Leptin In Men Research Articles

The influence of whole-body cryotherapy or winter swimming on the lipid profile and selected adipokines

PurposeThe aim of this study was to investigate the effect of a series of 20 whole-body cryotherapy (WBC) sessions and 20 winter swimming sessions on the lipid profile and selected adipokines.Materials/methodsThe experimental group consisted of 30 people who underwent a series of WBC treatments and 30 people who underwent a winter swimming. The control group consisted of 30 people - without intervention. Study 1: on the day of the commencement of whole-body cryotherapy / at the beginning of the winter swimming season; and Study 2: after a series of 20 cryotherapy sessions / at the end of the winter swimming season. The control group was also tested twice (4-week break). There were 20 WBC treatments − 5 times a week (4 weeks) and 20 cold water baths - once a week (20 weeks).ResultsA statistically significant increase in the concentration of adiponectin, resistin and leptin in women and resistin and leptin in men was observed after the winter swimming season. Differences were also found in the second study between the groups of women using WBC and the control group, as well as the groups of women swimming and the control group. In men, however, these differences were observed in WBC and the control group. The significance level of α = 0.05 was adopted in the analyzes.ConclusionsThe use of WBC may changes in the lipid profile and selected adipokines in men. Regular winter swimming may changes of selected adipokines in both women and men.

Sex- and body mass index-specific reference intervals for serum leptin: a population based study in China

BackgroundLeptin is a peptide hormone secreted by adipose tissue and is an important determinant of obesity and its complications. The purpose of this study was to establish sex- and body mass index (BMI)-specific reference intervals for serum leptin in a Chinese population and investigate the factors influencing leptin concentrations.MethodsFasting serum leptin levels were assayed in 469 men and 773 women from randomly sampled Chinese residents. Blood glucose, insulin, hemoglobin A1c (HbA1c), liver enzymes, blood lipid profiles, creatinine, and uric acid (UA) levels were measured. Pearson’s correlation coefficient and multiple linear regression analyses were used to estimate the relationship between serum leptin level and other variables. The reference intervals were determined by the 2.5th and 97.5th percentiles.ResultsThe mean ± standard deviation serum leptin level was much higher in women (20.92 ± 12.96 ng/mL) than in men (6.45 ± 5.53 ng/mL). The reference interval of serum leptin was 0.33–19.85 ng/mL in men and 3.60–54.86 ng/mL in women. The specific reference intervals of serum leptin in men with BMI of 20 to < 25 and 25 to < 27.5 kg/m2 were 0.42–12.32 and 2.17–20.22 ng/ml, respectively. The specific reference intervals of serum leptin in women with BMI of 20 to < 25 and 25 to < 27.5 kg/m2 were 4.11–38.09 and 8.27–48.66 ng/ml, respectively. BMI was significantly correlated with Ln (leptin) both in men (r = 0.698, P < 0.001) and women (r = 0.626, P < 0.001). In multivariate linear regression analysis, serum leptin was correlated with BMI, homeostasis model assessment of insulin resistance (HOMA-IR), UA in women, and plus triglyceride (TG) in men. The variance in serum leptin levels could be partially explained by these variables in both women (adjusted R2 = 0.447) and men (adjusted R2 = 0.552). In participants with leptin levels higher than the reference intervals, significantly higher levels of HOMA-IR, low-density lipoprotein cholesterol (LDL-C), UA, a higher proportion of central obesity (waist circumference [WC] > 90 cm), and metabolic syndrome were found in men, and significantly higher levels of HOMA-IR, UA and a higher proportion of central obesity (WC > 85 cm) were found in women.ConclusionThis is the first study to establish sex- and BMI-specific reference intervals of leptin for both sexes in a large Chinese population. Serum concentration of leptin was predicted by BMI, HOMA-IR, UA in women, and TG in men.

