Diabetes and susceptibility to COVID-19: Risk factors and preventive and therapeutic strategies

Role of nutrition in diabetes mellitus and infections

In this editorial, we have commented on the article that has been published in the recent issue of World Journal of Clinical Cases. The authors have described a case of unilateral thyroid cyst and have opined that the acute onset of infection may be linked to diabetes mellitus (DM). We have focused on the role of nutrition in the association between DM and infection. Patients with DM are at a high risk of infection, which could also be attributed to nutrition-related factors. Nutritional interventions for patients with diabetes are mainly based on a low-calorie diet, which can be achieved by adhering to a low-carbohydrate diet. However, dietary fiber supplementation is recommended to maintain the diversity of the gut microbiota. Furthermore, high-quality protein can prevent the increased risk of infection due to malnutrition. Supplementation of vitamins C, vitamins A, vitamins D, and folic acid improves blood sugar control and facilitates immune regulation. Mineral deficiencies augment the risk of infection, but the relationship with diabetes is mostly U-shaped and a good intake should be maintained.

Interactions of SARS-CoV-2 with Human Target Cells-A Metabolic View

Viruses are obligate intracellular parasites, and they exploit the cellular pathways and resources of their respective host cells to survive and successfully multiply. The strategies of viruses concerning how to take advantage of the metabolic capabilities of host cells for their own replication can vary considerably. The most common metabolic alterations triggered by viruses affect the central carbon metabolism of infected host cells, in particular glycolysis, the pentose phosphate pathway, and the tricarboxylic acid cycle. The upregulation of these processes is aimed to increase the supply of nucleotides, amino acids, and lipids since these metabolic products are crucial for efficient viral proliferation. In detail, however, this manipulation may affect multiple sites and regulatory mechanisms of host-cell metabolism, depending not only on the specific viruses but also on the type of infected host cells. In this review, we report metabolic situations and reprogramming in different human host cells, tissues, and organs that are favorable for acute and persistent SARS-CoV-2 infection. This knowledge may be fundamental for the development of host-directed therapies.