The purpose of the study was to measure serum leptin in normal weight and obese individuals, and assess its relation to anthropometric measures and metabolic indices.
The study was conducted at King Fahd Hospital of the University, Saudi Arabia, from January 2003 to June 2004. Subjects included in the study were all non-diabetic normotensive adults. Variables measured were body mass index (BMI), waist to hip ratio (WHR), blood pressure, serum leptin, insulin, glucose, and lipids.
Included were 43 non-obese subjects (20 men and 23 women) with the mean age of 25.8 + SD 5.3 y for men and 23.9 + SD 1.9 y for women and their mean BMI was 23.1 ± 1.4 for men and 23.0 ± 1.8 for women. Serum leptin was significantly higher in women 8.8 + SEM 2.10 than men 2.2 + SEM 0.26 ng /ml.Also included were 46 obese subjects (25 men and 21 women) with a mean age of 29.4 + SD 7.6 y for men and 28.8 + SD 6.2 y for women and a mean BMI of 35.5 ± 5.7 for men and 35.6 ± 4.4 for women. Serum leptin was significantly higher in women 23.0 + SEM 3.98, than men 12.5 + SEM 2.24 ng /ml. Serum leptin was significantly higher in obese men and women compared to non-obese subjects. Serum leptin significantly, and positively correlated with BMI (r 0.440), hip circumference (r 0.425), serum insulin (r 0.334), and HOMA IR (r 0.334).There was no correlation with mean age, mean systolic BP, mean diastolic BP, or WHR.
Serum leptin increased with obesity, and was higher in women than men, both lean and obese. Serum leptin correlated positively with BMI and hip circumference. Though, correlation between leptin and insulin resistance was found, they probably reflect two different metabolic compartments.