Physical fitness modulates peripheral brain-derived neurotrophic factor after a single physical exercise session in older adults with generalised anxiety disorder

This study aimed to explore the associations between physical fitness, acute exercise, and BDNF levels in older adults with GAD, considering cardiorespiratory fitness and the Val66Met polymorphism.

The study included 56 adults aged 60–75 with GAD, as well as 51 healthy controls. We measured BDNF levels before and after exercise and analysed genetic material for the Val66Met polymorphism. Participants' CRF was evaluated through VO2 max testing, and BDNF samples were collected pre- and post-exercise. We applied linear mixed models to examine factors influencing BDNF levels.

GAD patients had higher baseline BDNF levels than healthy controls, which became non-significant after accounting for outliers. A single bout of physical exercise resulted in a significant increase in BDNF levels in both the GAD group and the healthy control group, with a large effect size (d = 1.45). Notably, participants with higher VO₂ max exhibited contrasting BDNF responses: GAD patients with higher VO₂ max showed greater increases in BDNF post-exercise, whereas healthy controls with higher VO₂ max displayed smaller increases. This suggests differing physiological mechanisms in response to physical exercise dependent on clinical status. Gender significantly influenced BDNF levels, with females showing higher levels than males (d = 0.71). The Val66Met polymorphism, did not significantly predict BDNF levels.

This study is the first to examine the relationship between physical fitness, acute exercise, and BDNF levels in older adults with GAD. Patients and healthy controls showed different responsiveness in BDNF increase depending on cardiorespiratory fitness levels. Independent of clinical status, females had higher BDNF levels than males. These findings underscore the need for further research on the role of exercise intensity, genetic influences, and gender in BDNF responsiveness, particularly in older adults and clinical populations. Furthermore, more research on women’s menopause, physiological changes and effect on mental health is needed. 

Older adults with GAD should be encouraged to engage in regular physical activity to improve both physical fitness and cognitive function. Physiotherapists play a crucial role in designing exercise programs tailored to individual fitness levels and health conditions, considering factors like gender and clinical status. Future studies should explore the optimal exercise intensity and frequency for enhancing mental health outcomes in this population.