Integration of Diabetes Mellitus and Hypertension on Major Cardiovascular Events: An Experience From a 15-year Follow-up Cohort Study in EMR

Introduction: Patients with hypertension and diabetes are more susceptible to cardiovascular diseases (CVD) and mortality. This study aimed to evaluate the individual and combined effects of hypertension and diabetes on cardiovascular events and mortality in a Middle Eastern population-based cohort. Methods: Fifteen-year follow-up data were collected for 6323 adults aged 35 years and older who were free from CVD at baseline. The subjects were categorized into different groups according to hypertension and diabetes at baseline. Cox proportional hazards regression was implemented to estimate hazard ratios (HRs) of hypertension and diabetes for cardiovascular events (CVE), CVD mortality, and all-cause mortality. Population-attributable hazard fraction (PAHF) was used to assess the proportion of hazards of CVE and mortality attributable to hypertension or diabetes. Results: The incidence rates (95% CI) of CVE, CVE mortality, and all-cause mortality in the total population were 13.77(12.84-14.77), 3.01(2.59-3.49), and 9.92(9.15-10.77) per 1000 persons per year respectively. The HR of hypertension for CVE in the diabetic population was 1.98 (1.47-2.66) with a PAHF of 27.65(15.49-39.3). When the HRs and PAHF of diabetes were evaluated in hypertensive patients, they were statistically significant for CVE, CVE mortality, and all-cause mortality. Conclusion: Our study indicated that the joint effect of diabetes and hypertension is the dramatic increased risk of CVE. A considerable fraction of the excess risk of CVE in patients with diabetes was attributable to hypertension, on the other hand, diabetes was associated with a substantial hazard fraction of CVE and mortality in hypertensive patients.