Sammendrag
The aim of this study was to find the association between serum lipid ratios and insulin resistance among subjects with impaired glucose tolerance in Pakistan. It was also sought how effective was FBG to identify IGT subjects in context of using FBG as a screening tool for primary prevention.
Research design and methods:
Cross sectional analysis was conducted by utilizing the data from primary prevention project conducted within collaboration of Baqai Institute of Diabetology and Endocrinology (BIDE), Diabetic Association of Pakistan (DAP) and University of Oslo (UiO). Data analysis was divided into two section; the screening data, comprises of OGTT values of 1565 study participants after being short listed by using risk assessment form during the initial phase of project; and the baseline data, that constituted the anthropometric and biochemical variables of 242 subjects, included on basis of availability of all the required variables.
Results:
The prevalence of IFG, combined IFG-IGT and isolated IGT was found to be 10.9%, 11.3% and 12.1% respectively. The specificity and sensitivity of fasting blood glucose to diagnose IGT was 48.6% and 82.6%, while the positive predictive value was 50.7% and negative predictive value was found 81.1%. Data analysis at baseline showed no difference between mean ages and gender of combined IFG-IGT and isolated IGT group, however waist to hip ratio was significantly higher (p<0.05) in combined IFG-IGT group. Also, the levels of 2-hr blood glucose and serum triglycerides were higher in combined IFG-IGT group while fasting insulin levels were higher in isolated IGT group. All the lipid ratios (TC/HDL,TG/HDL and HDL/HDL) were found significantly correlated with fasting insulin levels and HOMA-IR in isolated IGT group. The AUC for TG/HDL ratio was 0.707 against the 75th percentile of fasting insulin level and HOMA-IR, while the cut off level >3.36 of TG/HDL ratio was found to have 65.5% sensitivity and 70% specificity with respect to the cut off of insulin resistance
Conclusion:
We have found significant correlation between serum lipid ratio and surrogate markers of insulin resistance in isolated IGT group. Due to the weak predictability of fasting blood glucose to diagnose IGT status, it is therefore suggested to use better option for the diagnosis of IGT in clinical practice. However, serum lipid ratios could be a potential option if used in conjunction with fasting blood glucose to identify subjects with isolated IGT who are found significantly more insulin resistant, and thus, can be more benefited by primary prevention of diabetes.