Associations Between Copper and Zinc and Risk of Hypertension in US Adults

Evidence linking copper and zinc to hypertension are limited and conflicting. Data from the National Health and Nutrition Examination Survey (NHANES) 2007-2014 were used. Zinc and copper intake from diet and supplements was assessed with 24-h dietary recall. Hypertension was defined as systolic blood pressure (SBP) ≥ 140 mmHg/diastolic blood pressure (DBP) ≥ 90 mmHg/treatment with hypertensive medications. In a sensitivity analysis, according to the 2017 American College of Cardiology and American Heart Association guideline, hypertension was also defined as SBP ≥ 130 mmHg/DBP ≥ 80 mmHg/treatment with hypertensive medications. A total of 17,811 adults (8430 men and 9381 women) were included. After adjustment for age, gender, body mass index (BMI), race, educational level, smoking status, family income, and total daily energy intake, the OR of hypertension for highest vs. lowest quartile intake of copper, zinc, and copper/zinc ratio was 1.11 (0.90-1.37), 1.11 (0.90-1.35), and 0.95 (0.81-1.11), respectively. In stratified analysis by BMI (< 25 kg/m², 25-30 kg/m², > 30 kg/m²), no significant association was found between hypertension and intakes of copper, zinc, and copper/zinc ratio (highest vs. lowest quartile) in multivariate analysis. In multivariate analysis, the OR of hypertension for highest vs. lowest quartile levels of serum copper, zinc, and copper/zinc ratio was 1.11 (0.61-2.04), 1.43 (0.84-2.44), and 0.68 (0.34-1.33), respectively. Similar results were found in the sensitivity analysis. Zinc and copper might be not independently associated with hypertension in US adults.