The bidirectional association between diabetes and long-COVID-19 - A systematic review

Developing a clinical-pathological framework of long COVID-related fatigue applied to public safety workers

In the wake of the COVID-19 pandemic, millions worldwide are still struggling with persistent or recurring symptoms known as long COVID. Fatigue is one of the most prevalent symptoms associated with long COVID, and for many it can be debilitating. Understanding the potential pathological processes that link fatigue to long COVID is critical to better guide treatment. Challenges with diagnosis and treatment are reviewed, recognizing that post-COVID fatigue does not always present with corroborating clinical evidence, a situation that is frustrating for both patients and healthcare providers. Firefighters are a group of public safety workers who are particularly impacted by long COVID-related fatigue. Firefighters must be able to engage in strenuous physical activity and deal with demanding psychological situations, both of which may be difficult for those suffering from fatigue. Disruption in public safety worker health can potentially impact community welfare. This review creates a framework to explain the clinical-pathological features of fatigue resulting from long COVID, addresses diagnosis and treatment challenges, and explores the unique impact fatigue may pose for public safety workers and their organizations.

The efficacy of antivirals, corticosteroids, and monoclonal antibodies as acute COVID-19 treatments in reducing the incidence of long COVID: a systematic review and meta-analysis

BACKGROUND

Whether treatment during acute COVID-19 results in protective efficacy against long COVID incidence remains unclear.

OBJECTIVES

To assess the relationship between acute COVID-19 treatments of antivirals, corticosteroids, and monoclonal antibodies (mAbs) and long COVID incidence, and their effects in different populations and individual symptoms.

METHODS

A systematic review and meta-analysis.

DATA SOURCES

Searches were conducted up to January 29, 2024 in PubMed, Medline, Web of Science, and Embase.

STUDY ELIGIBILITY CRITERIA

Articles that reported long COVID incidence post-acute COVID with a follow-up of at least 30 days with no language restrictions.

PARTICIPANTS

Patients with a COVID-19 diagnosis history.

INTERVENTIONS

Patients treated with antivirals, corticosteroids or mAbs.

ASSESSMENT OF RISK OF BIAS

Quality assessment was based on the Newcastle-Ottawa scale, risk of bias in nonrandomized studies of interventions-I and Cochrane risk of bias tool.

METHODS OF DATA SYNTHESIS

Basic characteristics were documented for each study. Random forest model and meta-regression were used to evaluate the correlation between treatments and long COVID.

RESULTS

Our search identified 2363 records, 32 of which were included in the qualitative synthesis and 25 included into the meta-analysis. Effect size from 14 papers investigating acute COVID-19 antiviral treatment concluded its protective efficacy against long COVID (OR, 0.61; 95% CI, 0.48-0.79; p 0.0002); however, corticosteroid (OR, 1.57; 95% CI, 0.80-3.09; p 0.1913), and mAbs treatments (OR, 0.94; 95% CI, 0.56-1.56; p 0.8012) did not generate such effect. Subsequent subgroup analysis revealed that antivirals provided stronger protection in the aged, male, unvaccinated and nondiabetic populations. Furthermore, antivirals effectively reduced 8 out of the 22 analysed long COVID symptoms.

CONCLUSIONS

Our meta-analysis determined that antivirals reduced long COVID incidence across populations and should thus be recommended for acute COVID-19 treatment. There was no relationship between mAbs treatment and long COVID, but studies should be conducted to clarify acute COVID-19 corticosteroids' potential harmful effects on the post-acute phase of COVID-19.

Prevalence of Post-COVID conditions among Mexican COVID-19 survivors: a nationwide cross-sectional study

BACKGROUND

There are limited population-representative data that describe the potential burden of Post-COVID conditions (PCC) in Mexico. We estimated the prevalence of PCC overall and by sociodemographic characteristics among a representative sample of adults previously diagnosed with COVID-19 in Mexico. We additionally, characterized the PCC symptoms, and estimated the association between diagnosed type-2 diabetes and hypertension with PCC.

