The study by principal researcher Tara Haas of 91亚色鈥檚 School of Kinesiology & Health Science and Muscle Health Research Centre in the Faculty of Health in collaboration with 91亚色 kinesiology Professor Michael Riddell was published online in the peer-reviewed journal in October.

Tara Haas

鈥淐ortisol is a steroid hormone normally present in our body in small amounts, but a continuous increase in cortisol levels is linked with the development of obesity and Type 2 diabetes,鈥� says Haas.聽 The research by her team looked at the effects of sustained increases in the levels of the stress hormone corticosterone (the form of cortisol found in rodents) on the smallest blood vessels, capillaries, within skeletal muscles.

What they found, says Haas, 鈥渨as a substantial reduction, by 30 per cent, in the number of capillaries within the muscle.鈥� As capillaries bring oxygen and nutrients to the muscle cells, this reduction could have significant consequences for muscle function and perhaps even blood sugar disposal.

鈥淭his is important as a reduction in the number of capillaries could influence the ability of a person to be active, which could cause their condition to worsen,鈥� says Haas. The finding may help to explain why people with Type 2 diabetes have difficulty growing new capillaries in other tissues, such as the heart.

Michael Riddell

The researchers then took a closer look at the mechanisms involved in the reduced capillary growth by using cultured endothelial cells 鈥� those cells that form capillaries 鈥� chronically treated with the stress hormone. They found that corticosterone repressed several major intracellular signal pathways involved in controlling cell proliferation and migration, which likely contributes to the lack of capillary growth.

鈥淭his research is significant because it highlights that a chronic elevation of stress hormone can have significant negative consequences to the small blood vessels within skeletal muscle that are in charge of providing much needed oxygen and nutrients,鈥� says Haas. 鈥淚t also points the way to identifying how cortisol, through its effects on blocking appropriate blood vessel growth, may contribute to cardiovascular complications of diabetes or obesity.鈥�

Skeletal muscle endothelial cells in culture

Haas says the findings warrant further research to determine if treatment with synthetic steroid hormones carries similar risks. The capillaries in the skeletal muscles studied were affected using a low, but continuous exposure, to the stress hormone. The amount of synthetic steroid hormones, such as hydrocortisone, people are usually prescribed to block inflammation in the body, can be 25 times higher than the amount used in the study.

Haas is a member of the newly formed Angiogenesis Research Group, which investigates the adaptation of the skeletal muscle capillary network to physiological and pathological conditions.聽 The research was supported by the Natural Sciences & Engineering Research Council of Canada (NSERC) Discovery Grants to Haas and Riddell, as well as awards to 91亚色 students, including Eric A. Shikatani, who was the recipient of a Heart & Stroke Foundation of Ontario Master鈥檚 Studentship Award. In addition, student Anastassia Trifonova was the recipient of a NSERC CGSM graduate scholarship, and Anna Krylova and Andrei Szigiato were recipients of NSERC Undergraduate Student Research awards.

By Sandra McLean, YFile deputy editor

Republished courtesy of YFile鈥� 91亚色鈥檚 daily e-bulletin to research stories on the research website.

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The study is the first to look at the effects of yoga on cortisol levels in women with fibromyalgia. The condition, which predominantly affects women, is characterized by chronic pain and fatigue; common symptoms include muscle stiffness, sleep disturbances, gastrointestinal discomfort, anxiety and depression.

Previous research has found that women with fibromyalgia have lower-than-average cortisol levels, which contribute to pain, fatigue and stress sensitivity. According to the study, participants鈥� saliva revealed elevated levels of total cortisol following a program of 75 minutes of hatha yoga twice weekly over the course of eight weeks.

"Ideally, our cortisol levels peak about 30 to 40 minutes after we get up in the morning and decline throughout the day until we鈥檙e ready to go to sleep," says the study鈥檚 lead author, Kathryn Curtis, a PhD student in 91亚色鈥檚 Department of Psychology, Faculty of Health. "The secretion of the hormone, cortisol, is dysregulated in women with fibromyalgia," she says.

Right: Yoga affects the release of cortisol

Cortisol is a steroid hormone that is produced and released by the adrenal gland and functions as a component of the hypothalamic-pituitary-adrenal (HPA) axis in response to stress.

"Hatha yoga promotes physical relaxation by decreasing activity of the sympathetic nervous system, which lowers heart rate and increases breath volume. We believe this in turn has a positive effect on the HPA axis," says Curtis.

Participants completed questionnaires to determine pain intensity pre- and post-study; they reported significant reductions in pain and associated symptoms, as well as psychological benefits. They felt less helpless, were more accepting of their condition and were less likely to "catastrophize" over current or future symptoms.

"We saw their levels of mindfulness increase 鈥� they were better able to detach from their psychological experience of pain," Curtis says. Mindfulness is a form of active mental awareness rooted in Buddhist traditions; it is achieved by paying total attention to the present moment with a non-judgmental awareness of inner and outer experiences.

"Yoga promotes this concept 鈥� that we are not our bodies, our experiences, or our pain. This is extremely useful in the management of pain," she says. "Moreover, our findings strongly suggest that psychological changes in turn affect our experience of physical pain."

The study 鈥� Curtis鈥檚 thesis 鈥� was published yesterday in the Journal of Pain Research. It is co-authored by her supervisor, 91亚色 psychology Professor Joel Katz, Canada Research Chair in Health Psychology, and Anna Osadchuk, a 91亚色 undergraduate student.

Curtis was supported by a Canadian Institutes of Health Research (CIHR) Canada Graduate Scholarship and a CIHR Strategic Training Grant Fellowship in Pain: Molecules to Community.

Republished courtesy of YFile 鈥� 91亚色鈥檚 daily e-bulletin.

The post 91亚色 study finds that yoga boosts stress-busting hormone and reduces pain appeared first on UAP 2026-30.