Durazo-Arvizu Ramón A, Dawson-Hughes Bess, Kramer Holly, Cao Guichan, Merkel Joyce, Coates Paul M, Sempos Christopher T
Am J Epidemiol. 2017 Apr 15;185(8):720-726. doi: 10.1093/aje/kww244.
We evaluated the impact of standardizing the originally measured serum total 25-hydroxyvitamin D (25(OH)D) values from Third National Health and Nutrition Examination Survey (NHANES III, 1988-1994) on the association between 25(OH)D and rate of all-cause mortality. Values were standardized to the gold-standard laboratory method. Follow-up from 1990-2006 consisted of 15,099 participants aged at least 20 years at baseline, among whom there were 3,784 deaths. Relative risk of death was adjusted for age, sex, race/ethnicity, and season using Poisson regression. Results were obtained for eight 25(OH)D (nmol/L) categories: <20 nmol/L, 20-29 nmol/L, 30-39 nmol/L, 40-49 nmol/L, 50-59 nmol/L, 60-74 nmol/L, 75-99 nmol/L (reference), and ≥100 nmol/L. Assay standardization dramatically shifted original 25(OH)D values toward zero. Accordingly, risk ≥120 nmol/L could not be evaluated (i.e., n = 7 and ndeaths = 2). Relative risk (95% confidence interval (CI)) <40 nmol/L remained significant (30-39 nmol/L: relative risk (RR) = 1.4 (95% CI: 1.1, 1.6); 20-29 nmol/L: RR = 1.6 (95% CI: 1.3, 1.9), and <20 nmol/L: RR = 2.1 (95% CI: 1.6, 2.7). However, adjusted relative risk estimates for 25(OH)D levels ≥40 nmol/L were no longer significant (40-49 nmol/L: RR = 1.2 (95% CI: 0.99, 1.4); 50-59 nmol/L: RR = 1.2 (95% CI: 1.04, 1.4); 60-74 nmol/L: RR = 1.1 (95% CI: 0.94, 1.2); 75-99 nmol/L: RR = 1.0 (referent), and ≥100 nmol/L: RR = 1.1 (95% CI: 0.6, 2.1). In summary, after standardization, risk of death from all causes increased with decreasing 25(OH)D <40 nmol/L, while there was no association with values in categories between 40 nmol/L and 120 nmol/L.
我们评估了对第三次全国健康与营养检查调查（NHANES III，1988 - 1994年）中最初测量的血清总25 - 羟基维生素D（25(OH)D）值进行标准化，对25(OH)D与全因死亡率之间关联的影响。将这些值按照金标准实验室方法进行标准化。1990年至2006年的随访包括15099名基线年龄至少20岁的参与者，其中有3784人死亡。使用泊松回归对死亡相对风险进行年龄、性别、种族/族裔和季节的校正。针对八个25(OH)D（nmol/L）类别得出结果：<20 nmol/L、20 - 29 nmol/L、30 - 39 nmol/L、40 - 49 nmol/L、50 - 59 nmol/L、60 - 74 nmol/L、75 - 99 nmol/L（参考值）和≥100 nmol/L。检测标准化使原始25(OH)D值大幅向零偏移。因此，无法评估≥120 nmol/L的风险（即，n = 7且ndeaths = 2）。<40 nmol/L的相对风险（95%置信区间（CI））仍然显著（30 - 39 nmol/L：相对风险（RR）= 1.4（95% CI：1.1，1.6）；20 - 29 nmol/L：RR = 1.6（95% CI：1.3，1.9），以及<20 nmol/L：RR = 2.1（95% CI：1.6，2.7）。然而，25(OH)D水平≥40 nmol/L的校正相对风险估计不再显著（40 - 49 nmol/L：RR = 1.2（95% CI：0.99，1.4）；50 - 59 nmol/L：RR = 1.2（95% CI：1.04，1.4）；60 - 74 nmol/L：RR = 1.1（95% CI：0.94，1.2）；75 - 99 nmol/L：RR = 1.0（参考值），以及≥100 nmol/L：RR = 1.1（95% CI：0.6，2.1）。总之，标准化后，25(OH)D<40 nmol/L时全因死亡风险随其降低而增加，而40 nmol/L至120 nmol/L各类别值之间无关联。
