Obesity as a driver of international differences in COVID-19 death rates.

AIMS: There is considerable variation in death rates from coronavirus disease 2019 (COVID-19) between countries, and these variations are not fully understood. The aim was to determine what proportion of the variation in death rates between countries can be explained in terms of obesity rates and other known risk factors for COVID-19. MATERIALS AND METHODS: COVID-19 death rates from 30 industrialized countries were analyzed using linear regression models. Covariates modelled population density, the age structure of the population, obesity, population health, per capita GDP, ethnic diversity, national temperature and government delay in imposing virus control measures. RESULTS: The multivariable regression model explained 63% of the inter-country variation in COVID-19 death rates. The initial model was optimized using stepwise selection. In descending order of absolute size of model coefficient, the covariates in the optimized model were: obesity rate, hypertension rate, population density, life expectancy, percentage of population over 65, percentage of population under 15, diabetes rate, the delay in imposing national COVID-19 control measures, per capita GDP and mean temperature (a negative coefficient indicating an association between higher national temperatures and lower death rates). CONCLUSIONS: A large proportion of the variation in COVID-19 death rates between countries can be explained by differences in obesity rates, population health, population density, age demographics, the delay in imposing national virus control measures, per capita GDP and climate. Some of the unexplained variation is probably attributable to inter-country differences in the definition of COVID-19 deaths and in the completeness of the recording of COVID-19 deaths. This article is protected by copyright. All rights reserved.