INTERRELATIONS BETWEEN LEPTIN & OBESITY

Abstract

Objective: Excess body weight is the sixth most important risk factor contributing to the overall burden ofdisease worldwide. The circulating leptins have been found to play a vital role in the regulation of appetite,glucose homeostasis and body fat. Therefore, this study was designed to measure serum leptin and insulinresistance in non obese and obese young adults and to correlate them with obesity parameters: body massindex, waist circumference, waist-to-hip ratio and metabolic indices.Methods: A total of 43 non- obese subjects, 20 male and 23 female aged 20- 25 years and 46 obese subjects,25 male and 21 female with age 28- 37 years were studied. All subjects selected for study were normotensiveand non-diabetic. Variables measured were Body Mass Index (BMI), waist to hip ratio(WHR), bloodpressure, serum leptin, insulin, fasting blood glucose, oral glucose tolerance test (OGTT), and lipid profile.Results: Serum leptin was significantly higher in females than males 8.8 ± 2.10 SEM and 2.2 ± 0.26 ng/mlSEM respectively in non-obese.As well, Serum leptin was significantly higher in females than males 23.0 ±3.98 SEM and 12.5 ± 2.24 ng/ml SEM respectively in obese group. Serum leptin was significantly higher inobese males, and obese females compared to non- obese subjects. Serum leptin significantly, and positivelycorrelated with BMI (r = 0.440), hip circumference (r =0.425), insulin (r = 0.334), and homeostasis Model ofAssessment - Insulin Resistance (HOMA-IR)r= 0.334 whereas HOMA-IR positively correlated with BMI,waist Circumference, fasting insulin, fasting blood glucose, triglycerides (TG), TG/HDL-Cholesterol ratioand negatively correlated with HDL-Cholesterol.Conclusions: Serum leptin levels increase with obesity, and are higher in females in both non-obese andobese individuals. Serum leptin significantly correlated with hip circumference. Increased serum leptin,especially in obese subjects, should be taken as a warning sign of energy imbalance, poor diet,hyperinsulinemia, insulin resistance, or changes in other metabolic risk factors that are stronglyassociated with cardiovascular diseases and type 2 diabetes. 
 Key words: Anthropometry, body mass index, insulin resistance, leptin, obesity,