Impact of Salt Intake and Renin-Angiotensin-Aldosterone System Blockade on Lung Severe Acute Respiratory Syndrome Coronavirus 2 Host Factors.

INTRODUCTION: The angiotensin-converting enzyme 2 (ACE2) as well as the transmembrane protease serine type 2 (TMPRSS2) have been found to play roles in cell entry for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus causing coronavirus disease 2019 (COVID-19). SARS-CoV-2 infection risk and severity of COVID-19 might be indicated by the expression of ACE2 and TMPRSS2 in the lung. METHODS: A high-salt diet rat model and renin-angiotensin-aldosterone system (RAAS) blockade were used to test whether these factors affect ACE2 and TMPRSS2 expression in the lung. A normal (0.3% NaCl), a medium (2% NaCl), or a high (8% NaCl) salt diet was fed to rats for 12 weeks, along with enalapril or telmisartan, before examining the lung for histopathological alteration. Using immunofluorescence and qRT-PCR, the localization as well as mRNA expression of ACE2 and TMPRSS2 were investigated. RESULTS: The findings provide evidence that both TMPRSS2 and ACE2 are highly expressed in bronchial epithelial cells as well as ACE2 was also expressed in alveolar type 2 cells. High-salt diet exposure in rats leads to elevated ACE2 expression on protein level. Treatment with RAAS blockers had no effect on lung tissue expression of ACE2 and TMPRSS2. CONCLUSIONS: These findings offer biological support regarding the safety of these drugs that are often prescribed to COVID-19 patients with cardiovascular comorbidity. High salt intake, on the other hand, might adversely affect COVID-19 outcome. Our preclinical data should stimulate clinical studies addressing this point of concern.

Comparison of Salt-Related Knowledge and Behaviors Status of WeChat Users between 2019 and 2020.

In order to identify the status of salt-related knowledge and behavior of the residents who were active in WeChat software between 2019 and 2020, 10-day salt-related surveys were conducted in 2019 and 2020 based on the WeChat public platform of China Healthy Lifestyle for All Campaign. Distribution and scores of salt-related knowledge, salt reduction behavior and high-salt intake behavior between 2019 and 2020 were compared. Data of 2109 participants in 2019 and 12,732 participants in 2020 were left for analysis. Overall, 88.2% of participants in 2019 had a willingness to reduce the amount of cooking salt in their households, significantly lower than 90.2% in 2020 (p-value < 0.05). In 2019 and 2020, over 80% of the participants knew fine dried noodles contain salt, but less than 30% knew ice cream contains salt. Over 78% of participants chose 5 g or 6 g for the maximum daily salt intake of healthy adults, and about 98% of participants knew that excessive salt intake would increase the risk of hypertension in both years. The percentage of participants who used salt measuring spoons asked restaurants to use less salt, read the sodium content on the nutrition facts table, chose foods with low sodium content and regularly used low-sodium salt, were 36.1%, 45.0%, 44.1%, 40.3% and 35.8% in 2019, and the percentage increased significantly to 46.4%, 49.2%, 50.8%, 47.1% and 43.4% in 2020 (all p-value < 0.05). The percentage of people regularly eating pickled mustard tubers, salted vegetables and sauce foods or using high-salt condiments also increased from 2019 to 2020. The median of salt-related knowledge scores, salt reduction behavior scores and high-salt intake behavior scores were 11, 2, 5 points in 2019, and 10, 3, 5 points in 2020, respectively. Compared to 2019, the salt-related knowledge score was relatively lower, while the salt reduction behavior score and high-salt intake behavior score were relatively higher in 2020. Besides, the score of salt-related knowledge and behaviors differed in different gender, age and hypertension groups. The COVID-19 epidemic may have influenced the salt-related knowledge and behaviors status of WeChat users in China. Promotion and education of salt-related knowledge and online behavior intervention are still needed, particularly for male and hypertension patients in the future.