Shanghai Municipal Hospital of Traditional Chinese Medicine, Shanghai University of Traditional Chinese Medicine, No.274, Middle Zhijiang Road, Shanghai, 200071, China.
Shanghai University of Traditional Chinese Medicine, 1200 Cailun Road, Pudong New District, Shanghai, 201203, China.
J Transl Med. 2022 May 23;20(1):237. doi: 10.1186/s12967-022-03426-3.
Physical activity (PA) may protect against infertility by modulating the hypothalamic-pituitary-gonadal axis, thereby reducing gonadotropin levels, elevating immune function, and inhibiting inflammation and circulating sex hormones. However, whether PA reduces the risk of infertility remains largely unknown. We therefore conducted a systematic review and meta-analysis to determine the preventive effects of PA on infertility.
We searched PubMed, Cochrane Library, EMBASE, and CINAHL databases to retrieve published epidemiologic studies on the relationship between PA and infertility. Following the PRISMA guidelines, we selected English literature publishedprior to 11 April 2022, and assessed study quality using the Newcastle-Ottawa Scale. Our protocol, including the full methods employed for this review, is available on PROSPERO (ID = CRD42020143344).
Six cohort studies and four case-control studies based on 708,965 subjects and 12,580 cases were eventually screened and retained. High levels of PA were shown to reduced risk of infertility relative to low levels (cumulative relative risk [RR] = 0.59, with a 95% confidence interval CI 0.49-0.71), and we reported results for cohort studies (RR = 0.63, 95% CI 0.50-0.79) and case-control studies (RR = 0.49, 95% CI 0.35-0.67). Our findings were comparable for men (RR = 0.65, 95% CI 0.41-1.04) and women (RR = 0.56, 95% CI 0.47-0.66). The meta-analysis of six risk estimates from five studies of low, moderate, and high PA levels showed that moderate PA may also reduce the risk of infertility compared with low PA (RR = 0.54, 95% CI 0.38-0.77). However, high PA also appeared to slightly augment the risk of infertility compared with moderate PA (RR = 1.31, 95% CI 1.08-1.59).
This present systematic review comprehensively reflected an inverse relationship between different levels of PA and infertility, and our meta-analysis showed that a moderate-to-high PA level significantly reduced the overall risk of infertility, and that this level of PA activity was a common protective factor. In addition, limited evidence suggested that compliance with international PA guidelines would greatly lower the risk of infertility (RR = 0.58, 95% CI 0.45-0.74; I = 0.0%). Future studies, however, need to be executed to further determine the frequency, optimal dosage, and duration required to effectively attenuate the risk of infertility.
体力活动（PA）可能通过调节下丘脑-垂体-性腺轴来预防不孕，从而降低促性腺激素水平，提高免疫功能，并抑制炎症和循环性激素。然而，PA 是否降低不孕的风险在很大程度上尚不清楚。因此，我们进行了一项系统评价和荟萃分析，以确定 PA 对不孕的预防作用。
我们检索了 PubMed、Cochrane 图书馆、EMBASE 和 CINAHL 数据库，以检索关于 PA 与不孕之间关系的已发表的流行病学研究。根据 PRISMA 指南，我们选择了截至 2022 年 4 月 11 日之前发表的英文文献，并使用纽卡斯尔-渥太华量表评估了研究质量。我们的方案，包括本综述所采用的完整方法，可在 PROSPERO（ID = CRD42020143344）上获得。
最终筛选并保留了基于 708965 名受试者和 12580 例病例的 6 项队列研究和 4 项病例对照研究。高水平的 PA 与低水平的 PA 相比，降低了不孕的风险（累积相对风险 [RR] = 0.59，95%置信区间 CI 0.49-0.71），我们报告了队列研究（RR = 0.63，95%CI 0.50-0.79）和病例对照研究（RR = 0.49，95%CI 0.35-0.67）的结果。我们的发现对于男性（RR = 0.65，95%CI 0.41-1.04）和女性（RR = 0.56，95%CI 0.47-0.66）是可比的。五项关于低、中、高 PA 水平的研究的六个风险估计值的荟萃分析表明，与低 PA 相比，中 PA 也可能降低不孕的风险（RR = 0.54，95%CI 0.38-0.77）。然而，高 PA 与中 PA 相比，似乎也略微增加了不孕的风险（RR = 1.31，95%CI 1.08-1.59）。
本系统评价全面反映了不同水平的 PA 与不孕之间的反比关系，我们的荟萃分析表明，中高水平的 PA 显著降低了总体不孕风险，而这种水平的 PA 活动是一种常见的保护因素。此外，有限的证据表明，遵守国际 PA 指南将大大降低不孕的风险（RR = 0.58，95%CI 0.45-0.74；I = 0.0%）。然而，未来需要进行更多的研究，以进一步确定有效降低不孕风险所需的频率、最佳剂量和持续时间。
