51
|
Kalra SP. Central leptin gene therapy ameliorates diabetes type 1 and 2 through two independent hypothalamic relays; a benefit beyond weight and appetite regulation. Peptides 2009; 30:1957-63. [PMID: 19647774 PMCID: PMC2755606 DOI: 10.1016/j.peptides.2009.07.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2009] [Revised: 07/22/2009] [Accepted: 07/23/2009] [Indexed: 01/12/2023]
Abstract
Although its role in energy homeostasis is firmly established, the evidence accumulated over a decade linking the adipocyte leptin-hypothalamus axis in the pathogenesis of diabetes mellitus has received little attention in the contemporary thinking. In this context various lines of evidence are collated here to show that (1) under the direction of leptin two independent relays emanating from the hypothalamus restrain insulin secretion from the pancreas and mobilize peripheral organs--liver, skeletal muscle and brown adipose tissue--to upregulate glucose disposal, and (2), leptin insufficiency in the hypothalamus produced by either leptinopenia or restriction of leptin transport across the blood brain barrier due to hyperleptinemia of obesity and aging, initiate antecedent pathophysiological sequalae of diabetes type 1 and 2. Further, we document here the efficacy of leptin replenishment in vivo, especially by supplying it to the hypothalamus with the aid of gene therapy, in preventing the antecedent pathophysiological sequalae--hyperinsulinemia, insulin resistance and hyperglycemia--in various animal models and clinical paradigms of diabetes type 1 and 2 with or without attendant obesity. Overall, the new insights on the long-lasting antidiabetic potential of two independent hypothalamic relays engendered by central leptin gene therapy and the preclinical safety indicators in rodents warrant further validation in subhuman primates and humans.
Collapse
Affiliation(s)
- Satya P Kalra
- Department of Neuroscience, McKnight Brain Institute, College of Medicine, University of Florida, PO Box 100244, Gainesville, FL 32610-0244, United States.
| |
Collapse
|
52
|
da Silva AA, do Carmo J, Dubinion J, Hall JE. The role of the sympathetic nervous system in obesity-related hypertension. Curr Hypertens Rep 2009; 11:206-11. [PMID: 19442330 DOI: 10.1007/s11906-009-0036-3] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Obesity is recognized as a major health problem throughout the world. Excess weight is a major cause of increased blood pressure in most patients with essential hypertension and greatly increases the risk for diabetes, cardiovascular diseases, and end-stage renal disease. Although the mechanisms by which obesity raises blood pressure are not completely understood, increased renal sodium reabsorption, impaired pressure natriuresis, and volume expansion appear to play important roles. Several potential mechanisms have been suggested to contribute to altered kidney function and hypertension in obesity, including activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system, as well as physical compression of the kidneys, especially when visceral obesity is present. Activation of the sympathetic nervous system in obesity may be due, in part, to hyperleptinemia and other factors secreted by adipocytes and the gastrointestinal tract, activation of the central nervous system melanocortin pathway, and baroreceptor dysfunction.
Collapse
Affiliation(s)
- Alexandre A da Silva
- Department of Physiology and Biophysics, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216-4505, USA.
| | | | | | | |
Collapse
|
53
|
Arnold AC, Shaltout HA, Gallagher PE, Diz DI. Leptin impairs cardiovagal baroreflex function at the level of the solitary tract nucleus. Hypertension 2009; 54:1001-8. [PMID: 19770402 DOI: 10.1161/hypertensionaha.109.138065] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Circulating leptin is elevated in some forms of obesity-related hypertension, associated with impaired baroreflex function. Leptin receptors are present on vagal afferent fibers and neurons within the solitary tract nucleus, providing an anatomic distribution consistent with baroreflex modulation. Although solitary tract nucleus microinjection of 144 fmol/60 nL of leptin had no significant effect on baroreflex sensitivity for control of the heart rate in urethane/chloralose-anesthetized Sprague-Dawley rats, 500 fmol of leptin impaired baroreflex sensitivity for bradycardia in response to increases in pressure (1.15+/-0.04 versus 0.52+/-0.12 ms/mm Hg; P<0.01). Transgenic ASrAOGEN rats with low brain angiotensinogen have an upregulation of the leptin receptor and p85 alpha mRNA in the dorsal medulla relative to Sprague-Dawley rats. Consistent with these observations, the response to leptin was enhanced in ASrAOGEN rats, because both the 144-fmol (1.46+/-0.08 versus 0.75+/-0.10 ms/mm Hg; P<0.001) and 500-fmol (1.36+/-0.32 versus 0.44+/-0.06 ms/mm Hg; P<0.05) leptin microinjections impaired baroreflex sensitivity. At these doses, leptin microinjection had no effect on resting pressure, heart rate, or the tachycardic response to decreases in pressure in Sprague-Dawley or ASrAOGEN rats. Thus, exogenous leptin at sites within the solitary tract nucleus impairs the baroreflex sensitivity for bradycardia induced by increases in arterial pressure, consistent with a permissive role in mediating increases in arterial pressure. Baroreflex inhibition was enhanced in animals with evidence of increased leptin receptor and relevant signaling pathway mRNA.
