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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. The researchers concluded that SAA levels are associated with higher COVID‐19 severity and mortality. They focused on the latest research, including 19 studies of more than 5600 patients with COVID‐19. “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.

https://www.ijidonline.com/article/S1201-9712(21)00243-5/fulltext

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

A study published in the European Heart Journal has found 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, compared with 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, 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 (total sleep duration, age, medical history, body mass index and smoking habits), the researchers found that women had an arousal burden lower than that of 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. Risk of dying from all causes was also increased by 1.6 times in SOF and 1.2 times in SHHS. Combining the two studies, women with an arousal burden of more than 6.5% had a 12.8% risk of dying from cardiovascular disease, nearly twice 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 with an arousal burden of more than 6.5%. When the researchers looked at 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 (9.6% and 28%, respectively).

https://academic.oup.com/eurheartj/advance-article/doi/10.1093/eurheartj/ehab151/6239256