OBJECTIVE: Leptin, an adipocyte-derived protein product of the obesity (ob) gene, is a multifunctional polypeptide associated with the development of obesity-related disorders in humans. There is considerable inter-individual variation in plasma leptin even among subjects with comparable obesity levels, which suggests that factors other than adipose mass may be involved in the regulation of leptin expression and/or production. The purpose of this study was to evaluate the potential role of glycemic status and adipose-derived cytokines in regulating plasma leptin levels among normal and overweight men. DESIGN: Cross-sectional study. SUBJECTS AND MEASUREMENTS: We measured plasma leptin, insulin, c-peptide and plasma soluble tumor necrosis factor receptor (sTNF-R) concentrations in 178 men. The subjects were selected from the Health Professionals Follow-up Study (HPFS), and aged 47-64 y in 1994, were free of cardiovascular disease, diabetes mellitus, malignant neoplasms, and had provided a fasting blood sample and a detailed lifestyle questionnaire. RESULTS: Men in the highest quintile of plasma leptin (mean = 12.7 ng/ml) weighed more, were less physically active and had higher circulating insulin, c-peptide, sTNF-R1 and sTNF-R2 concentrations than men in the lowest quintile (mean = 2.8 ng/ml). We found a significant correlation between plasma insulin, c-peptide, glycosylated hemoglobin (HbA1c), and sTNF-R1 on leptin concentrations (with Spearman correlation coefficients ranging from 0.17 to 0.48 and all P < 0.05). Only HbA1c and sTNF-R1 were independently and positively associated with plasma leptin after further adjusting for body mass index and other metabolic parameters of interest. Interestingly, these observed associations were limited to men with a BMI > or = 25 kg/m2. CONCLUSION: Our results suggest that glucose homeostasis and the activity of the TNF system may modulate leptin secretion and production among overweight men. Glucose homeostasis and TNF-alpha is important in metabolic disorders related to hyperleptinemia.
OBJECTIVE: Leptin, an adipocyte-derived protein product of the obesity (ob) gene, is a multifunctional polypeptide associated with the development of obesity-related disorders in humans. There is considerable inter-individual variation in plasma leptin even among subjects with comparable obesity levels, which suggests that factors other than adipose mass may be involved in the regulation of leptin expression and/or production. The purpose of this study was to evaluate the potential role of glycemic status and adipose-derived cytokines in regulating plasma leptin levels among normal and overweight men. DESIGN: Cross-sectional study. SUBJECTS AND MEASUREMENTS: We measured plasma leptin, insulin, c-peptide and plasma soluble tumor necrosis factor receptor (sTNF-R) concentrations in 178 men. The subjects were selected from the Health Professionals Follow-up Study (HPFS), and aged 47-64 y in 1994, were free of cardiovascular disease, diabetes mellitus, malignant neoplasms, and had provided a fasting blood sample and a detailed lifestyle questionnaire. RESULTS: Men in the highest quintile of plasma leptin (mean = 12.7 ng/ml) weighed more, were less physically active and had higher circulating insulin, c-peptide, sTNF-R1 and sTNF-R2 concentrations than men in the lowest quintile (mean = 2.8 ng/ml). We found a significant correlation between plasma insulin, c-peptide, glycosylated hemoglobin (HbA1c), and sTNF-R1 on leptin concentrations (with Spearman correlation coefficients ranging from 0.17 to 0.48 and all P < 0.05). Only HbA1c and sTNF-R1 were independently and positively associated with plasma leptin after further adjusting for body mass index and other metabolic parameters of interest. Interestingly, these observed associations were limited to men with a BMI > or = 25 kg/m2. CONCLUSION: Our results suggest that glucose homeostasis and the activity of the TNF system may modulate leptin secretion and production among overweight men. Glucose homeostasis and TNF-alpha is important in metabolic disorders related to hyperleptinemia.
Authors: Monika A Niewczas; Tomohito Gohda; Jan Skupien; Adam M Smiles; William H Walker; Florencia Rosetti; Xavier Cullere; John H Eckfeldt; Alessandro Doria; Tanya N Mayadas; James H Warram; Andrzej S Krolewski Journal: J Am Soc Nephrol Date: 2012-01-19 Impact factor: 10.121
Authors: M Cruz; C Maldonado-Bernal; R Mondragón-Gonzalez; R Sanchez-Barrera; N H Wacher; G Carvajal-Sandoval; J Kumate Journal: J Endocrinol Invest Date: 2008-08 Impact factor: 4.256
Authors: Atif Qasim; Nehal N Mehta; Mahlet G Tadesse; Megan L Wolfe; Thomas Rhodes; Cynthia Girman; Muredach P Reilly Journal: J Am Coll Cardiol Date: 2008-07-15 Impact factor: 24.094
Authors: Marc J Gunter; Donald R Hoover; Herbert Yu; Sylvia Wassertheil-Smoller; Thomas E Rohan; JoAnn E Manson; Barbara V Howard; Judith Wylie-Rosett; Garnet L Anderson; Gloria Y F Ho; Robert C Kaplan; Jixin Li; Xiaonan Xue; Tiffany G Harris; Robert D Burk; Howard D Strickler Journal: Cancer Res Date: 2008-01-01 Impact factor: 12.701
Authors: Marc J Gunter; Donald R Hoover; Herbert Yu; Sylvia Wassertheil-Smoller; Thomas E Rohan; JoAnn E Manson; Jixin Li; Gloria Y F Ho; Xiaonan Xue; Garnet L Anderson; Robert C Kaplan; Tiffany G Harris; Barbara V Howard; Judith Wylie-Rosett; Robert D Burk; Howard D Strickler Journal: J Natl Cancer Inst Date: 2008-12-30 Impact factor: 13.506
Authors: Marc J Gunter; Donald R Hoover; Herbert Yu; Sylvia Wassertheil-Smoller; Joann E Manson; Jixin Li; Tiffany G Harris; Thomas E Rohan; Xiaonan Xue; Gloria Y F Ho; Mark H Einstein; Robert C Kaplan; Robert D Burk; Judith Wylie-Rosett; Michael N Pollak; Garnet Anderson; Barbara V Howard; Howard D Strickler Journal: Cancer Epidemiol Biomarkers Prev Date: 2008-04 Impact factor: 4.254