Association of Obesity Status Trajectories with Changes in Prediabetes Glycemic Status

This study aimed to determine the association between trajectories of obesity status and prediabetes reversion to normoglycemia or progression to diabetes. The study included 14,452 participants from the National Health Insurance Service-National Health Screening (NHIS-HEALS) cohort who continuously had prediabetes glycemic status during the index period (2002-2008), defined by their fasting plasma glucose. The exposure of the study was the trajectories of obesity (defined by body mass index ≥ 25 kg/m²) generated using latent class growth analysis. The outcomes were reversion to normoglycemia or progression to diabetes, whichever occurred first during the follow-up period (2009-2016). The association between trajectories and changes in prediabetes status were examined using cause-specific hazard regression by obtaining the hazard ratio (HR) with a 95% CI. We identified three distinct trajectories which were "Stable obese", "Stable non-obese" and "Obese to non-obese". After a median follow-up of 2 years, 51.99% of participants had their glycemic status back to normoglycemia and 32.17% developed diabetes. Compared with participants in the "Stable obese" group, those in "Stable non-obese" and "Obese to non-obese" groups were more likely to have reversion to normoglycemia (HR with a 95% CI = 1.30 [1.23-1.37] and 1.15 [1.07-1.24], respectively) and lower risk of developing diabetes (0.78 [0.73-0.84] and 0.90 [0.82-0.98], respectively). The findings suggest that maintaining or achieving a non-obese status is linked to higher reversion to normoglycemia as well as lower risks of developing diabetes.