Cholesterol and Oxidative Stress in U.S. Pregnant Women Exposed to Lead

Association between blood lead levels and hyperlipidemiais: Results from the NHANES (1999-2018)

Background

Research on the association between blood lead (Pb) and lipid biomarkers have yielded inconsistent results, and epidemiological studies on blood Pb levels and hyperlipidemia are scarce. The present study aimed to examine the association between blood Pb levels and hyperlipidemia in adults from the National Health and Nutrition Examination Survey (NHANES).

Methods

A total of 43,196 participants in the NHANES from 1999 to 2018 were included in the final analysis. Hyperlipidemia was determined based on the National Cholesterol Education Program guidelines. Blood Pb levels were assessed using inductively-coupled plasma mass spectrometry. Weighted multivariable logistic regression analysis and subgroup analysis were conducted to determine the correlation between blood Pb levels and hyperlipidemia.

Results

In the multivariable logistic regression model, high blood Pb levels were significantly associated with hyperlipidemia after adjusting for confounders (OR 1.41; 95%CI: 1.18-1.67). Furthermore, elevated blood Pb levels were associated with an increased risk of hyperlipidemia across the four quartile (Q) groups (Q1: OR 1.00; Q2: OR 1.16 [95%CI: 1.04-1.29]; Q3: OR 1.39 [95%CI: 1.21-1.59]; and Q4: OR 1.33 [95%CI: 1.15-1.54]; P for trend <0.05). Significant moderating effects were found in the subgroup analysis stratified by age, education, hypertension, and diabetes (P < 0.05). In sensitivity analysis, the ORs for hyperlipidemia across the quartiles of blood Pb levels were 1.00, 1.17 (95%CI: 1.05-1.30), 1.42 (95%CI: 1.24-1.62), and 1.38 (95%CI: 1.19-1.60) for Q1, Q2, Q3, and Q4, respectively (P for trend <0.001) after removing adults with arteriosclerotic cardiovascular disease, and the ORs were 1.00, 1.13 (95%CI: 1.01-1.25), 1.38 (95%CI: 1.21-1.56), and 1.32 (95%CI: 1.16-1.52) for Q1, Q2, Q3, and Q4, respectively (P for trend <0.001) after including pregnant women.

Conclusion

The current study showed a positive association between blood lead levels and hyperlipidemia.

Associations between concentrations of selected perfluoroalkyl acids and concentrations of blood cadmium, lead, and total mercury

Data (N = 2552) from National Health and Nutrition Examination Survey for US adults aged ≥ 20 years for 2011-2016 were analyzed to estimate the associations between the concentrations of blood cadmium, lead, and total mercury and the concentrations of seven perfluoroalkyl acids (PFAA), namely, 2-(N-Methyl-perfluorooctane sulfonamido) acetic acid (MPAH), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorohexane sulfonic acid (PFHxS), and perfluorooctane sulfonic acid (PFOS). Concentrations of blood cadmium were negatively associated with the concentrations of PFHxS (β = - 0.05428, p < 0.01) and PFOS (β = - 0.0212, p = 0.02). Concentrations of blood lead were positively associated with the concentrations of MPAH (β = 0.03301, p < 0.01), PFOA (β = 0.04783, p = 0.01), PFNA (β = 0.11761, p < 0.01), PFDA (β = 0.08007, p < 0.01), PFUA (β = 0.11382, p < 0.01), and PFOS (β = 0.04996, p = 0.02). Percent increases in the concentration of blood lead were 0.32%, 0.46%, 1.13%, 0.77%, 1.09%, and 0.48% for 10% increases in the concentrations of MPAH, PFOA, PFNA, PFDA, PFUA, and PFOS, respectively. Concentrations of blood total mercury were positively associated with the concentrations of PFNA (β = 0.37105, p < 0.01), PFDA (β = 0.46875, p < 0.01), PFUA (β = 0.56934, p < 0.01), and PFOS (β = 0.17557, p < 0.01). Percent increases in the concentration of blood total mercury were 3.6%, 4.57%, 5.58%, and 1.69% for 10% increases in the concentrations of PFNA, PFDA, PFUA, and PFOS, respectively. Associations between the concentrations of PFAAs with blood total mercury were substantially stronger than the concentrations with blood lead. Higher the carbon chain length for PFAAs, stronger were the associations between PFAAs with lead and mercury.

Lead Exposure and Cardiovascular Disease among Young and Middle-Aged Adults

Lead and its effects on cardiovascular-related markers were explored in this cross-sectional study of young adults (18–44 years) and middle-aged adults (45–65 years) from the United States using the National Health and Nutrition Examination Survey (NHANES), 2009–2016. Degrees of exposure were created using blood lead level (BLL) as the biomarker of exposure based on the epidemiologically relevant threshold of BLL > 5 μg/dL. The mean values, in addition to the percentages of people represented for the markers of interest (systolic blood pressure [SBP], diastolic blood pressure [DBP], gamma-glutamyl transferase [GGT], non-high-density lipoprotein cholesterol [non-HDL-C]) were explored. Among those exposed to lead, the likelihood of elevated clinical markers (as defined by clinically relevant thresholds of above normal) were examined using binary logistic regression. In exploring exposure at the 5 μg/dL levels, there were significant differences in all the mean variables of interest between young and middle-aged adults. The binary logistic regression showed young and middle-aged adults exposed to lead were significantly more likely to have elevated markers (apart from DBP). In all, lead affects cardiovascular-related markers in young and middle-aged U.S. adults and thus we must continue to monitor lead exposure to promote health.