Abstract P219: Associations Between Endogenous Sex Hormone Levels And Adipokine Levels In The Multi-ethnic Study Of Atherosclerosis (MESA)

Background: Differences in sex hormone levels contribute to sex differences in cardiovascular disease (CVD). Adipokines, which are central to cardiometabolic disease, differ by sex and have divergent associations with CVD. However the link between sex hormones and adipokines is not well established. We hypothesized that an androgenic sex hormone profile is associated with higher leptin &amp; resistin and lower adiponectin levels among postmenopausal women and men. Methods: We performed an analysis of 1822 adults in MESA who had sex hormones and adipokines measured. Sex hormones [Testosterone (T), estradiol (E2), sex hormone binding globulin (SHBG)] were measured at exam 1; free T was estimated. Serum adipokines [leptin, resistin, adiponectin] were measured at visits 2 or 3, an average of 2.6 yrs later. We used multivariable linear regression to examine the cross-sectional associations between sex hormones and adipokines. Results: The mean age was 63 (10), 48% were women; 41% White, 13% Chinese American, 20% Black, 26% Hispanic. Leptin: After adjusting for demographics (model 1), higher free T &amp; E2 and lower SHBG were associated with greater leptin levels in women and men; higher DHEA was associated with lower leptin in men ( Table ). With full covariate adjustment (model 3), this remained statistically significant for E2 &amp; SHBG in women and for DHEA in men. Adiponectin: With demographic adjustment, higher free T, E2, DHEA &amp; lower SHBG were associated with lower adiponectin in women, and higher free T &amp; lower SHBG with lower adiponectin in men. After full covariate adjustment, these same relationships were slightly attenuated but remained significant for women and men. Resistin: no association in either sex. Conclusion: A more androgenic profile (higher free T &amp; lower SHBG) was independently associated with lower adiponectin in men and women. Higher E2 &amp; lower SHBG in women, and lower DHEA in men, were associated with leptin. These findings may provide mechanistic insight into the interplay between sex hormones, adipokines and CVD risk.

Using proximity extension proteomics assay to discover novel biomarkers associated with circulating leptin levels in patients with type 2 diabetes

We aimed to discover novel associations between leptin and circulating proteins which could link leptin to the development of cardiovascular disease in patients with type 2 diabetes (T2DM). In a discovery phase, we investigated associations between 88 plasma proteins, assessed with a proximity extension assay, and plasma leptin in a cohort of middle-aged patients with T2DM. Associations passing the significance threshold of a False discovery rate of 5% (corresponding to p < 0.0017) were replicated in patients with T2DM in an independent cohort. We also investigated if proteins mediated the longitudinal association between plasma leptin and the incidence of major cardiovascular events (MACE). One protein, adipocyte fatty acid binding protein (A-FABP), was significantly associated with leptin in both the discovery phase [95% CI (0.06, 0.17) p = 0.00002] and the replication cohort [95% CI (0.12, 0.39) p = 0.0003]. Multiplicative interaction analyses in the two cohorts suggest a stronger association between A-FABP and leptin in men than in women. In longitudinal analyses, the association between leptin and MACE was slightly attenuated after adding A-FABP to the multivariate model. Our analysis identified a consistent association between leptin and A-FABP in two independent cohorts of patients with T2DM, particularly in men.Trial registration: ClinicalTrials.gov identifier NCT 01049737.

Plasma leptin level mirrors metabolome alterations in young adults.

