Schrock Joshua M, Sugiyama Lawrence S, Naidoo Nirmala, Kowal Paul, Snodgrass J Josh
Institute for Sexual and Gender Minority Health and Wellbeing, Northwestern University, 625 N Michigan Avenue, Suite 14, Chicago, IL 60611, USA.
Department of Anthropology, Northwestern University, 1810 Hinman Avenue, Evanston, IL 60208, USA.
Evol Med Public Health. 2022 Apr 11;10(1):156-169. doi: 10.1093/emph/eoac011. eCollection 2022.
Human susceptibility to chronic non-communicable disease may be explained, in part, by mismatches between our evolved biology and contemporary environmental conditions. Disease-induced fatigue may function to reduce physical activity during acute infection, thereby making more energy available to mount an effective immune response. However, fatigue in the context of chronic disease may be maladaptive because long-term reductions in physical activity increase risks of disease progression and the acquisition of additional morbidities. Here, we test whether cumulative chronic morbidity is associated with subjective fatigue.
We constructed a cumulative chronic morbidity score using self-reported diagnoses and algorithm-based assessments, and a subjective fatigue score based on four questionnaire items using cross-sectional survey data from the Study on global AGEing and adult health, which features large samples of adults from six countries (China, Ghana, India, Mexico, Russia and South Africa).
In a mixed-effects linear model with participants nested in countries ( = 32 455), greater cumulative chronic morbidity is associated with greater subjective fatigue ( = 0.34, SE = 0.005, < 2e-16). This association replicates within each country and is robust to adjustment for key sociodemographic and physical covariates (sex, age, household wealth, physical function score, habitual physical activity, BMI and BMI).
Fatigue is a common but perhaps maladaptive neuropsychological response to chronic morbidity. Disease-induced fatigue may mediate a self-perpetuating cycle, in which chronic morbidity reduces physical activity, and less physical activity increases cumulative chronic morbidity. Longitudinal research is needed to test whether chronic morbidity, fatigue and physical activity form a cyclical feedback loop. Fatigue during acute illness may promote recovery, but persistent fatigue in the context of chronic disease may make matters worse. We present evidence from six countries that more chronic disease is associated with more fatigue. This fatigue may reduce physical activity, which increases risks of acquiring additional chronic health problems.
人类对慢性非传染性疾病的易感性，部分原因可能是我们进化而来的生物学特性与当代环境条件不匹配。疾病引发的疲劳可能在急性感染期间起到减少身体活动的作用，从而使更多能量可用于产生有效的免疫反应。然而，慢性病背景下的疲劳可能具有适应不良性，因为身体活动的长期减少会增加疾病进展和患上其他疾病的风险。在此，我们测试累积慢性发病率是否与主观疲劳相关。
我们利用自我报告的诊断结果和基于算法的评估构建了一个累积慢性发病率评分，并基于来自全球老龄化与成人健康研究的横断面调查数据中四个问卷项目构建了一个主观疲劳评分，该研究涵盖了来自六个国家（中国、加纳、印度、墨西哥、俄罗斯和南非）的大量成年人样本。
在一个将参与者嵌套在国家中的混合效应线性模型（n = 32455）中，更高的累积慢性发病率与更高的主观疲劳相关（β = 0.34，标准误 = 0.005，P < 2e - 16）。这种关联在每个国家内部都得到了重复，并且在对关键社会人口统计学和身体协变量（性别、年龄、家庭财富、身体功能评分、习惯性身体活动、体重指数和体重指数）进行调整后仍然稳健。
疲劳是对慢性疾病常见但可能适应不良的神经心理反应。疾病引发的疲劳可能介导一个自我延续的循环，其中慢性疾病会减少身体活动，而较少的身体活动又会增加累积慢性发病率。需要进行纵向研究来测试慢性疾病、疲劳和身体活动是否形成一个循环反馈回路。急性疾病期间的疲劳可能促进康复，但慢性病背景下的持续疲劳可能会使情况更糟。我们提供了来自六个国家的证据，表明更多的慢性疾病与更多的疲劳相关。这种疲劳可能会减少身体活动，从而增加患上其他慢性健康问题的风险。
