Diabetes Linked to Worse Long COVID Recovery, Higher Cardiovascular Risk After Hospitalisation
Key Insights
A University of São Paulo (search) study of 870 patients found that people with diabetes had significantly lower rates of full recovery seven months after COVID-19 (search) hospitalisation (89.8% vs. 94.3%).
Diabetic patients experienced nearly double the rate of post-discharge falls (21% vs. 11.1%) and higher cardiovascular complications including heart attack and angina.
Hospital stays were longer for patients with diabetes (16 days vs. 13 days), contributing to muscle loss and delayed return to daily autonomy.
A Brazilian study has revealed that people with diabetes face a significantly more difficult recovery trajectory following COVID-19 (search) hospitalisation, with higher rates of cardiovascular complications, greater frailty, and poorer quality of life persisting seven months after discharge.
The research, conducted at the University of São Paulo (search) and published in Scientific Reports, followed 870 individuals for up to seven months after hospitalisation — 320 with diabetes mellitus (search) and 550 without the disease. The study is part of a larger FAPESP-supported initiative that recruited more than 3,000 patients admitted to Hospital das Clínicas (search) (HC) between March and September 2020, during the first phase of the pandemic in Brazil before vaccines were available.
Recovery Disparities Emerge
Seven months after discharge, the gap in recovery was clear. Among patients without diabetes, 94.3% reported full recovery, compared to 89.8% of those with diabetes. "It's a considerable difference," said Maria Elizabeth Rossi da Silva, head of the Diabetes Unit at HC and one of the study's authors.
The wider clinical picture was more concerning than the recovery percentages alone suggest. People with diabetes demonstrated elevated frailty levels, a higher incidence of falls, and poorer quality of life across physical and cognitive domains. Mobility was particularly compromised: 21% of patients with diabetes reported falls after discharge, nearly double the 11.1% rate observed in the non-diabetic group.
Cardiovascular Burden and Prolonged Hospitalisation
The cardiovascular system of people with diabetes came under significant stress from the virus. "The systemic inflammation caused by diabetes compounds the direct toxicity of the virus, creating a scenario in which the heart becomes one of the main targets for serious complications. And the risk increases with the number of comorbidities the patient has," Silva explained.
Hospital stays were notably longer among patients with diabetes — a median of 16 days versus 13 days for those without the condition. "This combination of altered metabolism and prolonged hospital stay creates a cycle of muscle mass loss and vulnerability that hinders a return to daily autonomy," Silva told Agência FAPESP.
Mechanisms and Contributing Factors
The researchers point to several overlapping mechanisms. Diabetes is associated with chronic inflammation, vascular stress, and metabolic dysfunction. COVID-19 (search) adds another inflammatory insult, and together they may place extra strain on the heart, muscles, and recovery systems. Silva also noted that the virus can directly affect pancreatic cells or trigger insulin resistance, potentially worsening the underlying diabetic condition.
Socioeconomic factors further complicate outcomes. Silva emphasised that social inequalities — including limited access to medical care, stress, unhealthy diets, and lack of time for physical exercise — influence disease trajectories. "Health policies must consider these factors, offering specific follow-up care for patients with diabetes in the post-COVID period," she said.
New-Onset Diabetes After COVID-19 (search)
A notable secondary finding was that 7.3% of participants without diabetes at baseline developed the disease after COVID-19 (search) infection. While the direct role of the virus in destroying pancreatic cells cannot be ruled out, Silva urged caution in interpretation. "We must interpret this information with caution because, although the infection may catalyse the onset of diabetes, the pandemic itself and social isolation may also have influenced factors such as stress, poor diet, physical inactivity, and obesity, all of which can trigger diabetes," she said.
Implications for Long COVID (search) Care
The findings underscore that long COVID (search) care should not treat diabetes as background noise. "The study makes it abundantly clear that a healthcare framework is needed for this population with diabetes who have been infected with the COVID-19 (search) virus to prevent these survivors from becoming trapped in a cycle of readmissions," Silva stated.
For people with diabetes, the message is that recovery from COVID-19 (search) may require more than a discharge letter and a few weeks of rest. Cardiovascular health, mobility, frailty, glucose control, and quality of life all demand structured, prolonged monitoring. The study of patients hospitalised at HC is ongoing, with researchers now analysing data collected three years after infection to understand how COVID-19 impacts diabetes over the longer term.