Association Between Blood Lead Level and Uncontrolled Hypertension in the US Population (NHANES 1999-2016)

Background This study aims to explore whether higher blood lead levels (BLL) may be associated with failure to control blood pressure and subsequent uncontrolled hypertension. Methods and Results We used serial cross-sectional waves of the US National Health and Nutrition Examination Survey (NHANES) from 1999 to 2016. 30 762 subjects aged 20 years and above were included. Uncontrolled hypertension was defined as systolic blood pressure ≥130 mm Hg or diastolic blood pressure ≥80 mm Hg. We estimated odds ratios (ORs) of quartiles of BLL for any hypertension and uncontrolled hypertension by sex using logistic regression, adjusted for demographics, smoking status, serum cotinine, alcohol intake, body mass index, and menopause status in women. The weighted prevalence of hypertension was 46.7%, of which 80.1% were uncontrolled. Men, younger ages, ethnic minorities, people with lower income, never and current smokers, and people with higher BLL were less likely to have their hypertension controlled. In men, compared with the lowest quartile of BLL (<0.94 μg/dL), the highest 2 quartiles (0.94-1.50 μg/dL, 1.50-2.30 μg/dL) were associated with hypertension (Q2: OR, 1.12; 95% CI, 0.96-1.30; Q3: OR, 1.16; 95% CI, 1.01-1.34; Q4: OR, 1.25; 95% CI, 1.08-1.45), but not in women. In hypertensive men, higher BLL was related to uncontrolled hypertension compared with the lowest quartile (Q2: OR, 1.34; 95% CI, 0.98-1.85; Q3: OR, 1.70; 95% CI, 1.26-2.30; Q4: OR, 1.96; 95% CI, 1.45-2.65). In women, the relationship was similar (Q2: OR, 1.26; 95% CI, 0.95-1.67; Q3: OR, 1.48; 95% CI, 1.10-2.00; Q4: 1.70; 95% CI, 1.26-2.30). Conclusions BLL is associated with higher prevalence of hypertension and uncontrolled hypertension, with more pronounced association in men.