Collapse
Affiliation(s)
- Amy C Arnold
- Hypertension and Vascular Research Center and Physiology and Pharmacology Department, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1032, USA
| | | | | | | |
Collapse
|
54
|
Lee EJ, In KH, Ha ES, Lee KJ, Hur GY, Kang EH, Jung KH, Lee SY, Kim JH, Lee SY, Shin C, Shim JJ, Kang KH, Yoo SH. Asthma-like symptoms are increased in the metabolic syndrome. J Asthma 2009; 46:339-42. [PMID: 19484665 DOI: 10.1080/02770900802660931] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
BACKGROUND The prevalence of obesity and asthma has been increasing during the last several decades. Obesity has been reported to be associated with asthma. Obesity, especially abdominal obesity, is the main component of the metabolic syndrome. OBJECTIVES We thus hypothesized that metabolic syndrome is an important contributing factor for the development of asthma-like symptoms. METHODS The Korean Health and Genome Study started in 2001 as an ongoing population-based study of Korean adults 40 to 69 years of age. The prevalence of asthma-like symptoms in the previous 12 months was obtained by a questionnaire, and spirometric testing was conducted. RESULTS Among the 10,038 participants, the data from 9,942 individuals (4,716 men and 5,226 women) was available. Asthma-like symptoms (wheeze [p = 0.0006], resting dyspnea [p = 0.0062], and post-exercise dyspnea [p < 0.0001]) were increased in the subjects of the metabolic syndrome group. Subjects with asthma-like symptoms had a decreased lung function compared to subjects without asthma-like symptoms. Among the components of the metabolic syndrome, abdominal obesity and hypertension were the risk factors for asthma-like symptoms. CONCLUSIONS Metabolic syndrome is associated with asthma-like symptoms. Among the components of metabolic syndrome, abdominal obesity and hypertension are the risk factors for asthma-like symptoms.
Collapse
Affiliation(s)
- Eun Joo Lee
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
55
|
Hsieh PS, Jin JS, Chiang CF, Chan PC, Chen CH, Shih KC. COX-2-mediated inflammation in fat is crucial for obesity-linked insulin resistance and fatty liver. Obesity (Silver Spring) 2009; 17:1150-7. [PMID: 19247274 DOI: 10.1038/oby.2008.674] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The aim was to examine the role of cyclooxygenase (COX)-2-mediated inflammation in the development of obese linked insulin resistance and fatty liver. The rats were fed separately regular diet (CONT), high-fat diet (HFD) ad libitum, or energy restrictedly for 12 weeks. Rats fed HFD ad libitum were further divided into three subgroups co-treated with vehicle (HFa), or a selective COX-2 inhibitor celecoxib (HFa-Cel) or mesulid (HFa-Mes). Euglycemic hyperinsulinemic clamp (EHC) experiment was performed at the end of study. Another set of rats with similar grouping was further divided into those with a 4, 8, or 12-week intervention period for hepatic sampling. Body weight was increased significantly and similarly in HFa, HFa-Cel, and HFa-Mes. Time-dependent increases in plasma insulin, glucose, 8-isoprostanes, leptin levels, homeostasis model assessment of insulin resistance (HOMA-IR) and hepatic triglyceride contents shown in HFa were significantly reversed in HFa-Cel and HFa-Mes. During EHC period, the reduction in stimulation of whole body glucose uptake, suppression of hepatic glucose production and metabolic clearance rate of insulin shown in HFa were significantly reversed in HFa-Cel and HFa-Mes. The enhanced COX-2 and tumor necrosis factor-alpha (TNF-alpha) but attenuated PPAR-gamma and C/EBP-alpha mRNA expressions in epididymal fat shown in HFa were significantly reversed in HFa-Cel and HFa-Mes. The increases in average cell size of adipocytes and CD68 positive cells shown in HFa were also significantly reversed in HFa-Cel and HFa-Mes. Our findings suggest that COX-2 activation in fat inflammation is important in the development of insulin resistance and fatty liver in high fat induced obese rats.
Collapse
Affiliation(s)
- Po-Shiuan Hsieh
- Department of Physiology and Biophysics, National Defense Medical Center, Taipei, Taiwan.
| | | | | | | | | | | |
Collapse
|
56
|
Radin MJ, Sharkey LC, Holycross BJ. Adipokines: a review of biological and analytical principles and an update in dogs, cats, and horses. Vet Clin Pathol 2009; 38:136-56. [DOI: 10.1111/j.1939-165x.2009.00133.x] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
|
57
|
Karpoff L, Vinet A, Schuster I, Oudot C, Goret L, Dauzat M, Obert P, Perez-Martin A. Abnormal vascular reactivity at rest and exercise in obese boys. Eur J Clin Invest 2009; 39:94-102. [PMID: 19200162 DOI: 10.1111/j.1365-2362.2008.02068.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
BACKGROUND Obese children exhibit vascular disorders at rest depending on their pubertal status, degree of obesity, and level of insulin resistance. However, data regarding their vascular function during exercise remain scarce. The aims of the present study were to evaluate vascular morphology and function at rest, and lower limb blood flow during exercise, in prepubertal boys with mild-to-moderate obesity and in lean controls. MATERIALS AND METHODS Twelve moderately obese prepubertal boys [Body Mass Index (BMI: 23.9+/-2.6 kg m(-2))] and thirteen controls (BMI:17.4+/-1.8 kg m(-2)), matched for age (mean age: 11.6+/-0.6 years) were recruited. We measured carotid intima-media thickness (IMT) and wall compliance and incremental elastic modulus, resting brachial flow-mediated dilation (FMD) and nitrate-dependent dilation (NDD), lower limb blood flow during local knee-extensor incremental and maximal exercise, body fat content (DEXA), blood pressure, blood lipids, insulin and glucose. RESULTS Compared to lean controls, obese boys had greater IMT (0.47+/-0.06 vs. 0.42+/-0.03 mm, P<0.05) but lower FMD (4.6+/-2.8 vs. 8.8+/-3.2%, P<0.01) in spite of similar maximal shear rate, without NDD differences. Lower limb blood flow (mL min(-1).100 g(-1)) increased significantly from rest to maximal exercise in both groups, although obese children reached lower values than lean counterparts whatever the exercise intensity. CONCLUSIONS Mild-to-moderate obesity in prepubertal boys without insulin resistance is associated with impaired endothelial function and blunted muscle perfusion response to local dynamic exercise without alteration of vascular smooth muscle reactivity.
