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Hemilä H, de Man AME. Vitamin C deficiency can lead to pulmonary hypertension: a systematic review of case reports. BMC Pulm Med 2024; 24:140. [PMID: 38504249 PMCID: PMC10949735 DOI: 10.1186/s12890-024-02941-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Accepted: 03/01/2024] [Indexed: 03/21/2024] Open
Abstract
BACKGROUND In the early literature, unintentional vitamin C deficiency in humans was associated with heart failure. Experimental vitamin C deficiency in guinea pigs caused enlargement of the heart. The purpose of this study was to collect and analyze case reports on vitamin C and pulmonary hypertension. METHODS We searched Pubmed and Scopus for case studies in which vitamin C deficiency was considered to be the cause of pulmonary hypertension. We selected reports in which pulmonary hypertension was diagnosed by echocardiography or catheterization, for any age, sex, or dosage of vitamin C. We extracted quantitative data for our analysis. We used the mean pulmonary artery pressure (mPAP) as the outcome of primary interest. RESULTS We identified 32 case reports, 21 of which were published in the last 5 years. Dyspnea was reported in 69%, edema in 53% and fatigue in 28% of the patients. Vitamin C plasma levels, measured in 27 cases, were undetectable in 24 and very low in 3 cases. Diet was poor in 30 cases and 17 cases had neuropsychiatric disorders. Right ventricular enlargement was reported in 24 cases. During periods of vitamin C deficiency, the median mPAP was 48 mmHg (range 29-77 mmHg; N = 28). After the start of vitamin C administration, the median mPAP was 20 mmHg (range 12-33 mmHg; N = 18). For the latter 18 cases, mPAP was 2.4-fold (median) higher during vitamin C deficiency. Pulmonary vascular resistance (PVR) during vitamin C deficiency was reported for 9 cases, ranging from 4.1 to 41 Wood units. PVR was 9-fold (median; N = 5) higher during vitamin C deficiency than during vitamin C administration. In 8 cases, there was direct evidence that the cases were pulmonary artery hypertension (PAH). Probably the majority of the remaining cases were also PAH. CONCLUSIONS The cases analyzed in our study indicate that pulmonary hypertension can be one explanation for the reported heart failure of scurvy patients in the early literature. It would seem sensible to measure plasma vitamin C levels of patients with PH and examine the effects of vitamin C administration.
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Affiliation(s)
- Harri Hemilä
- Department of Public Health, University of Helsinki, POB 41, Helsinki, FI-00014, Finland.
| | - Angelique M E de Man
- Department of Intensive Care Medicine, Amsterdam University Medical Centers, location VUmc, Amsterdam, The Netherlands.
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2
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Satawiriya M, Khongphatthanayothin A, Limsuwan A. Reversible severe pulmonary hypertension related to scurvy in children. BMC Cardiovasc Disord 2024; 24:24. [PMID: 38172747 PMCID: PMC10765653 DOI: 10.1186/s12872-023-03629-6] [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] [Received: 08/26/2023] [Accepted: 11/22/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Severe pulmonary hypertension (PH) in childhood is rare and can manifest as a life-threatening episode. We present 2 children with restrictive dietary habits with severe pulmonary hypertension secondary to scurvy and iron deficiency anemia with treatment and outcome. CASE PRESENTATION The first case is a 2-year-old boy who presented with vomiting, diarrhea, and fever. After rehydration, he had recurrent episodes of hypotension with intermittent abdominal pain. Fluid resuscitation and inotropic medication were given. Then he suddenly collapsed. After 4-min cardiopulmonary resuscitation, his hemodynamic was stabilized. Most of the medical workup was unremarkable except for PH from the echocardiogram with estimated systolic pulmonary artery pressure (PAP) at 67 mmHg. Transient PH was diagnosed, and milrinone was prescribed. Since he had restrictive dietary habits and sclerotic rim at epiphysis in chest films, his vitamin C level was tested and reported low-level result. The second case is a 6-year-old boy with acute dyspnea, a month of low-grade fever, mild cyanosis, and a swollen left knee. Echocardiogram indicated moderate TR with estimated systolic PAP at 56 mmHg (systolic blood pressure 90 mmHg). Milrinone was given. Right cardiac catheterization showed PAP 66/38 (mean 50) mmHg and PVRi 5.7 WU.m2. Other medical conditions causing PH were excluded. With a history of improper dietary intake and clinical suspicion of scurvy, vitamin C was tested and reported undetectable level. Administration of vitamin C in both cases rapidly reversed pulmonary hypertension. CONCLUSION Pediatric PH related to vitamin C deficiency can manifest with a wide range of symptoms, varying from mild and nonspecific to severe life-threatening episodes characterized by pulmonary hypertensive crises. PH associated with scurvy is entirely reversible with appropriate investigation, diagnosis, and treatment. Our report highlights the importance of considering nutritional deficiencies as potential confounding factors in pediatric PH, emphasizing the need for comprehensive evaluation and management of these patients.