Leptin is known to regulate pathways of energy metabolism, reproduction, and control appetite. Whether plasma leptin levels reflect changes in metabolites of these pathways is unknown. We aimed to find whether there is an association between leptin levels and levels of metabolites of energy and hormone metabolism. We performed an untargeted metabolomics analysis of plasma from 110 healthy adults (men: women = 1:1; aged 18-40years), using liquid chromatography-tandem mass spectrometry. Blood samples were collected from all the study subjects in the fasting state. Clinical features and markers of obesity and Type 2 diabetes mellitus (T2DM) were assessed in all. The association between levels of metabolites and clinical and biochemical parameters was identified using the multivariable-adjusted linear regression model and PLS-DA analysis. The leptin level was found to have a significant association with a substantial number of metabolites in women and men. Leptin level was positively associated with glycocholic acid and arachidic acid, metabolites related to energy metabolisms, pregnanediol-3-glucuronide, a metabolite of progesterone metabolism, and quercetin 3'-sulfate, a diet-derived metabolite. Leptin level was negatively associated with ponasteroside A and barringtogenol C levels. Leptin level was positively correlated with adiponectin and negatively with total calorie intake and levels of triglyceride and very-low-density lipoprotein. Leptin levels were associated with lipid and sex hormone metabolism in women, while metabolites involved in amino acid metabolism were correlated to leptin in men. Our study indicates that leptin level reflects metabolome alterations and hence could be a useful marker to detect early changes in energy and hormone metabolisms.

Associations between lean mass and leptin in men with chronic spinal cord injury: Results from the FRASCI-muscle study.

Leptin is an adipo-myokine that regulates appetite and energy expenditure by a neuroendocrine feedback loop. Leptin levels are positively correlated with BMI in the spinal cord injury population and leptin levels are greater in individuals with spinal cord injury compared to uninjured controls. Leptin is produced in multiple tissues, including fat, bone, and skeletal muscle and is a putative biomarker of sedentary behavior in older adults. We assessed body composition leptin, adiponectin, and IL-6 levels in 205 men with chronic spinal cord injury. We found no association between age, injury duration, injury level, injury completeness, or walking status and leptin. There was a significant positive association between lean mass and leptin in men with SCI that was independent of fat. Adjusting for body composition, leptin levels were positively associated with IL-6 and negatively associated with adiponectin levels. When considering men with SCI and sarcopenic obesity, only fat mass remained positively associated with leptin. We found no association between IL-6, adiponectin, or lean mass and leptin in the sarcopenic obesity group. Our findings suggest that lean mass is an under recognized, but substantial, source of circulating leptin. Furthermore, SCI-related sarcopenic obesity may result in dysregulated adipo-myokine metabolism with local and systemic physiologic effects.

Complex relationship between sex hormones, insulin resistance and leptin in men with and without prostatic disease

Objectives: To assess sex hormones, leptin and insulin-resistance in men with prostate cancer (PCa) and benign prostatic hyperplasia (BPH) and to study associations between androgens and histologic score of prostate tissue in PCa.Subjects and methods: Two hundred ten men older than 45 years selected from 2906 participants of a population screening for PCa were studied: 70 with PCa, 70 with BPH and 70 controls (CG), matched by body mass index and age. Insulin, IGF-1, PSA, leptin, total, free (fT) and bioavailable testosterone (bT) and estradiol were measured. Each group was subdivided into two subgroups considering the presence of metabolic syndrome (MS); androgens and leptin levels were analyzed in the subgroups.Results: Prostate cancer and BPH patients presented higher total, fT and bT levels than CG. IGF-1, insulin and HOMA index were higher in BPH than in the other two groups. PCa presented higher leptin [median (range) 6.5 (1.3–28.0) versus 4.8 (1.1–12.3) ng/ml; p < 0.01] and estradiol [median (range) 37.0 (20–90) versus 29.0 (20–118) pg/ml; p = 0.025] levels than CG. After dividing men considering the presence of MS, leptin was higher and total testosterone was lower in MS patients in all the groups.Conclusions: It was observed a coexistence of an altered hormone profile with increased sex hormones and leptin in PCa patients, in accordance with the new perspective of PCa pathogenesis.

