Predicting New Onset Diabetes Mellitus in Older Taiwanese: Metabolic Syndrome or Impaired Fasting Glucose?

Aim: Metabolic syndrome (MS) has been shown to predict diabetes mellitus (DM) in previous studies, but little is known about older adults. The main purpose of this study is to evaluate whether MS predicts new onset diabetes (NOD) in older community-living Taiwanese. Methods: Community-living people aged over 40 who participated in annual health examinations held by community health clinics were invited to enrol in the study in 2000 and the status of DM was determined in 2005. Results: In total, 480 subjects (mean age: 63.7 +/- 10.8 years in year 2000, 43.8% males) were enrolled in this study. The prevalence of MS in 2000 was 25.4%. Overall, the 5-year cumulative incidence of NOD was 10.8%, and it was significantly higher in the MS group than non-MS group (17.2% vs. 8.7%, p=0.011). Adjusted for age and gender, MS significantly predicts NOD (OR: 2.20, 95% CI: 1.21-4.00, p=0.010). Moreover, both impaired fasting glucose (IFG) (OR: 4.48, 95% CI: 2.41-8.33, p<0.001) and hypertriglyceridemia (OR: 2.03, 95% Cl: 1.04-3.94, p=0.037) significantly predicted NOD among all 5 diagnostic components. In terms of predicting NOD, IFG showed a higher positive predictive value than MS (42.9% vs. 17.2%). Conclusion: Both MS and IFG can effectively predict NOD among community-living older Taiwanese in 5-year follow-up; however, IFG alone may be a more efficient predictor of NOD because of a higher positive predictive value and lower laboratory cost.