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Affiliation(s)
- Marin Satawiriya
- Division of Pediatric Cardiology, Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama 6 Rd, Rachathewi, Bangkok, 10400, Thailand
| | - Apichai Khongphatthanayothin
- Bangkok Heart Hospital, Bangkok, Thailand
- Center of Excellence in Arrhythmia Research Chulalongkorn University, Department of Medicine, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Alisa Limsuwan
- Division of Pediatric Cardiology, Department of Pediatrics, Faculty of Medicine Ramathibodi Hospital, Mahidol University, 270 Rama 6 Rd, Rachathewi, Bangkok, 10400, Thailand.
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3
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Hemilä H, Chalker E, de Man AME. Vitamin C May Improve Left Ventricular Ejection Fraction: A Meta-Analysis. Front Cardiovasc Med 2022; 9:789729. [PMID: 35282368 PMCID: PMC8913583 DOI: 10.3389/fcvm.2022.789729] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/21/2022] [Indexed: 01/02/2023] Open
Abstract
Background Vitamin C deprivation can lead to fatigue, dyspnea, oedema and chest pain, which are also symptoms of heart failure (HF). In animal studies vitamin C has improved contractility and mechanical efficiency of the heart. Compared with healthy people, patients with HF have lower vitamin C levels, which are not explained by differences in dietary intake levels, and more severe HF seems to be associated with lower plasma vitamin C levels. This meta-analysis looks at the effect of vitamin C on left ventricular ejection fraction (LVEF). Methods We searched for trials reporting the effects of vitamin C on LVEF. We assessed the quality of the trials, and pooled selected trials using the inverse variance, fixed effect options. We used meta-regression to examine the association between the effect of vitamin C on LVEF level and the baseline LVEF level. Results We identified 15 trials, three of which were excluded from our meta-analysis. In six cardiac trials with 246 patients, vitamin C increased LVEF on average by 12.0% (95% CI 8.1–15.9%; P < 0.001). In six non-cardiac trials including 177 participants, vitamin C increased LVEF on average by 5.3% (95% CI 2.0–8.5%; P = 0.001). In meta-regression analysis we found that the effect of vitamin C was larger in trials with the lowest baseline LVEF levels with P = 0.001 for the test of slope. The meta-regression line crossed the null effect level at a baseline LVEF level close to 70%, with progressively greater benefit from vitamin C with lower LVEF levels. Some of the included trials had methodological limitations. In a sensitivity analysis including only the four most methodologically sound cardiac trials, the effect of vitamin C was not substantially changed. Conclusions In this meta-analysis, vitamin C increased LVEF in both cardiac and non-cardiac patients, with a strong negative association between the size of the vitamin C effect and the baseline LVEF. Further research on vitamin C and HF should be carried out, particularly in patients who have low LVEF together with low vitamin C intake or low plasma levels. Different dosages and different routes of administration should be compared.
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Affiliation(s)
- Harri Hemilä
- Department of Public Health, University of Helsinki, Helsinki, Finland
- *Correspondence: Harri Hemilä
| | - Elizabeth Chalker
- Biological Data Science Institute, Australian National University, Canberra, ACT, Australia
| | - Angelique M. E. de Man
- Department of Intensive Care Medicine, Amsterdam University Medical Centers, Amsterdam, Netherlands
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Ferreira CCG, de Sá Pereira Belfort D, Neto PMC, Gouveia PADC. Reversible Pulmonary Hypertension Secondary to Scurvy in a Patient with a Psychiatric Disorder: a Case Report and Literature Review. Eur J Case Rep Intern Med 2020; 7:001404. [PMID: 32133311 PMCID: PMC7050966 DOI: 10.12890/2020_001404] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 11/30/2019] [Indexed: 01/22/2023] Open
Abstract
Pulmonary hypertension (PH) can be related to several diseases, such as connective tissue disorders and pulmonary embolism, or to drugs; it may also be idiopathic. Few cases have been reported demonstrating an association between ascorbic acid deficiency and reversible PH. We report the case of a patient who arrived at the emergency department with dyspnoea, tachycardia and lower limb perifollicular haemorrhage. Examinations, including a transthoracic echocardiogram, revealed enlarged right chambers and an estimated pulmonary artery systolic pressure of 61 mmHg. Further evaluation revealed poor food intake due to paranoid personality disorder, leading to ascorbic acid deficiency and manifestations of scurvy.
