Impact and prevalence of comorbidities and complications on the severity of COVID-19 in association with age, gender, obesity, and pre-existing smoking: A meta-analysis.

Background: COVID-19 patients usually present multiple comorbidities and complications associated with severe forms of SARS-CoV-2 infection. This study aimed to assess the risk factors and prevalence of comorbidities and complications contributing to the severity of COVID-19.

Methods: This meta-analysis was performed according to PRISMA guidelines. We searched various databases, including PubMed, Google Scholar, and Scopus (between 2020 and 2023), for eligible studies for this meta-analysis.

Results: Thirty-three studies were eligible, including 85,812 patients, of which 36 % (30,634/85,812) had severe disease, whereas 64 % (55,178/85,812) had non-severe disease. Severe cases were potentially correlated with the following factors: gender (male) (odd ratio (OR) = 1.52, 95 % CI: 1.34-1.73), advanced age (OR = 3.06, 95 % CI: 2.18-4.40) pre-existing smoking (OR = 1.33, 95 % CI: 1.01-1.75), obesity (OR = 2.11, 95 % CI: 1.47-3.04), diabetes (OR = 1.81, 95 % CI: 1.35-2.43), hypertension (OR = 2.22, 95 % CI: 1.72-2.87), coronary heart disease (OR = 2.17, 95 % CI: 1.42-3.31), CKD (OR = 2.27, 95 % CI: 1.26-4.06), COPD (OR = 1.95, 95 % CI: 1.22-3.09), malignancy (OR = 1.63, 95 % CI: 1.07-2.49) and cerebrovascular disease (OR = 2.76, 95 % CI: 1.63-4.62). All these comorbidities were significantly higher in the severe COVID-19 group compared with the non-severe COVID-19 group. In addition, the most severe complications were associated with shock (OR = 28.08, 95 % CI: 3.49-226.03), ARDS (OR = 13.09, 95 % CI: 5.87-29.18), AKI (OR = 16.91, 95 % CI: 1.87-152.45) and arrhythmia (OR = 7.47, 95 % CI: 2.96-18.83). However, these complications were the most likely to prevent recovery in patients with severe affections compared with non-severe affection groups.

Conclusion: All the comorbidities and complications listed above are more likely to cause severe forms of COVID-19 in some patients and hinder recovery. They are therefore risk factors to be controlled to minimize the undesirable effects of the disease.