PP.28.19

Objective: Adipose tissue is an active endocrine organ with autocrine/paracrine and endocrine metabolic functions. The aim of the study is to investigate the levels of leptin, adiponectin and lipids in patients with Essential Arterial Hypertension (EAH) and abdominal obesity (AO) depending on genes polymorphism of PPAR-γ2 (Pro12Ala) and ACE (I/D). Design and method: Study involved 110 EAH I-III stages patients with AO 1–3 grades severity: 56.4% women, 43.6% men; mean age 53.3 ± 6.05 years. Alleles of angiotensin converting enzyme – ACE (I/D) and peroxisome proliferator-activated receptor-γ2 – PPAR-γ2 (Pro12Ala) genes were studied with PCR. Overweight/AO determined according to ATP III, NCEP criteria. Control group included 50 healthy individuals. Leptin and Adiponectin plasma levels were detected by ELISA. Lipids investigated by total cholesterol (TC), triglycerides (TG), high and low density levels cholesterol (HDL, LDL). Leptin-resistance (LR) was determined by the ratio of leptin/TG (>2.7). Results analyzed according to the ESC/ESH 2013 guidelines. Results: Leptin level increased 2.48–3.35 times (61.4 ± 9.34 ng/ml, p = 0,024) in women with EAH III, AO 2–3 with decrease of adiponectin from 82.0 ± 3.05 to 73.6 ± 2.34 ng/ml, p = 0.025. Leptin in men elevated according to EAH and AO severity, remaining 2.2 times lower than in women (27.4 ± 6.54 ng/ml, p < 0.05). The levels of TC, TG, LDL and LR were 1.27–2.24 times higher in EAH II-III women than in men (p < 0.05). Atherogenic dyslipidemia type IIb (Frederickson) prevailed in 87.1% overweight and AO EAH patients, especially in ACE gene’ D-allele carriers and PPAR-γ2 Pro12-genotype. Leptin level was 1.28–3.78 times (p < = 0.048–0.008) higher in D-allele female carriers of ACE gene and in Pro12-genotype carriers of PPAR-γ2 gene (regardless of gender). DD-genotype and Pro-allele associated with 23.1–39.8% (p < 0.05) higher concentrations of LDL cholesterol, Pro12-genotype – with 23.9% (p = 0.048) higher content of TC and 2.23 times (p < 0.01) higher LR in men. Leptin synthesis and LR data increased 1.26–4.71 times (p < = 0,021–0,001) in EAH with AO DD-genotype carriers of ACE gene and Pro12- genotype of PPAR-γ2 gene. Conclusions: Hyperleptinemia, leptin-resistance, dyslipidemia in EAH and AO patients correlates with the allelic status of the ACE (I/D) and PPAR-γ2 (Pro12Ala) genes.

Leptin induces CD16 expression on human monocytes in a sex‐specific manner (680.13)

In addition to a centrally‐mediated influence on blood pressure, leptin stimulates monocyte migration, cytokine secretion, and other functions that contribute to hypertension and atherosclerotic plaque development. These functions are characteristics of CD16‐positive monocytes implicated in the clinical progression of atherosclerosis. This investigation sought to determine if leptin promoted the development of CD16‐positive monocytes in healthy men and women ranging in age from 20‐59 years. Circulating numbers of CD14+16++ monocytes, which preferentially migrate into nascent plaques, correlated with plasma leptin in men (R = 0.68, P = 0.01), but not women. In vitro, exogenous leptin increased percentages of CD14+16++ monocytes in cultures of male cells and reduced them in cultures of female cells (P=0.03 for leptin*sex interaction). For all subjects, circulating CD14+16++ cell counts correlated with systolic pressure (R=0.45, P=0.02) and carotid intima‐media thickness (R=0.36, P=0.04). There were no sex‐related differences in total expression of leptin receptors, measured by flow cytometry, or in relative expression of different isoforms of the receptor, measured by western blots. These results support the concept that leptin promotes the development of an atherogenic monocyte phenotype and has a stronger influence in men than in women.Grant Funding Source: Supported by NIH grant HL093663

