Erratum: Vitamin D Deficiency and Increased Risk of Bladder Carcinoma: A Meta-Analysis

Background/Aims: Vitamin D status in relation to bladder carcinoma risk was still inconsistent. This study was carried out to evaluate the relationship between vitamin D status and bladder carcinoma risk through a meta-analysis approach. Methods: Pubmed, Web of Science, CNKI, and Embase were searched systemically to find eligible studies from the earliest available date to April 16, 2015. The search terms “vitamin D”, “25-hydroxyvitamin D”, “bladder cancer” or “bladder carcinoma” were used to retrieve relevant studies. The exposure of interest was intake of vitamin D or serum vitamin D levels, and the outcome of interest was bladder carcinoma incidence or mortality. The pooled risk ratio (RR) values and their 95%CIs were calculated through meta-analysis. Results: Seven studies with a total of 62,141 participants met the inclusion criteria and were finally included into the meta-analysis. There was no heterogeneity among those included studies (I2 = 0%, P = 0.53). The pooled RR of bladder carcinoma for the lowest category versus the highest category of vitamin D was 1.34 (95% CI 1.17-1.53, P < 0.0001). Sensitivity analysis by omitting one study by turns showed all the pooled RRs were statistically significant. Meta-analysis of 5 studies reporting outcomes of serum vitamin D levels also showed that the low serum vitamin D level was associated with increased risk of bladder carcinoma (RR = 1.32, 95%CI 1.15-1.52, P = 0.0001). No obvious risk of publication bias was observed. Conclusion: Vitamin D deficiency is associated with increased risk of bladder carcinoma in present study.

背景/目的：目前关于维生素D（vitamin D）状态与膀胱癌（bladder carcinoma）发病风险的关联研究结论尚未达成一致。本研究旨在通过荟萃分析（meta-analysis）方法，探讨维生素D状态与膀胱癌发病风险之间的相关性。
方法：系统检索PubMed、Web of Science、中国知网（CNKI）及Embase数据库，检索时限为各数据库建库至2015年4月16日。检索词包括"vitamin D"、"25-hydroxyvitamin D（25-羟维生素D）"、"bladder cancer（膀胱癌）"或"bladder carcinoma（膀胱癌）"。本研究的暴露因素为维生素D摄入或血清维生素D水平，结局指标为膀胱癌的发病率或死亡率。通过荟萃分析计算合并相对危险度（RR，risk ratio）及其95%置信区间（95%CI）。
结果：共计7项符合纳入标准的研究被纳入本次荟萃分析，累计纳入受试者62141例。纳入研究间无显著异质性（I²=0%，P=0.53）。维生素D最低暴露组对比最高暴露组的膀胱癌合并相对危险度为1.34（95%CI：1.17~1.53，P<0.0001）。逐一剔除单项研究的敏感性分析显示，所有合并RR均具有统计学显著性。针对5项报告血清维生素D水平相关结局的研究进行亚组荟萃分析，结果同样表明低血清维生素D水平与膀胱癌发病风险升高相关（RR=1.32，95%CI：1.15~1.52，P=0.0001）。未观察到明显的发表偏倚风险。
结论：本研究结果证实，维生素D缺乏与膀胱癌发病风险升高存在显著关联。