Background: Association of triglycerides with type 2 diabetes is well known. However, their cause-effect relationship is not established. Some of the studies suggest that higher triglyceride levels may be the cause of type 2 diabetes whereas other studies show that hypertriglyceridemia is the result of type 2 diabetes. Present study was therefore undertaken to study the association of serum triglycerides with HOMA-IR in healthy subjects.

Objective: To study the association of serum triglyceride levels with HOMA-IR in normal glucose tolerance (NGT) first degree relatives of patients with diabetes.
Methods: Six hundred seventeen age and sex matched NGT subjects (on the basis of oral glucose tolerance test) were recruited and divided into two groups. Group 1: NGT subjects who had a first degree relative with diabetes (n=314) and group 2: NGT subjects without family history of diabetes (n=303). Anthropometry (body mass index and waist circumference), HbA1c, fasting serum insulin and lipid profile were estimated in all the study subjects. Both the groups were compared by independent t-test. Pearson’s coefficient of correlation was used to study the association between various parameters.    

Results: Mean age of study population was 40.24±7.17 years (group 1: 40.20±7.72, group 2: 40.28±6.58 years). Body mass index (group 1: 26.77±4.69, group 2: 25.11±4.48 kg/m2, P<0.001), waist circumference (group 1: 87.75±11.64, group 2: 84.08±10.81 cm, P<0.001), fasting plasma glucose (group 1: 88.02±11.91, group 2: 84.44±9.03 md/dl, P<0.001) and 2hr plasma glucose (group 1: 108.04±22.52, group 2: 102.69±18.16 mg/dl, P<0.001), HbA1c (group 1: 5.63±0.56, group 2: 5.48±0.48%, P=0.001), fasting serum insulin (group 1: 7.72±5.86, group 2: 5.75±4.36 IU/ml, P<0.001) and HOMA-IR (group 1: 1.69±1.44, group 2: 1.21±1.05, P<0.001) were significantly higher in group 1 compared to group 2. Triglycerides, total cholesterol, HDLc and LDLc levels were found to be comparable between both the groups. Serum triglyceride levels showed a significant positive correlation with fasting serum insulin (r=0.38, P<0.001), HOMA-IR (r=0.35, P<0.001), BMI (r=0.14, P=0.008) and waist circumference (r=0.24, P=<0.001) in group 1. No significant correlation was found between these indices in group 2.       

Conclusion: Serum triglyceride levels are associated with HOMA-IR and fasting serum insulin levels in NGT subjects who had a first degree relative with diabetes but not in those without family history of diabetes.

Association of triglycerides with HOMA-IR in normal glucose tolerant first degree relatives of patients with diabetes