Impact Of Hypertension versus Diabetes on Cardiovascular and All-cause Mortality in Iranian Older Adults: Results of 14 Years of Follow-up

Abstract

To evaluate the joint effect of hypertension (HTN) and diabetes (DM) on coronary heart disease (CHD), and stroke event, all-cause, and cardiovascular disease (CVD) mortality in Middle Eastern older adults, 2747 people (1436 women) aged ≥ 50 years, free of CVD at baseline, were categorized into four groups (HTN-/DM-, HTN+/DM-, HTN-/DM+, HTN+/DM+). Multivariate Cox proportional hazard models were run for different outcomes. To compare the impact of HTN versus DM, HTN+/DM- was considered as reference. In a median of 13.9 years, incidence rate of CHD, and stroke event, all-cause and CVD mortality in total population were 19.0, 4.7, 13.5, and 6.4 per 1000 person-years, respectively. The multivariate sex-adjusted hazard ratios (HRs) of HTN-/DM+ for CHD, stroke, all-cause mortality and CVD mortality were 1.19 (confidence interval (CI): 0.9-1.57), 1.07 (CI: 0.63-1.82), 1.62 (CI: 1.2-2.18), and 1.28 (CI: 0.83-1.97); the corresponding HRs for HTN+/DM+ were 1.96 (CI: 1.57-2.46), 1.66 (CI: 1.1-2.52), 2.32 (CI: 1.8-2.98), and 2.6 (CI: 1.85-3.65) respectively. The associations between HTN/DM status with stroke incidence and all-cause mortality were stronger among men than in women (P for interaction <0.05). Compared to HTN+/DM-, HTN-/DM+ increases all-cause mortality by 62%, however, they are not considerably different regarding CHD, stroke incidence and CVD mortality.

Figure 1

The multivariate adjusted hazard ratio (95% confidence interval) for coronary heart disease and stroke incidence, cardiovascular disease and all-cause mortality. Tehran Lipid and Glucose Study (1999–2014). Multivariate Cox proportional hazard model adjusted for sex, age, body mass index, waist to hip ratio, education level, current smoking, low physical activity, and hypercholesterolemia in 4 different combinations of hypertension and diabetes status i.e. HTN−/DM− (as the reference group), HTN+/DM−, HTN−/DM+, HTN+/DM+, for 4 different outcomes namely (a) Coronary heart disease incidence, (b) Stroke incidence (c) Cardiovascular disease mortality, and (d) All-cause mortality. CHD, coronary heart disease; CVD, cardiovascular disease; CI, confidence interval; HTN, hypertension; DM, type 2 diabetes mellitus.