Does occupational lifting affect the risk of hypertension? Cross-sectional and prospective associations in the Copenhagen City Heart Study

OBJECTIVE: The aim of this study was to investigate cross-sectional and prospective associations between heavy occupational lifting and hypertension. METHODS: Data from the third, fourth and fifth examinations of the Copenhagen City Heart Study were included. Multivariable logistic regression models were applied to adjust for sex, age, body mass index (BMI), smoking, education, self-rated cardiorespiratory fitness, vital exhaustion and baseline blood pressure, and were used to estimate (i) the cross-sectional association between heavy occupational lifting and hypertension, defined as using anti-hypertensives or having a systolic blood pressure (SBP) ≥140 mmHg or diastolic blood pressure (DBP) ≥90 mmHg, and (ii) the prospective association between heavy occupational lifting and risk of becoming a systolic blood pressure case, defined as an above median change (from baseline to follow-up) and/or a shift from no use of anti-hypertensives at baseline to use of anti-hypertensives at a ten-year follow-up. RESULTS: Both cross-sectional [odds ratio (OR) 1.06, 95% confidence interval (CI) 0.94–1.20] and prospective (OR 1.10, 95% CI 0.92–1.31) analysis indicated no relations. Explorative prospective analyses suggested linear associations between heavy occupational lifting and systolic blood pressure among participants using anti-hypertensives. Exposure to heavy occupational lifting tended to increase the incidence of hypertension (OR 1.30, 95% CI 0.97–1.73) among participants ≥50 years. CONCLUSIONS: No associations were seen among the general population. Positive associations were seen among users of anti-hypertensives and participants ≥50 years, indicating these groups as vulnerable to increases in blood pressure when exposed to occupational lifting.