Many of the COVID-19 patients already suffer other metabolic syndrome related illnesses. It indicates that metabolic syndrome (MS) is an important risk factor for COVID-19. Therefore, it is important to understand the interplay between MS and COVID-19, in order to set a proper treatment for the affected patients.
Patients with metabolic disorders like obesity, diabetes, cardiovascular and liver disease may face a higher risk of COVID-19 infection. All of the disorders contribute to a significantly worse development and prognosis of the infection. The proposed drugs that are in clinical trial for COVID-19 treatment must be carefully considered for clinical use, especially in patients with MS.
MS is a risk factor influencing the progression and prognosis of COVID-19. The drugs currently evaluated for the infection treatment are promising but need further studies to prove their efficacy and safety, due to the adverse effects may be exacerbated by combination therapy or due to viral infection. The development of a vaccine for immunization is still the best long-term solution. The disease evolution and the symptoms vary from asymptomatic patients to severe cases of respiratory failure, which can lead to death. Some risk factors may be associated with the evolution and disease severity.
Studies all around the world have shown that comorbidities such as heart diseases, diabetes, kidney disease, neurological disease, pneumopathy, obesity and malign disease are the most frequent factor for a fatal outcome. In this context, metabolic syndrome (MS) is inserted as a common denominator to these comorbidities, since it is defined as a set of metabolic disorders that include insulin resistance, dyslipidemia, central obesity and hypertension, which are risk factors for the development of type 2 diabetes and cardiovascular diseases. In 2017, it was estimated that MS affected 20% of North American population, 25% of European population and approximately 15% of Chinese population. Having this in mind, the relationship between MS and its comorbidities that aggravate the COVID-19 prognosis cannot be ignored.
Obesity and COVID-19
Obesity is a risk factor for several diseases, including infectious ones. The bodies of obese patients are in constant chronic inflammation, due to the high concentrations of inflammatory mediators (chemokines, adipokines and pro-inflammatory cytokines). This chronic inflammation causes a delayed and inferior immune response, with decreased activation of macrophages (part of the immune system cells) in infection course. In addition, the immune memory of obese individuals is also impaired, both humoral (antibodies) and cellular, weakening both adaptive response of immune system to disease and immunization of these patients. Obesity had previously been identified as a risk factor for viral infections due to its influence on the immune response. Therefore, obesity is an additional risk factor for a fatal outcome of COVID-19 infection.
Diabetes and COVID-19
In 2016, diabetes was seventh most deadly disease in the world. It represents a risk factor for the development of other pathologies like cardiovascular diseases, chronic kidney disease etc. Its relationship with infectious diseases is not yet fully understood. However, in addition to suppressing the patient’s immunity, it can cause metabolic dysfunction that directly affects homeostasis of the entire organism. Diabetes has been identified as the second most common comorbidity among cases of COVID-19, which is an additional risk factor for the outcome of the infection. Cardiovascular disease and COVID-19 Currently, cardiovascular diseases are the main cause of death, being responsible for 31% of deaths in 2016. Much of this is reflection of eating habits, sedentary lifestyle and smoking, all typical for the modern life-style.In addition to history of CVD being an aggravating factor in COVID-19 development, cardiovascular complications can also be result of the infection. The metabolic syndrome contributes to the development of cardiovascular diseases, and what is more, in the current pandemic situation, the sedentary life style takes its toll.
Liver and COVID-19
The liver is an important organ for the most diverse body metabolic functions. Damage caused to hepatic tissue by COVID-19 has been observed. Patients with fatty liver and non-alcoholic steatohepatitis (fat induced liver inflammation) are exposed to a higher risk of liver damage in case of COVID-19 infection. Inflammation of liver tissue resulting from pro-inflammatory cytokines released by adipose tissue becomes even more aggravated by COVID-19 infection. It was observed that approximately 20%–30% of patients with COVID-19 had elevated transaminases (AST, ALT), especially in those with metabolic disorders associated with obesity and non-alcoholic fatty liver disease. In this context, NAFLD, which is considered the hepatic manifestation of MS, characterized by the deposit of fat in liver tissue, is inserted as a comorbidity.
Metabolic syndrome and COVID-19: An update on the associated comorbidities and proposed therapies – NCBI
Dr. Goran Nikolov, internist, cardiologist