Collapse
Affiliation(s)
- L Karpoff
- Faculty of Sciences, Avignon, France
| | | | | | | | | | | | | | | |
Collapse
|
58
|
Claeyssen R, Andriollo-Sanchez M, Arnaud J, Touvard L, Alonso A, Chancerelle Y, Roussel AM, Agay D. Effect of sub-deficient zinc status on insulin sensitivity after burn injury in rats. Biol Trace Elem Res 2009; 127:132-42. [PMID: 18800198 DOI: 10.1007/s12011-008-8226-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 06/26/2008] [Indexed: 12/13/2022]
Abstract
Although zinc status is an important parameter in insulin sensitivity, data concerning its implication in noxious burn-induced insulin resistance are scarce. The present study was designed to evaluate the impact of zinc status before burn on the recovery of injury with focus on plasma insulin and glucose levels. The experiment was performed in male adult Wistar rats fed from weaning with a zinc normal diet (80 ppm) or a depleted zinc diet (10 ppm) for 8 weeks and burned to third degree on 20% of their total body surface area. Blood and tissue samples were collected 3, 6, and 24 h after injury in order to study biochemical parameters and the glucose/insulin response in relation with the zinc status. After burn, zinc-depleted rats presented an exacerbated decrease in plasma zinc level. In addition, the burn-induced insulin resistance, leading to protein catabolism, was emphasized, with higher plasma insulin, glucose, and leptin levels in zinc-deficient animals versus normal-fed rats. Our experimental results underlined the interest to early control the zinc status in order to limit the deleterious effects of oxidative stress and insulin resistance in burned patients.
Collapse
Affiliation(s)
- Richard Claeyssen
- Centre de Recherches du Service de Santé des Armées, 24 Avenue des Maquis du Grésivaudan, BP 87, 38702, La Tronche cedex, France
| | | | | | | | | | | | | | | |
Collapse
|
59
|
Steinberger J, Daniels SR, Eckel RH, Hayman L, Lustig RH, McCrindle B, Mietus-Snyder ML. Progress and challenges in metabolic syndrome in children and adolescents: a scientific statement from the American Heart Association Atherosclerosis, Hypertension, and Obesity in the Young Committee of the Council on Cardiovascular Disease in the Young; Council on Cardiovascular Nursing; and Council on Nutrition, Physical Activity, and Metabolism. Circulation 2009; 119:628-47. [PMID: 19139390 DOI: 10.1161/circulationaha.108.191394] [Citation(s) in RCA: 481] [Impact Index Per Article: 32.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
60
|
Tank J, Heusser K, Diedrich A, Hering D, Luft FC, Busjahn A, Narkiewicz K, Jordan J. Influences of gender on the interaction between sympathetic nerve traffic and central adiposity. J Clin Endocrinol Metab 2008; 93:4974-8. [PMID: 18782878 PMCID: PMC5393368 DOI: 10.1210/jc.2007-2820] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
CONTEXT Sympathetic activation promotes insulin resistance and arterial hypertension with increasing adiposity. A difference in the relationship between adiposity and sympathetic activity between women and men could contribute to the known gender difference in cardiovascular disease risk. OBJECTIVE We tested whether muscle sympathetic nerve activity (MSNA) is correlated differently with waist circumference, waist to hip ratio (WHR), and body mass index (BMI) in women and men. DESIGN AND SETTING We pooled data from two microneurography centers (Berlin, Germany; Gdansk, Poland) for a cross-sectional study. PARTICIPANTS We studied 111 normotensive, healthy Caucasian subjects (70 males and 41 females). Age ranged between 19 and 62 yr and BMI ranged between 18 and 40 kg/m(2). INTERVENTION No intervention was applied during the study. MEASUREMENTS Supine heart rate, blood pressure, and MSNA were recorded after at least 30 min rest. RESULTS MSNA in bursts per minute was age dependent in both sexes [r (male) = 0.56, r (female) = 0.34, P < 0.01]. Controlling for waist and hip circumferences, age dependence remained highly significant in men (r = 0.43) and women (r = 0.43). Adjusting for age, in men, waist circumference (r = 0.29), WHR (r = 0.39), and BMI (r = 0.31) were predictive for MSNA and directly correlated (P < 0.01) but not in women. Adjusting for BMI, in men, only WHR (r = 0.40) remained predictive for MSNA. CONCLUSION These data support the hypothesis of a gender difference in the regulation of the sympathetic nervous system, in which MSNA mainly relates to WHR in men but not women. The phenomenon may contribute to the sexual dimorphism in cardiovascular disease risk.
