Subjects with impaired glucose tolerance returned to normal glucose status for six years had lower long-term risk of diabetes: 20 years follow up of Daqing diabetes prevention study

Abstract

Objective: To explore the influence of lifestyle intervention on long-term diabetes in subjects with impaired glucose tolerance (IGT) returned to normal glucose tolerance (NGT) within 6 years. Methods: A total of 577 subjects (aged 25-74 years old) with IGT in Daqing were enrolled and randomly assigned to control, and diet, exercise and diet plus exercise groups in a six-year intervention trial in 1986. Subjects who were non-diabetic at the end of the intervention were followed up for additional 14 years. Results: Among all the subjects, 41.38% of them who had returned to NGT from IGT within 6 years maintained NGT status after 20 years, and had a lower incidence of diabetes than subjects maintained IGT status (46.55% vs. 75.25%). Of note, in the intervention group, the percentage of participants developed diabetes in the NGT subjects was significantly lower than that in the IGT group (43.71% vs. 76.25%) after 20 years. There was high long-term risk for diabetes in the IGT subjects after the adjustment of age, sex and baseline glucose (HR=1.81, 95%CI 1.27-2.58, P=0.001), whereas in the non-intervention group, no significant difference could be viewed in long-term diabetic risk between subjects maintained IGT status and those returned to NGT (71.43% vs. 65.22%) after adjusting of the same confounders (HR=1.03, 95%CI 0.45-2.35, P=0.94). Conclusions: IGT subjects who had returned to NGT in early years had lower risk for future diabetes than those who remained IGT. However, this beneficial effect could only be viewed in the intervention group, but not in the non-intervention group.