According to a study, having a high body mass index (BMI) rather than having high blood sugar levels is associated with an increased risk of Covid infection and a prolonged Covid confinement. The findings by Dr Anika Knuppel from the MRC Unit for Lifelong Health and Ageing, University College London, UK, and colleagues are being presented at this year’s European Association for the Study of Diabetes (EASD) Annual Meeting in Stockholm, Sweden, in September.
“Early in the pandemic research identified diabetes and obesity as risk factors for becoming severely ill with Covid. And we know that many people living with type 2 diabetes are also carrying excess weight. Our early findings support the idea that
obesity-related mechanisms may be responsible for the excess risks of Covid associated with diabetes, rather than high blood sugar perse,” said Dr Knuppel.
Previous research showed that people with diabetes and obesity are more likely to become severely ill and die if they catch Covid but are no more likely to contract it. However, the underlying mechanisms, and their role in prolonged post Covid symptoms (long COVID), remains unclear.
To find out more, researchers looked for associations between a range of
clinical characteristics measured before the pandemic–HbA1c (average blood sugar level), self-reported or medication-based diabetes, body mass index (BMI) and waist-to-hip ratio (WHR)— and self-reported Covid infection and long Covid in
nine ongoing UK cohort studies. The analyses included the most recent measurements (taken between 2002 and 2019) of HbA1c, weight, height, waist and hip circumference from each study as well as information from questionnaires on health and lifestyle.
Participants reported having Covid based on a positive test or strong suspicion. Long Covid was defined as symptoms that went on or affected functioning for longer than four weeks post-infection and were compared to those reporting symptoms for less than four weeks.
Analysis of data from 31,252 participants in nine studies found higher BMI was associated with greater odds of Covid infection—with the risk 7% higher for each 5kg/m2 increase in BMI. People with overweight (BMI 25- 29.9kg/m2) and obesity (30 kg/m2 or greater) had 10% and 16% greater odds of Covid infection, respectively, than healthy weight individuals.
Similar results were observed for long Covid — with the risk 20% higher for each 5kg/m2 increase in BMI. People with overweight and obesity had 20% and 36% greater odds of long Covid, respectively. Notably, studies focusing on average blood sugar level (HbA1c) and diabetes revealed no association with Covid infections or long Covid. The researchers stress the need for further research to explore the mechanisms underpinning these associations and to reduce the excess risk associated with high BMI. “Our early findings suggest a link of adiposity with Covid infection and long Covid even after taking into account socio-demographic factors and smoking.