The connection between stress and health issues is perhaps the best kept “public secret”. As the saying goes, the only people who do not believe in the pathology of stress are doctors…and the dead. I would add to this category the profession of statisticians who publish studies like the one below. Despite demonstrating “dose-dependent” relationship between the amount of hours people work per week and the severity of the resulting hypothyroidism, the authors of the study still refuse to suggest a cause-and-effect between stress from long work and the onset of hypothyroidism. If a rational argument can be made for the opposite hypothesis – i.e. people with hypothyroidism tend to work longer hours – then I am all ears. But the few doctors I contacted in regards to this study were at a loss of suggesting an alternative explanation and also think that long work hours (stress) are indeed a likely cause of hypothyroidism.
“…Increased weekly working hours are associated with a higher risk for hypothyroidism in workers with no evidence of thyroid autoimmunity, according to study results published in Thyroid. To determine if long work hours are associated with thyroid function, researchers conducted a cross-sectional study using data from 2160 South Korean adults (69.9% men). Individuals who had provided blood and urine samples, were working ≥36 hours per week and <12 hours per day, were not pregnant, did not have a history of thyroid disease, did not have a positive thyroid peroxidase antibody test, did not have isolated hypothyroidism or hyperthyroidism, and were not missing relevant data were included.”
“…There was a significant association between hypothyroidism and longer work hours per week, even after adjusting for all biological and lifestyle covariates (adjusted odds ratio [aOR], 1.46; 95% CI, 1.12-1.90) and excluding outliers in number of work hours per week (aOR, 1.99; 95% CI, 1.19-3.31) and individuals with overt thyroid dysfunction (aOR, 1.44; 95% CI, 1.11-1.88). Hyperthyroidism was not significantly associated with the number of hours worked per week. Moreover, hypothyroidism was approximately 2.6 times more prevalent in individuals who worked 53 to 83 hours per week compared with those who worked 36 to 42 hours per week. As the study was cross-sectional and observational in nature, causation could not be determined. The researchers suggested that “[f]urther research is needed to clarify the causal relationship and the underlying mechanism” of hypothyroidism in connection to longer working hours.