National Allergy Research Centre, Department of Dermatology and Allergy, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark; Department of Dermatology and Allergy, Herlev and Gentofte Hospital, University of Copenhagen, Hellerup, Denmark.
Department of Epidemiology Research, Statens Serum Institut, Copenhagen, Denmark.
J Allergy Clin Immunol. 2017 May;139(5):1568-1574.e1. doi: 10.1016/j.jaci.2016.11.021. Epub 2016 Dec 23.
Atopic dermatitis (AD) appears to be more common in regions with hard domestic water and in children with a fall/winter birth. However, it is unknown whether a synergistic effect exists.
We sought to evaluate the association between domestic water hardness and season of birth, respectively, with onset of AD within the first 18 months of life in a large Danish birth cohort.
Of children from the Danish National Birth Cohort, 52,950 were included. History of physician-diagnosed AD and population characteristics were obtained from interviews. Birth data were obtained from the Civil Registration System, and domestic water hardness data were obtained from the Geological Survey of Denmark and Greenland. The relative prevalence (RP) of AD was calculated by using log-linear binomial regression.
The prevalence of AD was 15.0% (7,942/52,950). The RP of AD was 5% (RP, 1.05; 95% CI, 1.03-1.07) higher for each 5° increase in domestic water hardness (range, 6.60-35.90 German degrees of hardness [118-641 mg/L]). Although the RP of AD was higher in children with a fall (RP, 1.24; 95% CI, 1.17-1.31) or winter (RP, 1.18; 95% CI, 1.11-1.25) birth, no significant interaction was observed with domestic water hardness. The population attributable risk of hard domestic water on AD was 2%.
We observed that early exposure to hard domestic water and a fall/winter birth was associated with an increase in the relative prevalence of AD within the first 18 months of life. Although the 2 exposures did not interact synergistically, a dose-response relationship was observed between domestic water hardness and AD.
特应性皮炎（AD）似乎在硬水地区和秋冬季节出生的儿童中更为常见。然而，目前尚不清楚是否存在协同作用。
我们旨在评估在丹麦大型出生队列中，硬水家庭用水和出生季节与 18 个月内 AD 发病的相关性。
研究纳入了丹麦国家出生队列中的 52950 名儿童。通过访谈获得了 AD 的医生诊断史和人口统计学特征，从民事登记系统获取了出生数据，并从丹麦和格陵兰地质调查局获取了家庭用水硬度数据。采用对数线性二项式回归计算 AD 的相对患病率（RP）。
AD 的患病率为 15.0%（7942/52950）。家庭用水硬度每增加 5°，AD 的 RP 增加 5%（RP，1.05；95%CI，1.03-1.07）（范围，6.60-35.90 德国度硬度[118-641mg/L]）。虽然秋季（RP，1.24；95%CI，1.17-1.31）或冬季（RP，1.18；95%CI，1.11-1.25）出生的儿童 AD 的 RP 更高，但未观察到与家庭用水硬度的显著交互作用。硬水对 AD 的人群归因风险为 2%。
我们发现，早期暴露于硬水家庭用水和秋冬季节出生与 18 个月内 AD 的相对患病率增加有关。尽管这两种暴露没有协同作用，但家庭用水硬度与 AD 之间存在剂量-反应关系。