Collapse
Affiliation(s)
- Jens Tank
- Institute of Clinical Pharmacology, Hannover Medical School, Carl Neuberg Strasse 1, 30625 Hannover, Germany
| | | | | | | | | | | | | | | |
Collapse
|
61
|
Diaz-Arjonilla M, Schwarcz M, Swerdloff RS, Wang C. Obesity, low testosterone levels and erectile dysfunction. Int J Impot Res 2008; 21:89-98. [DOI: 10.1038/ijir.2008.42] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
62
|
Barwell ND, Malkova D, Moran CN, Cleland SJ, Packard CJ, Zammit VA, Gill JMR. Exercise training has greater effects on insulin sensitivity in daughters of patients with type 2 diabetes than in women with no family history of diabetes. Diabetologia 2008; 51:1912-9. [PMID: 18663427 PMCID: PMC2584356 DOI: 10.1007/s00125-008-1097-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 06/20/2008] [Indexed: 01/07/2023]
Abstract
AIMS/HYPOTHESIS Sedentary offspring of patients with type 2 diabetes are often more insulin-resistant than persons with no family history of diabetes, but when active or fit offspring of type 2 diabetic patients are compared with non-diabetic persons, differences in insulin resistance are less evident. This study aimed to determine the effects of an exercise training intervention on insulin sensitivity in both groups. METHODS Women offspring (n = 34) of type 2 diabetic patients (offspring age 35.6 +/- 7.0 years, BMI 28.1 +/- 5.1 kg/m(2)) and 36 matched female controls (age 33.6 +/- 6.1 years, BMI 27.3 +/- 4.7 kg/m(2)) participated. Body composition, fitness and metabolic measurements were made at baseline and after a controlled 7 week exercise intervention. RESULTS At baseline, insulin sensitivity index (ISI) was 22% lower in offspring than controls (p < 0.05), despite similar body fat and maximal oxygen uptake (.VO(2max)) values in the two groups. ISI increased by 23% (p < 0.05) in offspring following the exercise intervention, compared with 7% (NS) in the controls. Increases in .VO(2max) were similar in both groups (controls 12%, offspring 15%, p < 0.05 for both). Plasma leptin concentrations decreased significantly in the offspring (-24%, p < 0.01) but not in controls (0%, NS). Change in ISI correlated significantly with baseline ISI (r = -0.47, p < 0.0005) and change in leptin (r = -0.43, p < 0.0005). The latter relationship was not attenuated by adjustment for changes in body fat. CONCLUSIONS/INTERPRETATION Offspring, but not controls, significantly increased ISI in response to an exercise intervention, indicating that insulin sensitivity is more highly modulated by physical activity in daughters of patients with type 2 diabetes than in women with no family history of the disease.
Collapse
Affiliation(s)
- N. D. Barwell
- Institute of Diet, Exercise and Lifestyle (IDEAL), Faculty of Biomedical and Life Sciences, West Medical Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ UK
| | - D. Malkova
- Institute of Diet, Exercise and Lifestyle (IDEAL), Faculty of Biomedical and Life Sciences, West Medical Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ UK
- Division of Developmental Medicine, University of Glasgow, Glasgow, UK
| | - C. N. Moran
- Institute of Diet, Exercise and Lifestyle (IDEAL), Faculty of Biomedical and Life Sciences, West Medical Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ UK
| | - S. J. Cleland
- Division of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - C. J. Packard
- Division of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, UK
| | - V. A. Zammit
- Clinical Sciences Research Institute, Warwick Medical School, University of Warwick, Warwick, UK
| | - J. M. R. Gill
- Institute of Diet, Exercise and Lifestyle (IDEAL), Faculty of Biomedical and Life Sciences, West Medical Building, University of Glasgow, University Avenue, Glasgow, G12 8QQ UK
| |
Collapse
|
63
|
Galletti F, D'Elia L, Barba G, Siani A, Cappuccio FP, Farinaro E, Iacone R, Russo O, De Palma D, Ippolito R, Strazzullo P. High-circulating leptin levels are associated with greater risk of hypertension in men independently of body mass and insulin resistance: results of an eight-year follow-up study. J Clin Endocrinol Metab 2008; 93:3922-6. [PMID: 18682500 DOI: 10.1210/jc.2008-1280] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
BACKGROUND We previously reported a significant association between plasma leptin (LPT) concentration and blood pressure (BP), which was partly independent of serum insulin levels and insulin resistance. The aims of this study were to detect whether serum LPT levels predict the development of hypertension (HPT) in the 8-yr follow-up investigation of a sample of an adult male population (the Olivetti Heart Study), and to evaluate the role of body mass index (BMI) and insulin resistance in this putative association. PATIENTS AND METHODS The study population was made up of 489 untreated normotensive subjects examined in 1994-1995 (age: 50.1 +/- 6.7 yr; BMI: 26.3 +/- 2.8 kg/m(2); BP: 120 +/- 10/78 +/- 6 mm Hg; and homeostatic model assessment index: 2.1 +/- 1.6). RESULTS The HPT incidence over 8 yr was 35%. The participants with incident HPT had similar age but higher BMI (P < 0.001), serum LPT (P < 0.001), and BP (P < 0.01) at baseline. One sd positive difference in baseline serum LPT log was associated at univariate analysis with a 49% higher rate of HPT [95% confidence interval (CI) 22-83; P < 0.001]). In three different models of multivariable logistical regression analysis, LPT was respectively associated with a 41% greater risk to develop HPT (95% CI 15-74; P < 0.001) upon adjustment for age and baseline BP, with a 48% (95% CI 20-81) greater risk when adding the homeostatic assessment model index to the model, and with 33% greater risk (95% CI 6-67; P < 0.02) upon adjustment for BMI. CONCLUSIONS In this sample of originally normotensive men, circulating LPT level was a significant predictor of the risk to develop HPT over 8 yr, independently of BMI and insulin resistance.
