Normalization of glucose intolerance in first-degree relatives of patients with type 2 diabetes

Abstract

Aims The aim of this study was to estimate the conversion rate to normal glucose tolerance (NGT) from a state of abnormal glucose metabolism and to identify characteristics predicting the conversion rate in first-degree relatives (FDRs) of patients with type 2 diabetes with glucose intolerance. Methods A total of 2368 (614 men and 1754 women) FDRs of consecutive patients with type 2 diabetes aged 20–70 years in 2003–2005 were followed through 2007. Glucose tolerance classification was based on the criteria of the American Diabetes Association base on standard 75 g 2-h oral glucose tolerance test. The study group consisted of 370 participants with glucose intolerance at baseline. Results The conversion rates to normal glucose tolerance from impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) were 16.2% (95% confidence interval (CI) 13.30, 19.10) and 10.9% (95% CI: 5.7, 16.1) per year after an average of 2 years, respectively. Lower baseline fasting plasma glucose (HR 1.02, 95% CI: 1.01, 1.04) and 2-h (HR 1.02, 95% CI: 1.01, 1.04) glucose predicted conversion to NGT, as did changes in body mass index (BMI), waist circumference (WC), and lipids. Conclusions This is the first estimate of conversion rate and predictors from IFG and IGT to NGT in FDRs of people with type 2 diabetes in Iran. Lower baseline fasting, 2-h plasma glucose and changes in BMI, WC, and lipids predicted reversal to NGT at 24 months follow-up.