New research has uncovered biological differences that explain why women with long Covid experience more severe and persistent symptoms than men.

Long Covid is diagnosed when neurological, respiratory or gastrointestinal symptoms persist for three months or more after SARS-CoV-2 infection.

Women are about three times more likely than men to develop it, but the biology behind this gap has been unclear.

The research from the University of Alberta suggests potential treatment targets that could help the 3.5 million Canadians who reported long Covid as of June 2023, according to Statistics Canada.

Principal investigator Shokrollah Elahi is an immunology professor in the Mike Petryk School of Dentistry.

The researcher said: “We are focusing on a subset of patients with the most devastating symptoms that are very similar to chronic fatigue syndrome.

“They didn’t have these symptoms prior to Covid and most had only mild Covid-19 disease, so they were not hospitalised.”

Elahi’s team ran blood and genetic tests on 78 patients with long Covid one year after their acute diagnosis, plus 62 controls who did not develop long Covid after infection.

By analysing immune cells, blood biomarkers (measurable signals of disease) and RNA sequencing (a method to read gene activity), the researchers identified a distinct immune signature in female versus male patients.

They found evidence of “gut leakiness” in female patients — when the intestinal barrier becomes more permeable and allows substances to pass into the bloodstream — including raised levels of intestinal fatty acid-binding protein, lipopolysaccharide and soluble CD14.

These signs of gut inflammation can trigger wider inflammation once in circulation.

“This suggests that probably at the earliest stage of disease when patients get acute SARS-CoV-2 infection, there is a tendency that the females’ guts are more prone to viral infection,” Elahi said.

The team also observed lower red blood cell production — anaemia — in female patients, suggesting elevated inflammatory factors in women with long Covid may impair blood formation.

In addition, they reported dysregulated sex hormones in long Covid: reduced testosterone in affected women, decreased oestrogen in male patients, and lower cortisol in both.

Women with lower testosterone had higher inflammatory markers. Because testosterone can help dampen inflammation, reduced levels may leave women more vulnerable to ongoing inflammatory responses. Lower testosterone was also linked to brain fog, depression, pain and fatigue.

The findings suggest hormone imbalance plays an important role in long Covid, particularly in how it affects women, Elahi said.

These results mirror some features of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), which also disproportionately affects women.

For example, chronic inflammation is common to both, although anaemia is not typically associated with chronic fatigue.

The team’s conclusions are supported by another recent international study of more than 500 patients that also identified anaemia as a major biological driver of long Covid.

Elahi plans to validate the findings by testing potential treatments in mouse models of long Covid and is seeking funding for a clinical trial.

He proposes an individualised approach guided by test results that could include anaemia treatment, anti-inflammatory medicines and, in some cases, sex hormones.

He also aims to further explore similarities between neurological symptoms of long Covid and those seen in HIV.

Daily self-guided hypnosis cut hot flushes by over 50 per cent in postmenopausal women, a new clinical trial has found.

The multicentre randomised clinical trial tested a six-week, self-administered hypnosis programme against a sham control using white noise.

It enrolled 250 postmenopausal women with frequent hot flushes — sudden heat surges that can disrupt sleep and daily life.

Nearly 25 per cent of participants had a history of breast cancer, a group often unable to use hormone therapies because of safety concerns.

Lead researcher Gary R. Elkins, professor of psychology and neuroscience and director of the Mind-Body Medicine Research Laboratory at Baylor, said the findings offer hope for women seeking non-hormonal options.

Elkins said: “It is estimated that over 25 million women in the United States have hot flushes, with up to 80 per cent of women in the general population reporting hot flushes during the menopause transition, and 96 per cent of women with breast cancer report hot flushes soon after beginning anti-cancer therapy.

He added: “While hormone replacement therapy is highly effective in reducing hot flushes, it is not a safe choice for everyone, and therefore, women need additional safe and effective alternatives.”

After six weeks of daily self-hypnosis audio recordings, participants reported a 53.4 per cent reduction in both frequency and intensity of hot flushes. At the three-month follow-up, hot flushes were reduced by 60.9 per cent, compared with 40.9 per cent for the control group.

Women with a history of breast cancer saw a 64 per cent reduction after six weeks.

The trial is the first to compare self-guided hypnosis with an active control, helping to separate treatment effects from expectancy or the placebo effect — improvement driven by belief rather than the intervention itself.

Elkins said: “This was a major breakthrough and innovation, as almost all prior studies of mind-body interventions have only used wait-list, psycho-education or simple relaxation to compare the active hypnotherapy intervention.”

He added: “Also, all sessions were self-administered hypnosis, which demonstrated that women could learn how to use hypnosis for hot flushes on their own with support and guidance.

“It can be practised at home without needing to travel for doctor visits, and it is relatively inexpensive compared to in-person sessions.

“Once a person learns how to use self-hypnosis to reduce hot flushes and improve sleep, it can be used for other purposes such as managing anxiety, coping with pain and for stress management.”

At 12 weeks, the hypnosis group showed greater gains in sleep, mood, concentration and quality of life. Nearly 90 per cent reported feeling better, versus 64 per cent in the control arm.

Elkins said: “We are very excited about the findings from this important study.

He added: “Our ongoing research aims to further determine how self-hypnosis can significantly improve sleep for breast cancer survivors and women in the peri- to post-menopause transition.”

Through this and other studies, Elkins and colleagues say hypnotherapy is the only behavioural intervention consistently shown to reduce hot flush frequency and severity to a clinically significant level in postmenopausal women and breast cancer survivors.