Patients with coronavirus disease 2019 (COVID-19) are reported to have a greater prevalence of hyperglycaemia. Cytokine release as a consequence of severe acute respiratory syndrome coronavirus 2 infection may precipitate the onset of metabolic alterations by affecting glucose homeostasis. Here we describe abnormalities in glycometabolic control, insulin resistance and beta cell function in patients with COVID-19 without any pre-existing history or diagnosis of diabetes, and document glycaemic abnormalities in recovered patients 2 months after onset of disease. In a cohort of 551 patients hospitalized for COVID-19 in Italy, we found that 46% of patients were hyperglycaemic, whereas 27% were normoglycaemic. Using clinical assays and continuous glucose monitoring in a subset of patients, we detected altered glycometabolic control, with insulin resistance and an abnormal cytokine profile, even in normoglycaemic patients. Glycaemic abnormalities can be detected for at least 2 months in patients who recovered from COVID-19. Our data demonstrate that COVID-19 is associated with aberrant glycometabolic control, which can persist even after recovery, suggesting that further investigation of metabolic abnormalities in the context of long COVID is warranted.
A substantial proportion of patients who have recovered from coronavirus disease-2019 (COVID-19) experience COVID-19–related symptoms even months after hospital discharge. We extensively immunologically characterized patients who recovered from COVID-19. In these patients, T cells were exhausted, with increased PD-1
+
T cells, as compared with healthy controls. Plasma levels of IL-1
β
, IL-1RA, and IL-8, among others, were also increased in patients who recovered from COVID-19. This altered immunophenotype was mirrored by a reduced ex vivo T cell response to both nonspecific and specific stimulation, revealing a dysfunctional status of T cells, including a poor response to SARS-CoV-2 antigens. Altered levels of plasma soluble PD-L1, as well as of
PD1
promoter methylation and
PD1
-targeting miR–15-5p, in CD8
+
T cells were also observed, suggesting abnormal function of the PD-1/PD-L1 immune checkpoint axis. Notably, ex vivo blockade of PD-1 nearly normalized the aforementioned immunophenotype and restored T cell function, reverting the observed post–COVID-19 immune abnormalities; indeed, we also noted an increased T cell–mediated response to SARS-CoV-2 peptides. Finally, in a neutralization assay, PD-1 blockade did not alter the ability of T cells to neutralize SARS-CoV-2 spike pseudotyped lentivirus infection. Immune checkpoint blockade ameliorates post–COVID-19 immune abnormalities and stimulates an anti–SARS-CoV-2 immune response.
Recent studies have shown that SARS-CoV-2 infection may induce metabolic distress, leading to hyperglycemia in patients affected by COVID-19. We investigated the potential indirect and direct effects of SARS-CoV-2 on human pancreatic islets in 10 patients who became hyperglycemic after COVID-19. While there was no evidence of peripheral anti-islet autoimmunity, the serum of these patients displayed toxicity on human pancreatic islets, which can be abrogated by the use of anti-IL1β, anti-IL-6 and anti-TNF-α, cytokines known to be highly upregulated during COVID-19. Interestingly, the receptors of those aforementioned cytokines were highly expressed on human pancreatic islets. An increase in peripheral unmethylated INS DNA, a marker of cell death, was evident in several patients with COVID-19. Pathology of the pancreas from deceased hyperglycemic patients who had COVID-19, revealed mild lymphocytic infiltration of pancreatic islets and pancreatic lymph nodes. Moreover, SARS-CoV-2-specific viral RNA, along with the presence of several immature insulin granules or proinsulin, were detected in post-mortem pancreatic tissues, suggestive of β-cell altered proinsulin processing, as well as β-cell degeneration and hyperstimulation. These data demonstrate that SARS-CoV-2 may negatively affect human pancreatic islets function and survival by creating inflammatory conditions and possibly with a direct tropism, which may in turn lead to metabolic abnormalities observed in patients with COVID-19.
95 cases itself. A number of significant discrepancies emerged between the re-analysis and the findings reported in the paper both in terms of means and standard deviations of key outcome variables across the trial. These involved very substantial differences that we judged to be extremely unlikely to have arisen due to variations in composition of the original and re-analysed samples. We also discovered previously unidentified/reported problems with missing data and recording irregularities regarding changes in treatment regimen and subject identifiers.
Background
Weight loss in patients with metabolic syndrome has positive effects on cardiovascular and type 2 diabetes risks, but its effects on peripheral cytokines and lipid profiles in patients are still unclear.
Aim
To determine the effects of diet-induced weight loss on metabolic parameters, lipids and cytokine profiles.
Methods
Eighteen adult males with metabolic syndrome (defined according to IDF 2009) and Body Mass Index (BMI) between 25 and 35 kg/m2 were subjected to a balanced hypocaloric diet for 6 months to reach at least a 5% body weight loss.
Results
After weight loss, a significant improvement in BMI, waist circumference, insulin, fasting blood glucose and HOMA-IR (homeostasis model assessment of insulin resistance) was observed. The analysis of LDL (low-density lipoprotein cholesterol) and HDL (high-density lipoprotein cholesterol) lipoproteins showed a change in their composition with a massive transfer of triacylglycerols from HDL to LDL. This was associated with a significant reduction in peripheral pro-inflammatory cytokines such as IL-6, TNF-α, IL-8 and MIP-1β, leading to an overall decreased inflammatory score. An interesting positive correlation was also observed among peripheral cytokines levels after diet and peripheral levels of CETP (cholesteryl ester transfer protein), an enzyme with a key role in lipid change.
Conclusion
Weight loss through caloric restriction is associated with an improvement in peripheral lipid and cytokine profiles that may play a major role in improving cardiovascular risk.
Graphic abstract
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