Adverse Cardiovascular Events Are Infrequent but Significantly Associated With Systolic and Pre-Systolic Hypertension: An Occupational Cohort Study

Abstract

Background: Cardiovascular diseases (CVDs) remain the leading cause of global mortality. Different blood pressure subtypes may have varying associations with cardiovascular events, but evidence remains inconclusive in the working population. The objective of the study was to evaluate the incidence and differences between hypertension and prehypertension subtypes in the development of cardiovascular events in an occupational cohort.

Methods: A retrospective cohort study including 12,027 workers monitored over 8 years. The outcome variable was the development of CVD, including myocardial infarction and/or stroke. Hypertension subtypes were classified as normotension (systolic blood pressure (SBP) < 140 mm Hg and diastolic blood pressure (DBP) < 90 mm Hg), isolated systolic hypertension (SBP ≥ 140 mm Hg and DBP < 90 mm Hg), isolated diastolic hypertension (SBP < 140 mm Hg and DBP ≥ 90 mm Hg), and systolic-diastolic hypertension (SBP ≥ 140 mm Hg and DBP ≥ 90 mm Hg). Prehypertension subtypes were defined as isolated systolic prehypertension (SBP 120 - 139 mm Hg and DBP < 80 mm Hg), isolated diastolic prehypertension (SBP < 120 mm Hg and DBP 80 - 89 mm Hg), and systolic-diastolic prehypertension (SBP 120 - 139 mm Hg and DBP 80 - 89 mm Hg). Cox models were used to estimate crude hazard ratios (cHRs) and adjusted hazard ratios (aHRs), controlling for sociodemographic variables and cardiovascular risk factors.

Results: Isolated systolic hypertension (aHR: 6.78, 95% confidence interval (CI): 3.10 - 14.8) and isolated systolic prehypertension (aHR: 3.42, 95% CI: 1.73 - 6.74) showed significant associations with cardiovascular events, even after adjusting for confounding variables. Neither isolated diastolic nor systolic-diastolic prehypertension and hypertension showed significant associations.

Conclusions: While cardiovascular events were infrequent in this occupational cohort, those that occurred showed significant associations with both systolic hypertension and pre-systolic hypertension, suggesting the importance of systolic pressure monitoring in workplace health surveillance.