Collapse
Affiliation(s)
- F Galletti
- Department of Clinical and Experimental Medicine, Federico II University Medical School, Via S. Pansini, 5, 80131 Naples, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
64
|
Abstract
After an initial attempt by the WHO to define metabolic syndrome (MS) on a pathophysiologically oriented approach requiring the assessment of insulin resistance markers, the NCEP-ATPIII and more recently the IDF proposed more clinically oriented criteria to help, toward a preventive medicine goal, to identify patients who are likely to have features of the MS and be at increased risk of type 2 diabetes and cardio vascular disease. The notion of MS is built around abnormalities of the metabolism of lipids and carbon hydrates, a rise of blood pressure, and visceral obesity of abdominal localization. These parameters report only partially on mechanisms leading to the development of the MS. The physiopathology of MS is partially understood even today and likely results from the combination of environmental, genetic and epigenetic factors. Abdominal visceral obesity, a state of low-grade chronic inflammation and insulin resistance are the main processes susceptible to explain the various constituents of this syndrome.
Collapse
Affiliation(s)
- D Jullien
- Université Lyon 1, faculté de médecine RTH Laennec, 69288 Lyon cedex 02, France.
| |
Collapse
|
65
|
Renin-angiotensin system, natriuretic peptides, obesity, metabolic syndrome, and hypertension: an integrated view in humans. J Hypertens 2008; 26:831-43. [PMID: 18398321 DOI: 10.1097/hjh.0b013e3282f624a0] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The obesity pandemic is closely related to hypertension and metabolic syndrome. Visceral adipose tissue plays a key role in the metabolic and cardiovascular complications of being overweight. The pathophysiological link between visceral adiposity and cardiometabolic complications focuses on insulin sensitivity, sympathetic nervous system, renin-angiotensin-aldosterone system (RAAS) and, only recently, on cardiac natriuretic peptide system (CNPS). RAAS and CNPS are endogenous antagonistic systems on sodium balance, cardiovascular system, and metabolism. The circulating RAAS is dysregulated in obese patients, and adipose tissue has a full local renin-angiotensin system that is active at local and systemic level. Adipocyte biology and metabolism are influenced by local renin-angiotensin system, with angiotensin II acting as a 'growth factor' for adipocytes. CNPS induces natriuresis and diuresis, reduces blood pressure, and, moreover, has powerful lipolytic and lipomobilizing activity in humans but not in rodents. In obesity, lower plasmatic natriuretic peptides levels with increasing BMI, waist circumference, and metabolic syndrome have been documented. Thus, reduced CNPS effects coupled with increased RAAS activity have a central role in obesity and its deadly complications. We propose herein an integrated view of the dysregulation of these two antagonistic systems in human obesity complicated with hypertension, metabolic syndrome, and increased cardiovascular risk.
Collapse
|
66
|
Abstract
The dramatic increase in the prevalence of obesity and its strong association with cardiovascular disease have resulted in unprecedented interest in understanding the effects of obesity on the cardiovascular system. A consistent, but puzzling clinical observation is that obesity confers an increased susceptibility to the development of cardiac disease, while at the same time affording protection against subsequent mortality (termed the obesity paradox). In this review we focus on evidence available from human and animal model studies and summarize the ways in which obesity can influence structure and function of the heart. We also review current hypotheses regarding mechanisms linking obesity and various aspects of cardiac remodeling. There is currently great interest in the role of adipokines, factors secreted from adipose tissue, and their role in the numerous cardiovascular complications of obesity. Here we focus on the role of leptin and the emerging promise of adiponectin as a cardioprotective agent. The challenge of understanding the association between obesity and heart failure is complicated by the multifaceted interplay between various hemodynamic, metabolic, and other physiological factors that ultimately impact the myocardium. Furthermore, the end result of obesity-associated changes in the myocardial structure and function may vary at distinct stages in the progression of remodeling, may depend on the individual pathophysiology of heart failure, and may even remain undetected for decades before clinical manifestation. Here we summarize our current knowledge of this complex yet intriguing topic.
Collapse
Affiliation(s)
- E Dale Abel
- Department of Biology, York University, Toronto, Canada
| | | | | |
Collapse
|
67
|
Abstract
Psoriasis is a chronic and debilitating inflammatory disease associated with serious comorbidities. Psoriasis can have a significant impact on a patient's quality of life and is associated with loss of productivity, depression, and an increased prevalence of malignancy. Emerging comorbidities of psoriasis include cardiovascular disease and metabolic syndrome. Psoriasis patients have an increased prevalence of the core components of metabolic syndrome, including obesity, dyslipidemia, and insulin resistance. The relationship between psoriasis and comorbidities such as metabolic syndrome and cardiovascular disease is likely linked to the underlying chronic inflammatory nature of psoriasis. The molecular mechanisms involved in psoriasis-associated dysregulation of metabolic function are believed to be due, in large part, to the action of increased levels of proinflammatory factors, such as tumor necrosis factor-alpha, that are central to the pathogenesis of psoriasis. Recent studies investigating the effects of tumor necrosis factor antagonists on the treatment of cardiovascular disease and metabolic syndrome support this concept.
