Association of Obesity and Serum Gamma Glutamyl Transferase with Impaired Fasting Glucose in Adults at a Tertiary Level Hospital of Bangladesh.

Obesity is a worldwide health concern due to its rising tendency both in developing and developed countries. Obesity is known to be associated with a number of disorders including type 2 diabetes mellitus, hypertension and cardiovascular diseases. Gamma glutamyl transferase (GGT) is synthesized in liver. GGT is considered as an oxidative stress marker. Serum GGT is increased in patients with cardiovascular diseases and diabetes mellitus (DM). Impaired fasting glucose (IFG) is a risk factor for cardiovascular diseases. The aim of this study was to find out the association of obesity and serum GGT with IFG. This cross-sectional analytical study was conducted in the Biochemistry department of Sir Salimullah Medical College, Dhaka from March 2018 to February 2019. The ages of the subjects were 25-55 years. The study subjects were 120 and were divided into two groups. The groups were Normal fasting glucose (NFG) group and IFG group according to WHO diagnostic criteria. Body mass index (BMI) was used as a measure of general obesity and waist circumference (WC) and waist-hip ratio (WHR) were used as measures of abdominal or central obesity. OGTT was performed from collected blood. GGT and lipid profile were measured from serum. In IFG group, BMI, WC, WHR and GGT levels were significantly elevated (p<0.01) than NFG group i.e. BMI (22.70±1.35 vs. 28.37±2.33kg/m²), WC (79.96±5.31 vs. 93.42±4.21cm), WHR (0.92±0.06 vs. 0.97±0.07), and GGT (24.19±8.41 vs. 67.23±14.40U/L). Fasting Plasma Glucose (FPG) level were significantly higher (p<0.01) in obese group than over weight and normal BMI groups 4.70±0.08, 5.30±1.3 and 6.50±0.3 respectively. FPG were higher in male and female obese group than normal WC group (4.8±1.1 vs. 6.3±0.60mmol/L) and (4.4±0.7 vs. 6.2±0.80mmol/L). Odds Ratio (OR) and (95% CI) for IFG were 6.53 and 21.0 with BMI tertile 2(23.1- 27.5kg/m²) and tertile 3(≥27.5kg/m²) where T₁ (<23.0kg/m²) was considered as reference category. OR for IFG were 4.1 and 20.25 with GGT tertile 2(24.0-42.0) U/L and tertile 3(>42.0) U/L where T₁ (<24.0) U/L was considered as reference category. Multiple regression analysis shows positive correlation of FPG with BMI, WC, WHR and GGT.