Background: Meteorin-like (Metrnl) is a newly identified adipokine implicated in the pathogenesis
of type 2 diabetes mellitus (T2DM), yet data on the circulating levels of Metrnl in patients with T2DM are controversial.
To derive a more precise estimation on circulating Metrnl levels in T2DM patients, we conducted
Methods: The existing studies on the circulating levels of Metrnl in patients with T2DM published up to 16 January
2020 were comprehensively retrieved from PubMed, Web of Science, EMBASE, and The Cochrane library
database. Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated using
random-effects model. Heterogeneity was assessed and quantified by Cochrane’s Q and I2
statistic. All statistical
analyses were performed using Stata 12.0 software.
Results: Nine studies with 867 T2DM patients and 831 normal glucose tolerance (NGT) controls were included
in the final analysis according to the inclusion criteria. No significant difference in circulating Metrnl levels
was found between T2DM patients and NGT individuals (pooled SMD = -0.429, 95% CI = -1.077 to 0.219).
Compared to controls, circulating Metrnl levels were significantly higher in the subgroups with BMI <25
kg/m2, using plasma sample and patient sample size ≥100, while circulating Metrnl levels were significantly
lower in subgroups with age ≤50 years and homeostatic model assessment for insulin resistance (HOMA-IR)
Conclusion: This meta-analysis indicates no significant change in circulating Metrnl levels in T2DM patients.
However, this result may be influenced by age, BMI, sample type, HOMA-IR and patients sample size. Further
longitudinal studies are warranted to offer more insights into the relationship between Metrnl and T2DM.