Association of HDL and LDL levels with osteoporosis in rheumatoid arthritis: a retrospective cohort study

Objectives A correlation exists between lipids and osteoporosis (OP), as well as between lipids and rheumatoid arthritis (RA). However, lipids, the relationship between RA and OP is still unclear. This study mainly investigates the relationship between lipid levels and OP risk in RA patients. Methods Retrospective collection of RA patient data from July 2017 to May 2022, encompassing baseline demographics, treatment regimens, laboratory results, and bone mineral density (BMD) measurements. Analyses, stratified by BMD subgroups, were conducted using propensity score matching (PSM) based on age, sex, and baseline duration, and binary logistic regression to examine the interplay between lipoprotein levels and other risk factors. The relationship between continuous variables and OP risk was assessed using restricted cubic spline (RCS), followed by a reanalysis of the correlation between varying lipoprotein levels and different factors, segmented according to RCS-determined cutoffs. Results The study included 2673 RA patients. Binary logistic regression revealed significant associations between high-density lipoprotein (HDL), low-density lipoprotein (LDL), and RA-OP (p < 0.01). Specifically, HDL emerged as a protective factor against OP (OR = 0.40, 95% CI 0.250-0.629; p < 0.001), whereas LDL was identified as a risk factor (OR = 1.56, 95% CI 1.290-1.890; p < 0.001). Furthermore, HDL (RCS cutoff point 1.28 mmol/L) showed a negative, linear correlation with RA-related OP, while LDL (RCS cutoff point 2.63 mmol/L) demonstrated a positive, linear correlation. Conclusions The levels of HDL and LDL may be indicators of OP occurrence in RA patients.