Blood pressure and risk of developing type 2 diabetes mellitus: the Women's Health Study.

AIMS To examine the relationship of blood pressure (BP) and BP progression with the subsequent development of type 2 diabetes. METHODS AND RESULTS We performed a prospective cohort study among 38 172 women free of diabetes and cardiovascular disease at baseline. Women were classified into four categories according to self-reported baseline BP (<120/75 mmHg, 120-129/75-84 mmHg, 130-139/85-89 mmHg and hypertension) and were further classified according to progression to a higher BP category during the first 48 months of follow-up. The main outcome measure was time to incident type 2 diabetes. During 10.2 years of follow-up, 1672 women developed type 2 diabetes. The multivariable adjusted hazard ratios (HRs) (95% confidence interval) for incident diabetes across BP categories were 0.66 (0.55-0.80), 1.0 (referent), 1.45 (1.23-1.71), and 2.03 (1.77-2.32) (P-value for trend <0.0001). Stratification by body mass index revealed similar results. Adjusted HRs (95% confidence intervals) for incident diabetes after 48 months among women who had no BP progression, women with BP progression but remaining normotensive, and women who developed hypertension during the first 48 months were 1.0, 1.26 (0.97-1.64), and 1.64 (1.33-2.02) compared with 2.39 (1.95-2.93) in women with baseline hypertension (P-value for trend <0.0001). CONCLUSION Baseline BP and BP progression are strong and independent predictors of incident type 2 diabetes among initially healthy women.