Serum leptin values in the healthy obese and non-obese subjects of Rawalpindi.

OBJECTIVE To determine serum leptin concentrations from a sample of Rawalpindi population in relation to body mass index, age and gender. METHODS The observational, comparative study was conducted at the Armed Forces Institute of Pathology, Rawalpindi, and Benazir Bhutto Hospital, Rawalpindi from August 2008 to December 2008. Subjects were 100 including healthy obese, overweight and non-obese of both genders aged between 20-50 years. Sampling was done by non-probability convenience method. Body Mass Index was calculated by formula BMI = weight in kg/height in m2: non-obese subjects were defined as 18.5-23.0 kg/m2; overweight 23.1-27.4 kg/m2; and obese 27.5-40 kg/m2. Serum glucose was measured using Glucose oxidase-phenol amino phenazone (GOD-PAP) method and serum leptin by sandwich enzyme-linked immunosorbent assay method. RESULTS Serum leptin concentrations were higher in obese subjects (mean 52.8 +/- 24.6 ng/mL; range 28.2-77.4 ng/mL; P < 0.001) than in non-obese subjects (mean 12.7 +/- 6.1 ng/mL, range 6.6-18.8ng/mL). Mean Body Mass Index in obese group was 31.7 +/- 3.1 kg/m2 (range 28.6-34.8 kg/m2) while it was 21.2 +/- 1.5 kg/m2 (range 19.7-22.7 kg/m2) in the nonobese group. Body Mass Index was strongly positively correlated with serum leptin concentration (r = 0.59, p < 0.001) in the obese group. The mean serum leptin concentration was much higher in the healthy obese and non-obese women (64.4 ng/mL and 8.7 ng/mL respectively) than in men of both categories (40.4 ng/mL and 5.5 ng/mL respectively). Age had no significant relation with serum leptin level (p = 0.416). CONCLUSIONS In the study sample, serum leptin concentration was positively correlated with Body Mass Index in healthy obese and non-obese subjects of both genders. The levels were higher in women than in men. Age had no significant relation with serum leptin level in this age group.