Factors associated with regression from prediabetes to normal glucose tolerance in a Korean general population: A community-based 10-year prospective cohort study.

Abstract

A proportion of people with prediabetes convert back to normal glucose tolerance. We sought to determine the clinical variables associated with conversion from prediabetes to normal glucose tolerance, with a focus on insulin secretory capacity, insulin sensitivity and body composition. We followed 1731 people with prediabetes at baseline from the Korean Genome and Epidemiology Study every 2years for 10years. Oral glucose tolerance tests (OGTT) were performed, and muscle and fat mass were estimated using bioelectrical impedance analysis. During 10years of follow-up, 36% (623/1731) of people with prediabetes converted to normal glucose tolerance. Higher baseline fasting glucose, 2-h OGTT glucose and triglyceride levels were inversely associated with this conversion. Higher 60-min insulinogenic index (IGI60 ) at baseline was independently associated with this conversion [HR per sd (95% CI) 1.09 (1.02-1.17); P=0.01]. However, other indices reflecting insulin sensitivity, including the composite insulin sensitivity index, were not associated with this conversion. In addition, a higher baseline muscle to fat ratio was independently associated with conversion to normal glucose tolerance [HR per sd (95% CI) 1.15 (1.04-1.26); P=0.005]. People with conversion to normal glucose tolerance showed a greater increase in the 60-min insulinogenic index and disposition index and a smaller decrease in the composite insulin sensitivity index compared with people without conversion during 10years of follow-up (all p-values <0.001). A higher insulin secretory capacity at baseline and during follow-up and higher baseline muscle to fat ratio were independently associated with an improvement in glucose tolerance in Korean adults with prediabetes.