Relationship between Serum Leptin and Adiponectin Levels in Obese Nigerians with Type 2 Diabetes Subjects

Abstract

Background: Obesity is rising globally, independent of ethnicity, race and age, and is associated with increased risk of cardiovascular mortality and morbidity especially in persons living with diabetes. The effect of adipokines such as leptin, resistin and adiponectin which are secreted by adipose tissue factors has been linked to the increased risk of the cardiovascular mortality and morbidity. Aim: This study aims to assess the levels of serum leptin and serum adiponectin in obese type 2 diabetes subjects, and their relationship with cardio-metabolic component (using lipid profile). Method: This is a cross-sectional comparative hospital-based study in which one hundred and fifty participants grouped into 60 obese, 60 non-obese none diabetic and 30 non-obese non-diabetic adults with similar age from the Endocrinology outpatient’s clinic, General outpatient department (GOPD) and staff clinic of Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC). Anthropometric parameters and other relevant clinical details of all subjects were obtained. Fasting venous blood samples were taken from all subjects for the determination of fasting plasma glucose (FPG), fasting lipid profile, glycosylated haemoglobin levels (HbA 1C ), fasting serum insulin, leptin, and adiponectin. Data was analysed using the Statistical Package of Social Sciences (SPSS) version 23.0. Results: Twenty-eight (46.7%)) subjects were males while 32 subjects (53.3%) were females (in obese groups). There was no statistical difference between these two groups for both sexes (p = 1.000). The age range for all subjects was 34 to 64 years with their mean age being 52 ± 7.3 years, and for type 2 subjects and the obese non-diabetic 50.7 ± 7.3 years respectively. The mean body mass index of the non-obese and non-diabetic was 23.7 ± 4 Kg/m 2 while the anthropometric measurements of the obese two groups were similar. The lipid profile, serum leptin and adiponectin in both the obese groups showed no difference. The relationship between components of obesity and serum leptin level in all subjects showed that serum leptin levels had significant positive correlation with BMI, WC, and serum insulin level. The correlation between adiponectin and lipid profile showed a positive correlation between serum adiponectin values and High-density lipoprotein (HDL) in obese diabetic (p = 0.02) but not in the non-diabetic group. Conclusion: In this study, there was no correlation in the serum leptin levels with the anthropometric parameters of obesity studied. For the components of the lipid profile, Triglycerides and low-density lipoprotein cholesterol (LDL) correlated with serum adiponectin and HDL showed a positive correlation with adiponectin. It is concluded that the effects of both serum adiponectin and serum leptin are driven by obesity rather than the glycaemic status of the obese subjects.