Association of circulating leptin, growth hormone, and ghrelin with fibromyalgia: A meta-analysis

Objective

The aim of this study was to evaluate the relationship between levels of leptin, growth hormone (GH), and ghrelin in the bloodstream and fibromyalgia.

Methods

We conducted a meta-analysis to compare the serum/plasma levels of leptin, GH, and ghrelin in individuals with fibromyalgia, as compared to healthy controls. The analysis included sixteen articles, which provided data from 697 fibromyalgia patients and 560 controls.

Results

The meta-analysis found that there was no significant difference in leptin levels between fibromyalgia patients and controls overall (SMD = 0.324, 95% CI = −0.264 to 0.913, P = 0.281). However, when subgroup analysis was done based on geographically different populations, it showed a positive association between high leptin levels and fibromyalgia in European populations (SMD = 1.131, 95% CI = 0.197 to 2.064, P = 0.018), while no significant association was found in Latin American populations (SMD = −0.160, 95% CI = −0.847 to 0.528, P = 0.649). As for GH levels, there was no significant difference between fibromyalgia patients and controls overall (SMD = −0.903, 95% CI = −2.036 to 0.231, P = 0.119). However, when subgroup analysis was done based on geographically different populations, it revealed a significant decrease in GH levels in European populations with fibromyalgia (SMD = −2.341, 95% CI = −3.664 to −1.017, P = 0.001), while no significant association was found in North American populations. Lastly, the analysis of ghrelin levels showed no significant association with fibromyalgia overall (SMD = −0.661, 95% CI = −1.382 to 0.059, P = 0.072).

Conclusion

This meta-analysis shows that patients with fibromyalgia in Europeans have significantly higher levels of circulating leptin and GH. However, no significant association was found between ghrelin levels and fibromyalgia.