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To evaluate the effect of menopausal status and body mass index (BMI) on circulating leptin and adiponectin concentrations and investigate whether there is an influence of menopausal transition on the relationships of these adipokines and leptin to adiponectin (L/A) ratio with lipid profile and insulin resistance in a sample of Tunisian women. One hundred ninety-six premenopausal (mean age 35.3±7.6 years) and 180 postmenopausal women (mean age 53.4±6.2 years) were included in the study. Participants were stratified into obese and normal weight groups based upon their baseline BMI. Fasting glucose, HDL-cholesterol (HDL-C), triglycerides (TG), total cholesterol (TC), insulin, leptin, and adiponectin concentrations were measured. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Premenopausal women had significantly higher leptin and L/A ratio and lower adiponectin levels than postmenopausal women. Menopause had no effect on the mean values of BMI, insulin or HOMA-IR, HDL-C, and TG. Using a multiple linear regression model, menopausal status was identified, as significant independent predictor for leptin and adiponectin levels. Irrespective of the menopausal status, obese women exhibited higher leptin and L/A ratio and lower adiponectin levels compared to those with normal weight. Comparison between the two menopausal stages in obese and normal weight groups showed that leptin and L/A ratio decreased, while adiponectin increased from pre- to postmenopausal stage only in obese group. The L/A ratio correlated better with lipid profile and HOMA-IR in postmenopausal stage. The present study showed a significant interaction between menopause and BMI on leptin and adiponectin secretion. Menopausal transition affects the relationships of these adipokines with lipids and insulin resistance., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objectives: This study was undertaken to investigate the impact of the Pro12Ala (rs1801282) polymorphism of the peroxisome proliferator-activated receptor gamma-2 (PPARgamma-2) gene on obesity or body mass index (BMI) and plasma leptin, insulin, adiponectin and lipid levels in a sample of the Tunisian population., Design and Methods: The study included 387 obese patients and 288 control subjects. The Pro12Ala genotype was determined by polymerase chain reaction followed by a digestion with the restriction of endonuclease BstUI., Results: In the whole population, there is no significant difference in genotype frequencies of the Pro12Ala polymorphism between obese patients and controls. However, separate analysis by gender revealed that obese men (but not women) had significantly higher frequency of Pro/Ala genotypes compared to controls (12.2% vs. 4.1%; chi(2)=6.76, p=0.009). In comparison to Pro/Pro homozygotes, Ala-allele bearers had a significantly higher risk of obesity [OR (95% CI)=3.26 (1.28-8.33)]. When obese subjects were stratified according to type 2 diabetes status, the association with obesity was only significant in obese non-diabetic patients [OR (95% CI)=3.74 (1.43-9.74), p=0.007]. Additionally, obese male patients carrying the Ala-allele had significantly higher body mass index (p=0.007) and plasma leptin levels (p=0.023) compared to those homozygous for Pro-allele. The significant effect of Pro12Ala polymorphism on plasma leptin levels disappeared after adjustment for age and BMI., Conclusion: The present study provides evidence that the Pro12Ala polymorphism of the PPARgamma-2 gene is associated with obesity in non-diabetic men from Tunisian origin.

Objectives: The aim of this study was to examine the association of the G-2548A polymorphism of the human leptin gene (LEP) with body mass index (BMI), plasma leptin, insulin, and lipid parameters in a sample of Tunisian population., Design and Methods: Two hundred and twenty nine obese patients (BMI>or=30 kg/m(2)) were screened and compared to 251 normal weight subjects (BMI<25 kg/m(2)). The human leptin gene promoter G-2548A genotype was determined by polymerase chain reaction followed by a digestion with the restriction of endonuclease CfoI., Results: In the entire study sample, carriers of -2548A allele had significantly lower leptin levels than homozygous for -2548G allele (14.28+/-9.10 ng/mL vs. 18.27+/-12 ng/mL, p<0.001 respectively) adjusted for BMI and gender. In obese patients but not control, subjects carrying the -2548A allele exhibited lower leptin levels than those with GG genotype (16.96+/-8.27 ng/mL vs. 21.37+/-11.72 ng/mL, p=0.001 respectively) adjusted for BMI and gender. In this group, carriership of the -2548A allele was identified, by multiple linear regression models, as significant independent predictor for leptin levels variability. Separate analyses by gender revealed that only in obese women, the -2548A allele was found to be associated with lower leptin levels independently of BMI (p=0.004)., Conclusions: The present study showed that G-2548A LEP polymorphism is associated with lower leptin levels in Tunisian obese women.

Background and Aims: The leptin receptor (LEPR) plays a crucial role in the regulation of body weight. Several common polymorphisms have been described in the human LEPR gene including the p.Q223R polymorphism (rs1137101). The association of this polymorphism with obesity or related metabolic phenotypes has been controversial. The aim of this study was to investigate the impact of the LEPR p.Q223R polymorphism on body mass index (BMI), plasma leptin and lipid parameters in a sample of the Tunisian population., Methods: The study included 391 obese patients and 302 normal weight subjects. LEPR p.Q223R genotypes were identified by the PCR-RFLP analysis., Results: Obese patients homozygous for RR genotype showed lower leptin levels than those with other genotypes (p = 0.005) adjusted for age, BMI and gender. Stratified analysis by gender revealed that obese male patients carrying the R allele showed significantly lower BMI (p = 0.007) and leptin levels (p = 0.037) than subjects homozygous for the Q allele. In obese women, the LEPR p.Q223R polymorphism was found associated with lower leptin concentrations (p = 0.05). After adjustment for age and BMI, the association between the LEPR variant and plasma leptin remained significant only within female patients (p = 0.027). A general linear model including leptin as dependant variable and age, BMI, menopausal status and genotype as covariates revealed that the LEPR p.Q223R polymorphism is independently associated with leptin levels in obese women (p = 0.026)., Conclusions: Our findings suggest that the LEPR p.Q223R polymorphism influences plasma leptin levels and BMI in obese patients.

Objective: To examine the association of a common -2548G/A (rs7799039) promoter variant of the human leptin gene (LEP) with obesity or body mass index (BMI) and its associated phenotypes such as blood pressure variability and the prevalence of hypertension in a sample of the Tunisian population., Design and Methods: Two hundred and twenty-nine obese patients were screened and compared with 251 normal weight subjects. The -2548G/A LEP polymorphism was analysed by PCR-RFLP procedure., Results: No significant association was found between the -2548G/A polymorphism and obesity or BMI. However, in obese patients subjects with AA genotype had significantly higher systolic (p = 0.003) and diastolic (p = 0.002) blood pressure compared with those with GA or GG genotypes. Stratified analysis by gender revealed that male patients but not female homozygous for -2548A allele exhibited significantly increased systolic (p = 0.01) and diastolic (p<0.001) blood pressure than did carriers of -2548G allele. Multiple linear regression analysis revealed that AA genotype significantly affect systolic and diastolic blood pressure in obese men. Additionally, significant association between AA genotype and higher prevalence of hypertension was found in male patients (p = 0.03)., Conclusion: The present study showed that the -2548G/A LEP polymorphism is associated with blood pressure in obese male patients.