Serum zinc concentrations and incident hypertension: new findings from a population-based cohort study.

OBJECTIVE Zinc is an essential trace element that plays a key role in several cellular processes and has been suggested to be involved in blood pressure regulation. We aimed to prospectively investigate the association between baseline concentrations of serum zinc and incident hypertension. METHODS We analyzed data involving 1652 men aged 42-61 years without a known history of hypertension at baseline in the Kuopio Ischemic Heart Disease population-based cohort study, with the assessment of serum zinc concentrations. Hazard ratios [95% confidence intervals (CIs)] for incident hypertension were assessed. RESULTS During a median follow-up of 24.7 years, 259 participants developed hypertension. Serum zinc was weakly correlated with several risk markers for hypertension and nonlinearly associated with incident hypertension. In analyses adjusted for age, the hazard ratio (95% CIs) for hypertension in a comparison of the top quartile vs. bottom quartiles 1-3 of zinc concentration was 1.65 (1.27-2.15; P < 0.001), which was minimally attenuated on adjustment for several established risk factors 1.48 (1.13-1.93; P = 0.004). The association remained unchanged on further adjustment for renal function, socioeconomic status, and dietary factors. The findings were generally consistent across several clinical subgroups. There was no evidence of an association of dietary zinc intake with risk of hypertension. CONCLUSION This prospective study suggests higher serum zinc concentration is positively and independently associated with incident hypertension in men. Further evidence from large-scale population-based studies is needed to support these findings and assess the mechanisms underlying the association.