Comparison of Food Intakes of Diabetes, Hypertension and Heart Disease Patients with Clinical Symptoms of COVID-19 and Asymptomatic Controls.

Background: In recent months, Coronavirus Disease 2019 (COVID-19) is a global health challenge. Nutrition is a key determining factor of health. In the present research, we assess and compare dietary food groups and nutrient supplements intake of diabetic, hypertensive and heart disease patients with clinical symptoms of COVID-19 and asymptomatic controls. Methods: This retrospective case-control research was conducted on 98 patients with diabetes, hypertension, and/or heart disease that 37 of them were COVID-19 positive with clinical symptoms. Dietary intakes of participants were recorded using a food frequency questionnaire (FFQ), which was designed and validated for the Iranian population. Results: 54% of all subjects had nutritional supplements consumption in the last 6 months, and there was no signicant difference in the type of nutritional supplements between cases and controls. There was no signicant difference in the median intake of food groups, in the last year, in metabolic syndrome patients with clinical symptoms of COVID-19 compared to controls. Crud OR shown, adequate consumption of any food groups was not associated with the occurrence of COVID-19. Conclusion: While dietary intake and nutritional supplements may be excellent promise for preventing clinical symptoms of COVID-19, however, up to now, researches are not enough for recommending these supplements above the Recommended Dietary Allowances (RDA) for prevention and/or treatment of COVID-19.

Results: 54% of all subjects had nutritional supplements consumption in the last 6 months, and there was no signi cant difference in the type of nutritional supplements between cases and controls. There was no signi cant difference in the median intake of food groups, in the last year, in metabolic syndrome patients with clinical symptoms of COVID-19 compared to controls. Crud OR shown, adequate consumption of any food groups was not associated with the occurrence of COVID-19.
Conclusion: While dietary intake and nutritional supplements may be excellent promise for preventing clinical symptoms of COVID-19, however, up to now, researches are not enough for recommending these supplements above the Recommended Dietary Allowances (RDA) for prevention and/or treatment of COVID-19.

Background
Recent months, Coronavirus Disease 2019 (COVID-19) is a global health challenge which leads to acute respiratory distress syndrome, respiratory and multiorgan failure, and increases mortality rate in metabolic syndrome (MetS) patients [1,2]. Nutrition is a key determining factor of health [3]. A recent study suggested that malnutrition can impact on immune cell metabolism and function [4]. Nearly 33.6% of adults population in Iran are suffering from MetS which is possibly caused by increased intake of the Western diet (WD) containing high amounts of saturated fat (HFD), re ned carbohydrates and sugars, and low levels of ber, unsaturated fats, and antioxidants [5,6] Modern diet seems an important factor in uencing the severity symptoms of COVID-19, through damaging the immune system [7,8].
A recent systematic review proposed nutrients with probable antivirus properties [9]. However, up to now, no research has evaluated the history of food intake and incidence of COVID-19 infection. Patients with history of diabetes, hypertension, and heart disease have a worse prognosis and are at greater risk for more severe symptoms and mortality from COVID-19.

Study design and participants
We conducted a retrospective case-control research on 98 patients with diabetes, hypertension, and/or heart disease that 37 of them were COVID-19 positive with clinical symptoms. A total of 37 COVID-19 positive patients that recurred, had laboratory-con rmed SARS-CoV-2 (Severe acute respiratory syndrome coronavirus 2) infection diagnosis by RTePCR (Reverse Transcriptase Polymerase Chain Reaction) of nasopharyngeal swabs, and hospitalized and/or referring to the outpatient clinic of Khatam Al-Anbia Hospital, in Shoushtar city, Khuzestan province, in Iran, between June and Aug 2020. We compared the case group with 61 MetS patients exposed to SARS-CoV-2 and asymptotic (control group).
Control group were selected from physicians, nurses, and staff working in hospitals, and medical centers and also, near family members of infected patients with SARS-CoV-2 that encountered the virus but no observed clinical symptoms of COVID-19. Dietary intakes of participants were recorded using a food frequency questionnaire (FFQ), which was designed and validated for the Iranian population [10]. The frequency of food groups (based on the food pyramid) that consumed, in the last year, asked in forms of daily, weekly, monthly, yearly, or never and then converted and reported to the unit per day.

Statistical analyses
The datasets used and analyzed during the current study are available from the corresponding author upon the reasonable request. Categorical variables were reported as frequency rates and percentages (%). Categorical variables compared using chi-squared test. Continuous data with normal or non-normal distribution were described using mean ± standard deviation (mean ± SD) or median (25th, and 75th percentile), respectively. Mann-Whitney U Test and Independent t-test used to compare continuous variables. Logistic regression was used to estimate the strength of the association between daily food groups and the odds ratios (ORs) of COVID-19. All statistical analyses were performed using SPSS (Statistical Package for the Social Sciences) version 17.0 (SPSS Inc, Chicago, IL, USA). Two-sided Pvalues with P < 0.05 were considered statistically signi cant.

Results
In our study, case and control groups were matched in terms of body mass index (BMI), gender, and age. There was no signi cant difference in the characteristics of participants between the two groups. The median BMI of all participants was 26. 46. 54% of all subjects had a consumption of nutritional supplements in the last 6 months, and there was no signi cant difference in the type of nutritional supplements between cases and controls. Table 1 demonstrates a comparison of daily food groups intake between two groups. Unexpectedly, we observed no signi cant difference in the median intake of food groups, in the last year, in MetS patients with clinical symptoms of COVID-19 compared to controls.
The results of the logistic regression models about the relation between daily food groups intake and the occurrence of COVID-19, with OR and 95% con dence intervals (CI), illustrated in Table 2. Crud OR shown, adequate consumption of any food group was not associated with the occurrence of COVID-19.

Discussion
Our study is the rst case-control research to compare dietary food intakes in MetS patients with clinical symptoms of COVID-19 and controls. The present data support that no speci c food groups or nutritional supplement have an effect on the occurrence of COVID-19. However, a previously published opinion suggested mechanisms involved in the potential role of diet and nutrients in the prevention of COVID-19 via the strengthening of the immune system and reducing in ammation and oxidative stress [11,12]. The mechanisms likely underlie such bene cial roles are not completely understood and other unknown factors may have interfered.