Relationship between dietary patterns and internal exposure levels of cadmium and lead among middle-aged and elderly populations in cadmium-polluted areas: a cross-sectional survey

Abstract

ObjectiveTo explore the relationship between different dietary patterns and internal exposure levels of cadmium and lead among middle-aged and elderly populations in cadmium-polluted areas, and to provide a scientific basis for adopting reasonable dietary patterns to reduce cadmium and lead internal exposure levels in these populations. MethodsFrom July to December 2019, 600 middle-aged and elderly individuals who had lived in cadmium-polluted areas in northern Guangdong province for ≥ 20 years were randomly recruited to participate in questionnaire surveys, physical examinations, and measurements of urinary cadmium (UCd), blood cadmium (BCd), and blood lead (BPb). Factor analysis was used to determine the dietary patterns of the middle-aged and elderly populations, and a multifactor generalized linear model was used to analyze the relationship between dietary patterns and natural log-transformed heavy metal (LnUCd, LnBCd, LnBPb) levels. ResultsA total of 414 middle-aged and elderly individuals from cadmium-polluted areas in northern Guangdong province were finally included in the analysis. Four dietary patterns were obtained through factor analysis: fruits and vegetables, high-quality protein, protein beverages, and flour, with a cumulative variance contribution rate of 50.618%. The M (P25, P75) of UCd, BCd, and BPb levels in the middle-aged and elderly populations were 7.32 (4.12, 14.85) μg/g Ucr, 6.42 (3.40, 11.55) μg/L, and 55.93 (38.76, 79.12) μg/L, respectively. After adjusting for confounding factors such as gender, age, occupation, region, smoking status, medication history, and body mass index, the results of the multifactor generalized linear model analysis showed that the LnBPb levels of middle-aged and elderly individuals with fruit and vegetable dietary pattern factor scores at the T2 level (β = – 0.121, 95%CI: – 0.225 – – 0.017) and T3 level (β = – 0.108, 95%CI: – 0.213 – – 0.003) were lower than those with factor scores at the T1 level. The LnUCd level (β = – 0.224, 95%CI: – 0.436 – – 0.013) and LnBCd level (β = – 0.245, 95%CI: – 0.434 – – 0.057) of middle-aged and elderly individuals with high-quality protein dietary pattern factor scores at the T3 level were lower than those with factor scores at the T1 level. ConclusionA preference for fruit and vegetable dietary patterns was associated with lower blood lead levels, while a preference for high-quality protein dietary patterns was associated with lower urinary cadmium and blood cadmium levels among middle-aged and elderly populations in cadmium-polluted areas.

Keywords

• cadmium
• lead
• internal exposure levels
• dietary patterns
• relationship
• middle-aged and elderly populations
• cadmium-polluted areas