Department of Nutritional Sciences, Faculty of Health and Medical Sciences, University of Surrey, GuildfordGU2 7XH, UK.
Department of Audiology, School of Life and Health Sciences, Aston University, BirminghamB4 7ET, UK.
Br J Nutr. 2023 Mar 14;129(5):795-812. doi: 10.1017/S0007114522001441. Epub 2022 May 10.
Iodine, through the thyroid hormones, is required for the development of the auditory cortex and cochlea (the sensory organ for hearing). Deafness is a well-documented feature of endemic cretinism resulting from severe iodine deficiency. However, the range of effects of suboptimal iodine intake during auditory development on the hearing ability of children is less clear. We therefore aimed to systematically review the evidence for the association between iodine exposure (i.e. intake/status/supplementation) during development (i.e. pregnancy and/or childhood) and hearing outcomes in children. We searched PubMed and Embase and identified 330 studies, of which thirteen were included in this review. Only three of the thirteen studies were of low risk of bias or of good quality, this therefore limited our ability to draw firm conclusions. Nine of the studies (69 %) were in children (one RCT, two non-RCT interventions and six cross-sectional studies) and four (31 %) were in pregnant women (one RCT, one cohort study and two case reports). The RCT of iodine supplementation in mildly iodine-deficient pregnant women found no effect on offspring hearing thresholds. However, hearing was a secondary outcome of the trial and not all women were from an iodine-deficient area. Iodine supplementation of severely iodine-deficient children (in both non-RCT interventions) resulted in improved hearing thresholds. Five of six cross-sectional studies (83 %) found that higher iodine status in children was associated with better hearing. The current evidence base for the association between iodine status and hearing outcomes is limited and further good-quality research on this topic is needed.
碘通过甲状腺激素，是听觉皮层和耳蜗（听觉感官）发育所必需的。耳聋是由严重碘缺乏引起的地方性克汀病的一个有充分记录的特征。然而，在听觉发育过程中摄入不足的碘对儿童听力能力的影响范围尚不清楚。因此，我们旨在系统地回顾在儿童发育期间（即妊娠和/或儿童期）暴露于碘（即摄入/状态/补充）与儿童听力结果之间的关联的证据。我们在 PubMed 和 Embase 上进行了搜索，共确定了 330 项研究，其中 13 项研究纳入了本综述。这 13 项研究中只有 3 项的偏倚风险低或质量好，因此限制了我们得出明确结论的能力。9 项研究（69%）在儿童中进行（1 项 RCT、2 项非 RCT 干预和 6 项横断面研究），4 项（31%）在孕妇中进行（1 项 RCT、1 项队列研究和 2 项病例报告）。碘补充轻度碘缺乏孕妇的 RCT 发现对后代听力阈值没有影响。然而，听力是该试验的次要结果，并非所有女性都来自碘缺乏地区。严重碘缺乏儿童（两项非 RCT 干预）的碘补充导致听力阈值改善。6 项横断面研究中有 5 项（83%）发现儿童的碘状态越高，听力越好。目前，关于碘状态与听力结果之间关联的证据基础有限，需要进一步开展这一主题的高质量研究。
