The relationships between blood lead levels and nocturia prevalence in adults: A retrospective study

Abstract Purpose The purpose of this study was to examine the association between blood lead levels and the prevalence of nocturia in American adults. Methods We analyzed data from the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2020, focusing on individuals aged 20 years or older ( n = 11,919). Blood lead levels were categorized into two groups (<2 µg/dL and ≥2 µg/dL), and the presence of nocturia was assessed based on questionnaire responses. We used multivariable logistic regression models to explore the association between blood lead levels and nocturia while adjusting for various covariates, including sex, ratio of family income to poverty (RIP), lipid profile, age, body mass index (BMI), race, citizenship, sleep trouble, diabetes, and hypertension. To verify whether certain covariates influence blood lead levels and the risk of nocturia, we conducted subgroup analyses. Results Of the study participants, 31.70% reported experiencing nocturia. Individuals with higher blood lead levels (≥2 µg/dL) exhibited a higher likelihood of experiencing nocturia compared to those with lower levels (<2 µg/dL) in all three models (Model 1: OR 1.46, 95% CI 1.29–1.66, p < 0.0001; Model 2: OR 1.25, 95% CI 1.09–1.44, p = 0.002; Model 3: OR 1.22, 95%CI 1.06–1.41, p = 0.01). Subgroup analyses revealed that factors such as age, sex, sleep trouble, diabetes, hypertension, BMI, RIP, and race did not affect the association between blood lead levels and the risk of nocturia (P for interaction >0.05). Conclusions This study reported the correlation between blood lead levels and nocturia. We found that compared to blood lead levels below 2 µg/dL, when lead levels reached or exceeded 2 µg/dL, the risk of nocturia occurrence increased by 22%. Clinical trial registration This study is based on existing data from a public database and not from a specific clinical trial; hence, clinical registration information is not provided.