Lower cardiorespiratory fitness levels were linked to a higher risk for depression and anxiety disorders, according to findings from a systematic review and meta-analysis published in Journal of Affective Disorders.
“Low cardiorespiratory fitness has become increasingly common in recent years,” Aaron Kandola, MSc, PhD student in the division of psychiatry at University College London, told Healio Psychiatry. “The influence of low cardiorespiratory fitness on physical health is well-established, but there is evidence to suggest that it could also be a risk factor for common mental health disorders, including depression and anxiety.”
Researchers searched through relevant clinical databases for prospective cohort studies reporting on the relationship between cardiorespiratory fitness and incidence of any depressive or anxiety disorder, including major depressive disorder, dysthymic depression, generalized anxiety disorders, panic disorders, phobias and social anxiety disorder. They used random effects meta-analysis to calculate a pooled hazard ratio.
Kandola and colleagues pooled data from four studies, which included at least 27,733,154 person-years of data. They reported that low (HR = 1.47; 95% CI, 1.23-1.76) and medium (HR = 1.23; 95% CI, 1.09-1.38) cardiorespiratory fitness were linked to a 47% and 23% greater risk for common mental health disorders, respectively, compared with high cardiorespiratory fitness. However, there was substantial heterogeneity.
Data pooled from three studies on depression (based on at least 3,540,450 person-years) showed that low (HR = 1.64; 95% CI, 1.29-2.08) and medium (HR = 1.31; 95% CI, 1.1-1.55) cardiorespiratory fitness were linked to greater incidence of depression compared with high fitness. Though there were not enough studies to conduct a meta-analysis, results from three out of four studies that included anxiety as an outcome measure indicated that cardiorespiratory fitness was tied to a lower risk for anxiety.
In addition, the investigators also reported a possible dose-response relationship between cardiorespiratory fitness and risk for common mental health disorders.
“Our results suggest that lower levels of cardiorespiratory fitness are associated with a greater risk of common mental health disorders,” Kandola told Healio Psychiatry.
“The studies included in our review are observational, so it not possible to say whether lower cardiorespiratory fitness levels are a cause,” he continued. “But exercise levels are the biggest determinant of cardiorespiratory fitness and there does seem to be a causal relationship between exercise and common mental health disorders. In fact, as little as 3 to 5 weeks of regular aerobic exercise can significantly improve cardiorespiratory fitness levels and this could have protective benefits for common mental health disorders.” – by Savannah Demko