Visceral adiposity, subcutaneous adiposity, and severe coronavirus disease-2019 (COVID-19): Systematic review and meta-analysis

BACKGROUND AND AIMS: Body mass index (BMI) has previously been shown to increase mortality and disease severity in patients with COVID-19, but the pooled effect estimate was heterogeneous. Although BMI is widely used as an indicator, it cannot distinguish visceral from subcutaneous fat. This systematic review and meta-analysis aimed to investigate the association between visceral adiposity, subcutaneous fat, and severe COVID-19. METHODS: We performed a systematic literature search using the databases: PubMed, Embase, and EuropePMC. Data on visceral fat area (VTA), subcutaneous fat area (SFA), and total fat area (TFA) were collected. The outcome of interest was severe COVID-19. We used a REML random-effects model to pool the mean differences and odds ratio (OR). RESULTS: There were 5 studies comprising of 539 patients. Patients with severe COVID-19 have a higher VTA (mean difference 41.7 cm(2) [27.0, 56.4], p < 0.001; I(2): 0%) and TFA (mean difference 64.6 cm(2) [26.2, 103.1], p = 0.001; I(2): 0%). There was no significant difference in terms of SFA between patients with severe and non-severe COVID-19 (mean difference 9.3 cm(2) [-4.9, 23.4], p = 0.199; I(2): 1.2%). Pooled ORs showed that VTA was associated with severe COVID-19 (OR 1.9 [1.1, 2.2], p = 0.002; I(2): 49.3%). CONCLUSION: Visceral adiposity was associated with increased COVID-19 severity, while subcutaneous adiposity was not. PROSPERO ID: CRD42020215876.