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Affiliation(s)
| | - Deborah de Sá Pereira Belfort
- Internal Medicine Service, Federal University of Pernambuco, Recife, Brazil.,Heart Institute (InCor), University of São Paulo, São Paulo, Brazil
| | - Paulo Miranda Cavalcante Neto
- Internal Medicine Service, Federal University of Pernambuco, Recife, Brazil.,Respiratory Diseases Service, Institute of Medical Assistance to the State Public Servant, São Paulo, Brazil
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5
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Hemilä H, Chalker E. Vitamin C Can Shorten the Length of Stay in the ICU: A Meta-Analysis. Nutrients 2019; 11:E708. [PMID: 30934660 PMCID: PMC6521194 DOI: 10.3390/nu11040708] [Citation(s) in RCA: 155] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/12/2019] [Accepted: 03/18/2019] [Indexed: 12/12/2022] Open
Abstract
A number of controlled trials have previously found that in some contexts, vitamin C can have beneficial effects on blood pressure, infections, bronchoconstriction, atrial fibrillation, and acute kidney injury. However, the practical significance of these effects is not clear. The purpose of this meta-analysis was to evaluate whether vitamin C has an effect on the practical outcomes: length of stay in the intensive care unit (ICU) and duration of mechanical ventilation. We identified 18 relevant controlled trials with a total of 2004 patients, 13 of which investigated patients undergoing elective cardiac surgery. We carried out the meta-analysis using the inverse variance, fixed effect options, using the ratio of means scale. In 12 trials with 1766 patients, vitamin C reduced the length of ICU stay on average by 7.8% (95% CI: 4.2% to 11.2%; p = 0.00003). In six trials, orally administered vitamin C in doses of 1⁻3 g/day (weighted mean 2.0 g/day) reduced the length of ICU stay by 8.6% (p = 0.003). In three trials in which patients needed mechanical ventilation for over 24 hours, vitamin C shortened the duration of mechanical ventilation by 18.2% (95% CI 7.7% to 27%; p = 0.001). Given the insignificant cost of vitamin C, even an 8% reduction in ICU stay is worth exploring. The effects of vitamin C on ICU patients should be investigated in more detail.
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Affiliation(s)
- Harri Hemilä
- Department of Public Health, University of Helsinki, POB 41, FI-00014 Helsinki, Finland.
| | - Elizabeth Chalker
- School of Public Health, University of Sydney, Sydney 2006, Australia.
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6
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Dean T, Kaushik N, Williams S, Zinter M, Kim P. Cardiac arrest and pulmonary hypertension in scurvy: a case report. Pulm Circ 2018; 9:2045894018812052. [PMID: 30351242 PMCID: PMC6457075 DOI: 10.1177/2045894018812052] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
We report a case of a six-year-old boy who presented after a cardiac arrest, likely due to a pulmonary hypertensive crisis in the setting of vitamin C deficiency. After initially presenting with subacute multifocal bone lesions of unknown etiology, he experienced a pulseless electrical activity cardiac arrest while undergoing a diagnostic procedure under sedation. During his post-arrest convalescence, he developed persistent tachycardia and peripheral edema. An echocardiogram revealed findings consistent with significant pulmonary arterial hypertension, which was found to be responsive to inhaled nitric oxide. Laboratory investigation revealed undetectable levels of vitamin C, resulting in disclosure of a history of severe restrictive eating behavior. With ascorbate supplementation, the patient's pulmonary vasodilators were weaned and discontinued. Given his complete recovery, we suspect that the cardiac arrest and pulmonary hypertension were the consequence of a rare, but reversible, complication of scurvy.
