The 2019 Coronavirus Virus Disease (COVID-19) represents a global public health challenge in the twenty-first century. As of June 2020, the virus had spread across 216 countries across the globe. This paper aims to analyze and identify those existing comorbidities among COVID-19 patients that represent potential risk factors for COVID-19 complications, severe illness, and death. Multiple database resources were searched. The resources include the University of Saskatchewan library USearch, Google Scholar, PubMed, Medline, and the Google search engine. Thirty-seven articles, which included 15 different types of chronic diseases, were selected. Among the reviewed diseases and conditions, cancer, diabetes, lymphopenia, hypertension, kidney disease, smoking, chronic obstructive pulmonary disease (COPD), and organ transplant were found to represent potential risk factors for COVID-19 complications, severe illness, and death. Other conditions that require further research as to whether they predispose subjects to severe illness and death include coronary artery disease, cerebrovascular disease, valvular heart disease, gastrointestinal diseases, HIV/AIDS, asthma, and liver disease. In conclusion, this article explains the association between diseases mentioned above and the severity of COVID-19 and clearly shows the population at risk. This paper will help government bodies and decision-makers prioritize resources for these populations to reduce mortality rates and overall quality of life.

Background: Dietary quality indices are practical as an instrument to investigate the extent of adhering to a special diet to prevent cardiovascular disease (CVD) in type 2 diabetes mellitus (T2DM). Considering the lack of any systematic review with regards to this issue, our aim was to examine observational studies to test the relationship between dietary quality indices and CVD risk factors in T2DM. Methods: Systematic search was performed in Web of knowledge, PubMed, Cochrane, Science direct, Google Scholar and Scopus databases from January 1990 to July 2020. The studies exploring the relationship between dietary quality indices (diet quality score (DQS), dietary diversity score (DDS), healthy diet indicator (HDI), healthy eating index (HEI), diet quality index (DQI), Mediterranean diet score (MDS)) and lipid profile, anthropometric indices, glucose profile as well as blood pressure were eligible to be included in this review. Overall, mean changes, odd ratio (RR), correlation coefficients, and beta coefficient of outcomes were extracted, with the quality assessment of studies performed applying The Newcastle-Ottawa scale. Results: From among 1627 papers, 10 articles were included: Eight cross-sectional and two prospective (cohort) studies. The association between HEI as well as MDS and CVD risk factors was more evident in the included studies. Fasting blood sugar, hemoglobin A1c, body mass index, and waist circumference revealed the greatest inverse significant relationship with dietary quality indices in adults with T2DM. Conclusion: Overall, the findings of this study suggest that the level of CVD risk factors in T2DM decreases significantly with increase in the score of dietary quality indices. Further studies in future are required to confirm these findings.