Effect of a Non-pharmacological Intervention (Nutritional Therapy and Pulmonary Rehabilitation) on Endothelial Function, Body Composition, and Physical Functionality in Recovered COVID-19 Patients.

Coronavirus Disease 2019 (COVID-19), caused by SARS-CoV-2, represents a global public health crisis that has resulted in severe complications and death in more than 500,000 individuals worldwide.

The risk factors for severe COVID-19 include age over 70 years, hypertension, diabetes mellitus, smoking, coronary artery disease, and obesity, which have been associated with endothelial dysfunction (ED). The coexistence of chronic non-communicable diseases significantly exacerbates the inflammatory response, increasing the risk of adverse events and poor prognosis. Similarly, a high probability of cardiovascular diseases in subjects is at elevated risk of severe COVID-19, due to the overexpression of angiotensin-converting enzyme 2. In addition, in our country, the leading causes of death are related to metabolic diseases: 19% of men and women between the ages of 30 and 69 die from cardiovascular diseases, with diabetes ranking as the second leading cause of death. Furthermore, 76.6% of the population is overweight or obese, and 25.5% has hypertension, factors that render our population particularly susceptible to moderate to severe COVID-19.

Moreover, both pharmacological and non-pharmacological treatments have primarily focused on the acute phase of infection. However, it is essential to implement treatment protocols, including pulmonary rehabilitation and nutritional therapy with citrulline supplementation or immunonutrients with anti-inflammatory properties, to prevent Post-Intensive Care Syndrome, reduce systemic inflammation, and improve endothelial function. These interventions may collectively enhance protein synthesis, attenuate muscle mass loss, and promote patient autonomy, functional recovery, and overall quality of life.

Post-COVID-19 syndrome Post-COVID-19 syndrome has been defined as the persistence of symptoms and/or delayed long-term remission of complications arising from SARS-CoV-2 infection, occurring beyond 4 weeks after initial symptom onset.

Nutritional supplementation L-citrulline L-Citrulline is a non-essential, water-soluble alpha-amino acid and a potent endogenous precursor of L-arginine, which increases the bioavailability of NO. In endothelial cells, NO is synthesized from L-arginine by endothelial nitric oxide synthase, yielding NO and L-citrulline.