Systolic blood pressure and risk of cardiovascular diseases in type 2 diabetes: an observational study from the Swedish national diabetes register.
J Hypertens. 2010 Oct;28(10):2026-35. Cederholm J, Gudbjörnsdottir S, Eliasson B, Zethelius B, Eeg-Olofsson K, Nilsson PM; NDR. Department of Public Health and Caring Sciences/Family Medicine and Clinical Epidemiology, Uppsala University, Uppsala, Sweden.
OBJECTIVES: To estimate risks of fatal/nonfatal coronary heart disease (CHD), stroke and cardiovascular disease (CVD) with SBP in an observational study of patients with type 2 diabetes.
METHODS: Twelve thousand, six hundred and seventy-seven patients aged 30-75 years, treated with antihypertensive drugs, without previous congestive heart failure, followed for 5 years.
RESULTS: Risk curves of CHD and stroke increased progressively with higher baseline or updated mean SBP in a Cox model, in all participants, and in two subgroups without (n = 10 304) or with (n = 2373) a history of CVD, with no J-shaped risk curves at low SBP levels. Hazard ratios for CHD and stroke per 10-mmHg increase in updated mean SBP in all participants, adjusting for clinical characteristics and traditional risk factors, were 1.08 (1.04-1.13) and 1.20 (1.13-1.27), P < 0.001. With updated mean SBP of 110-129 mmHg as reference, SBP of at least 140 mmHg showed risk increases of 37% for CHD, 86% for stroke and 44% for CVD (P = 0.001 to <0.001), whereas SBP of 130-139 mmHg showed nonsignificant risk increases for these outcomes. With baseline SBP of 110-129 mmHg, CHD and CVD risks increased with further SBP reduction, hazard ratios were 1.77 and 1.73 (P = 0.002), but decreased considerably for CHD, stroke and CVD with higher baseline SBP.
CONCLUSION: Risks of CHD and stroke increased progressively with higher SBP, with no J-shaped curves, although risk increase was significant only for SBP of at least 140 mmHg, but not comparing 130-139 and 110-129 mmHg. Additionally, baseline SBP of 110-129 mmHg showed increased CHD and CVD risk with further SBP reduction during follow-up, whereas baseline SBP of at least 130 showed benefits.