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Background Research on the association between sunburn and autoimmune diseases including rheumatoid arthritis is scarce. To date, no study has looked at the relationship between over-exposure to ultraviolet (UV) radiation indicated by sunburn and rheumatoid arthritis (RA). We addressed this gap using the United States National Health and Nutrition Examination Survey (NHANES) database following a hypothesis that no relationship exists between sunburn and rheumatoid arthritis. Methods A cross-sectional study was performed using the United States NHANES data cycle from 2015 to 2016. Participants without rheumatoid arthritis and sunburn data have been excluded from this study. Chi-square test and survey-weighted logistic regression were conducted to study the strength of the association between overexposure to UV radiation indicated by sunburn and RA. Some RA risk factors have been included in the study to identify effect modifiers and confounders for building the parsimonious model. Results Based on the odds ratio (OR), individual overexposure to ultraviolet radiation had no higher or lower chance of reporting a diagnosis of RA [OR=0.87, 95% confidence interval (CI): 0.46 - 1.64]. Age was identified as a confounder. The Adjusted Odds Ratio (AOR) when accounting for age was AOR=1.09, 95% CI: 0.59 - 2.03. In the final model, there was not enough statistical evidence to conclude an association between sunburn and RA after adjusting for age. Conclusions Using the NHANES data to analyze the relationship between overexposure to UV radiation indicated by sunburn and RA; the analyses results suggested that sunburn may not be associated with higher or lower odds of developing rheumatoid arthritis.
RESUMO
OBJECTIVES: Chronic exposure to arsenic has been reported as a risk factor for nonmelanoma skin cancer, notably squamous cell carcinoma. However, current knowledge is limited about the association between arsenic exposure and melanoma. Our objectives were to (1) measure the association between total urinary arsenic levels and melanoma compared with nonmelanoma skin cancer and no cancer and (2) analyze the association between water source and melanoma and nonmelanoma skin cancer. METHODS: We collected cross-sectional data from the 2003-2016 cycles of the National Health and Nutrition Examination Survey. We conducted univariate and multivariate logistic regressions. To evaluate the possible association of skin cancer with source of tap water, we calculated odds ratios for participants with melanoma and nonmelanoma skin cancer, compared with participants with no cancer. RESULTS: White race, higher education, higher socioeconomic status, and smoking history were associated with melanoma and nonmelanoma skin cancer in the full study population. After adjusting for age and race/ethnicity, the adjusted odds ratio of participants with >50 µg/L of total urinary arsenic for melanoma or nonmelanoma skin cancer was 1.87 (95% CI, 0.58-6.05) and 2.23 (95% CI, 1.12-4.45) times higher compared with no cancer, respectively. Participants with nonmelanoma skin cancer had 2.06 increased odds of reporting a nonmunicipal water source compared with participants without cancer. CONCLUSIONS: We did not find a relationship between the incidence of melanoma and exposure to arsenic among US adults. Nonmunicipal water sources were associated with nonmelanoma skin cancer and should be further investigated.