Background

Selenium (Se) is a trace element with a narrow safety margin.

Objectives

To evaluate the cross-sectional and longitudinal dose-response association between Se exposure and measures of impaired physical function and disability in older adults.

Design

NHANES 2011–2014 cross-sectional (US, n = 1733, age ≥60 years) and Seniors-ENRICA-2 2017–2019 cross-sectional and longitudinal (Spain, n = 2548 and 1741, respectively, age ≥65 years) data were analyzed. Whole blood and serum Se levels were measured using inductively coupled plasma-mass spectrometry. Lower-extremity performance was assessed with the Short Physical Performance Battery, and muscle weakness with a dynamometer. Incident mobility and agility limitations, and disability in instrumental activities of daily living (IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders, including physical activity. Results across studies were pooled using random-effects meta-analysis.

Results

Meta-analyzed odds ratios (95% confidence interval) per log2 increase in whole blood Se were 0.54 (0.32; 0.76) for weakness, 0.59 (0.34; 0.83) for impaired lower-extremity performance, 0.48 (0.31; 0.68) for mobility limitations, 0.71 (0.45; 0.97) for agility limitations, and 0.34 (0.12; 0.56) for disability in at least one IADL. Analyses for serum Se in NHANES showed similar results. Findings suggest the inverse association with grip strength is progressive below 140 μg/L (p-value for non-linear trend in the Seniors-ENRICA-2 study = 0.13), and above 140 μg/L (p-value for non-linear trend in NHANES = 0.11). In the Seniors-ENRICA-2 cohort, with a 2.2 year follow-up period, a doubling in baseline Se levels were associated with a lower incidence of weakness [odds ratio (95% confidence interval): 0.45 (0.22; 0.91)], impaired lower-extremity performance [0.63 (0.32; 1.23)], mobility [0.43 (0.21; 0.91)] and agility [0.38 (0.18; 0.78)] limitations.

Discussion

In US and Spanish older adults, Se concentrations were inversely associated with physical function limitations. Further studies are needed to elucidate underlying mechanisms.

中文翻译：

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美国和西班牙老年人的硒和身体机能受损

背景

硒（Se）是微量元素，其安全裕度很窄。

目标

为了评估硒暴露与老年人身体机能和残疾受损的量度之间的横向和纵向剂量反应关系。

设计

NHANES 2011-2014年横断面（美国，n = 1733，年龄≥60岁）和Seniors-ENRICA-2 2017-2019年横断面和纵向（西班牙，n分别为2548和1741，年龄≥65岁）数据被分析。使用感应耦合等离子体质谱法测量全血和血清硒水平。下肢表现用“短物理表现电池”进行评估，肌肉无力通过测力计进行评估。使用标准调查表确定了事件的活动性和敏捷性限制以及日常生活中的工具活动中的残障（IADL）。针对相关混杂因素（包括体育锻炼）对分析进行了调整。使用随机效应荟萃分析汇总研究的结果。

结果

对全血Se的每log2增加进行荟萃分析的比值比（95％置信区间），虚弱情况为0.54（0.32; 0.76），下肢功能障碍的情况为0.59（0.34; 0.83），行动受限为0.48（0.31; 0.68） ，对于敏捷性限制为0.71（0.45; 0.97），对于至少一个IADL中的残疾为0.34（0.12; 0.56）。NHANES中血清硒的分析显示了相似的结果。研究结果表明，与抓地力的反相关在140μg/ L以下（老年人-ENRICA-2研究中非线性趋势的p值= 0.13）和140μg/ L以上（非线性p值）逐渐发展NHANES的趋势= 0.11）。在老年人（ENRICA-2）队列中，有2.2年的随访期，基线硒水平加倍与无力发生率降低相关[赔率（95％置信区间）：0.45（0.22; 0.91）]，

讨论区

在美国和西班牙老年人中，硒浓度与身体机能限制成反比。需要进一步研究以阐明潜在机制。