Serum Leptin is Associated With Metabolic Syndrome in Obese Mexican Subjects

The metabolic syndrome (MetS) is a cluster of metabolic abnormalities including insulin resistance, dyslipidemia, high blood pressure, and abdominal adiposity. Obese patients develop leptin resistance, and an increased waist circumference (WC) due to deposition of abdominal fat. The aim of this study was to evaluate the association between circulating leptin levels and MetS among sample adult Mexican workers. A total of 204 workers aged 20-56 were evaluated. Anthropometric index, blood pressure, fasting plasma glucose, and lipid profile were measured by spectrophotometric methods. Fasting insulin and leptin were measured by inmunoenzimatic methods. Furthermore, homeostasis model assessment for insulin resistance (HOMA-IR) was calculated. The prevalence of MetS according to the ATP-III criteria was 33.8% and leptin concentrations were 2.5 times higher in women than men. Subjects with MetS had higher levels of leptin (26.7 ± 13.7) compared with those without MetS (20.1 ± 13.9; P <0.001). Leptin increased significantly while BMI increased as well (normal 14.0 ± 8.9, overweight 22.7 ± 11.7 and obese 31.4 ± 14.6) in addition to other variables such as WC, HDL-C, insulin levels, and HOMA index. Each component of MetS was stratified by sex and submitted by linear regression with a 95% of accuracy. The 50% and 53% of the BMI is explained by the concentration of leptin in men and women, respectively (P < 0.001). This study found that leptin was associated with the MetS, especially in obesity and insulin resistance, indicating a high risk for university workers to develop hypertension, DM2, and cardiovascular disease.

GW24-e3743 Association between levels of leptin and metabolic syndrome in Xinjiang Uygur Population

ObjectivesThe aim of the present study was to analyse the association between levels of leptin and metabolic syndrome (MS) and the components of MS in Xinjiang Uygur Population.MethodsA total of...

Serum leptin concentrations in relation to dietary patterns in Chinese men and women.

The present study aimed to evaluate the independent associations between serum leptin concentration and dietary patterns in a Chinese population. A cross-sectional study. Data obtained from the 2006 wave of the China Health and Nutrition Survey in Jiangsu Province, China. The sample contained 1061 Chinese adults (488 men and 573 women). BMI was calculated as a parameter of obesity. Factor analysis was used to derive dietary patterns. ANCOVA was performed to assess the associations between serum leptin concentration and the dietary patterns. Four dietary patterns were derived: Western, High-wheat, Traditional and Hedonic. The Western pattern (rich in meat, milk and cake) was significantly associated with a higher level of serum leptin in men and women, both in an unadjusted model (both P for trend < 0·001) and after adjusting for sex, age, income, total energy intake, physical activity, smoking status and BMI (P for trend = 0·007 for men and P for trend < 0·001 for women). The other three dietary patterns were not significantly associated with serum leptin after adjustment. Sensitivity analysis showed there was an interaction between age and the Western pattern in relation to leptin level. An interaction also existed between current smoking status and the Western pattern. Serum leptin concentration was positively associated with the Western dietary pattern in a Chinese population independent of BMI, energy intake and other factors.

Pregnancy‐associated plasma protein‐A is related to gender and to adipocytokine levels: results of The Health Survey of Catalonia

Pregnancy-associated plasma protein-A (PAPP-A) is a protease promoting IGF1 tissue availability and considered as a new biomarker of cardiovascular disease. To evaluate the relationship between PAPP-A concentrations and anthropometric variables, physical activity, smoking status, glucose homoeostasis and adipocytokines in healthy adults. One hundred and forty-nine subjects (77 women; mean age 39·7 ± 14 years; mean BMI 23·7 ± 1·9 kg/m(2) ) were randomly selected from 8000 adults of The Health Survey of Catalonia. Possible effects of gender, age, body composition, smoking status, physical activity, glucose homoeostasis and adipocytokines on PAPP-A concentrations were assessed. Pregnancy-associated plasma protein-A was significantly higher in men than in women [1·04 (0·61-0·44) vs 0·61 (0·41-0·90) μIU/ml; P < 0·0001]; there were no differences in relation to physical activity or smoking status. PAPP-A showed a negative correlation with leptin in men (P = 0·01) and women (P = 0·05), and a positive correlation with adiponectin (P = 0·006) in women and a trend (P = 0·073) in men. Homoeostasis model assessment of insulin resistance (HOMA-IR) showed a negative correlation with PAPP-A only in women (P = 0·019). No association was found with blood pressure, IGF1, lipids or glucose in either gender. When a multiple regression analysis was performed including gender, age, BMI, waist-hip ratio, HOMA-IR, adiponectin and leptin as confounders, PAPP-A was independently correlated with adiponectin (β = 0·23; P = 0·02) and leptin (β = -0·33; P = 0·04). Our study shows a sexual dimorphism of PAPP-A, and a possible influence of leptin and adiponectin on its concentrations in healthy subjects. The mechanisms responsible for this relationship remain to be determined.

