Research news in brief

Biomarker for inflammation predicts COVID-19 risk

Varying severity of COVID-19 symptoms in patients is reflected by levels of a chemical biomarker in their body which scientists say could be used to better manage treatments and other interventions, including vaccinations. In a study published in the International Journal of Infectious Diseases, researchers in Italy and Australia examined levels of a chemical called serum amyloid A (SAA), a protein synthesised in the liver which can spike up to 1000-fold within the first 24–48 hours of an infection. In turn, an increase in SAA can further perpetuate inflammation and cause clot abnormalities and organ damage, researchers say, concluding SAA levels are associated with higher COVID-19 severity and mortality. The authors focused on the latest research including 19 studies of more than 5600 COVID-19 patients for specific markers to predict disease severity and progression. “Our analyses showed that COVID-19 patients with severe disease or who eventually died had significantly higher levels of SAA when compared to patients with mild COVID-19,” they wrote. “Patients with severe forms of [COVID-19] have excessive inflammation, alterations in clot formation, and significant damage in several organs, particularly the lung, the kidney, the heart, and the liver.” Given the key role of inflammation in COVID-19, markers that reflect a state of excessive inflammation might be particularly useful for risk stratification and effective management. “This chemical may help, together with other patient characteristics, in predicting which COVID-19 patients are likely to deteriorate and require aggressive management,” the researchers wrote.

Disrupted sleep is linked to increased risk of death, particularly in women

A study published in the European Heart Journal has shown a link between the frequency and duration of unconscious wakefulness during night-time sleep and an increased risk of dying from diseases of the heart and blood vessels, and death from any cause, particularly in women. The study of 8001 men and women, found that women who experienced unconscious wakefulness most often and for longer periods of time had nearly double the risk of dying from cardiovascular disease during an average of between 6 and 11 years’ follow-up, when compared to the risk in the general female population. The association was less clear in men, and their risk of cardiovascular death increased by just over a quarter compared with the general male population. Unconscious wakefulness, also known as cortical arousal, is a normal part of sleep. It occurs spontaneously and is part of the body’s ability to respond to potentially dangerous situations, such as noise or breathing becoming obstructed. Pain, limb movements, trauma, temperature and light can also be triggers. The researchers looked at data from sleep monitors worn overnight by men and women taking part in one of three studies: 2782 men in the Osteoporotic Fractures in Men Sleep Study (MrOS), 424 women in the Study of Osteoporotic Fractures (SOF), and 2221 men and 2574 women in the Sleep Heart Health Study (SHHS). After adjusting for factors that could affect the results such as total sleep duration, age, medical history, body mass index (BMI) and smoking habits, the researchers found that women had an arousal burden that was lower than men. However, those who had an arousal burden that accounted for more than 6.5% of their night’s sleep had a greater risk of dying from cardiovascular disease during the follow-up period than women with a lower arousal burden: double the risk in SOF and 1.6 times the risk in SHHS. Their risk of dying from all causes was also increased by 1.6 times in SOF and 1.2 times in SHHS. Taking the women from both studies together, those with an arousal burden of more than 6.5% had a 12.8% risk of dying from cardiovascular disease, nearly double that of women of a similar age in the general population who had a risk of 6.7%. The risk of dying from any cause was 21% among women in the general population, which increased to 31.5% among women in the two studies with an arousal burden of more than 6.5%. When the researchers looked at all the men in both studies, those with an arousal burden of more than 8.5% had a risk of 13.4% and 33.7% of dying from cardiovascular disease or any cause, respectively, compared with the risk in the general population of men of similar ages of 9.6% and 28%, respectively.

Multivitamins, some supplements may lessen risk of positive COVID-19 test

Taking multivitamins, omega-3, probiotics or vitamin D supplements may lessen the risk of testing positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for COVID-19 – at least among women –according to a large population study published in BMJ Nutrition Prevention and Health. The researchers analysed information supplied by 372 720 UK subscribers to the COVID-19 Symptom Study app about their regular use of dietary supplements throughout May, June and July 2020, during the first wave of the pandemic, as well as any COVID-19 swab test results. Between May and July, 175 652 UK subscribers regularly took dietary supplements and 197 068 did not. Around two-thirds (67%) were women and over half were overweight (BMI of 27). In all, 23 521 people tested positive for SARS-CoV-2 and 349 199 tested negative between May and July. Taking probiotics, omega-3 fatty acids, multivitamins or vitamin D was associated with a lower risk of SARS-CoV-2 infection: by 14%, 12%, 13% and 9%, respectively, after accounting for potentially influential factors, including underlying conditions and usual diet. No such effects were observed among those taking vitamin C, zinc, or garlic supplements. And when the researchers looked specifically at sex, age and weight (BMI), the protective associations for probiotics, omega-3 fatty acids, multivitamins and vitamin D were observed only in women of all ages and weights. No such clear associations were seen in men. Despite some differences, the same overall patterns were mirrored in both the US (45 757) and Swedish (27 373) subscribers. This is an observational study, and as such, can’t establish cause.

Cellular impact of “heat-not-burn” products may be no less harmful than cigarettes

The impact on lung cells of “heat-not-burn” products – a hybrid between traditional cigarettes and electronic vaping devices – may be no less harmful than that of conventional cigarettes, suggest the findings of a small comparative study, published in Thorax. Heat-not-burn products contain nicotine and tobacco, but have been marketed by the tobacco industry as a less harmful alternative to conventional cigarettes on the grounds that they don’t produce specific harmful chemicals that are released when tobacco burns. The researchers compared endothelial dysfunction, oxidative stress, and platelet activation in 20 non-smokers (average age 28 years), 20 long term conventional cigarette smokers (average age 27 years), and 20 long term users of heat-not-burn products (average age 33 years). The conventional smokers had been smoking for an average of 3.5 years, at an average of 13 cigarettes a day; the heat-not-burn users had been getting through around 11 products every day for an average of 5 years. The findings showed that compared with not smoking, long term use of heat-not-burn products was associated with reduced endothelial function and increased oxidative stress and platelet activation. There were no significant differences between conventional cigarette smokers and users of heat-not-burn products. This is an observational study, so it can’t establish cause. In a linked study, a team of researchers assessed whether the use of heat-not-burn products helped Japanese workers to give up tobacco for good. They offered a smoking cessation program to 158 users of conventional cigarettes (94) alone and/or heat-not-burn products (64) between November 2018 and April 2019. The workplace program included prescription varenicrine or nicotine replacement therapy (NRT), counselling, and information about stopping smoking. The quit rate was logged in August 2019, when 45 (29%) of the workers had successfully stopped using all tobacco products. Those who availed themselves of pharmacological support were more likely to quit than those who did not (67% v 11%) as were those who received counselling (69% v 21%). Analysis of the results showed that people who used varenicrine or NRT were three times more likely to stop smoking tobacco than those who did not. But those who either used heat-not-burn products alone or in addition to conventional cigarettes (dual users) were 23% less likely than exclusive cigarette smokers to give up tobacco altogether, after accounting for age, tobacco dependence, previous quit attempts and use of pharmacological support. This is also an observational study.