Non-linear U-shaped association between serum zinc concentration and the risk of elevated blood pressure in adults: A...

The association between serum zinc (SZn) concentration and elevated blood pressure (BP) incidence was investigated.

Adult men and women (n = 2117) with normal BP (NBP) who had completed data, including SZn concentrations at baseline, were included (2009-2011) and followed through 2018-2022 for the development of elevated BP (i.e., defined as systolic BP 120-129 mm Hg and a diastolic BP below 80 mm Hg). A univariate regression spline was used to assess the dose-response association and identify the best placement of SZn knots for developing elevated BP. Multivariable Cox proportional hazard models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of elevated BP across the categories of SZn [< 84, 84-131 (as reference), and ≥ 131 μg/dL].

Elevated BP developed in 15.5% of the participants over time. Spline regression demonstrated a non-linear and U-shaped association between SZn and the risk of elevated BP. The multivariable-adjusted Cox regression showed that below and exceeded the reference range of SZn (<84 and ≥131 μg/dL, respectively) were associated with an increased risk of elevated BP (HR=1.65, 95% CI=1.16-2.36, and HR=1.50, 95% CI=1.06-2.13, respectively). Sex-stratified analysis indicated a stronger association between low SZn and elevated BP in men (HR=2.05, 95% CI=1.19-3.51), while high SZn was more strongly associated with elevated BP in women (HR=1.73, 95% CI=1.10-2.71).

Both low and high SZn levels are associated with the risk of elevated BP, indicating a U-shaped relationship. Sex-specific patterns suggest that men may be more susceptible to zinc deficiency, while women appear more sensitive to zinc excess.