Recently, a large body of studies has focused on the leptin levels in psychiatric disorders. This study aimed to measure serum leptin levels in fibromyalgia syndrome (FMS) due to a significantly higher prevalence of psychiatric disorder and to determine the relationship between leptin and FMS.
The present study was a cross-sectional descriptive study. Fifty FMS female patients and 50 healthy females serving as a control group were included. Serum samples tested for serum leptin levels were determined by a specific enzyme-linked immunosorbent assay (ELISA).
Serum leptin levels were significantly lower in FMS patients compared to the control group. The mean serum leptin in patients with FMS was 7.1 ± 6.8 ng/mL compared to 9.4 ± 4.5 ng/mL in the controls (mean difference, -2.48, 95% CI: -4.78, -0.18, P = 0.035). Serum leptin level is inversely correlated with visual analogue scale (VAS) of pain (P = 0.016), VAS of fatigue (P = 0.002), VAS of global severity (P = 0.011), VAS of anxiety (P = 0.027), global self-rating index (P = 0.020), Health Assessment Questionnaire score (P = 0.016), fibromyalgia impact questionnaire (FIQ) (P = 0.025), Beck Depression Inventory (P = 0.002), tender points (TPs) count (P = 0.041), TPs score (P = 0.015), and Pittsburg Sleep Quality Index (P = 0.006). Mean serum leptin levels were also significantly lower in FMS patients with post-exertion pain (P = 0.010), depression (P = 0.029), mood disturbance (P = 0.018), anxiety (P = 0.030), short memory difficulties (P = 0.017), sleep disturbance (P = 0.028), restless leg syndrome (P = 0.016), temperomandibular joint syndrome affection (P = 0.043), palpitation (P = 0.022), and irritable bowel syndrome (P = 0.028) than those without.
We found a significant decrease in serum leptin in FMS patients compared to controls and this decrease correlated with disease severity.