Impaired bone formation and osteoporosis in postmenopausal elderly onset rheumatoid arthritis patients

ABSTRACT

Bone metabolism may be uncoupled in postmenopausal rheumatoid arthritis [RA]. Osteoporotic fracture in RA is highest for the hip especially in elderly women. To detect the bone mineral density [BMD] and markers of bone turnover in postmenopausal RA patients and study the influence of age at disease onset. Correlation with clinical and laboratory manifestations and disease activity were considered. Sixty postmenopausal RA patients were recruited into two groups, group I 30 elderly onset [EORA] and group II 30 young onset [YORA] patients. Thirty age and sex matched healthy subjects served as control. Full history taking, clinical examination, relevant investigations including calcium, phosphorus, total alkaline phosphatase [ALP], bone specific alkaline phosphatase [BALP], osteocalcin [OC], and N-terminal cross-linked telopeptides of type I collagen [NTX] were measured and BMD assessed by DEXA in all patients and control. Disease activity score in 28 joints [DAS-28] was calculated. The NTX was remarkably increased and the BMD decreased in RA patients. Osteocalcin in RA was 3.87 +/- 1.15 ng/ml being obviously lower in EORA patients compared to YORA and control. In EORA, a significant correlation was present between the ALP and OC [r 0.41, p 0.025] and the NTX and BALP [r 0.46, p 0.011] and a negative correlation between the hip BMD and DAS-28 [r -0.43, p 0.019]. Impaired bone formation and uncoupling of bone turnover are more evident in postmenopausal EORA patients which form a risk predictor of fracture hip in this subgroup of patients