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Affiliation(s)
- Terry Dean
- 1 University of California San Francisco Benioff Children's Hospital - Oakland, Oakland, CA, USA.,2 University of California San Francisco Benioff Children's Hospital - Mission Bay, San Francisco, USA
| | - Neeru Kaushik
- 1 University of California San Francisco Benioff Children's Hospital - Oakland, Oakland, CA, USA
| | - Sharron Williams
- 1 University of California San Francisco Benioff Children's Hospital - Oakland, Oakland, CA, USA
| | - Matthew Zinter
- 1 University of California San Francisco Benioff Children's Hospital - Oakland, Oakland, CA, USA.,2 University of California San Francisco Benioff Children's Hospital - Mission Bay, San Francisco, USA
| | - Paul Kim
- 1 University of California San Francisco Benioff Children's Hospital - Oakland, Oakland, CA, USA
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7
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Abstract
PH can sometimes be a challenging diagnosis. Echocardiography can assess RV overload and evaluate sudden changing in PASP. Although rare, scurvy should be part of an expanded differential diagnosis of PH.
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Hurr C, Patik JC, Kim K, Christmas KM, Brothers RM. Tempol augments the blunted cutaneous microvascular thermal reactivity in healthy young African Americans. Exp Physiol 2018; 103:343-349. [PMID: 29271085 DOI: 10.1113/ep086776] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/18/2017] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? The purpose was to determine whether there is a difference between African Americans and Caucasians in cutaneous microvascular function and whether this difference is attributable to elevated oxidative stress. What is the main finding and its importance? The main finding is that African Americans have an attenuated cutaneous vasodilatation during local heating relative to Caucasians that is restored with local infusion of the superoxide dismutase mimetic, tempol. This suggests that superoxide mediates microvascular dysfunction and might contribute to the greater prevalence of cardiovascular disease in this population. ABSTRACT African Americans (AA) have elevated risk for cardiovascular disease relative to other populations. We hypothesized that the cutaneous hyperaemic response to local heating is reduced in young AA relative to Caucasian Americans (CA) and that this is attributable to elevated oxidative stress. As such, ascorbic acid (a global antioxidant) and tempol (a superoxide dismutase mimetic) would improve this response in AA. Microdialysis fibres received lactated Ringer solution (control), 10 mm ascorbic acid or 10 μm 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (tempol) at a rate of 2.0 μl min-1 . Cutaneous vascular conductance (CVC) was calculated as the red blood cell flux divided by mean arterial pressure. Data were presented as a percentage of maximal CVC (%CVCmax ) induced by 44°C heating plus sodium nitroprusside. Twenty-four (12 AA, 12 CA) young (23 ± 4 years old) subjects participated. During 39°C heating, the %CVCmax was lower in AA at the control (CA, 65 ± 20% versus AA, 47 ± 15%; P < 0.05) and ascorbic acid sites (CA, 73 ± 14% versus AA: 49 ± 17%; P < 0.01). At the tempol site, there were no differences between groups. This was followed by infusion of 10 mm l-NAME at all sites to assess the contribution of nitric oxide to vasodilatation during local heating. The contribution of nitric oxide was lower in AA relative to CA at 39°C; however, this was restored with tempol. These data suggest that: (i) cutaneous vasodilatation in response to local heating is blunted in AA relative to CA; and (ii) elevated superoxide generation attenuates nitric oxide-mediated cutaneous vasodilatation in AA.
