944 - Hormone Replacement Therapy Significantly Reduces Arthritis and Functional Decline in Menopausal Women: NHANES Analysis

Objectives: Menopausal musculoskeletal symptoms including arthralgia, stiffness, myalgia, and functional decline affect up to half of postmenopausal women and are biologically linked to estrogen deficiency (receptor expression in cartilage, synovium, and muscle; pro-inflammatory milieu; altered collagen/joint metabolism). We aimed to determine whether hormone replacement therapy (HRT) use is associated with musculoskeletal outcomes in a nationally representative sample of postmenopausal women.

Design: Cross-sectional analysis of NHANES 2013–2018 including 3,689 women aged 45–69 years. HRT exposure was ascertained via prescription medication files and self-report from reproductive health questionnaires. Primary outcomes were doctor-diagnosed arthritis and functional limitations (Physical Functioning Questionnaire items reflecting difficulty in activities of daily living). We created 1:1 age-matched pairs (±1 year), matching 498 HRT users to 498 nonusers. Associations were estimated using conditional logistic regression for matched pairs; paired proportions were compared with McNemar’s test. Sensitivity analyses and multivariable adjustment assessed robustness to potential confounding.

Results: Among 498 matched pairs, HRT users had lower odds of doctor-diagnosed arthritis than controls (5.4% vs 11.6%; OR 0.43, 95% CI 0.27–0.70; p=0.001) and lower odds of functional limitations (1.4% vs 3.4%; OR 0.40, 95% CI 0.17–0.98; p=0.045). Absolute differences were −6.2 percentage points (arthritis) and −2.0 percentage points (functional limitations). Findings were consistent across sensitivity analyses and after controlling for potential confounders.

Conclusions: In a nationally representative, age-matched analysis, HRT use was associated with substantially lower odds of arthritis and functional limitations in postmenopausal women, with clinically meaningful absolute differences. These results align with biologic mechanisms of estrogen on joint and muscle tissues and suggest that potential musculoskeletal benefits should factor into HRT risk–benefit discussions. Future longitudinal and interventional studies should test causality and dose–response effects.