Applied Physiology and Wellness, Southern Methodist University, Dallas, TX.
Department of Health Sciences, Boston University, Boston, MA.
Med Sci Sports Exerc. 2019 Mar;51(3):395-404. doi: 10.1249/MSS.0000000000001821.
Impairments in sudomotor function during passive whole-body heating have been reported in multiple sclerosis (MS), a demyelinating disease of the CNS that disrupts autonomic function. However, the capability of the thermoregulatory system to control body temperature during exercise has never been assessed in MS. Thus, the aim of the present study was to test the hypothesis that thermoregulatory function is impaired in MS patients compared with healthy controls (CON) exercising at similar rates of metabolic heat production.
Sweating and skin blood flow responses were compared between 12 individuals diagnosed with relapsing-remitting MS (9 females, 3 males) and 12 sex-, age-, mass-, and BSA-matched CON during a single bout of cycling exercise (rate of metabolic heat production: ∼4.5 W·kg) for 60 min in a climate-controlled room (25°C, 30% RH).
Individuals with MS exhibited an attenuated increase in cumulative whole-body sweat loss after 30 min (MS, 72 ± 51 g; CON, 104 ± 37 g; P = 0.04) and 60 min (MS, 209 ± 94 g; CON, 285 ± 62 g; P = 0.02), as well as lower sweating thermosensitivity (MS, 0.49 ± 0.26 mg·cm·min·°C; CON, 0.86 ± 0.30 mg·cm·min·°C; P = 0.049). Despite evidence for thermoregulatory dysfunction, there were no differences between MS and CON in esophageal or rectal temperatures at 30- or 60-min time points (P > 0.05). Cutaneous vasculature responses were also not different in MS compared with CON (P > 0.05).
Taken together, MS blunts sweating responses during exercise while cutaneous vasculature responses are preserved. Altered mechanisms of body temperature regulation in persons with MS may lead to temporary worsening of disease symptoms and limit exercise tolerance under more thermally challenging conditions.
在多发性硬化症（MS）中，已经报道了被动全身加热期间的出汗功能障碍，这是一种中枢神经系统脱髓鞘疾病，会破坏自主功能。然而，在 MS 患者中，体温调节系统在运动期间控制体温的能力从未得到评估。因此，本研究的目的是检验以下假设，即在以相似代谢产热率进行运动时，MS 患者的体温调节功能受损。
在气候控制室内（25°C，30%RH），12 名确诊为复发性缓解型 MS（9 名女性，3 名男性）患者和 12 名性别、年龄、体重和体表面积匹配的对照组（CON）进行了单次 60 分钟的踏车运动（代谢产热率：约 4.5 W·kg），比较了出汗和皮肤血流反应。
MS 患者在 30 分钟后（MS，72 ± 51 g；CON，104 ± 37 g；P = 0.04）和 60 分钟后（MS，209 ± 94 g；CON，285 ± 62 g；P = 0.02）的全身总汗损失累积增加幅度较小，并且出汗热敏性较低（MS，0.49 ± 0.26 mg·cm·min·°C；CON，0.86 ± 0.30 mg·cm·min·°C；P = 0.049）。尽管存在体温调节功能障碍的证据，但在 30 分钟和 60 分钟的时间点，MS 和 CON 之间的食管或直肠温度均无差异（P > 0.05）。与 CON 相比，MS 患者的皮肤血管反应也没有差异（P > 0.05）。
总之，MS 患者在运动期间出汗反应减弱，而皮肤血管反应保持不变。MS 患者体温调节机制的改变可能导致疾病症状暂时恶化，并在更热的环境下限制运动耐受能力。