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Affiliation(s)
- Chansol Hurr
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA.,Department of Pharmacology and Physiology, The George Washington University, Washington, DC, USA
| | - Jordan C Patik
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA.,Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA
| | - KiYoung Kim
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA.,Department of Pathology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Kevin M Christmas
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA.,Department of Bioengineering, The University of Washington, Seattle, WA, USA
| | - R Matthew Brothers
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA.,Department of Kinesiology, The University of Texas at Arlington, Arlington, TX, USA
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9
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Ji X, Hu X, Zou C, Ruan H, Fan X, Tang C, Shi W, Mei L, Zhu H, Hussain M, Zeng L, Zhang X, Wu X. Vitamin C deficiency exacerbates diabetic glomerular injury through activation of transforming growth factor-β signaling. Biochim Biophys Acta Gen Subj 2017; 1861:2186-2195. [PMID: 28652077 DOI: 10.1016/j.bbagen.2017.06.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 06/20/2017] [Accepted: 06/22/2017] [Indexed: 01/04/2023]
Abstract
BACKGROUND The hyperglycemia and hyperoxidation that characterize diabetes lead to reduced vitamin C (VC) in diabetic humans and experimentally diabetic animals. Herein, we access the effects of VC deficiency on the diabetic kidney injury and explore the underlying mechanism. METHODS l-gulonolactone oxidase conventional knockout (Gulo-/-) mice genetically unable to synthesize VC were subjected to streptozotocin-induced diabetic kidney injury and the role of VC deficiency was evaluated by biochemical and histological approaches. Rat mesangial cells were cultured to investigate the underlying mechanism. RESULTS Functionally, VC deficiency aggravates the streptozotocin-induced renal insufficiency, exhibiting the increased urine albumin, water intake, and urine volume in Gulo-/- mice. Morphologically, VC deficiency exacerbates the streptozotocin-induced kidney injury, exhibiting the increased glomerular expansion, deposition of Periodic Acid-Schiff- and Masson-positive materials, and expression of α-smooth muscle actin, fibronectin and type 4 collagen in glomeruli of Gulo-/- mice. Mechanistically, VC activates protein kinase B (Akt) to destabilize Ski and thereby induce the expression of Smad7, resulting in suppression of TGF-β/Smad signaling and extracellular matrix deposition in mesangial cells. CONCLUSIONS VC is essential for the renal function maintenance in diabetes. GENERAL SIGNIFICANCE Compensation for the loss of VC could be an effective remedy for diabetic kidney injury.
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Affiliation(s)
- Xing Ji
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China
| | - Xinhua Hu
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China
| | - Chaochun Zou
- Department of Endocrinology, the Affiliated Children Hospital, Zhejiang University Medical School, Hangzhou 310006, China
| | - Hongfeng Ruan
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China
| | - Xueying Fan
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China
| | - Chao Tang
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China
| | - Wei Shi
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China
| | - Liu Mei
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China
| | - Haibin Zhu
- Department of Gynecology and Obstetrics, the First Affiliated Hospital, Zhejiang University Medical School, Hangzhou 310009, China
| | - Musaddique Hussain
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China
| | - Linghui Zeng
- Department of Pharmacology, Zhejiang University City College, Hangzhou 310023, China
| | - Xiaodong Zhang
- Department of Cell Biology, Wuhan University College of Life Science, Wuhan 430072, China
| | - Ximei Wu
- Department of Pharmacology, Zhejiang University Medical School, Hangzhou 310058, China.
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10
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Kenny GP, Sigal RJ, McGinn R. Body temperature regulation in diabetes. Temperature (Austin) 2016; 3:119-45. [PMID: 27227101 PMCID: PMC4861190 DOI: 10.1080/23328940.2015.1131506] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 12/09/2015] [Accepted: 12/09/2015] [Indexed: 01/06/2023] Open
Abstract
The effects of type 1 and type 2 diabetes on the body's physiological response to thermal stress is a relatively new topic in research. Diabetes tends to place individuals at greater risk for heat-related illness during heat waves and physical activity due to an impaired capacity to dissipate heat. Specifically, individuals with diabetes have been reported to have lower skin blood flow and sweating responses during heat exposure and this can have important consequences on cardiovascular regulation and glycemic control. Those who are particularly vulnerable include individuals with poor glycemic control and who are affected by diabetes-related complications. On the other hand, good glycemic control and maintenance of aerobic fitness can often delay the diabetes-related complications and possibly the impairments in heat loss. Despite this, it is alarming to note the lack of information regarding diabetes and heat stress given the vulnerability of this population. In contrast, few studies have examined the effects of cold exposure on individuals with diabetes with the exception of its therapeutic potential, particularly for type 2 diabetes. This review summarizes the current state of knowledge regarding the impact of diabetes on heat and cold exposure with respect to the core temperature regulation, cardiovascular adjustments and glycemic control while also considering the beneficial effects of maintaining aerobic fitness.
