Serum adipokines levels in patients with systemic sclerosis: A meta-analysis

Background: Systemic sclerosis is an chronic inflammatory autoimmune diseases. Adipokine has been reported to play an important role in modulating immune responses. Recent studies suggest that adipokine also plays some roles in the pathogenesis of systemic sclerosis (SSc). However, published data regarding the relationship between plasma/serum adipokine levels and SSc are contradictory. The aim of this study was at performing a meta-analysis to derive a more accurate estimation and further investigate the association of plasma/serum leptin and adiponectin levels with SSc patients.Methods: PubMed, and Web of Science databases (up to Feb 20, 2016) were used to obtain all relative published literatures. The study quality was assessed by the Newcastle-Ottawa scale. Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by random-effect model analysis.Results: A total of fourteen studies were finally included in this meta-analysis. Among them, six of which were studied for the serum adiponectin levels in SSc patients, six of which were studied for the serum leptin levels in SSc patients, and two of them were studied both for serum adiponectin levels and serum leptin levels in SSc patients. The meta-analysis results showed that the serum adiponectin levels in SSc patients were significantly lower than that in normal controls (SMD = -0.608ng/ml, 95% CI = -1.029 to -0.186, p=0.005). However, there were no significant differences in serum leptin levels between SSc patients and healthy controls (SMD = -0.990ng/ml, 95% CI = -2.340 to 0.359, p=0.150). The subgroup analysis showed that Asia SSc patients with age less than 50 years old had lower plasma/serum adiponectin levels when compared with controls.Conclusion: The serum adiponectin levels, but not serum leptin levels, in SSc patients were significantly lower than that in normal controls.