The association of the age at type 2 diabetes onset with diabetes progression

<p dir="ltr">Objective</p><p dir="ltr">To examine whether age at type 2 diabetes onset impacts disease progression, assessed by changes in glycaemic control and clinical biomarkers during follow-up.</p><p dir="ltr">Research Design and Methods</p><p dir="ltr">Participants from the Kerala Diabetes Prevention Program (K-DPP) and the US Diabetes Prevention Program (US-DPP) who developed type 2 diabetes during the trial were analysed. Data on fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), triglycerides (TG), HDL, LDL, BMI, blood pressure, and estimated glomerular filtration rate (eGFR) were collected at diabetes onset and at end of follow-up. Linear and mixed-effects regressions assessed the association and rate of biomarkers change, by age at onset.</p><p dir="ltr">Results</p><p dir="ltr">We included 802 US-DPP (mean age:52.6 years) and 146 K-DPP participants (mean age:47.7 years). Younger-onset participants had higher BMI at onset and end of follow-up (mean follow-up:7.9 years US-DPP;7.6 years K-DPP), with relatively small BMI change over time in the US-DPP. In fully adjusted models, FPG and HbA1c 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. In the US-DPP, younger-onset was associated with higher eGFR, lower HDL and systolic blood pressure (SBP); similar directions were seen in K-DPP but non-significant for HDL. SBP fell slightly in older-onset US participants during follow-up, but not in younger-onset participants.</p><p dir="ltr">Conclusions</p><p dir="ltr">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, glycaemia increased slightly faster in individuals with younger-onset diabetes.</p>