Discussion
The most striking finding of our study was that the presence of
metabolic syndrome significantly increased mortality in patients with
COVID 19 pneumonia. Among comorbid conditions in COVID 19 patients, the
highest mortality rates were observed in CAD (10.5%), diabetes mellitus
(7.3%), chronic respiratory diseases (6.3%), hypertension (6.0%) and
cancer (5.6%) patients11. In a recent study conducted
on black COVID 19 patients, the presence of metabolic syndrome was shown
to increase mortality, the need for intensive care and mechanical
ventilation, but the presence of comorbidities associated with metabolic
syndrome, such as hypertension and diabetes alone, were not related with
it12. In another study involving 1870 patients, the
presence of metabolic syndrome in COVID 19 patients increased mortality,
the need for intensive care and mechanical ventilation. Among
comorbidities associated with metabolic syndrome, diabetes was reported
to increase mortality alone13. It is still unclear
whether metabolic syndrome as a whole or its individual components
increase this risk in COVID 19 patients. In our study, CAD, diabetes,
hypertension, and hypertriglyceridemia were associated with increased
mortality. However, metabolic syndrome was shown to increase mortality
by 32.8 times. In addition, intensive care requirement and
hospitalization were significantly higher in COVID 19 patients with
metabolic syndrome.
In the literature, there are no studies regarding the effect of
hypertriglyceridemia in COVID 19 patients, except in cases of
hypertriglyceridemia secondary to tocilizumab, lopinavir and ritonavir
therapy14. The mortality-increasing effect of
hypertriglyceridemia found in our study may be parallel to the effect of
coronary artery disease on mortality. In our study, since specific
causes of death such as acute myocardial infarction and ischemic CV
could not be verified, this finding could not be interpreted.
Although metabolic syndrome is more common in the elderly, mortality
associated with metabolic syndrome decreases with
age15,16. In many studies of COVID 19 patients,
advanced age has been identified as the most important risk factor for
increased mortality2,3,17,18. Similarly, in our study,
the average age of patients with metabolic syndrome was higher and
advanced age was associated with increased mortality.
Metabolic syndrome is one of the common comorbidities in patients with
COPD. It is associated with physical inactivity and sedentary lifestyle,
smoking and inflammatory cell activation in adipose tissue and
lungs19,20. In many studies of COVID 19 patients, COPD
has been identified as an independent risk factor that increases disease
severity or mortality21,22,23. In our study, COPD was
more frequent in COVID 19 patients with metabolic syndrome, and
mortality rates were higher in patients with COPD.
The metabolic syndrome and aging is associated with a reduced cellular
stress response that would make tissues more vulnerable to injury from
Covid-19 increasing morbidity and mortality. Increased proinflammatory
cytokines, such as IL-6 and TNF-α, in patients with metabolic syndrome
are likely responsible for the development of diabetes, hypertension and
coronary artery diseases, due to subclinical and persistent
inflammation. This persistent inflammatory state causes an increase in
acute phase reactants such as CRP, fibrinogen, and ferritin and is
thought to worsen the clinical course of COVID
1924,25. In our study, COVID 19 patients with
metabolic syndrome had lower oxygen saturations, higher CRP levels and
more widespread radiological involvement at presentation compared to
those without metabolic syndrome. High CRP levels and radiological
weight score were associated with increased mortality. The worse
clinical, laboratory and radiological values at admission in COVID 19
patients with metabolic syndrome can be considered an indicator of the
worsening of this constant and persistent inflammatory state with COVID
19 in the background.
The most important limitation of the study is that it is a retrospective
study. Therefore, many patients had to be excluded because of lack of
data for metabolic syndrome.