Association of Age at Type 2 Diabetes Onset With Diabetes Progression

OBJECTIVE To examine whether age at type 2 diabetes onset affects disease progression, assessed by changes in glycemic control and clinical biomarkers during follow-up. RESEARCH DESIGN AND METHODS Participants in the Kerala Diabetes Prevention Program (K-DPP) and U.S. Diabetes Prevention Program (US-DPP) who developed type 2 diabetes during the trial were analyzed. Data on fasting plasma glucose (FPG), hemoglobin A 1c (HbA 1c ), triglycerides (TGs), HDL, LDL, BMI, blood pressure, and estimated glomerular filtration rate (eGFR) were collected at diabetes onset and end of follow-up. Linear and mixed-effects regressions assessed the association and rate of biomarker change by age at onset. RESULTS We included 802 US-DPP (mean age 52.6 years) and 146 K-DPP participants (mean age 47.7 years). Younger-onset participants had a higher BMI at onset and end of follow-up (mean follow-up 7.9 and 7.6 years for US-DPP and K-DPP, respectively), with a relatively small BMI change over time in US-DPP participants. In fully adjusted models, FPG and HbA 1c at onset were not associated with age at onset. Both measures increased faster in younger-onset participants, although the association was not significant in K-DPP participants. In US-DPP participants, younger age at onset was associated with higher eGFR and lower HDL and systolic blood pressure (SBP); similar directions were seen in K-DPP participants, but the association with HDL was nonsignificant. SBP fell slightly in older-onset US-DPP participants during follow-up but not in younger-onset participants. CONCLUSIONS Younger-onset diabetes was associated with greater adiposity, lower HDL, and better SBP and eGFR at onset, with differences largely persisting during follow-up. During follow-up, glycemia increased slightly faster in individuals with younger-onset diabetes.