The association between leptin and diabetes: A meta-analysis.

Purpose: The study object was to determine the relationship between leptin and diabetes.

Methods: We searched for the literature on the relationship between leptin and diabetes from PubMed, EMBASE, Cochrane Library, and CNKI databases. We carried out the meta-analysis by calculating the Std. Mean Difference (SMD) and 95% confidence intervals (CIs) to study the relationship between leptin and diabetes. We performed the Chi-square-based Q test and I statistics to evaluate the potential heterogeneity, and the sensitivity analysis was performed to evaluate the stability of our results. Moreover, Begg's test was performed to evaluate the publication bias.

Results: There are 10 studies in this study for meta-analysis, which include 1879 patients (diabetic (n = 1024); and nondiabetic patients (n = 855)). The results indicated that the levels of serum leptin were significantly increased in patients with diabetes (SMD = 1.78, 95% CI [0.81, 2.76]), especially those with gestational diabetes mellitus compared with controls (SMD = 3.03, 95% CI [1.21, 4.86]). However, the results showed that there was no difference in serum leptin levels between type 2 diabetes and controls (SMD = 0.34, 95% CI [-1.06, 1.74]).

Conclusions: Our analysis indicated that the levels of serum leptin were significantly elevated in patients with diabetes especially those with gestational diabetes mellitus compared with controls.