Obesity increases likelihood of peak COVID-19 antibody levels after infection
Adults with obesity or severe obesity who test positive for COVID-19 are more likely to have peak antibody titer levels compared with those without obesity, according to a study published in Obesity.
“In COVID-19 infections, higher antibody counts are strongly associated with obesity, especially for patients younger than 50 years old,” Shelly Soffer, MD, a physician at Assuta Ashdod University Hospital in Israel, told Healio. “The high antibody count among patients with severe obesity and COVID-19 may indicate a strong immune response, potentially resulting from a severe infection that is more evident in patients with severe obesity.”
Soffer and colleagues conducted a retrospective cohort study of adults in the Mount Sinai Health System who underwent a COVID-19 serology test from March 1 to Dec. 14, 2020. Any test results with an antibody titer ratio of at least 1:80 was defined as a positive test, and peak antibody titer ratio was defined as 1:2,880. Participants were divided into five groups based on BMI. People with a BMI of 30 kg/m2 to 39.9 kg/m2 were placed in the obesity group, and the severe obesity group included those with a BMI of 40 kg/m2 or higher.
Of 39,342 adults included in the analysis, 12,314 had a positive antibody titer level of at least 1:80. Of the entire study cohort, there was a higher prevalence of peak titer levels found for adults with severe obesity (52%) and obesity (44.7%) compared with those with overweight (37.7%), normal weight (29.2%) or underweight (34.5%, P < .001). Similar associations were observed after stratifying by test status and age.
There was no difference between the BMI groups for people with a prior COVID-19-related hospital admission. For those without a prior COVID-19-related admission, obesity and severe obesity were associated with higher peak titer rates.
Of the five BMI groups, adults with severe obesity were most likely to have peak antibody titers (adjusted OR = 2.5; 95% CI, 2.1-3; P < .001). Those in the obesity subgroup also had elevated odds for peak antibody titer (aOR = 1.8; 95% CI, 1.6-2; P < .001). Other covariates that increased the odds for peak antibody titers included overweight, age decile, chronic kidney disease, congestive heart failure and diabetes.
Soffer said a large scale, multicenter follow-up of people who had COVID-19 is needed in the future to measure the long-term antibody response.
“Also very important is the analysis of reinfection rates, and recurrency of severe disease, stratified by neutralizing antibody levels and BMI,” Soffer said.
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Shelly Soffer, MD, can be reached at firstname.lastname@example.org.