Bryce Carl
Nellis Family Medicine Residency, 4700 N Las Vegas Blvd, Nellis Air Force Base, NV 89191.
Mil Med. 2018 Mar 1;183(suppl_1):547-551. doi: 10.1093/milmed/usx152.
Greater serum levels and dietary intake of vitamin D have been inversely associated with the risk of multiple cancers including colon cancer. Most colorectal cancers are thought to arise from adenomatous polyps, which become dysplastic under the influence of numerous factors. Prospective data are needed to distinguish between association or a causative role of vitamin D in the pathogenesis of colorectal cancer.
A prospective cohort study was designed, located at a hospital-based screening colonoscopy referral center, including Department of Defense beneficiaries aged 18 yr or older. A serum 25-hydroxyvitamin D level was drawn, and colonoscopy findings were recorded. A power calculation using p = 0.8, alpha = 0.05 generated a necessary sample size of n = 224 to detect an association between vitamin D level and adenomatous polyp. Unconditional multivariable logistic regression modeling was used to evaluate associations between outcomes, adjusted for known risk factors.
Of final population (n) = 228, 155 (68%) were diagnosed with vitamin D insufficiency (<30 ng/mL) and 104 (46%) were found to have adenomatous polyps. Adjusted odds ratio for adenomatous colon polyp given vitamin D <30 ng/mL = 1.16 (95% CI 0.57-2.36).
Serum vitamin D level was not associated with increased adenomatous polyp detection at screening colonoscopy in this population.
血清维生素D水平升高及饮食中维生素D摄入量增加与包括结肠癌在内的多种癌症风险呈负相关。大多数结直肠癌被认为起源于腺瘤性息肉，在多种因素影响下会发生发育异常。需要前瞻性数据来区分维生素D在结直肠癌发病机制中的关联作用或因果作用。
设计了一项前瞻性队列研究，地点为一家以医院为基础的结肠镜筛查转诊中心，纳入年龄在18岁及以上的国防部受益人。检测血清25-羟维生素D水平，并记录结肠镜检查结果。使用p = 0.8、α = 0.05进行功效计算，得出检测维生素D水平与腺瘤性息肉之间关联所需的样本量n = 224。采用无条件多变量逻辑回归模型评估结局之间的关联，并对已知风险因素进行校正。
在最终的228名研究对象中，155名（68%）被诊断为维生素D不足（<30 ng/mL），104名（46%）发现有腺瘤性息肉。维生素D<30 ng/mL时腺瘤性结肠息肉的校正比值比为1.16（95%置信区间0.57 - 2.36）。
在该人群中，血清维生素D水平与结肠镜筛查时腺瘤性息肉检出率增加无关。
