When Ziyad Al-Aly’s research team told him how often diabetes appeared to strike COVID-19 survivors, he thought the data must be wrong, so he asked his five colleagues to crunch the numbers again.
Weeks later, they returned the same findings after sifting through millions of patient records. By then Al-Aly had also gone digging into the scientific literature and was starting to come to terms with an alarming reality: COVID-19 isn’t just deadlier for people with diabetes, it’s also triggering the metabolic disease in many who didn’t previously have it.
“It took a while to convince me,” said Al-Aly, who directs the clinical epidemiology center at the Veterans Affairs St. Louis Health Care System in Missouri. “It was hard to believe that COVID could be doing this.”
Among COVID-19’s many ripple effects, the worsening of the global diabetes burden could carry a heavy public health toll. The underlying mechanisms stoking new-onset diabetes aren’t clear, though some doctors suspect the SARS-CoV-2 virus may damage the pancreas, the gland that makes insulin that is needed to convert blood-sugar into energy. Sedentary lifestyles brought on by lockdowns could also be playing a role, as might late diagnoses after people avoided doctors’ offices. Even some children’s mild coronavirus cases can be followed by the swift onset of diabetes, scientists found.
Considered a lung disease in the early days of the pandemic, COVID-19 is increasingly recognized for its ability to ravage multiple organs and bodily systems, causing persistent and sometimes debilitating symptoms in 1 in 10 sufferers months after their apparent recovery.
Lingering metabolic complications, sometimes requiring high doses of insulin, suggest a subset of survivors are developing diabetes — swelling the ranks of the more than the 463 million people living with the chronic condition.
The disease, in which the body fails to produce enough or properly use insulin, cost an estimated $760 billion in the year before COVID-19 struck, driven by life-shortening complications spanning stroke and kidney failure to foot ulcers and blindness.
Al-Aly and colleagues were the first to measure the effect in the U.S. based on evidence from the national health care databases of the Department of Veterans Affairs. They found that COVID-19 survivors were about 39% more likely to have a new diabetes diagnosis in the six months after infection than non-infected users of the VA health system. The risk works out to about 6.5 additional diabetes cases for every 1,000 COVID-19 patients who don’t end up in the hospital. For those who do, the probability jumps to 37 per 1,000 — and it’s even higher for patients who required intensive care.
The numbers should be viewed in the context of COVID-19’s sprawling reach, according to Al-Aly. During the winter peak, more than 130,000 patients were hospitalized with the coronavirus in the U.S. alone. Globally, SARS-CoV-2 is reported to have infected more than 153 million people, including over 20 million in India, the country with the most people living with diabetes after China.
Al-Aly’s data was published last month in Nature, three weeks after a study of almost 50,000 hospitalized COVID-19 patients in England found that they were 50% more likely to have diabetes some 20 weeks after discharge than matched controls.