A recent study published in PNAS Nexus identified obesity and age as risk factors for SARS-CoV-2 infection among exposed participants.
Researchers from Massachusetts General Brigham analyzed electronic medical records (EMRs) from 687,813 participants between March 2020 and January 25, 2021, focusing on 72,613 participants who tested positive for COVID-19 or reported exposure to the virus. The study aimed to determine whether patients with obesity had increased susceptibility to SARS-CoV-2 infection compared to participants without obesity after self-reported exposure.
Among the 72,613 participants who reported exposure to SARS-CoV-2, 18,447 (25.4%) received a positive test result. The exposed participants were divided into age groups: 1,568 (2.2%) were under 13 years, 2,057 (3.5%) were aged 13–19, 17,940 (24.7%) were between 20–39 years, 28,825 (39.7%) were in the 40–64 age range, and 21,773 (30%) were over 64 years old. The study population consisted of 42,678 females (58.8%) and 29,935 males (41.2%). A total of 24,438 participants in the study were identified as having obesity, making up 33.7% of those exposed.
The racial distribution of the exposed population included 52,595 White participants (72.4%), 8,955 Hispanic participants (12.3%), 4,864 Black participants (6.7%), and 2,494 Asian participants (3.4%). In the study population, 34.8% had hypertension, while 13.4% were diagnosed with type 2 diabetes mellitus.
Findings indicated that participants with obesity had an increased likelihood of testing positive for SARS-CoV-2 upon self-reported exposure, with an adjusted odds ratio of 1.34 (95% confidence interval: 1.29–1.39). This increased risk persisted across all age groups and remained significant after adjusting for confounding factors such as age, sex, type 2 diabetes mellitus, and hypertension. However, obesity was not a statistically significant risk factor in participants with diabetes.
The researchers demonstrated a strong correlation between their data and Massachusetts state data, supporting the representativeness of their sample. They also noted temporal consistency in the results throughout the study period.
The authors discussed potential mechanisms, such as adipose tissue potentially acting as a reservoir for the virus. They suggested that future studies should evaluate shared signaling pathways in individuals with obesity to identify potential drug targets.
Limitations of the study include the use of self-reported exposure as a proxy for actual exposure to SARS-CoV-2 and potential inaccuracies in EMRs. The authors noted that their findings may not be applicable to more diverse populations.
The study was partially funded by Kowa Company, Ltd, although the company was not involved beyond funding. The authors declared no competing interests.