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Affiliation(s)
- Glen P Kenny
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, Ottawa, ON, Canada; Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - Ronald J Sigal
- Clinical Epidemiology Program, Ottawa Hospital Research Institute, Ottawa, ON, Canada; Departments of Medicine, Cardiac Sciences, and Community Health Sciences, Cumming School of Medicine, Faculties of Medicine and Kinesiology, University of Calgary, Calgary, AB, Canada
| | - Ryan McGinn
- Human and Environmental Physiology Research Unit, Faculty of Health Sciences, Ottawa, ON, Canada; Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
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11
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Meade RD, Fujii N, Alexander LM, Paull G, Louie JC, Flouris AD, Kenny GP. Local infusion of ascorbate augments NO-dependent cutaneous vasodilatation during intense exercise in the heat. J Physiol 2015; 593:4055-65. [PMID: 26110415 PMCID: PMC4575586 DOI: 10.1113/jp270787] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Accepted: 06/10/2015] [Indexed: 01/30/2023] Open
Abstract
Recent work demonstrates that nitric oxide (NO) contributes to cutaneous vasodilatation during moderate (400 W of metabolic heat production) but not high (700 W of metabolic heat production) intensity exercise bouts performed in the heat (35°C). The present study evaluated whether the impairment in NO-dependent cutaneous vasodilatation was the result of a greater accumulation of reactive oxygen species during high (700 W of metabolic heat production) relative to moderate (500 W of metabolic heat production) intensity exercise. It was shown that local infusion of ascorbate (an anti-oxidant) improves NO-dependent forearm cutaneous vasodilatation during high intensity exercise in the heat. These findings provide novel insight into the physiological mechanisms governing cutaneous blood flow during exercise-induced heat stress and provide direction for future research exploring whether oxidative stress underlies the impairments in heat dissipation that may occur in older adults, as well as in individuals with pathophysiological conditions such as type 2 diabetes. Nitric oxide (NO)-dependent cutaneous vasodilatation is reportedly diminished during exercise performed at a high (700 W) relative to moderate (400 W) rate of metabolic heat production. The present study evaluated whether this impairment results from increased oxidative stress associated with an accumulation of reactive oxygen species (ROS) during high intensity exercise. On two separate days, 11 young (mean ± SD, 24 ± 4 years) males cycled in the heat (35°C) at a moderate (500 W) or high (700 W) rate of metabolic heat production. Each session included two 30 min exercise bouts followed by 20 and 40 min of recovery, respectively. Cutaneous vascular conductance (CVC) was monitored at four forearm skin sites continuously perfused via intradermal microdialysis with: (1) lactated Ringer solution (Control); (2) 10 mm ascorbate (Ascorbate); (3) 10 mm l-NAME; or (4) 10 mm ascorbate + 10 mm l-NAME (Ascorbate + l-NAME). At the end of each 500 W exercise bout, CVC was attenuated with l-NAME (∼35% CVCmax ) and Ascorbate + l-NAME (∼43% CVCmax ) compared to Control (∼60% CVCmax ; all P < 0.04); however, Ascorbate did not modulate CVC during exercise (∼60% CVCmax ; both P > 0.87). Conversely, CVC was elevated with Ascorbate (∼72% CVCmax ; both P < 0.03) but remained similar to Control (∼59% CVCmax ) with l-NAME (∼50% CVCmax ) and Ascorbate + l-NAME (∼47% CVCmax ; all P > 0.05) at the end of both 700 W exercise bouts. We conclude that oxidative stress associated with an accumulation of ascorbate-sensitive ROS impairs NO-dependent cutaneous vasodilatation during intense exercise.
