Glycemic control and COVID-19 outcomes: the missing metabolic players.

Dear Editor,

The recent article by Zhan et al. deserves laud for focusing on a pertinent subject of metabolic prognostication in coronavirus disease 2019 (COVID-19). Nonetheless, the index research endeavor evaluating the association between glycemic control and short- to long-term COVID-19 outcomes in a prospective cohort study including 574 COVID-19 patients with type 2 diabetes mellitus, misses out on closely related important metabolic prognostic players.

Appropriate to the context, the lack of account for obesity as a comorbidity in the study deserves attention. This becomes particularly relevant when the former has been demonstrated to have a considerable prognostic significance in COVID-19., A meta-analysis by Cai et al. included 46 studies with a total of 625 153 COVID-19 patients to conclude that the obese patient cohort had a significantly escalated risk of severe disease, mechanical ventilation (MV), intensive care unit (ICU) admission and mortality (odds ratio (OR); 95% confidence interval (CI); I2: 3.81; 1.97–7.35; 57.4%, 1.66; 1.42–1.94; 41.3%, 2.25; 1.55–3.27; 71.5%, 1.61; 1.29–2.01; 83.1%, respectively). Indeed, Zhan et al. also employ a composite endpoint of the need for ICU admission, MV, in-hospital mortality or disease progression, to define short-term composite outcome in their study.

At the same time, prognostic implications of dyslipidemia are difficult to overlook in a study like Zhang et al. featuring metabolic disturbances at the cornerstone of poor outcomes in COVID-19. Notably, Liu et al. outlined an association of dyslipidemia with the disease severity of COVID-19 (OR; 95% CI; I2: 1.27; 1.11–1.44; 39.8%, P-values = 0.038) across an accumulated data from 12 studies and overall 12 995 COVID-19 patients. The dyslipidemic subset additionally demonstrated 2.13 times an accentuated mortality risk in their analysis compared to those without dyslipidemia (P-values = 0.001).

Albeit the fact remains that Zhan et al. were evaluating the prognostic ramifications of a dynamic management factor of glucose homeostasis, the importance of intricately linked baseline risk-predisposition cannot be overemphasized. The pivotal prognostic role of a composite risk-assessment is nested in the findings of a very recent study by Wu et al. They delineated that the COVID-19 patients with an underlying metabolic syndrome (defined utilizing the modified World Health Organization (WHO) criterion) manifested 56% and 81% heightened risk of ICU admission and mortality, respectively (P-values < 0.001). These results emanated subsequent to a multivariable analysis on a large retrospective data with a 39% incidence of metabolic syndrome (834 out of 2146 patients).

Needless to say, incorporation of the aforementioned missing metabolic players could have enhanced the lucidity of the Zhan et al. study findings, which classifies as another remarkable research aligned with the covetable aim of comprehending the potential factors associated with short- to long-term outcomes in COVID-19.

Conflict of interest. None declared.