Collapse
|
68
|
Kapsimalis F, Varouchakis G, Manousaki A, Daskas S, Nikita D, Kryger M, Gourgoulianis K. Association of sleep apnea severity and obesity with insulin resistance, C-reactive protein, and leptin levels in male patients with obstructive sleep apnea. Lung 2008; 186:209-217. [PMID: 18365276 DOI: 10.1007/s00408-008-9082-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Accepted: 02/21/2008] [Indexed: 02/08/2023]
Abstract
Obesity is the major confounding factor in the relationship between obstructive sleep apnea and increased risk for cardiovascular disease. The aim of the study was to investigate the association of sleep apnea severity with insulin resistance, leptin, and CRP levels in a cohort of male patients. Sixty-seven men referred to our sleep laboratory for evaluation of suspected obstructive sleep apnea syndrome (OSAS) were divided into three groups according to apnea severity: non-OSAS group (n=15), mild to moderate OSAS group (n=26), and severe OSAS (n=26). Insulin resistance was estimated by the homeostasis model assessment method. HOMA values were similar in the three groups: (3.2+/-2.2 vs. 3.3+/-1.8 vs. 3.6+/-1.5, respectively, p=0.71). Leptin levels were higher in the mild to moderate OSAS group (23.1+/-21.8 ng/ml, p<0.05) and in the severe OSAS group (20.2+/-17.5 ng/ml, p<0.05) than in the non-OSAS group (9.4+/-6.4 ng/ml). CRP levels were significantly higher in severe sleep apnea (0.35+/-0.3 vs. 0.19+/-0.1 mg/dl, p<0.05). In multiple regression analyses, waist-to-hip ratio (WHR) was the most significant determinant of HOMA estimation for insulin resistance. WHR and the percentage of total sleep time spent with hypoxemia (%TST with SaO2 <90%) were significant predictors for leptin levels, while body mass index (BMI) and the %TST with SaO2 <90% were the best predicting parameters for CRP levels. Insulin resistance estimated by the HOMA method in male patients with OSAS was not associated with sleep apnea severity independent of obesity. The severity of nocturnal hypoxemia was associated with leptin and CRP levels independent of obesity.
Collapse
Affiliation(s)
- Fotis Kapsimalis
- Department of Pulmonary Medicine, Sleep Laboratory, Henry Dunant Hospital, 107 Mesogeion Avenue, Athens, Greece.
| | - George Varouchakis
- Department of Pulmonary Medicine, Sleep Laboratory, Henry Dunant Hospital, 107 Mesogeion Avenue, Athens, Greece
| | - Asimina Manousaki
- Department of Clinical Biochemistry, Henry Dunant Hospital, Athens, Greece
| | - Spiros Daskas
- Department of Clinical Biochemistry, Henry Dunant Hospital, Athens, Greece
| | - Dimitra Nikita
- Department of Clinical Biochemistry, Henry Dunant Hospital, Athens, Greece
| | - Meir Kryger
- Sleep Medicine, Research and Education, Gaylord Hospital, Wallingford, Connecticut, 06492, USA
| | | |
Collapse
|
69
|
Oz O, Tuncel E, Eryilmaz S, Fazlioglu M, Gul CB, Ersoy C, Ocak N, Dirican M, Cangur S, Baran I, Imamoglu S. Arterial elasticity and plasma levels of adiponectin and leptin in type 2 diabetic patients treated with thiazolidinediones. Endocrine 2008; 33:101-5. [PMID: 18392690 DOI: 10.1007/s12020-008-9058-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 03/26/2008] [Indexed: 01/13/2023]
Abstract
BACKGROUND Thiazolidinediones (TZDs) improve peripheral insulin sensitivity, but the effect on arterial stiffness is less clear. The aim of the present study was to assess the differential effect of pioglitazone or rosiglitazone on arterial stiffness and plasma levels of adiponectin and leptin in patients with type 2 diabetes mellitus. METHODS Thirty-five type 2 diabetic subjects were randomly assigned to receive pioglitazone (30 mg/day; n = 14), rosiglitazone (4 mg/day; n = 11), or placebo (medical nutrition therapy; n = 10) for 12 weeks. Changes in plasma glucose, glycosylated hemoglobin, insulin resistance (HOMA-IR), total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, adiponectin, and leptin were evaluated at baseline and after 12 weeks. In parallel, large arterial compliance (C1) and small arterial compliance (C2) were measured at baseline and at the end of treatment period. RESULTS At 12 weeks, the rosiglitazone (P = 0.026) and pioglitazone (P = 0.004) groups had a significant increase from baseline in adiponectin that was not seen in the medical nutrition therapy group. No significant changes in plasma leptin and in C1 and C2 elasticity indexes were observed over the entire study period in any of the treatment groups. CONCLUSIONS In this study of patients with type 2 diabetes, treatment with TZDs was associated with a significant improvement in adiponectin levels, although no significant effects were seen on leptin levels and arterial elasticity.
