Department of Medicine, Dalhousie Medicine New Brunswick & Dalhousie University, Saint John, New Brunswick, Canada.
Department of Medicine, Division of Physical Medicine & Rehabilitation, University of Toronto, Toronto, Ontario, Canada.
Am J Ind Med. 2023 Jul;66(7):610-619. doi: 10.1002/ajim.23477. Epub 2023 Apr 5.
With rising temperature extremes, older workers are becoming increasingly vulnerable to heat-related injuries because of age- and disease-associated decrements in thermoregulatory function. Endothelial monocyte-activating polypeptide-II (EMAP-II) is a proinflammatory cytokine that has not yet been well-characterized during heat stress, and which may mediate the inflammatory response to high levels of physiological strain.
We evaluated serum EMAP-II concentrations before and after 180 min of moderate-intensity work (200 W/m ) in temperate (wet-bulb globe temperature [WBGT] 16°C) and hot (WBGT 32°C) environments in heat-unacclimatized, healthy young (n = 13; mean [SD]; 22 [3] years) and older men (n = 12; 59 [4] years), and unacclimatized older men with hypertension (HTN) (n = 10; 60 [4] years) or type 2 diabetes (T2D) (n = 9; 60 [5] years). Core temperature and heart rate were measured continuously.
In the hot environment, work tolerance time was lower in older men with HTN and T2D compared to healthy older men (both p < 0.049). While core temperature and heart rate reserve increased significantly (p < 0.001), they did not differ across groups. End-exercise serum EMAP-II concentrations were higher in young men relative to their older counterparts due to higher baseline levels (both p ≤ 0.02). Elevations in serum EMAP-II concentrations were similar between healthy older men and older men with HTN, while serum EMAP-II concentrations did not change in older men with T2D following prolonged work in the heat.
Serum EMAP-II concentrations increased following prolonged moderate-intensity work in the heat and this response is influenced by age and the presence of HTN or T2D.
随着极端温度的上升，由于年龄和疾病相关的体温调节功能下降，老年工人越来越容易受到与热有关的伤害。内皮细胞单核细胞激活肽-II（EMAP-II）是一种促炎细胞因子，在热应激期间尚未得到很好的描述，它可能介导对高水平生理应激的炎症反应。
我们评估了未适应热环境的健康年轻男性（n=13；平均[标准差]；22[3]岁）和老年男性（n=12；59[4]岁），以及未适应热环境的老年男性高血压（HTN）（n=10；60[4]岁）或 2 型糖尿病（T2D）（n=9；60[5]岁）在温和强度工作（200W/m）180 分钟前后，在温带（湿球温度球温度[WBGT]16°C）和炎热（WBGT 32°C）环境下的血清 EMAP-II 浓度。连续测量核心温度和心率。
在炎热的环境中，患有 HTN 和 T2D 的老年男性的工作耐受时间明显低于健康的老年男性（均 p<0.049）。虽然核心温度和心率储备显著增加（p<0.001），但它们在各组之间没有差异。由于基线水平较高，年轻男性的血清 EMAP-II 浓度相对其老年男性的血清 EMAP-II 浓度更高（均 p≤0.02）。健康老年男性和 HTN 老年男性的血清 EMAP-II 浓度升高相似，而 T2D 老年男性在炎热环境中长时间工作后，血清 EMAP-II 浓度没有变化。
在炎热环境中进行长时间的中度强度工作后，血清 EMAP-II 浓度升高，而这种反应受年龄和 HTN 或 T2D 的影响。