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Affiliation(s)
- Robert D Meade
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of OttawaOttawa, ON, Canada
| | - Naoto Fujii
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of OttawaOttawa, ON, Canada
| | - Lacy M Alexander
- Department of Kinesiology, Noll Laboratory, Pennsylvania State University, University ParkState College, PA, USA
| | - Gabrielle Paull
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of OttawaOttawa, ON, Canada
| | - Jeffrey C Louie
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of OttawaOttawa, ON, Canada
| | - Andreas D Flouris
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of OttawaOttawa, ON, Canada
- FAME Laboratory, Department of Exercise Science, University of ThessalyTrikala, Greece
| | - Glen P Kenny
- Human and Environmental Physiology Research Unit, School of Human Kinetics, University of OttawaOttawa, ON, Canada
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12
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DuPont JJ, Ramick MG, Farquhar WB, Townsend RR, Edwards DG. NADPH oxidase-derived reactive oxygen species contribute to impaired cutaneous microvascular function in chronic kidney disease. Am J Physiol Renal Physiol 2014; 306:F1499-506. [PMID: 24761000 PMCID: PMC4059972 DOI: 10.1152/ajprenal.00058.2014] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Accepted: 04/21/2014] [Indexed: 01/11/2023] Open
Abstract
Oxidative stress promotes vascular dysfunction in chronic kidney disease (CKD). We utilized the cutaneous circulation to test the hypothesis that reactive oxygen species derived from NADPH oxidase and xanthine oxidase impair nitric oxide (NO)-dependent cutaneous vasodilation in CKD. Twenty subjects, 10 stage 3 and 4 patients with CKD (61 ± 4 yr; 5 men/5 women; eGFR: 39 ± 4 ml·min(-1)·1.73 m(-2)) and 10 healthy controls (55 ± 2 yr; 4 men/6 women; eGFR: >60 ml·min(-1)·1.73 m(-2)) were instrumented with 4 intradermal microdialysis fibers for the delivery of 1) Ringer solution (Control), 2) 10 μM tempol (scavenge superoxide), 3) 100 μM apocynin (NAD(P)H oxidase inhibition), and 4) 10 μM allopurinol (xanthine oxidase inhibition). Skin blood flow was measured via laser-Doppler flowmetry during standardized local heating (42°C). N(g)-nitro-l-arginine methyl ester (L-NAME; 10 mM) was infused to quantify the NO-dependent portion of the response. Cutaneous vascular conductance (CVC) was calculated as a percentage of the maximum CVC achieved during sodium nitroprusside infusion at 43°C. Cutaneous vasodilation was attenuated in patients with CKD (77 ± 3 vs. 88 ± 3%, P = 0.01), but augmented with tempol and apocynin (tempol: 88 ± 2 (P = 0.03), apocynin: 91 ± 2% (P = 0.001). The NO-dependent portion of the response was reduced in patients with CKD (41 ± 4 vs. 58 ± 2%, P = 0.04), but improved with tempol and apocynin (tempol: 58 ± 3 (P = 0.03), apocynin: 58 ± 4% (P = 0.03). Inhibition of xanthine oxidase did not alter cutaneous vasodilation in either group (P > 0.05). These data suggest that NAD(P)H oxidase is a source of reactive oxygen species and contributes to microvascular dysfunction in patients with CKD.
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Affiliation(s)
- Jennifer J DuPont
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - Meghan G Ramick
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware
| | - William B Farquhar
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; Department of Biological Sciences, University of Delaware, Newark, Delaware; and
| | - Raymond R Townsend
- Clinical and Translational Research Center, University of Pennsylvania, Philadelphia, Pennsylvania
| | - David G Edwards
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, Delaware; Department of Biological Sciences, University of Delaware, Newark, Delaware; and
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13
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Duvall MG, Pikman Y, Kantor DB, Ariagno K, Summers L, Sectish TC, Mullen MP. Pulmonary hypertension associated with scurvy and vitamin deficiencies in an autistic child. Pediatrics 2013; 132:e1699-703. [PMID: 24190688 DOI: 10.1542/peds.2012-3054] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Restricted dietary intake is common among children with behavioral issues. Here we report a case of a severely autistic child who presented initially with limp but who soon developed cough, tachypnea, hypoxia, and tachycardia. An echocardiogram revealed evidence of pulmonary hypertension (PH) with severely dilated right ventricle and elevated right-sided pressures. The etiology of his PH was unclear but further laboratory evaluation demonstrated severe nutritional deficiencies, in particular an undetectable ascorbic acid (vitamin C) level as well as deficient levels of thiamine (vitamin B1), pyridoxine (vitamin B6), cobalamin (vitamin B12), and vitamin D. Repletion of these vitamins was associated with resolution of his PH and his musculoskeletal complaints. We report this case and a review of the relevant literature as a clinical lesson to expand the differential diagnosis of limp in children who may be difficult to assess as well as to report on an unusual association between severe vitamin deficiencies and PH.
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Affiliation(s)
- Melody G Duvall
- Boston Children's Hospital, Division of Critical Care Medicine, Department of Anesthesia, 300 Longwood Ave, Boston, MA 02115.
