This week's roundup of some of the latest scientific studies on the coronavirus and efforts to find treatments and vaccines for COVID-19 revisits risks caused by abnormal blood sugar levels, examines after-effects of disease and addresses a challenge in the health care sector.

High blood sugar tied to COVID-19 risk in nondiabetics

High blood sugar may portend a rocky course for COVID-19 patients who seek hospital care, even if they do not have diabetes, according to a new study of 11,000 COVID-19 patients in Spain.

None were critically ill when they got to the hospital. But researchers found those who arrived with above-normal blood sugar levels had higher odds of dying there – regardless of whether they were diabetic.

Overall, 20% of the patients died while hospitalized, including 16% of individuals with blood sugar below 140 milligrams per deciliter (mg/dL) at admission, 34% of those with levels of 140 to 180 mg/dL, and 41% of patients with levels above 180 mg/dL. (A level of 200 mg/dL or higher indicates diabetes.)

After taking age and medical conditions into account, patients with the highest levels were 50% more likely to die in the hospital than patients with the lowest levels. People with elevated blood sugar were also at higher risk of needing intensive care and mechanical breathing assistance.

In a report published in Annals of Medicine, the researchers say prompt control of blood sugar should be mandatory in the management of patients hospitalized with COVID-19, regardless of whether they have diabetes.

No good answer yet for decontaminating masks for reuse

No single method for decontaminating health care workers' personal protective equipment (PPE) for reuse stands out as best, according to a study published in the American Journal of Infection Control, and reuse is not recommended if it can be avoided.

Researchers analyzed 40 studies that tested various methods for sterilization of N95 masks and higher-end filters. They included steam, hydrogen peroxide, ultraviolet light, microwaves and electric cookers, among others. Disinfection agents such as bleach, soap and water and alcohol were also tested. The outcomes differed by mask model, manufacturer and sterilization or disinfection process.

Furthermore, most methods appeared to result in at least some structural damage or weakening of the masks' filtration ability, according to coauthor Vanessa de Brito Poveda of University of Sao Paulo, Brazil.

Along with disinfection or sterilization processes, health systems that reuse masks must consider the need for traceability, if the same mask may be shared by different professionals; controlling the number of reuses of each mask; training personnel to inspect mask integrity and functionality after routine wear and tear and cleaning methods to eliminate organic matter and soil (like residual cosmetics).

"The scientific evidence available until this moment does not support any process as safe," de Brito Poveda said, although she believes automated methods are safer than manual methods.

Lingering pain after COVID-19 may be nerve injuries

Patients with lingering pain after COVID-19 may have nerve injuries, according to a report published last week in Radiology.

The researchers said lingering pain in COVID-19 survivors can be due to nerve dysfunction caused by the virus itself or it may be a side effect of treatment received in the hospital. These could include nerve issues arising from being positioned in a way that helped the lungs recover but put pressure on other body parts, or from pressure on a nerve from blood that pooled after blood clot prevention.

High-tech imaging methods like magnetic resonance and ultra-high-resolution ultrasound can help identify the location and extent of nerve damage, the researchers found when they reviewed earlier study reports.

"Clinicians should (suspect nerve injury) in COVID patients who are left with chronic pain and weakness, particularly since early diagnosis and appropriate treatment is crucial to prevent irreversible damage," coauthor Dr. Swati Deshmukh of Northwestern University in Evanston, Illinois told Reuters.

During the pandemic, Deshmukh added, when patients come in with unexplained new nerve and muscle symptoms, doctors should consider testing them for COVID-19.