Triglyceride-glucose index: A surrogate marker of homeostasis model assessment of insulin resistance to predict diabetic nephropathy.

Objectives: To determine the association of triglyceride-glucose index with homeostasis model assessment of insulin resistance in type 2 diabetes mellitus patients, and to determine the association of triglyceride-glucose index with urinary albumin-to-creatinine ratio for predicting diabetic nephropathy.

Methods: The observational, cross-sectional study was conducted from September 2021 to September 2022 at the Department of Chemical Pathology, Pakistan Railway Hospital, Rawalpindi, Pakistan and comprised recently-diagnosed type 2 diabetes mellitus patients. Recorded data included age, gender, vitals, diabetes duration, body mass index and other pertinent demographic and clinical information. Measurements included spot urine albumin-to-creatinine ratio, triglycerideglucose index, homeostasis model assesment of insulin resistance as well as fasting serum insulin, fasting plasma glucose, glycosylated haemoglobin, triglycerides, total cholesterol and serum creatinine. On the basis of triglyceride-glucose index scores, the participants were divided into 4 quartiles; Q1=4.5-5, Q2=5.1-5.5, Q3=5.6-6, and Q4=>6. Data was analysed using SPSS 26.

Results: Of the 218 patients, 141(64.7%) were females and 77(35.3%) were males. The overall mean age was 49.22±11.46 years. There were 102(46.8%) overweight patients, 33(15.1%) obese and 82(37.2%) had normal weight. There were 58(26.6%) patients in Q1, 86(39.4%) in Q2, 46(21.1%) in Q3 and 28(12.8%) in Q4. Those in Q4 showed elevated fasting plasma glucose, glycated haemoglobin, triglycerides, total cholesterol, low-density lipoprotein cholesterol, homeostasis model assessment of insulin resistance and urine albumin-to-creatinine ratio (p<0.05), as well as low values for high-density lipoprotein cholesterol and estimated glomerular filtration rate(p<0.05). Fasting serum insulin was negatively linked to glycated haemoglobin (r=-0.12, p=0.07). Triglyceride-glucose index (r=0.76, p<0.001), homeostasis model assessment of insulin resistance (r=0.48, p<0.001), and urine albumin-to-creatinine ratio (r=0.10,p=0.05) positively correlated with glycated haemoglobin. Fasting serum insulin (r=-0.13, p=0.05), negatively correlated with triglyceride-glucose index, while homeostasis model assessment of insulin resistance (r= 0.32, p<0.001) and urine albumin-to-creatinine ratio (r=0.28, p=0.05) had a positive correlation. The estimated glomerular filtration rate was significantly positively linked with fasting serum insulin (r=0.05, p=0.05), and correlated significantly negatively with triglyceride-glucose index (r=-0.35, p=0.01), homeostasis model assessment of insulin resistance (r=-0.01, p=0.86) and urine albumin-to-creatinine ratio (r=-0.02, p=0.8).

Conclusions: The triglyceride-glucose index showed a strong association with homeostasis model assessment of insulin resistance, and surpassed it in terms of predicting diabetic nephropathy in type 2 diabetes mellitus patients.