Development of new, highly reliable high-throughput mass spectrometric methods for measuring aldosterone and renin should further enhance detection and reliability of diagnostic workup for PA.
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Abstract
A small region on chromosome 9p21.3, discovered in parallel by three groups in the year 2007, is typical of the new understanding of the genetic basis of myocardial infarction (MI). The finding emerged from the application of novel high-throughput genome-wide approaches, the risk-associated allele is frequent, acts independently of traditional risk factors, and confers a modest yet highly reproducible hazard. Since then, another 10 chromosomal regions have been identified to affect the risk of MI or coronary artery disease (CAD). Although the number of risk alleles is growing rapidly, several conclusions can already be drawn from the findings to date. First, it appears that multiple hitherto unknown molecular mechanisms--initiated by these chromosomal variants--ultimately precipitate CAD. Secondly, essentially all Caucasians carry a variable number of risk alleles such that disease manifestation is affected to some extent by these inherited factors in basically all individuals. This means that a better understanding of underlying functional genomic mechanisms may offer novel opportunities to neutralize a broadly based genetic susceptibility for CAD in a large proportion of the population. In parallel, the newly discovered genes open novel opportunities for disease prediction. In summary, modern MI genetics carries the promise to identify individuals at high risk and to improve prevention and therapy of this important disease.
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Affiliation(s)
- Heribert Schunkert
- Universität zu Lübeck, Medizinische Klinik II, Ratzeburger Allee 160, 23538 Lübeck, Germany.
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Abstract
PURPOSE OF REVIEW Hypertension and edema are clinical manifestations of the extracellular volume expansion generated by abnormal renal sodium handling. Perturbations in epithelial sodium channel (ENaC) activity disrupt volume homeostasis. ENaC activity can be enhanced by proteases that cleave its long extracellular domains. Recent evidence suggests that this mechanism may be involved in individuals with volume overload and proteinuria. RECENT FINDINGS Several observations indicate a link between proteinuria and hypertension, with proteinuria preceding and predicting the onset of incident hypertension in some individuals. Recently, enhanced cleavage of ENaC's extracellular loops was identified in kidney tissue of proteinuric mice. Plasmin, a serine protease known for its role in fibrinolysis, has been implicated as an activator of ENaC in proteinuric states as nephrotic urine activates ENaC expressed in a mouse collecting duct cell line, aprotinin-affinity precipitation of nephrotic urine abolishes its ability to activate ENaC, plasmin is a major component within aprotinin-affinity purified nephrotic urine and is absent in nonproteinuric urine, and plasmin activates ENaC by cleaving the extracellular loop of its gamma subunit. SUMMARY Enhancement of ENaC activity by proteases represents a likely mechanism for extracellular volume overload relevant to some individuals with proteinuria. Proteases not normally found in the urine can enter the urinary space across damaged glomeruli and activate ENaC. Further understanding of this mechanism may guide targeted therapeutics in individuals with proteinuria, edema, and hypertension.
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