The Impact of Leptin and Adiponectin on Incident Type 2 Diabetes Is Modified by Sex and Insulin Resistance

Adiponectin and leptin and their ratio have been associated with incident type 2 diabetes (T2DM), although the data presented are conflicting and the populations studied have been small. In this large, prospective, nested, case referent study, we hypothesized that these associations are sex specific and may be modified by insulin resistance. Men and women aged 30-60 years with incident T2DM (n=640) and a prior health survey within the Västerbotten Intervention Programme (VIP) and matched referents (n=1564) were identified. Using conditional logistic regression analyses, we tested whether baseline plasma adiponectin and leptin levels and their ratio independently predicted incident T2DM, stratified for gender and insulin resistance. Adjusted for traditional risk factors, fourth-quartile levels of adiponectin were associated with a reduced risk of T2DM in men [odds ratio (OR) 0.55 (0.36-0.86)] and women [OR 0.47 (0.27-0.83)]. Quartile four of the leptin/adiponectin ratio predicted T2DM in both men [OR 3.08 (1.68-5.67)] and women [OR 3.31 (1.56-7.03)], whereas quartile-four levels of leptin predicted T2DM only in men [OR 2.30 (1.32-4.02)]. When stratified for insulin sensitivity and adjusted for body mass index (BMI), log(e)-transformed leptin predicted T2DM in insulin-sensitive men [OR 1.56 (1.13-2.17)] but not in insulin-resistant men [OR 1.03 (0.76-1.39)]. The effect of adiponectin and the leptin/adiponectin ratio was not influenced by the insulin sensitivity status. Leptin in men and adiponectin in both sexes were independent predictors of T2DM. The association was modified by the degree of insulin sensitivity. The leptin/adiponectin ratio may add predictive information beyond the separate hormones.

Leptin Levels and Depressive Symptoms in People With Type 2 Diabetes

Depression in Type 2 diabetes is associated with obesity, cardiovascular disease, and mortality. Leptin is a plausible mediating factor because it has been related to obesity, depression, and cardiovascular disease in nondiabetic populations. We sought to assess whether leptin is related to depressive symptoms in people with Type 2 diabetes. One thousand fifty-seven subjects (48.5% women, mean [standard deviation] age = 67.9 [4.2] years) with Type 2 diabetes were assessed for depressive symptoms using the Hospital Anxiety and Depression Scale and other clinical variables by interview and physical examination. Plasma leptin was determined by radioimmunoassay. Multiple linear regression was performed to assess the relationship between depressive symptoms and ln leptin while adjusting for other covariates. A mediation analysis was performed to test whether depressive symptoms mediated the relationship between obesity and leptin. In univariate analyses, symptoms of depression were related to leptin in men (r = 0.214, p < .001) and women (r = 0.146, p = .007). When adjusting for other covariates including body mass index, ischemic heart disease, glycated hemoglobin, duration of diabetes, and treatment with antidepressants, insulin, or glucocorticoids, using a hierarchical multiple linear regression, depressive symptoms (ln Hospital Anxiety and Depression Scale-depression score) were significant only in men (B = 0.083, standard error = 0.037, p = .03). In the mediation analysis, depressive symptoms partially mediated the effect of obesity (body mass index) on leptin in men but not in women. There is a sex difference in the relationship between depressive symptoms and leptin in people with Type 2 diabetes, with a positive association in men but not in women. Adipocyte-derived factors are associated with depressive symptoms in Type 2 diabetes.