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14
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Greaney JL, DuPont JJ, Lennon-Edwards SL, Sanders PW, Edwards DG, Farquhar WB. Dietary sodium loading impairs microvascular function independent of blood pressure in humans: role of oxidative stress. J Physiol 2012; 590:5519-28. [PMID: 22907057 DOI: 10.1113/jphysiol.2012.236992] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Animal studies have reported dietary salt-induced reductions in vascular function independent of increases in blood pressure (BP). The purpose of this study was to determine if short-term dietary sodium loading impairs cutaneous microvascular function in normotensive adults with salt resistance. Following a control run-in diet, 12 normotensive adults (31 ± 2 years) were randomized to a 7 day low-sodium (LS; 20 mmol day(-1)) and 7 day high-sodium (HS; 350 mmol day(-1)) diet (controlled feeding study). Salt resistance, defined as a 5 mmHg change in 24 h mean BP determined while on the LS and HS diets, was confirmed in all subjects undergoing study (LS: 84 ± 1 mmHg vs. HS: 85 ± 2 mmHg; P > 0.05). On the last day of each diet, subjects were instrumented with two microdialysis fibres for the local delivery of Ringer solution and 20 mm ascorbic acid (AA). Laser Doppler flowmetry was used to measure red blood cell flux during local heating-induced vasodilatation (42°C). After the established plateau, 10 mm l-NAME was perfused to quantify NO-dependent vasodilatation. All data were expressed as a percentage of maximal cutaneous vascular conductance (CVC) at each site (28 mm sodium nitroprusside; 43°C). Sodium excretion increased during the HS diet (P < 0.05). The plateau % CVCmax was reduced during HS (LS: 93 ± 1 % CVCmax vs. HS: 80 ± 2 % CVCmax; P < 0.05). During the HS diet, AA improved the plateau % CVCmax (Ringer: 80 ± 2 % CVCmax vs. AA: 89 ± 3 % CVCmax; P < 0.05) and restored the NO contribution (Ringer: 44 ± 3 % CVCmax vs. AA: 59 ± 6 % CVCmax; P < 0.05). These data demonstrate that dietary sodium loading impairs cutaneous microvascular function independent of BP in normotensive adults and suggest a role for oxidative stress.
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Affiliation(s)
- Jody L Greaney
- Department of Kinesiology and Applied Physiology, University of Delaware, Newark, DE, USA
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15
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Yamazaki F. Oral vitamin C enhances the adrenergic vasoconstrictor response to local cooling in human skin. J Appl Physiol (1985) 2012; 112:1689-97. [DOI: 10.1152/japplphysiol.00043.2012] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Local administration of ascorbic acid (Asc) at a supraphysiological concentration inhibits the cutaneous vasoconstrictor response to local cooling (LC). However, whether orally ingesting Asc inhibits the LC-induced vasoconstrictor response remains unknown. The purpose of the present study was to examine the acute influence of oral Asc on the adrenergic vasoconstrictor response to LC in human skin. In experiment 1, skin blood flow (SkBF) was measured by laser-Doppler flowmetry at three sites (forearm, calf, palm). The three skin sites were locally cooled from 34 to 24°C at −1°C/min and maintained at 24°C for 20 min before (Pre) and 1.5 h after (Post) oral Asc (2-g single dose) or placebo supplementation. Cutaneous vascular conductance (CVC) was calculated as the ratio of SkBF to blood pressure and expressed relative to the baseline value before LC. Oral Asc enhanced ( P < 0.05) the reductions in CVC in the forearm (Pre, −50.3 ± 3.3%; Post, −57.8 ± 2.2%), calf (Pre, −52.6 ± 3.7%; Post, −66.1 ± 4.3%), and palm (Pre, −46.2 ± 6.2%; Post, −60.4 ± 5.6%) during LC. The placebo did not change the responses at any site. In experiment 2, to examine whether the increased vasoconstrictor response caused by oral Asc is due to the adrenergic system, the release of neurotransmitters from adrenergic nerves in forearm skin was blocked locally by iontophoresis of bretylium tosylate (BT). Oral Asc enhanced ( P < 0.05) the reductions in CVC at untreated control sites but did not change the responses at BT-treated sites during LC. In experiment 3, to further examine whether adrenergically mediated vasoconstriction is enhanced by oral Asc, 0.1 mM tyramine was administered using intradermal microdialysis in the forearm skin at 34°C in the Pre and Post periods. Oral Asc increased ( P < 0.05) the tyramine-induced reduction in CVC. These findings suggest that oral Asc acutely enhances the cutaneous vasoconstrictor responses to LC through the modification of adrenergic sympathetic mechanisms.
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Affiliation(s)
- Fumio Yamazaki
- Laboratory for Human Physiology, School of Health Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan
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