Metformin increases pressure pain threshold in lean women with polycystic ovary syndrome

Abstract

BackgroundDespite the strong preclinical rationale, there are only very few data considering the utility of metformin as a potential pain therapeutic in humans. The aim of this study was to determine the association between metformin therapy and pressure pain threshold (PPT) in lean women with polycystic ovary syndrome (PCOS). We hypothesized that metformin therapy in lean PCOS women increases PPT.Materials and methodsTwenty-seven lean PCOS women with free androgen index phenotype >5 and 18 lean healthy controls were enrolled in the study. Fifteen of the PCOS women were randomly assigned to be treated with metformin 1,500 mg daily for 6 months. PPT and plasma β-endorphin levels were measured in all women at the beginning of the study and after 6 months of observation.ResultsWe observed an increase in PPT values measured on deltoid and trapezius muscle in the PCOS with metformin group after 6 months of metformin administration (4.81±0.88 kg/cm2, P<0.001 on deltoid muscle, and 5.71±1.16 kg/cm2 on trapezius muscle). We did not observe any significant changes in PPT values in the PCOS without treatment group and in controls. We did not observe any significant changes in serum β-endorphin levels in any studied groups during the 6-month observation.ConclusionWe conclude that metformin therapy increases PPT in lean PCOS women, without affecting plasma β-endorphin concentration. Our results may suggest the potential role of metformin in pain therapy. We propose that larger, randomized studies on metformin impact on pain perception should be performed.

Antihyperalgesic Effects of Indomethacin, Ketorolac, and Metamizole in Rats: Effects of Metformin

“…Accordingly, metformin has been shown to have antinociceptive properties in different models of inflammatory pain [Russe et al, 2013;Pecikoza et al, 2016] and diabetic neuropathic pain [Melemedjian et al, 2011;Byrne et al, 2015;Ma et al, 2015;Huang et al, 2016]. The analgesic effect of metformin has also been described in humans [Taylor et al, 2013;Kialka et al, 2016]. In our study, we did not observe any antihyperalgesic effect of metformin after local administration (800 mg/paw).…”

Metformin Inhibits Prostate Cancer Progression by Targeting Tumor-Associated Inflammatory Infiltration

“…However, results from different studies are kind of controversial. Multiple lines of evidence indicate that metformin possesses antinociceptive properties in different models of inflammatory pain (53) and diabetic neuropathic pain (54), as well as in humans (55). However, a more recent study using carrageenan-induced thermal hyperalgesia animal model did not observe any antihyperalgesic effect when metformin is either locally (800 mg/paw) or systemically administered (200 mg/kg; ref.…”

Pharmacological activation of AMPK inhibits incision-evoked mechanical hypersensitivity and the development of hyperalgesic priming in mice

“…A previous study suggested that metformin may be effective for low back pain (Taylor et al, 2013) but a subsequent retrospective study did not find a positive effect for metformin in pain patients (Smith and Ang, 2015). The first prospective study of metformin for pain was recently conducted in women with polycystic ovary syndrome (Kialka et al, 2016). This study found a positive effect of metformin on pressure pain thresholds.…”