Collapse
Affiliation(s)
- Ozen Oz
- Department of Internal Medicine, Uludag University Medical School, Gorukle, Bursa, 16059, Turkey.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
70
|
Akin F, Bastemir M, Kaptanoglu B. Relationship between Insulin and Sex Hormone-Binding Globulin Levels during Weight Loss in Obese Women. ANNALS OF NUTRITION AND METABOLISM 2008; 51:557-62. [DOI: 10.1159/000114210] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2007] [Accepted: 06/25/2007] [Indexed: 12/29/2022]
|
71
|
Tentolouris N, Argyrakopoulou G, Katsilambros N. Perturbed autonomic nervous system function in metabolic syndrome. Neuromolecular Med 2008; 10:169-78. [PMID: 18224460 DOI: 10.1007/s12017-008-8022-5] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2007] [Accepted: 12/17/2007] [Indexed: 01/26/2023]
Abstract
The metabolic syndrome is characterized by the clustering of various common metabolic abnormalities in an individual and it is associated with increased risk for the development of type 2 diabetes and cardiovascular diseases. Its prevalence in the general population is approximately 25%. Central fat accumulation and insulin resistance are considered as the common denominators of the abnormalities of the metabolic syndrome. Subjects with metabolic syndrome have autonomic nervous system dysfunction characterized by predominance of the sympathetic nervous system in many organs, i.e. heart, kidneys, vasculature, adipose tissue, and muscles. Sympathetic nervous system activation in metabolic syndrome is detected as increased heart rate and blood pressure, diminished heart rate variability, baroreceptor dysfunction, enhanced lipolysis in visceral fat, increased muscle sympathetic nerve activity, and high urine or plasma catecholamine concentrations as well as turnover rates. The augmented sympathetic activity in individuals with metabolic syndrome worsens prognosis of this high-risk population. The mechanisms linking metabolic syndrome with sympathetic activation are complex and not clearly understood. Whether sympathetic overactivity is involved in the development of the metabolic syndrome or is a consequence of it remains to be elucidated since data from prospective studies are missing. Intervention studies have demonstrated that the autonomic disturbances of the metabolic syndrome may be reversible.
Collapse
Affiliation(s)
- Nicholas Tentolouris
- 1st Department of Propaedeutic Medicine, Athens University Medical School, Athens, Greece.
| | | | | |
Collapse
|
72
|
Abstract
PURPOSE OF REVIEW Identifying and treating obesity hypoventilation syndrome is an important therapeutic goal, especially given the high morbidity and mortality associated with untreated disease. Significant weight loss or effective treatment of upper airway obstruction will reverse daytime hypoventilation, suggesting that these two mechanisms play key roles in the development and progression of this disorder. Only a subset of morbidly obese patients will develop awake hypercapnia, however, even in the presence of sleep disordered breathing. This implies that complex interplay between a number of known and unknown mechanisms is needed to produce daytime respiratory failure in this patient population. RECENT FINDINGS Work in the mouse model of obesity has been central in advancing our understanding of the role leptin plays in stimulating ventilation. Leptin deficiency or development of leptin resistance in obesity leads to alterations in central respiratory drive and reduced ventilatory responsiveness, permitting development of carbon dioxide retention. Changes in neuromodulators resulting from the effects of hypoxia may further exacerbate the problem by depressing arousal from sleep in the face of abnormal breathing. SUMMARY Understanding the various mechanisms contributing to development of obesity hypoventilation is important in order to identify new approaches to effective long-term management of this disorder.
Collapse
Affiliation(s)
- Amanda J Piper
- Department of Respiratory and Sleep Medicine, Royal Prince Alfred Hospital, Camperdown, and Sleep and Circadian Group, Woolcock Institute of Medical Research, University of Sydney, Sydney, Australia.
| | | |
Collapse
|
73
|
Nikoobakht MR, Tajik P, Karami AA, Moradi K, Mortazavi A, Kosari F. Premature ejaculation and serum leptin level: a diagnostic case-control study. J Sex Med 2008; 5:2942-6. [PMID: 18194178 DOI: 10.1111/j.1743-6109.2007.00730.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Premature ejaculation (PE) is regarded as the most common male sexual disorder. To date, there is no accurate and objective diagnostic test for PE. AIM To determine the diagnostic value of serum leptin level for PE. METHODS In a case-control design, the serum leptin level of 46 PE patients referred to our outpatient clinic were determined and compared with 44 control patients referred to the same clinic with the complaint of nephrolithiasis. PE was defined based on the Diagnostic and Statistical Manual of Mental Disorders IV criteria and an intravaginal ejaculatory latency time of less than a minute. MAIN OUTCOME MEASURES Serum leptin level and presence of PE. RESULTS The PE patients had significantly higher serum leptin levels (8.3+/-3 ng/mL) than the controls (3.3+/-1 ng/mL) (P<0.001). Sensitivity and specificity for the test as a predictive diagnostic tool for PE were 80.4% and 97.7%, respectively, at the cutoff value of 6.3 ng/mL. CONCLUSIONS According to our results, leptin level in patients with PE was significantly higher than in the control subjects. More studies are necessary to determine the value of serum leptin as a diagnostic tool for PE.
Collapse
|
74
|
Abstract
Obesity has become a global epidemic and carries a considerable negative impact in regard to quality of life and life expectancy. A primary problem is that obese individuals are at increased risk of suffering from cardiovascular disease complications such as myocardial infarction and stroke. Because fat accumulation is a consistent aspect of obesity, mechanisms that may link adipose tissue to cardiovascular disease complications should be considered. Proteins expressed from adipose tissue, known as adipokines, are hypothesized to have important effects on the progression and incidence of cardiovascular disease complications. This review examines the evidence that adipokines play a direct role in vascular thrombosis, an important event in cardiovascular disease complications.
