Female Sex, Increased BMI Linked to Increased Likelihood of Long COVID

Vassilios Vassiliou, MD, PhD

In one of the largest studies on long COVID from the United Kingdom since the pandemic began, a new analysis suggests those with an increased body mass index (BMI) and women were more likely to experience long COVID.

A community-based, web-survey study conducted in Norfolk, East England, results of the 1487-patient study demonstrate men had a 25% lower risk of post-COVID symptoms compared to women and each 1 kg/m² increase in BMI was associated with a 3% increase in risk.

“We show that more than a half of the survey respondents who tested positive for Covid in the East of England during the first year of the pandemic went on to report long Covid symptoms,” said Vassilios Vassiliou, MD, PhD, a clinical professor of cardiac medicine atthe University of East Anglia’s Norwich Medical School, in a statement. “All of these people were infected in the months before the Covid vaccination programme was rolled out and they suffered from numerous new symptoms that were not present before their Covid infection.

As wave after wave of the pandemic came and went, the prominent focus among researchers and clinicians has changed as well. From use of masks to prevent spread, to the risk of thrombosis with vaccines or infection, and more, the focus for many has, now, shifted to the effects of long COVID and potential risk factors for predicting those with increased susceptibility to long COVID symptoms following infection.

Vassiliou and a team of colleagues designed the current study with the intent of developing a more comprehensive understanding of long COVID in the area surrounding University of East Anglia. With this in mind, investigators created a web-based survey that was sent to patients in Protect Norfolk and Waveney post-COVID-19 syndrome Project, which included adults with a confirmed COVID-19 infection via RT-PCR prior to December 6, 2020. This survey contains questions related to both pre-COVID health and post-COVID symptoms as well as questions pertaining to healthcare use.

The survey was sent to 6318 patients and responses were obtained from 23.5% (n=1487) of this cohort. At the time of the survey, 11 respondents had received their first dose of the COVID mRNA BNT162b2 vaccine. The cohort of respondents had a mean age of 50 (SD, 18.1), 61% were female, and, among the 879 with BMI measurements available, the mean BMI was 28.4 (SD, 6.9) kg/m². Of the 1487 respondents, 774 experienced post-COVID-19 syndrome symptoms.

For the purpose of analysis, investigators used logistic regression analysis to estimate associations between potential predictors for long COVID symptoms and future healthcare utilization. Investigators pointed out baseline characteristics of the study cohort were obtained from National Health Service digital databases.

Upon analysis, results indicated male sex compared to female sex was considered a protective factor against post-COVID symptoms (RR, 0.748 [95% CI, 0.605-0.924]) while BMI was associated with an increased risk of developing symptoms (Per 1 kg/m²: RR, 1.031 [95% CI, 1.016-1.047]). Of the 1487 respondents, 25.4% reported use of health care services following their index COVID-19 infection, with 73.2% of these patients reporting post-COVID symptoms.

When assessing factors associated with further health care service use, results suggested male sex (RR, 0.618 [95% CI, 0.464-0.818]) was associated with a reduction in risk while BMI (RR, 1.027 [95% CI, 1.009-1.046]) was associated with an increased likelihood of using further health care services. Investigators highlighted experiencing post-COVID-19 symptoms was associated with a more than 3-fold increase in likelihood of using health care services (RR, 3.280 [95% CI, 2.540-4.262]).

“We hope that our work will help policymakers plan local services and also inform the wider public of the scale of the long COVID pandemic,” Vassiliou added in the aforementioned statement.

This study, “Post-COVID-19 syndrome risk factors and further use of health services in East England,” was published in PLOS Global Public Health.