Relationship of leptin, growth hormone, and insulin-like growth factor levels with body mass index and disease severity in patients with fibromyalgia syndrome.

OBJECTIVE: A high prevalence of obesity in fibromyalgia syndrome (FMS) predisposes patients to metabolic changes. It is not clear how the clinical manifestations of the disease affect metabolism. This study aimed to investigate leptin, growth hormone (GH), and insulin-like growth factor (IGF-1) levels in FMS, and their relationship with body mass index (BMI) and disease severity.

METHOD: This case-control study included 60 patients with FMS and 42 age- and sex-matched healthy controls. BMIs were recorded for all participants. The disease severity was assessed using the Fibromyalgia Impact Questionnaire (FIQ) and a visual analog scale (VAS). The serum levels of leptin, GH, and IGF-1 of all participants were measured using specific enzyme-linked immunosorbent assays.

RESULTS: Both groups had similar age (p = 0.058), sex (p = 0.25), and BMI (p = 0.29) distribution. The mean age of the FMS and the control groups was 40.7 ± 10.8 years and 36.2 ± 13.6 years, respectively. The mean BMI was 26.7 kg/m2 in the FMS group. The GH (p = 0.037) and IGF-1 (p = 0.002) levels were statistically lower, and leptin (p = 0.002) levels were considerably higher in the FMS group than in the control group. The leptin values were positively correlated with age (p = 0.001; r = 0.386) and BMI (p < 0.001; r = 445). Insulin-like growth factor levels were negatively correlated with age (p < 0.001; r = - 0.605) and BMI (p < 0.001; r = - 0.564). Similarly, GH levels were negatively correlated with age (p = 0.040; r = - 0.243) and BMI (p < 0.001; p = - 0.420). None of the three hormones were associated with FIQ and VAS.

CONCLUSION: We found that leptin (high), GH (low), and IGF-1 (low) levels were statistically different, together with being independent of disease severity (FIQ, VAS), and correlated with BMI in the FMS group. These findings may be related with hypothalamo-pituitary axis dysfunction, BMI, and energy metabolism.