The role of androgens on experimental pain sensitivity: a systemic review and meta-analysis.

Animal studies have shown androgens, especially testosterone, may have an analgesic effect on nociceptive behavior. However, it is unclear if this effect is present in humans. This review and meta-analysis aim to summarize and synthesize the role of androgens on experimental pain sensitivity in humans. Studies were included if they examined the (1) relationships between androgens and experimental pain sensitivity, (2) group differences in androgen or pain levels, and (3) the effect of androgen interventions on experimental pain sensitivity. After a comprehensive search, 31 papers were identified. When possible, meta-analyses were performed. Most studies examined the impact of testosterone on experimental pain, and only a few studies focused on other androgens, such as dehydroepiandrosterone and dehydroepiandrosterone sulfate. Overall, the current data do not support the effect of androgens on experimental pain sensitivity in adult men and women with or without chronic pain. In addition, meta-analyses of Pearson correlations did not find relationships between testosterone levels and pain ratings of heat stimulus (3 studies, n = 93, Z correlation coefficient = -0.43, confidence intervals [-1.50, 0.64]) or electrical pain thresholds (4 studies, n = 147, Z correlation coefficient = 0.24, confidence intervals [-0.10, 0.58]). Moreover, contradicting results were found in intervention studies that increased or decreased testosterone levels. Thus, it is suggested that the role of testosterone on experimental pain sensitivity may be minor, even though there is a wide heterogeneity between studies. Future studies should examine the impact of other androgens and the interaction between testosterone and other hormones on experimental pain sensitivity.