STRONG POSITIVE ASSOCIATION OF SERUM LEPTIN CONCENTRATIONS WITH BODY MASS INDEX (BMI): A COMPARATIVE OBSERVATIONAL RESEARCH

Objective: The determination of the concentrations of the serum leptin from a selected sample population in the perspective of gender, age and BMI was the objective of this research. Methods: Our research design was comparative, observational which was carried out in Nishtar Hospital, Multan (September, 2016 – January, 2017). The research sample comprised of hundred healthy overweight, obese and non-obese females and males in the age bracket of 20 – 50 years. The sample population was selected with the help of non-probability convenience technique. The formula of BMI calculation was (kilogram / height in m2): non-obese, overweight and obese subjects were defined as (18.5 – 23.0), (23.1 – 27.4) and obese (27.5 – 40) kilogram / m2. We measured serum glucose with the help of Glucose oxidase-phenol amino phenazone (GOD – PAP) technique and we measured serum leptin through sandwich enzyme-linked immunosorbent assay technique. Results: The concentrations of the serum leptin were observed high in the obese participants (mean value 52.8 ± 24.6 ng / mL; range limit 28.2 – 77.4 ng / mL; P-value as < 0.001) in comparison to the non-obese participants (mean value 12.7 ± 6.1 ng / mL, range limit as 6.6 – 18.8 ng / mL). Obese group was noticed with a mean value of BMI as (31.7 ± 3.1 kg / m2) in the range of (28.6 – 34.8 kg / m2); whereas, in the non-obese participants it was observed as (21.2 ± 1.5 kg / m2) in the range of (19.7 – 22.7 kg / m2). There was a strong and positive association of the concentration of the serum leptin in the obese participants as (r = 0.59, P-value < 0.001) as observed in obese participants. The mean value of the concentrations of serum leptin were high in the healthy obese & non-obese females as respectively (64.4 ng / mL) and (8.7 ng / mL) than men respectively observed as (40.4 ng / mL) & (5.5 ng / mL). There was no significant association of the level of serum leptin with the age with a significant P-value of (0.416). Conclusions: In our research sample the concentration of the serum leptin has a strong positive association with the BMI in the non-obese and healthy obese both males and females. Women were observed with higher levels in comparison to men; whereas the association of age with the levels of was not significant as we observed in this particular research. Keywords: Body Mass Index (BMI), Serum leptin, Non-obese, Obese and Overweight