key: cord-0752852-6vrkbwp6
authors: Jayawardena, Ranil; Jeyakumar, Dhanushya T.; Misra, Anoop; Hills, Andrew P.; Ranasinghe, Priyanga
title: Obesity: A potential risk factor for infection and mortality in the current COVID-19 epidemic
date: 2020-11-11
journal: Diabetes Metab Syndr
DOI: 10.1016/j.dsx.2020.11.001
sha: 378f062b4ed9bcb51bc3dedf9dd247278920ae8d
doc_id: 752852
cord_uid: 6vrkbwp6

BACKGROUND AND AIMS: COVID-19 is an ongoing global pandemic, affecting nearly 35 million people from 214 countries as at September 30, 2020. Emerging evidence suggests that obesity is a potential risk factor for communicable diseases, including viral infections. Therefore, we investigated the relationship between obesity prevalence of the total adult population and COVID-19 infection and mortality rates, in different countries. METHODS: A total of 54 countries from six continents were selected. Country-specific obesity prevalence data were retrieved from the latest non-communicable diseases profiles released by the Non-communicable Diseases and Mental Health Cluster of World Health Organization, while the real time statistics from the Worldometer website were used to extract data on COVID-19 infections and mortality per million of the total population as of September 30, 2020. RESULTS: Obesity prevalence data ranged from 2.0% (Vietnam) to 35.0% (Saudi Arabia). Among the selected countries, the highest number of COVID-19 cases per million was documented in Qatar (n = 44,789) while the lowest was reported from Vietnam (n = 11). Highest mortality per million population due to COVID-19 infections occurred in Peru (n = 981), in contrast with the smallest number reported in Mongolia (n = 0). A significant positive correlation (r = 0.46; p < 0.001) was observed between the total number of COVID-19 infections and the prevalence of obesity. COVID-19 mortality was also significantly correlated (r = 0.34; p < 0.05) with the prevalence of obesity. CONCLUSIONS: Obesity prevalence in each country was significantly associated with both infection and mortality rate of COVID-19.

COVID-19 has emerged as a global pandemic, affecting almost 35 million people as of 30 th September 2020. While the USA, India and Brazil reported the highest number of confirmed cases, there are significant variations in the prevalence, severity and mortality associated with COVID-19 among different countries [1] . Variations are possibly attributable to differences in health care facilities and potential risk factors such as gender, age, chronic diseases, and other underlying health conditions [2] . For example, in a survival analysis conducted soon after the outbreak of COVID-19 in Wuhan Province, China, a high severity rate was observed among male patients over 65 years with underlying comorbidities such as diabetes, hypertension, coronary heart disease, and respiratory diseases [3] . Moreover, a recent study exploring multiple potential mechanisms responsible for the severity of COVID-19 infections, suggested that obesity could be a risk factor which mediates progression to a critical stage [4] .

Obesity has long been linked with higher risk of non-communicable diseases (NCDs) [5] , however previous research has established it is also associated with an increased risk of viral infections [6] . According to World Health Organization (WHO) estimates, more than 1.9 billion adults (≥ 18 years), were overweight and over 650 million were obese in 2016. This number has tripled within the last two decades [7] . A retrospective review of adult patients admitted with COVID-19 showed that 33% of obese patients had a higher rate of ICU admission and intubation, compared to normal-weight patients (21%, p=0.001) and 78% of this number were more likely to suffer from fever and shortness of breath [8] Therefore, it will be valuable to explore the impact of country-specific obesity prevalence on both infection rate and severity of COVID-19. It is critically important to plan and implement sound preventive and therapeutic strategies to reduce the risk of severity and mortality of COVID-19, and to tackle the resultant economic crisis. Hence, we aimed to investigate the relationship of country-specific obesity prevalence with respect to infection and mortality rates from COVID-19 across different countries.

J o u r n a l P r e -p r o o f

The real time statistics of total numbers of COVID-19 cases and deaths per million of the total population of selected countries as of 30 th September 2020, were retrieved from the Worldometer website [1] . This source includes data from individual countries derived directly from official government reports or indirectly, through local media sources which are deemed reliable. Recent country profiles released by the Non-communicable Diseases and Mental Health Cluster (NMH) of World Health Organization presenting key facts on NCDs, were examined for obesity prevalence data [12] , where obesity has been defined as BMI <30 kg m -2 . Countries were selected based on the following inclusion/exclusion criteria: a) total population of the country >1 million; b) attenuated the first wave of COVID-19; c) scale flattened following a clear first peak; d) >10000 PCR tests done per million of the total population and e) not facing a second wave at the time of reporting.

