Association of Leptin with Body Pain in Women

Abstract

Leptin, an appetite-regulatory hormone, is also known to act as a proinflammatory adipokine. One of the effects of increased systemic leptin concentrations may be greater sensitivity to pain. We report the results of two studies examining the association between leptin and pain: a small pilot longitudinal study, followed by a large cross-sectional study. In Study 1, three women with physician-diagnosed fibromyalgia provided blood draws daily for 25 consecutive days, as well as daily self-reported musculoskeletal pain. Daily fluctuations in serum leptin were positively associated with pain across all three participants (F (1,63) = 12.8, p < 0.001), with leptin predicting ∼49% of the pain variance. In Study 2, the relationship between leptin and body pain was examined in a retrospective cross-sectional analysis of 5676 generally healthy postmenopausal women from the Women's Health Initiative. Leptin levels obtained from single blood draws were tested for a relationship with self-reported body pain. Body mass index (BMI) was also included as a predictor of pain. Both leptin and BMI were found to be independently associated with self-reported pain (p = 0.001 and p < 0.001, respectively), with higher leptin levels and greater BMI each being associated with greater pain. Leptin appears to be a predictor of body pain both within- and between-individuals and may be a driver of generalized pain states such as fibromyalgia.

FIG. 1.

Relationship between daily serum leptin and daily pain in three women with fibromyalgia. Sequence plots. Solid line represents leptin and dashed line represents pain over 25 consecutive days (x-axis). Both leptin and pain have been individual centered with a z-score transformation to put all data on the same y-scale. For general descriptive purposes, individual Pearson's correlations are provided. The relationship between leptin and pain for the three individuals was as follows: 0.77 (p < 0.001), 0.77 (p < 0.001), and 0.50 (p = 0.018).