Plasma/Serum Leptin Levels in Patients with Ankylosing Spondylitis: A Systematic Review and Meta-analysis.

BACKGROUND AND AIMS: Leptin is an adipokine that has several effects on metabolism and immune system in patients with ankylosing spondylitis (AS). The present investigations of the relationship between plasma/serum leptin levels and AS are contradictory. To derive a more precise estimation on the plasma/serum leptin levels in AS patients and related factors, a meta-analysis was performed.

METHODS

Published literature that compares plasma/serum leptin levels between AS group and control group from PubMed, Embase, Cochrane Library and other databases were searched. The study quality was assessed by the Newcastle-Ottawa scale. Pooled standardized mean difference (SMD) with its 95% confidence interval (CI) was calculated by fixed-effects or random-effect model analyses. Statistical heterogeneity within studies was examined by the Q statistic.

RESULTS

A total of eight studies including 391 AS patients and 293 healthy controls were finally included in the meta-analysis. No significant differences in plasma/serum leptin levels was found between AS patients and healthy controls when all studies were pooled into the meta-analysis (pooled SMD = 0.384, 95% CI = -1.522 to 0.753). Meanwhile, subgroup analyses by gender also showed no significant differences in plasma/serum leptin levels between case group and controls.

CONCLUSION

There is no significant difference in plasma/serum leptin levels between AS patients and controls.