Characteristics of the study participants according to serum zinc level quartile.

Values are expressed as means ± standard errors or percentages and as geometric means and 95% confidence intervals for skewed distributions*. Quartile 1 (Q1): the lowest zinc levels, Q2: low-medium zinc levels, Q3: high-medium zinc levels, and Q4: the highest zinc levels. SBP = systolic blood pressure; DBP = diastolic blood pressure; HDL = high-density lipoprotein; HOMA-IR = homeostasis model assessment of insulin resistance; eGFR = estimated glomerular filtration rate.