Adiponectin and leptin in Afro-Caribbean men and women with HIV infection: Association with insulin resistance and type 2 diabetes

Aim Insulin resistance and type 2 diabetes (T2D) are commonly seen in human immunodeficiency virus (HIV) infection and are related to antiretroviral therapy. Adiponectin and leptin secreted by adipocytes are both linked to body-fat distribution and insulin sensitivity. The present study aimed to assess the prevalence of insulin resistance and T2D, and their association with adiponectin and leptin, in Afro-Caribbean men and women with HIV infection. Methods This cross-sectional study was conducted in an unselected sample of 237 HIV-1-infected patients. Clinical and metabolic parameters were measured, including fasting and postload plasma insulin, and circulating adiponectin and leptin levels. Insulin resistance was estimated by homoeostasis model assessment (HOMA-IR). Adjusted multiple logistic regressions were used to estimate the association of insulin resistance with adipokine levels and patients’ characteristics. Results A total of 132 men (mean age: 49 years) and 105 women (mean age: 48 years) were included in the study. Prevalences of T2D and insulin resistance were higher in women than in men [16.2% vs 8.3% ( P = 0.06) and 24% vs 9.9% ( P < 10 −3), respectively]. Abdominal obesity was found in 47% of women and in 7% of men ( P < 10 −4). Insulin resistance was independently associated with adiponectin in women and with leptin in men. Conclusion Insulin resistance is frequent in Afro-Caribbean women with HIV infection. Overweight and obesity are major risk factors in such a population. Systematic screening for insulin resistance should be carried out in this population, which has a high prevalence of T2D.

Leptin Is Associated With Blood Pressure and Hypertension in Women From the National Heart, Lung, and Blood Institute Family Heart Study

Leptin is a key neuroendocrine hormone regulating food intake, metabolism, and fat accumulation, and it may also affect blood pressure and contribute to hypertension through sympathetic activation in the vasculature or at the renal level. Although previous studies have shown that the distribution of leptin is significantly different between males and females, as is the risk of hypertension between males and females, results regarding the role of leptin in the gender-specific regulation of blood pressure are controversial. Thus, we performed family-based association analyses in the National Heart, Lung, and Blood Institute Family Heart Study to test the hypothesis that LEPTIN gene variants and the plasma leptin level influence variability in blood pressure and the risk of hypertension differently by gender. We identified significant associations between LEPTIN single nucleotide polymorphisms with blood pressure and hypertension, but in postmenopausal women only. We also identified significant associations between plasma leptin levels and both blood pressure and hypertension in women. The current study supports a role for LEPTIN and plasma leptin levels in blood pressure regulation in women. It also provides insight into the gender differences in hypertension, as well as the differential distribution and activity of leptin in men and women.

Effects of seafood consumption and weight loss on fasting leptin and ghrelin concentrations in overweight and obese European young adults

Energy restriction affects circulating leptin and ghrelin concentrations. To investigate whether seafood consumption affects fasting leptin and ghrelin concentrations in addition to weight loss. In this 8-week dietary intervention, subjects (324 Icelandic, Spanish and Irish subjects, 20-40 years, BMI 27.5-32.5 kg/m(2)) were randomized to energy-restricted diets (-30%) of identical macronutrient composition but different amount of seafood: control (no seafood); lean fish (150 g cod, three times per week); fatty fish (150 g salmon, three times per week); EPA&DHA [daily docosahexaenoic (DHA)/eicosapentaenoic acid (EPA) capsules]. Anthropometric data, ghrelin, leptin, and insulin were measured at baseline and endpoint. Linear models investigated the effects of seafood on fasting leptin, ghrelin and insulin. Body weight (-5.2 +/- 3.0 kg), leptin (-34.8%) and insulin (-13.5%) decreased, while ghrelin increased (5.6%) (all P < 0.001). According to linear models endpoint insulin was significantly lower in the EPA&DHA group (-16.4%, P = 0.025) compared to control, endpoint leptin in men was lower in the salmon group (-22.9%, P = 0.026), and the EPA&DHA group tended to have higher endpoint ghrelin (5.6%, P = 0.060), an effect seen only in women indicated by a significant gender x EPA&DHA interaction. Weight loss explained the effects of fatty seafood on leptin and ghrelin, but not insulin. Consumption of fatty seafood can modulate fasting insulin, ghrelin and leptin during an 8-week intervention. Effects are partly gender specific and are partly explained by weight loss. Consumption of lean fish does not affect circulating hormones in comparison to control. The most consistent effect on circulating hormones is mediated by weight loss.

