The clinical characteristics and trend of conversion to type 2 diabetes mellitus of individuals with normal glucose tolerance-hyperinsulinemia / 中华内科杂志

ABSTRACT

Objective To study the outcomes and influencing factors of the conversion from normal glucose tolerance -hyperinsulinemia (NCT-HINS) to diabetes in the population of a community in Beijing.Methods All the subjects investigated received 75 g oral glucose tolerance test (OGTT) for diabetes screening carried out in May, 2006 and May, 2008. Data were calculated to analyze the outcomes and influencing factors of the conversion. HINS was diagnosed if fasting serum insulin & 15 mIU/L and/or 2-hour serum insulin after glucose loading ≥ 80 mIU/L Results The prevalence of NGT-HINS in the community in 2006 and 2008 was 5.28% and 8.67% (P<0.01) respectively and that of diabetes mellitus (DM) and impaired glucose regulation (IGR) was 3.52% , 6.56% in 2006 and 4.42% ,6.47% in 2008.The probability of the conversion from NGT-HINS to IGR and DM was 18.6% and 2.3% , being much higher than that from normal glucose tolerance- normoinsulinemia (NGT-NINS) (5.4% and 0.7% , P <0.01). However, the probability of the conversion from NGT-HINS to DM was 2.3% , which was much lower than that from IGR (26.3% , P <0.01). The reason might be that individuals with NGT-HINS had a higher waist circumference, BMI, fasting plasma glucose, 2 h plasma glucose and TG but a lower HDL-C than individuals with NGT-NINS in 2006. The HOMA β-cell function index/HOMA insulin resistance index (HBCI/IR) of individuals with NGT-HINS was much lower than that of individuals with NGT-NINS, but much higher than that of individuals with IGR. Logistic regression analysis showed that age, TG and HBCI/IR were the major influencing factors of the conversion from NGT to glucose metabolic disorders.Conclusions The probability of conversion from NGT to DM was increased remarkably when HINS was diagnosed. The reason might be that individuals with NGT-HINS suffered more metabolic risk factors and had a decreased β-cell function. Therefore, individuals with NGT-HINS should be paid attention to in diabetes prevention study.