Data were extracted from the NCD country profiles and the Worldometer website by one reviewer (DTJ) using a standardized form and checked for accuracy by a second reviewer (PR). The data extracted were: country name, continent, total population, number of COVID- 

The results of our analysis demonstrate that obesity prevalence is a potential risk factor for both COVID-19 infection rate and mortality. This is in accordance with findings of previous studies [9, 10, 14] . To the best of our knowledge, this is the first research to report on the potential the impact of country-specific obesity prevalence on infection and mortality rate associated with the COVID-19 epidemic.

Only 54 of 214 affected countries globally, surpassed the first wave of COVID-19 infections and satisfied other inclusion criteria. Nearly one third of the countries were selected from the Asian continent. However, this is consistent with previous epidemiological findings, highlighting that the very first outbreak of the SARS CoV-2 virus occurred in China and subsequently spread to other continents [15] . Consequently, these countries were able to flatten the number of COVID-19 infections earlier compared to others that have emerged as new epicenters [16] . For example, Mongolia, which shares a border with China, has successfully contained the virus with a reported 300 cases and zero deaths [1] . This result may have been possible due to early and strict border closures or being one of the least densely populated countries in the world [17] .

Our results revealed that obesity prevalence is a significant risk factor among the susceptible individuals to be infected by SARS-CoV-2 virus, but the largest proportion of COVID-19 mortalities were reported among countries with moderate obesity prevalence. Generally, countries with higher obesity prevalence rates are also economically developed and citizens provided with well-established and highly equipped health care facilities. Therefore, we presume that the lower number of COVID-19 fatalities in these countries, despite a higher infection rate, can be attributed to their advanced medical care. Remarkably, the wealthiest J o u r n a l P r e -p r o o f country included in our study [18] , Qatar, reported the maximum number of COVID-19 infections (n=44,789) with only 76 mortalities, despite a high obesity prevalence rate (34%).

The same pattern was observed in other affluent countries such as Saudi Arabia, Germany, Australia and New Zealand with a significantly lower number of fatalities despite more than 25% of the total adult population with obesity. This paradox can be attributed to several factors, advanced preventive and curative health policies, political leadership and mean age of the population. In contrast, South American countries like Peru, Chile and Ecuador have a higher number of mortalities, despite a moderate level of obesity, due to limited health care facilities [19] . We observed that Spain and Sweden had a higher rate of COVID-19 mortalities compared to other European countries, as they were affected in the initial months soon after the breakout and during that time, knowledge regarding the treatment of COVID-19 was limited.

Our study has several limitations. The BMI value of 30 kg m -2 was considered as the cut-off point for defining obesity among the sample population. Even though this is in accordance with other observational studies [20] , different cut-off points can be employed to define obesity among different ethnic groups. For instance, among Asian countries, a BMI value of 27 kg m -2 , i.e. lower than WHO criteria, is used as the cut-off value for obesity [21] . In contrast, for Pacific Islanders, a BMI value of 32 kg m -2 , higher than WHO criteria, is used as the cut-off value for obesity [22] . Furthermore, obesity data were obtained from a secondary source -WHO, therefore updated and most recent prevalence data may have been missed.

Although recently published regional data on the prevalence of obesity are available for countries like Singapore, we used WHO country reports with the intention of possibly reducing substantial discrepancies between countries.

In addition, we excluded countries such as the USA, India and Brazil as they failed to satisfy one of our inclusion criteria of successfully flattening the curve of COVID-19 infections.

Infection curves in these countries are still on exponential phase with nearly one-third of total global COVID-19 [1] . However, the countries which satisfy our inclusion criteria will likely change in coming days/weeks, and we expect to incorporate the changes in future analyses.

Indeed, people worldwide should be encouraged to improve their life style with low calorie balance diets [23] comprised of vitamins (A and D), trace elements (Zinc and Selenium), nutraceuticals, and probiotics [24] and moderate to high physical activity levels [25] . The goal should be to reduce obesity prevalence in each country, which could be challenging despite the quarantine measures, and work from home behaviours during this pandemic. 

Global, regional, and national estimates of the population at increased risk of severe COVID-19 due to underlying health conditions in 2020: a modelling study

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Noncommunicable diseases country profiles World Health Organization

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Altitude and excess mortality during COVID-19 pandemic in Peru