Exploration in association between vitamin D, sleep quality, and osteoarthritis: A modeling study. Medicine Previous studies on the relationship between vitamin D, sleep quality, and osteoarthritis (OA) have been controversial and the aim of this study is to analyze the association. In this study, relevant data from 2 survey cycles (2009-2010 with 2011-2012) are downloaded from the CDC's NHANES project to analyze the relationship between vitamin D, sleep quality, and osteoarthritis, as well as other related risk factors. The analysis of statistics in this study is performed using t-tests and chi-square tests, modeling is performed using logistic regression based on NHANES weights, and other risk factors are analyzed using forest plots. In association models between serum vitamin D, sleep quality, and OA is statistically significant during the stepwise inclusion of covariates. In model 1, Q3 (OR = 1.83; 95% CI: 1.05, 3.23) and Q4 (OR = 2.22; 95% CI: 1.27, 3.94) are significant. Neither model 2 nor model 3 is statistically significant and P for trend is more than .05 in all 3 models. After the inclusion of all covariates, forest plot showed that sleep deprivation (OR = 1.64; 95% CI: 1.05, 2.56), advanced age (OR = 1.03; 95% CI: 1.01, 1.04), female (OR = 1.79; 95% CI: 1.14, 2.85), overweight (25 ≤ BMI < 30) (OR = 1.92; 95% CI: 1.05, 3.61), and obesity (≥30) (OR = 2.06; 95% CI: 1.11, 3.93) are risk factors for OA. This study is based on a larger sample and a stepwise logistic regression of multiple covariates. We concluded that vitamin D may not influence OA. However other risk factors for OA are confirmed, including advanced age, female and high BMI, especially bad sleep quality. 10.1097/MD.0000000000040021

Iron overload is positively associated with the incidence of osteoarthritis: A NHANES cross-sectional study. Medicine With the aging of the global population and the increase in the number of people with conditions such as obesity, the incidence of osteoarthritis (OA) is increasing annually. Clinical studies have shown that excessive accumulation of iron in joints is associated with age-related OA. However, there have been no reports on the relationship between iron metabolism and osteoarthritis. A STROBE-compliant cross-sectional observational study, was carried out and analyzed from the National Health and Nutrition Examination Survey from 2001 to 2020, including data on serum iron, transferrin saturation, serum ferritin, total iron-binding capacity, and transferrin receptors, as well as data on osteoarthritis. This cross-sectional study was conducted to explore the relationship between serum iron levels, osteoarthritis, and related metabolic factors. By adjusting the model and using quantile logistic regression models, the interaction between human body iron content and the aforementioned variables was analyzed. A total of 56,323 participants over 5 cycles were assessed for iron levels. After adjusting the model for age, sex, race, education level, marital status, total energy intake, physical activity, drinking, BMI, smoking, hypertension, and diabetes, we found that in different quantile regression results, serum iron was associated with OA, Q4: OR = 1.231 (95%CI: 1.009-1.501, P < .05). Ferritin is associated with OA, Q2: OR = 1.309 (95%CI: 1.012-1.692, P < .05); Q3: OR = 1.424 (95%CI: 1.129-1.797, P < .01); Q4: OR = 1.280 (95%CI: 1.013-1.616, P < .05). This cross-sectional study found that serum iron and transferrin saturation levels were positively correlated with OA incidence, suggesting that iron overload is a risk factor for OA. Large-sample prospective cohort studies are needed to confirm the correlation between iron overload and OA. 10.1097/MD.0000000000040089