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

<b><i>Background/Aims: </i></b>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. <b><i>Methods: </i></b>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. <b><i>Results: </i></b>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 &lt; 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. <b><i>Conclusion: </i></b>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）风险相关性的研究结论仍未达成一致。本研究采用Meta分析（meta-analysis）方法，旨在探讨维生素D状态与膀胱癌风险之间的关联。
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。检索词包括维生素D、25-羟维生素D（25-hydroxyvitamin D）、膀胱癌（bladder cancer）或膀胱癌，以获取符合纳入标准的相关研究。本研究的暴露因素为维生素D摄入或血清维生素D水平，结局指标为膀胱癌发病率或死亡率。通过Meta分析计算合并风险比（risk ratio, RR）及其95%置信区间（95%CI）。
结果：最终共有7项符合纳入标准的研究被纳入本Meta分析，累计纳入62141名研究对象。纳入研究间无明显异质性（I²=0%，P=0.53）。维生素D最低暴露组相较于最高暴露组的膀胱癌合并RR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结果显示，所有合并RR均具有统计学意义。针对5项报告血清维生素D水平相关结局的研究进行的Meta分析结果同样表明，低血清维生素D水平与膀胱癌风险升高相关（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：本研究结果显示，维生素D缺乏与膀胱癌风险升高存在相关性。