Plasma α–melanocyte-stimulating hormone: sex differences and correlations with obesity

Rodent experiments raise the possibility of a regulatory role of peripheral α–melanocyte-stimulating hormone ( α-MSH) in obesity and metabolism, but human data on peripheral α-MSH levels remain fragmentary. Because of the possible relationship between α-MSH and obesity, we endeavored to test the hypothesis that higher levels of α-MSH in obese patients would correlate with leptin levels and with other markers of obesity. Sixty normal-weight to obese healthy men and women participated. Weight, measures of body composition, and diet diaries were obtained; fasting blood was analyzed for α-MSH, lipids, glucose, insulin, leptin, and adiponectin. To begin to understand the source of peripherally measured hormones, α-MSH was also measured in serum samples from 5 individuals with untreated Addison disease. Levels of α-MSH were higher in men vs women (10.1 ± 4.3 vs 7.6 ± 3.4 pmol/L, P = .019), and α-MSH levels were higher in patients with Addison disease vs controls (17.7 ± 2.3 vs 8.7 ± 0.52 pmol/L, P < .001). Measures of adiposity correlated with insulin and leptin in men and women, and with adiponectin in women. α–Melanocyte-stimulating hormone levels did not correlate significantly with any parameter of adiposity or diet composition. The elevated α-MSH levels in patients with untreated Addison disease suggest possible pituitary secretion of α-MSH to the periphery. The lack of correlation between peripheral α-MSH and parameters of adiposity suggests that endogenous plasma α-MSH levels are not a metric for body composition per se.

Androgen receptor CAG repeat polymorphism is associated with serum testosterone levels, obesity and serum leptin in men with type 2 diabetes

To determine the relationships between androgen receptor CAG repeat polymorphism length (AR CAG), sex hormones and clinical variables in men with type 2 diabetes (DM2). Men with DM2 are known to have a high prevalence of low testosterone levels. Studies suggest that testosterone replacement therapy may improve insulin sensitivity and glycaemic control in men with DM2 and reduces central obesity and serum leptin. AR CAG is known to correlate negatively with AR sensitivity and positively with body fat, insulin levels, and leptin in healthy men. Cross-sectional study set in a district general hospital diabetes centre. Sex hormones, AR CAG and symptoms of hypogonadism were assessed in 233 men with DM2. Associations were sought between these variables and others such as obesity, leptin, glycaemic control, and blood pressure. Testosterone was negatively associated and AR CAG positively associated with obesity and leptin. The associations of AR CAG with leptin and obesity were independent of testosterone, estradiol, gonadotropins, and age. AR CAG was also independently associated with total, bioavailable and free testosterone, LH, waist circumference, body mass index, leptin, and systolic blood pressure. There was no association of AR CAG with sex hormone binding globulin, estradiol, HbA(1C) or the symptoms of hypogonadism. The association of longer AR CAG with obesity and leptin suggests that shorter AR CAG may have an influence in maintaining healthy anthropomorphics and metabolism in men with DM2. Testosterone and LH levels are higher in men with longer AR CAG, probably reflecting reduced negative feedback through a less sensitive receptor.