Women with post-acute COVID-19 syndrome have worse airway structure than men
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Key takeaways:
- Worse measures of airway structure were found in women vs. men 3 months after a COVID-19 infection.
- Women with post-acute COVID-19 also had poorer quality of life scores.
WASHINGTON — Three months after a COVID-19 infection, women with post-acute COVID-19 syndrome had worse airway measurements on CT scans than men, according to an abstract presented at the American Thoracic Society International Conference.
“Our findings offer insight into why females are more likely to experience persistent symptoms and poor quality of life attributed to long COVID,” Harkiran Kaur Kooner, BS, PhD student in the department of medical biophysics at Western University, told Healio. “The impact for the everyday clinician is the possibility of identifying people in whom persistent symptoms and poor quality of life are related to airways disease, thereby opening the door for targeted treatment.”
Kooner and colleagues analyzed 44 patients with post-acute COVID-19 syndrome, including 23 men (mean age, 57 years) and 21 women (mean age, 50 years), to see how measures of airway and pulmonary vascular structures found on CT scans differ between men and women 3 months after a COVID-19 infection and impact post-acute COVID-19 syndrome.
Total airway count, wall area, wall thickness percent and lumen area from patients’ CT scans were all generated through VIDAvision, whereas total blood volume and blood volume for vessels with cross-sectional area less than 5 mm2, between 5 and 10 mm2, and greater than 10 mm2 were found through Chest-Imaging-Platform.
Researchers used univariate linear models to compare measurements found for each of the sexes, and these models accounted for age, height, BMI, lung volume and chronic lung disease.
At baseline (3 months after contracting COVID-19) and follow-up (15 months after infection), researchers also collected results from pulmonary function tests and 6-minute walk tests.
Out of the total cohort, follow-up was recorded for 33 patients.
Compared with men, researchers found that women had several significant differences in CT airway measures at baseline that indicated worse structure, including smaller total airway count (mean, 286 vs. 252; P = .002), higher wall area (65.9 mm2 vs. 66.4 mm2; P < .001), higher wall thickness percent (17.5% ± 0.8 vs. 17.5% ± 0.6; P = .007) and smaller lumen area (15.2 mm2 vs. 12.3 mm2; P < .001) after adjusting for the outlined variables. These findings were unexpected, Kooner told Healio.
“We know that female lung airways are generally smaller in caliber compared to airways in males of the same size,” she said. “We also know that females are more likely to experience respiratory symptoms during COVID-19 infection and more likely to develop long COVID. We didn’t expect to see that even when we adjusted for age, size, lung volume and the presence of previous respiratory disease, we still found sex differences in CT total airway count, airway lumen and wall thickness. This is important because this airway result may explain symptomatic sex differences in patients with long COVID.”
In terms of measures of pulmonary vascular structure, researchers observed no significant differences between the sexes.
“This finding leaves the airway differences or worse airways disease as the most-likely cause of the increased symptom burden reported by females compared to males with long COVID,” Kooner told Healio.
In addition to CT measurements, patients completed the St. George’s Respiratory Questionnaire so researchers could assess health-related quality of life scores between both sexes. Compared with men, women had poorer quality of life at baseline, which was represented by a higher score (36 vs. 29). Women continued to have a higher score in follow-up (25 vs. 22) but showed more improvement in their score from baseline than men.
When evaluating 6-minute walk test results at 15 months, researchers found a link between baseline wall thickness percent and better test distance in men; however, they did not find this link in women.
“Future studies will likely focus on a larger group of participants with long COVID,” Kooner told Healio. “It is also possible that machine- and deep-learning methods can be used on baseline CT scans to create predictive models of long-COVID outcomes.”
For more information:
Harkiran Kaur Kooner, BS, can be reached at hkooner4@uwo.ca.