The association between systemic sclerosis and bone mineral density- a meta-analysis of observational studies

Previous research has shown inconsistent effect of systemic sclerosis (SSc) on bone mineral density (BMD). The objective of this study was to perform a meta-analysis of previous articles to investigate the differences in BMD (g/cm(2) ) between SSc and non-SSc populations and to discuss potential underlying mechanisms. Twelve full-text articles (including an outlier study and two studies with identical data) with 662 SSc patients and 886 controls were identified by searching Medline prior to 10 September, 2013 using search terms 'Systemic sclerosis' OR 'scleroderma' and 'osteoporosis' OR 'bone density' OR 'bone mass'. BMD (mean and standard deviation), T-scores and Z-scores at lumbar spine, femoral neck and total hip measured by dual-energy X-ray absorptiometry were extracted. Meta-analysis showed that a lower level of BMD was found in SSc patients, with weighted mean difference of -0.343 (95% CI: -0.500 to -0.186) at femoral neck, -0.084 (95% CI: -0.110 to -0.057) at total hip and -0.104 (95% CI: -0.135 to -0.073) at the lumbar spine. We conclude that patients with SSc may have a lower BMD level than healthy controls.