Low serum albumin concentration is associated with increased risk of osteoporosis in postmenopausal patients with rheumatoid arthritis

• Published in: Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2022-11, Vol.27 (6), p.1283-1290
• Main Authors: Nagayama, Yoshio, Ebina, Kosuke, Tsuboi, Hideki, Hirao, Makoto, Hashimoto, Jun, Yoshikawa, Hideki, Okada, Seiji, Nakata, Ken
• Format: Article
• Language: English
• ISSN: 0949-2658; 1436-2023
• DOI: 10.1016/j.jos.2021.08.018

The risk of osteoporosis in patients with rheumatoid arthritis (RA) is frequently overlooked, and investigating a simple indicator in routine care may be beneficial to motivate osteoporosis examination. The aim of this retrospective, case-controlled study was to identify the correlation between serum albumin concentrations and the prevalence of osteoporosis in postmenopausal patients with RA. This study enrolled 197 patients who underwent dual-energy X-ray absorptiometry of lumbar spine (LS) and proximal femur without osteoporosis treatment [mean age, 67.5 years; disease duration, 12.8 years; Disease Activity Score assessing 28 joints with C-reactive protein, 2.0; prednisolone dose, 4.9 mg/day (usage, 42.6%); and LS T-score, −1.9]. Patients were classified into 2 groups: osteoporosis, defined as ≥ 1 part bone mineral density T-score ≤ −2.5 or history of fragility fracture of the vertebra or proximal femur (121 patients), and non-osteoporosis (76 patients). Groups were then matched by propensity score using clinical backgrounds affecting bone metabolism. In non-matched model, serum albumin concentration was significantly associated with osteoporosis-related factors such as aging, inflammation, physical disability, and glucocorticoid dose. Multivariate logistic regression revealed that serum albumin concentration was independently and significantly associated with osteoporosis risk (odds ratio = 0.22, 95% confidence interval = 0.08, 0.61, p = 0.0033). After propensity score matching, 57 patients for each group showed that in addition to the LS and femoral neck T-scores (p