Objective: To examine how T2D onset age affects A1C trajectory and A1C lowering with insulin and other drugs.

Methods: We conducted a cohort study (2000-16) in adults aged 18-75 years (y) with young-onset T2D (YOD; onset age <40 y) and usual-onset T2D (UOD; onset age ≥40 y). In the Hong Kong Diabetes Registry (n=21,016), we estimated the mean glycemic burden (area under curve of A1C over time) across the lifespan, stratifying by onset age. In the population-based Hong Kong Diabetes Surveillance Database (n=328,199), we examined the effect of onset age on A1C trajectory for incident T2D using linear mixed effects models, accounting for drugs using time-varying covariates. We followed for 10 y, censoring at death or insulin start. For those started on insulin (n=20,877), we used similar methods to examine the effect of time to insulin start on the post-insulin A1C trajectory.

Results: Glycemic burden was tripled in YOD versus UOD (38.8 versus 11.8 A1C-y). After accounting for drugs, YOD was associated with a higher baseline A1C (7.6%) and slope (0.05%/y) versus UOD (7.4%, 0.00%/y). Non-insulin drugs lowered A1C similarly across onset ages. The post-insulin A1C remained elevated for YOD, regardless of time to insulin start, but improved significantly for UOD.

Conclusions: YOD is associated with an aggressive A1C rise and excess glycemic burden despite insulin and other drugs. More effective strategies are needed to lower A1C in people with YOD.

C. Ke: None. A. Luk: None. B.R. Shah: None. T. Stukel: None. E.S. Lau: None. R.C. Ma: Advisory Panel; Self; Boehringer Ingelheim International GmbH. Research Support; Self; AstraZeneca, Bayer AG, Pfizer Inc. Stock/Shareholder; Self; GemVCare. Other Relationship; Self; AstraZeneca. A.P. Kong: Advisory Panel; Self; Lilly Diabetes. Research Support; Self; AstraZeneca, Lilly Diabetes. Speaker's Bureau; Self; Abbott. Other Relationship; Self; AstraZeneca, Novartis Pharmaceuticals Corporation, Sanofi. E. Chow: Research Support; Self; Powder Pharmaceuticals Inc., Sanofi-Aventis. J.C. Chan: Board Member; Self; Asia Diabetes Foundation. Consultant; Self; AstraZeneca, Boehringer Ingelheim Pharmaceuticals, Inc., Lilly Diabetes, Medtronic, Merck Sharp & Dohme Corp., Sanofi-Aventis. Research Support; Self; Amgen Inc., AstraZeneca, Lee Powder, Lilly Diabetes, Pfizer Inc., Sanofi-Aventis. Speaker's Bureau; Self; Ascensia Diabetes Care. Stock/Shareholder; Self; GemVCare.


University of Toronto; Royal College of Physicians and Surgeons of Canada; Canadian Society of Endocrinology and Metabolism; Chinese University of Hong Kong; Asia Diabetes Foundation

Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered. More information is available at http://www.diabetesjournals.org/content/license.