Kravietz Adam, Kab Sofiane, Wald Lucien, Dugravot Aline, Singh-Manoux Archana, Moisan Frédéric, Elbaz Alexis
University of Miami Miller School of Medicine, Miami, Florida, USA.
Santé publique France, Direction santé travail, F-94415 Saint-Maurice, France; CESP, Fac. de médecine - Univ. Paris-Sud, Fac. de médecine - UVSQ, INSERM, Université Paris-Saclay, 94805 Villejuif, France.
Environ Res. 2017 Apr;154:50-56. doi: 10.1016/j.envres.2016.12.008. Epub 2016 Dec 26.
Vitamin D is thought to contribute to brain health, but it is unclear whether low vitamin D levels are associated with increased incidence of Parkinson's disease (PD). Using ultraviolet B (UV-B) as a surrogate for vitamin D levels, we conducted a nationwide ecologic study in France in order to examine the association of UV-B with PD incidence.
We used French national drug claims databases to identify PD cases using a validated algorithm. UV-B data from the solar radiation database were derived from satellite images. We estimated PD incidence (2010-2012) at the canton level (small administrative French unit) and used multilevel Poisson regression to examine its association with UV-B (2005 annual average), after adjustment for age, sex, deprivation index, density of neurologists, smoking, proportion of agricultural land, and vitamin D supplementation.
Analyses are based on 69,010 incident PD patients. The association between UV-B and PD incidence was quadratic (P<0.001) and modified by age (P<0.001). Below 70y, incidence was higher in the bottom quintile (relative risk, RR=1.18, 95% CI=1.08-1.29) compared with the middle UV-B quintile, and lower in the top quintile (RR=0.85 [0.77-0.94]). An opposite pattern was observed in older subjects (RR=0.92 [0.89-0.96]; RR=1.06 [1.02-1.11]). Analysis based on continuous UV-B yielded similar conclusions.
In this nationwide study, there was an age-dependent quadratic association between UV-B and PD incidence. This study suggests that reasonable UV-B exposure is associated with lower PD risk in younger persons and that future studies should examine dose-response relations and take age into account.
维生素D被认为对大脑健康有益，但尚不清楚低维生素D水平是否与帕金森病（PD）发病率增加有关。我们以紫外线B（UV-B）作为维生素D水平的替代指标，在法国进行了一项全国性生态研究，以探讨UV-B与PD发病率之间的关联。
我们使用法国国家药物报销数据库，通过经过验证的算法识别PD病例。太阳辐射数据库中的UV-B数据来自卫星图像。我们估计了县级（法国小行政单位）的PD发病率（2010 - 2012年），并在调整年龄、性别、贫困指数、神经科医生密度、吸烟、农业用地比例和维生素D补充剂后，使用多水平泊松回归分析其与UV-B（2005年年均值）的关联。
分析基于69,010例新发PD患者。UV-B与PD发病率之间的关联呈二次曲线关系（P<0.001），并受年龄影响（P<0.001）。70岁以下人群中，UV-B最低五分位数组的发病率高于中间五分位数组（相对风险，RR = 1.18，95%可信区间 = 1.08 - 1.29），而最高五分位数组的发病率较低（RR = 0.85 [0.77 - 0.94]）。在老年受试者中观察到相反的模式（RR = 0.92 [0.89 - 0.96]；RR = 1.06 [1.02 - 1.11]）。基于连续UV-B的分析得出了类似结论。
在这项全国性研究中，UV-B与PD发病率之间存在年龄依赖性二次曲线关联。这项研究表明，合理的UV-B暴露与年轻人较低的PD风险相关，未来的研究应考察剂量反应关系并考虑年龄因素。
