Positive association between baseline arterial stiffness and new-onset diabetes: a population-based cohort study

Objective: The temporal relationship between increased arterial stiffness and diabetes remains unclear. This study aimed to investigate whether arterial stiffness was associated with new-onset diabetes. Design and method: The study population comprised participants from the Vitamin D Assessment (ViDA) Study, a randomised controlled trial of vitamin D supplementation that recruited participants mostly from family practices in Auckland, New Zealand from 5 April 2011 to 6 November 2012. Arterial stiffness was measured at baseline by aortic pulse wave velocity (aPWV), augmentation index (AIx) and pulse pressure (PP). Vitamin D did not affect the risk of the main study outcomes including cardiovascular disease. The final study population was 4479 participants after excluding those with existing diabetes (as determined by dispensed prescriptions and self-report). New-onset diabetes was determined by linkage to dispensed prescription and national hospital discharge registers. Cox proportional hazards regression was used to assess the incidence of diabetes in relation to aPWV, AIx and PP. Results: The mean (SD) age of participants at baseline was 66.2 (8.3), 2556 (57.1%) were male and 3880 (86.6%) were of European or other ethnicity, with the remainder being Polynesian (including indigenous Maori) or South Asian. During a mean (SD) follow-up of 6.86 ± 0.43 years, 364 (8.1%) participants developed diabetes. Following adjustment for age, sex, ethnicity, mean arterial pressure, body mass index and vitamin D supplementation (vitamin D vs placebo), aPWV and PP, but not AIx were associated with an increase in new onset-diabetes (per SD increase, aPWV hazard ratio, 1.36, 95% CI, 1.13 to 1.64; PP hazard ratio, 1.40 95% CI, 1.16 to 1.68; AIx hazard ratio, 1.02, 95% CI, 0.91 to 1.14). Conclusions: Arterial stiffness, as measured by aPWV and PP, independent of other risk factors, may be a useful predictor of new-onset diabetes.