HYPERTENSION, TYPE 2 DIABETES, AND CARDIOVASCULAR RISK: A SYSTEMATIC REVIEW AND META-ANALYSIS

Abstract

Hypertension and type 2 diabetes mellitus (T2DM) are major cardiometabolic risk factors worldwide, yet observational evidence has not always distinguished their independent associations with specific cardiovascular outcome families. To systematically review recent observational studies examining the independent association of hypertension, and separately T2DM, with cardiovascular risk, and to conduct quantitative synthesis only in prespecified subgroups with sufficient methodological comparability. PubMed/MEDLINE, Scopus, and Web of Science were searched in January 2025 for English-language cohort studies published from January 2011 onward. Sixteen cohort studies met PECO eligibility criteria (nine hypertension, seven T2DM). Methodological quality was assessed using the Newcastle-Ottawa Scale. Random-effects meta-analysis was conducted only for prespecified subgroups with at least three sufficiently comparable hazard-based estimates; smaller or non-comparable strata were synthesized narratively. Reporting followed PRISMA 2020 and MOOSE guidance. Stage 1 hypertension was associated with higher broad composite CVD risk (HR = 1.42; 95% CI: 1.24–1.62; I² = 81.1%; n = 6). T2DM was associated with higher heart failure risk (HR = 1.57; 95% CI: 1.38–1.78; I² = 79.7%; n = 4). Narrative evidence for hypertension-related stroke, cardiovascular mortality, T2DM-related broad CVD, coronary events, and cardiovascular mortality was directionally positive but limited by small study counts and lack of direct quantitative comparability. Recent observational evidence supports an association of stage 1 hypertension with broad composite CVD and of T2DM with heart failure, while evidence for other outcome families remains suggestive rather than definitive. Findings support cautious, exposure-specific cardiometabolic risk assessment and should not be interpreted as providing equally certain estimates across all cardiovascular domains.