Childbirth History Increases Arthritis Risk in Women: The Role of Lipid Metabolism and Physical Activity

OBJECTIVE To investigate the association between childbirth and arthritis, with a focus on the mediating effect of blood lipid indexes and protective role of physical Activity. METHODS The cross-sectional study utilized data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2020. Blood lipid indexes were included triglyceride, total cholesterol (TC), LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C, mmol/L). Then, remnant cholesterol (RC) was calculated. RESULTS A total of 6491 participants were included in this study, 2144 (33.03%) women occurred arthritis. Compared to never pregnancy women, the rates of arthritis in the participants with had childbirth were significantly increase (36.03% vs 17.94%, p < 0.001). After adjusted, the risk of arthritis for the women had childbirth was significantly increased (OR = 4.17, p < 0.0001). In addition, the birth number and birth interval cycle would increase the risk of arthritis caused by childbirth experience. There was a nonlinear (L-shaped) relationship were observed in blood triglyceride and RC (p for nonlinearity < .001). Mediation analysis demonstrated that blood RC accounted for 8.45% of observed association between childbirth and arthritis (p < 0.001). RC was the highest WQS weigh among four cholesterols, with the highest contributions 0.63. There was a nonlinear (U-shaped) relationship between vigorous recreational activities and the risk of arthritis (p for nonlinearity < 0.001). CONCLUSIONS Childbirth history is a significant yet underrecognized risk factor for arthritis in women, mediated in part by persistent lipid abnormalities, particularly elevated RC, while physical activity offers protective benefits.