News & Comment

Dipeptidylpeptidase (DPP)-4 is a key regulator of the incretin system. For several years DPP-4 inhibitors in addition to GLP-1 analogues are of major importance in the clinical management of obesity and type 2 diabetes. DPP-4 is also known as CD26 and represents a membrane bound protease on the surface of several eukaryotic cell types. Of interest, DPP-4, like ACE2, has been shown to serve as a binding partner for corona-like viruses to enter host immune cells. Since metabolic diseases are major risk factors for the present COVID-19 pandemic, we examined circulating soluble DPP-4 serum concentrations in patients suffering from severe COVID-19 infection and in healthy human subjects in a case control design. In this analysis sDPP-4 levels were significantly lower in COVID-19 patients compared to controls (242.70 ± 202.12 ng/mL versus 497.70 ± 188.13 ng/mL, p = 0.02). We also examined sDPP-4 serum concentrations in patients suffering from sepsis not due to corona-like viruses. In these subjects, sDPP-4 levels were not different compared to healthy case controls (p = 0.14), which might suggest the decrease of sDPP-4 to be specific for corona-like virus infections. Currently, most data point towards membrane bound ACE2 in contrast to DPP-4 as the major binding partner for COVID-19 internalization into host immune cells. However, the finding that the circulating soluble form of DPP-4 is reduced in hospitalized patients might suggest a regulatory role for both, ACE and DPP-4, in COVID-19 infections, especially since obesity and type 2 diabetes are major risk factor for a severe course of the disease

Coronavirus disease 2019 (COVID-19) is a declared global pandemic with multiple risk factors. Based on recent empirical studies, obesity is considered by several researchers as one of the serious risk factors for coronavirus-related complications. Yet, other scholars argue in favor of the existence of an obesity survival paradox. The objective of the current study is to analyze the potential relationships between different corona indicators and obesity on a statewide level. Since the United States is ranked as one of the OECD countries with a high level of overweight and obesity among its citizens—the majority of US states exceed the 30% benchmark of obese population—it is an especially interesting case study to explore this issue. In an attempt to estimate projected probabilities for infection by coronavirus and mortality rates as a function of obesity prevalence, the fractional logit regression is employed. Findings may support the counter-intuitive possibility of an obesity survival paradox. Consequently, ethical guidelines referring to priority in intubation and intensive care treatments should account for these complex relationships between obesity and corona. Both projected rates of infection and mortality drop with elevated prevalence of obesity. The reasons for these findings might be explained by several conditions such as elevated social distancing from more obese persons, increased metabolic reserves, more aggressive treatment, and unidentified factors that should be examined in future research.