Rheumatoid Arthritis: Evidence for Bone Loss in Premenopausal Women

TATIANA FREITAS TOURINHO, AÍRTON STEIN, JOSÉ A.S. CASTRO, and JOÃO C.T. BRENOL

ABSTRACT.

Objective. To assess bone mineral density (BMD) status in patients with rheumatoid arthritis (RA).

Methods. Rheumatoid factor-positive premenopausal women with RA meeting the American College of Rheumatology criteria were enrolled. Exclusion criteria included diseases or drugs that affect BMD, except for glucocorticoids, and smoking. Evaluation consisted of a questionnaire, physical examination, and laboratory tests. Lumbar spine and right proximal femur BMD were measured with a DPX-Lunar DEXA scanner. Data were analyzed by Student t test, chi-square, and multivariate analysis.

Results. We studied 78 patients with RA and 39 controls; 82% were Caucasian, with mean age 35.5 ± 6.7 years, and mean disease duration 48 ± 51 months. Among patients, 74.4% had been treated with glucocorticoids, with a mean daily dose of 9.7 ± 5.9 mg. Mean lumbar spine BMD was 1.157 ± 0.124 g/cm² in the RA patients, and 1.223 ± 0.147 g/cm² in controls (p < 0.01). Mean right proximal femur BMD did not differ significantly. Lumbar spine osteopenia correlated with "no physical activity at work" status, low body weight, and duration of glucocorticoid therapy. Femoral neck osteopenia correlated with "no physical activity at work" status, Steinbrocker class III, erosions of the hands, and high erythrocyte sedimentation rate (ESR). Trochanteric osteopenia correlated with "no physical activity at work" status, erosions on hand radiographs, low body weight, high ESR, and anemia.

Conclusion. Patients with RA of relatively short disease duration already exhibited significantly lower lumbar spine BMD. The identification of prognostic markers for bone loss in patients with RA should not only prompt early therapeutic intervention, but also facilitate early preventive measures. (J Rheumatol 2005;32:1020-5)

Key Indexing Terms:

RHEUMATOID ARTHRITIS
OSTEOPOROSIS
BONE MASS
DENSITOMETRY
GLUCOCORTICOID

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From the Department of Internal Medicine and Department of Epidemiology, Fundação Federal Faculdade de Ciências Médicas, Porto Alegre, Rio Grande do Sul, Brazil.

T. Freitas Tourinho, MD, MSc; J.A.S. Castro, MD, PhD; J.C.T. Brenol, MD, PhD, Department of Internal Medicine; A. Stein, MD, PhD, Department of Epidemiology.

Address reprint requests to Dr. T. Freitas Tourinho, Department of Internal Medicine, Fundação Federal Faculdade de Ciências Médicas, Av. Plínio Brasil Milano, n. 812, sala 604, Higienópolis, Porto Alegre, RS, CEP 90520-000 Brazil. E-mail: tatianaft@brturbo.com.br

Accepted for publication January 25, 2005.

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