Department of Preventive Medicine and Public Health, School of Medicine, Universidad Autónoma de Madrid/ IdiPAZ, Madrid, Spain; CIBER of Epidemiology and Public Health (CIBERESP), Madrid, Spain; Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA.
Department of Environmental Health Sciences, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA; Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA; Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD, USA.
Environ Res. 2015 Feb;137:424-31. doi: 10.1016/j.envres.2015.01.013. Epub 2015 Jan 24.
Environmental lead and cadmium exposure is associated with higher risk of several age-related chronic diseases, including cardiovascular disease, chronic kidney disease and osteoporosis. These diseases may lead to frailty, a geriatric syndrome characterized by diminished physiologic reserve in multiple systems with decreased ability to cope with acute stressors. However, no previous study has evaluated the association between lead or cadmium exposure and frailty.
Cross-sectional study among individuals aged ≥ 60 years who participated in the third U.S. National Health and Nutrition Examination Survey and had either blood lead (N=5272) or urine cadmium (N=4887) determinations. Frailty was ascertained with a slight modification of the Fried criteria, so that individuals meeting ≥ 3 of 5 pre-defined criteria (exhaustion, low body weight, low physical activity, weakness and slow walking speed), were considered as frail. The association between lead and cadmium with frailty was evaluated using logistic regression with adjustment for relevant confounders.
Median (intertertile range) concentrations of blood lead and urine cadmium were 3.9 µg/dl (2.9-4.9) and 0.62 µg/l (0.41-0.91), respectively. The prevalence of frailty was 7.1%. The adjusted odds ratios (95% confidence interval) of frailty comparing the second and third to the lowest tertile of blood lead were, respectively, 1.40 (0.96-2.04) and 1.75 (1.33-2.31). Lead concentrations were also associated with the frequency of exhaustion, weakness and slowness. The corresponding odds ratios (95% confidence interval) for cadmium were, respectively, 0.97 (0.68-1.39) and 1.55 (1.03-2.32), but this association did not hold after excluding participants with reduced glomerular filtration rate: 0.70 (0.43-1.14) and 1.09 (0.56-2.11), respectively.
In the US older adult population, blood lead but not urine cadmium concentrations showed a direct dose-response relationship with frailty. These findings support that lead exposure increases frailty in older adults.
环境铅和镉暴露与多种与年龄相关的慢性疾病的风险增加有关，包括心血管疾病、慢性肾脏病和骨质疏松症。这些疾病可能导致虚弱，这是一种老年综合征，其特征是多个系统的生理储备减少，应对急性应激的能力下降。然而，以前没有研究评估过铅或镉暴露与虚弱之间的关系。
横断面研究纳入了参加第三次美国国家健康和营养调查且有血铅（N=5272）或尿镉（N=4887）测定值的年龄≥60 岁的个体。通过对弗莱德标准进行轻微修改来确定虚弱，即符合≥5 项预先定义标准中的 3 项（疲劳、低体重、低体力活动、虚弱和缓慢行走速度）的个体被认为是虚弱。使用逻辑回归评估铅和镉与虚弱之间的关联，并调整相关混杂因素。
血铅和尿镉的中位数（四分位距）浓度分别为 3.9µg/dl（2.9-4.9）和 0.62µg/l（0.41-0.91），虚弱的患病率为 7.1%。与血铅最低三分位相比，第二三分位和第三三分位的虚弱调整比值比（95%置信区间）分别为 1.40（0.96-2.04）和 1.75（1.33-2.31）。铅浓度也与疲劳、虚弱和缓慢的发生频率有关。镉对应的比值比（95%置信区间）分别为 0.97（0.68-1.39）和 1.55（1.03-2.32），但排除肾小球滤过率降低的参与者后，这种关联不再成立：分别为 0.70（0.43-1.14）和 1.09（0.56-2.11）。
在美国老年人群中，血铅浓度而非尿镉浓度与虚弱呈直接剂量-反应关系。这些发现支持铅暴露会增加老年人的虚弱。