Collapse
Affiliation(s)
- Peter F Bodary
- Department of Nutrition and Food Science, College of Liberal Arts and Sciences, Wayne State University, Detroit, Mich, USA.
| |
Collapse
|
75
|
Bibliography. Current world literature. Obesity and nutrition. Curr Opin Endocrinol Diabetes Obes 2007; 14:421-6. [PMID: 17940474 DOI: 10.1097/med.0b013e3282f0ca40] [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]
|
76
|
Abstract
Upper body obesity and the related metabolic disorder type 2 diabetes have been identified as risk factors for breast cancer, and associated with late-stage disease and a poor prognosis. Components of the metabolic syndrome, including visceral adiposity, insulin resistance, hyperglycemia and hyperinsulinemia, with or without clinically manifest diabetes mellitus, low serum high-density lipoprotein cholesterol and hypertension have all been related to increased breast cancer risk. The biochemical mechanisms include extraglandular oestrogen production, reduced sex hormone-binding globulin with consequent elevation of the bioactive plasma free oestradiol and increased insulin biosynthesis, all of which exert mitogenic effects on both untransformed and neoplastic breast epithelial cells. Obesity, type 2 diabetes and the metabolic syndrome also have in common an increased production of leptin and a decreased production of adiponectin by adipose tissue, with consequent elevations and reductions, respectively, in the circulating levels of these two adipokines. These changes in plasma leptin and adiponectin, acting through endocrine and paracrine mechanisms, have been associated in several studies with an increase in breast cancer risk and, perhaps, to more aggressive tumours; studies in vitro showed that leptin stimulates, and adiponectin inhibits, tumour cell proliferation and the microvessel angiogenesis which is essential for breast cancer development and progression.
Collapse
Affiliation(s)
- L Vona-Davis
- Department of Surgery and Mary Babb Randolph Cancer Center, West Virginia University, Morgantown, WV 26506-9238, USA.
| | | | | |
Collapse
|
77
|
Bibliography. Current world literature. Diabetes and the endocrine pancreas II. Curr Opin Endocrinol Diabetes Obes 2007; 14:329-57. [PMID: 17940461 DOI: 10.1097/med.0b013e3282c3a898] [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]
|
78
|
Katagiri H, Yamada T, Oka Y. Adiposity and cardiovascular disorders: disturbance of the regulatory system consisting of humoral and neuronal signals. Circ Res 2007; 101:27-39. [PMID: 17615379 DOI: 10.1161/circresaha.107.151621] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Obesity, a major healthcare issue, is associated with significant cardiovascular morbidities, including hypertension and atherosclerosis. Numerous intensive studies conducted this decade have revealed that adipose tissue is a major endocrine organ that secretes a variety of bioactive substances, termed adipocytokines. Adipocytokine secretion profiles are altered as obesity develops, which may increase the risk of obesity-related cardiovascular disorders. For instance, leptin is upregulated in obese subjects and plays important roles in the pathophysiology of obesity-related atherogenesis through multiple mechanisms, such as its proliferative, proinflammatory, prothrombotic, and prooxidant actions. In contrast, adiponectin, which is downregulated in obese subjects, has protective effects against cardiovascular disorders at various atherogenic stages. In addition to these factors secreted by adipose tissue, neuronal circuits involving autonomic nerves are now being recognized as an important metabolic regulatory system and have thus attracted considerable attentions. Alterations in fat accumulation in intraabdominal organs, such as visceral adipose tissue and the liver, send afferent neuronal signals to the brain, leading to modulation of sympathetic tonus and thereby affecting the vasculature. Moreover, these humoral and neuronal signaling pathways communicate with each other, resulting in cooperative metabolic regulation among tissues/organs throughout the body. Further elucidation of these regulatory systems is anticipated to lead to new approaches to devising therapeutic strategies for the metabolic syndrome.
Collapse
Affiliation(s)
- Hideki Katagiri
- Division of Advanced Therapeutics for Metabolic Diseases, Center for Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
| | | | | |
Collapse
|
79
|
Serum uric acid and leptin levels in metabolic syndrome: a quandary over the role of uric acid. Metabolism 2007; 56:751-6. [PMID: 17512306 DOI: 10.1016/j.metabol.2007.01.006] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Accepted: 01/17/2007] [Indexed: 11/29/2022]
Abstract
This study investigates the impact of uric acid (UA) on the risk factors associated with metabolic syndrome. In addition, this study explores the relationship between UA and insulin resistance and serum leptin levels in metabolic syndrome. A total of 470 subjects (252 women and 218 men) were recruited from the Department of Health Management at Chang Gung Medical Center (Linkou, Taiwan). Metabolic syndrome was defined using a modified Adult Treatment Panel III (ATP III) definition. The formula for the homeostasis model assessment of insulin resistance (HOMA-IR) is as follows: fasting serum insulin (microU/mL) x fasting plasma glucose (mmol/L)/22.5. Diabetes mellitus was diagnosed in 45 subjects (9.6%); 82 subjects (17.4%) had hypertension. Hyperuricemia was diagnosed in 144 subjects (30.6%). Of these subjects, 115 (63 females and 52 males) (24.5%) were diagnosed as having metabolic syndrome. Patients with hyperuricemia had increased body mass index, waist-to-hip ratio, and triglyceride (Tg) level. The subjects also had lower high-density lipoprotein and greater hypertension. Hormone assays showed an elevation of leptin, immunoreactive insulin (IRI), and HOMA-IR in the hyperuricemia group. Uric acid appeared to be better correlated with Tg, blood pressure (both systolic and diastolic), obesity, immunoreactive insulin, and HOMA-IR. Uric acid did not correlate with leptin or blood glucose levels. Metabolic syndrome and Tg/high-density lipoprotein ratio showed a statistically significant difference in HOMA-IR using 3.8 as a cutoff value. Otherwise, there was no difference in leptin value. In conclusion, serum UA is significantly related to risk factors of metabolic syndrome except for blood glucose. Waist-to-hip ratio and HOMA-IR were statistically different in subjects with and without metabolic syndrome.
Collapse
|