LAUSR

First, the presence of reduction in bone mass in patients with SSc should be considered in perspective of bone quantity, but what about bone quality? Ruaro et al. and Koumakis et al. assessed bone quality by trabecular bone score (TBS), but vast majority of SSc patients were postmenopausal with severe disease inferred by the fact that all patients were hospitalized in a tertiary center at the time of evaluation. Thus, those data are not applicable to younger patients or male patients with less severe disease [2, 3]. Even though younger SSc patients have low osteoporotic fracture risk, subclinical osteoporosis may develop. Increased bone mineral density (BMD) commonly reported in overweight women may be a result of soft tissue interference [4, 5]. Evaluating the effect of SSc on BMD is one-sided, and fracture risk might be increased in spite of normal BMD. The severity of skin and other organ involvement was not associated with the BMD values [6]. Hence, using only BMD is inadequate to predict fracture risk in SSc, and TBS should be measured as a complementary tool. Second, the study was performed in accordance with the preferred reporting items for systematic reviews and metaanalysis (PRISMA 2009), the protocol for which is not registered in the International Prospective Register of Systematic Reviews. Several PRISMA extensions have been published in 2015, including PRISMA-P. Registration of protocols is now recognized as desirable in order to promote transparency and to minimize the risk of selective outcome reporting bias [7]. Third, diagnosis of SSc was not always made based on the ACR/EULAR 2013 criteria, therefore, limiting generalizability of the results to earlier or milder SSc patients who fulfill the new classification criteria. Also, no previous study has explicitly examined relationship between bone density and all SSc parameters such as SSc subtype, scleroderma health assessment questionnaire, alcohol intake, cigarettes, proton-pump inhibitor therapy, BMD, TBS, body mass index, and the whole spectrum of bone turnover markers. In conclusion, a limitation of this analysis is that it does not provide conclusive information regarding the independence of each examined variable as a valid risk factor; risk factors were investigated as one of many factors assessed for their association with the outcome. It is necessary to delineate the burden of disease better, identify predictive clinical and biochemical measures, and assess effectiveness of bone-specific agents. Should we use TBS and BMD as clinical tools for routine screening in SSc, and when to start using it remains unknown.