The effect of bicycling on PSA levels: a systematic review and meta-analysis.

Abstract

Recent literature has suggested that bicycling may be associated with increases in serum PSA levels, a diagnostic and prognostic marker for prostate cancer. To further investigate this relationship, we conducted a systematic review and meta-analysis of current literature in this field. MEDLINE, CENTRAL, CINAHL and SPORTDiscus were searched using MeSH terms and keywords for English publications related to bicycle riding and PSA. Studies were included if PSA was measured relative to cycling activity in healthy men who were free of any prostatic condition. Case studies were excluded. Eight studies met our inclusion criteria, comprising 912 participants that engaged in, or self-reported, bicycling activity. Six studies investigated the acute pre-post change in PSA following bicycling activity that ranged from a single cycling bout of 15 min to a 4-day cycling event. Following cycling activity, two studies reported total PSA increased from baseline by up to 3.3-fold, free PSA increased in one study by 0.08±0.18 ng ml(-)(1) and did not change in four studies. One study compared PSA in elite/professional cyclists versus non-cyclists and demonstrated no significant difference in PSA measurements between groups. Data from six studies were meta-analyzed and demonstrated no significant increase in PSA associated with cycling from pre to post (mean change +0.027 ng ml(-)(1), s.e.m.=0.08, P=0.74, 95% confidence interval (CI)=-0.17-0.23). Our findings suggest that there is no effect of cycling on PSA; however, the limited number of trials and the absence of randomized controlled trials limit the interpretation of our results. Additionally, the median sample size only consisted of 42 subjects. Therefore, our study may have low statistical power to detect a difference in PSA. Although, a higher sample size may demonstrate statistical significance, it may not be clinically significant. Studies of higher empirical quality are needed.