METHODS

We used data from the 2021 National Health and Nutrition Survey in Mexico, a nationally and regionally representative survey, from August 1st to October 31st, 2021. Using the WHO definition, we estimated the prevalence of PCC by sociodemographics and prevalence of PCC symptoms. We fit multivariable log-binomial regression models to estimate the associations.

RESULTS

The prevalence of PCC was 37.0%. The most common persistent symptoms were fatigue (56.8%), myalgia or arthralgia (47.5%), respiratory distress and dyspnea (42.7%), headache (34.0%), and cough (25.7%). The prevalence was higher in older people, women, and individuals with low socioeconomic status. There was no significant association between hypertension and PCC or diabetes and PCC prevalence.

CONCLUSIONS

About one-third of the adult Mexican population who had COVID-19 in 2021 had Post-COVID conditions. Our population-based estimates can help assess potential priorities for PCC-related health services, which is critical in light of our weak health system and limited funding.

Incidence, Risk, and Clinical Course of New-Onset Diabetes in Long COVID: Protocol for a Systematic Review and Meta-Analysis of Cohort Studies

BACKGROUND

COVID-19, an infectious disease pandemic, affected millions of people globally, resulting in high morbidity and mortality. Causing further concern, significant proportions of COVID-19 survivors endure the lingering health effects of SARS-CoV-2, the pathogen that causes COVID-19. One of the diseases manifesting as a postacute sequela of COVID-19 (also known as "long COVID") is new-onset diabetes.

OBJECTIVE

The aim of this study is to examine the incidence of new-onset diabetes in patients with long COVID and assess the excess risk compared with individuals who tested negative for COVID-19. The study also aims to estimate the population-attributable fraction for COVID-19 as a risk factor for new-onset diabetes in long COVID and investigate the clinical course of new-onset diabetes cases.

METHODS

This is a protocol for a systematic review and meta-analysis. PubMed, MEDLINE, Embase, Scopus, and Web of Science databases will be systematically searched to identify articles published between December 2019 and July 2024. A comprehensive search strategy for each database will be developed using a combination of Medical Subject Headings terms, subject headings, and text words to identify eligible studies. Cohort studies and randomized controlled trials (only control arms) involving patients with COVID-19 of any age, with follow-up data on new-onset diabetes in long COVID, will be considered for inclusion. Controls will comprise individuals who tested negative for COVID-19, with or without other respiratory tract infections. Three independent reviewers (AST, NB, and TT) will perform article selection, data extraction, and quality assessment of the studies. A fourth reviewer (ST) will review the identified studies for final inclusion in the analysis. The random-effects DerSimonian-Laird models will be used to estimate the pooled incidence proportion (%), incidence rate of diabetes (per 1000 person-years), and risk ratio (with 95% CIs) for diabetes incidence.

RESULTS

A total of 1972 articles were identified through the initial search conducted in August 2023. After excluding duplicates, conducting title and abstract screening, and completing full-text reviews, 41 articles were found to be eligible for inclusion. The search will be updated in July 2024. Currently, data extraction is underway, and the meta-analysis is expected to be completed in August 2024. Publication of the study findings is anticipated by the end of 2024.

CONCLUSIONS

The study findings should provide valuable insights to inform both clinical practice and public health policies regarding the effective management of new-onset diabetes in patients with long COVID.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/54853.

Association between newly diagnosed hyperglycemia/diabetes mellitus, atherogenic index of plasma and obesity in post-COVID-19 syndrome patients

PURPOSE

The COVID-19 pandemic represents a great global concern and its associated morbidities. The goal of this study was to determine the incidence of newly diagnosed hyperglycemia and diabetes among COVID-19 survivors and to evaluate whether obesity and lipid profile have an effect on this group using the atherogenic index of plasma (AIP).

METHODS

In the retrospective study, 511 adults with a previously diagnosed "Severe Acute Respiratory Syndrome Coronavirus 2" who admitted to COVID-19 follow-up outpatient clinic were evaluated. Data was collected on patient demographics, comorbidities, and some laboratory results. Logistic regression was used to estimate associated factors.

RESULTS

Newly diagnosed type 2 diabetes mellitus (T2DM) was defined in 17 patients (3.32%), hyperglycemia in 86 patients (16.82%). The results of analysis were examined, gender, age, BMI and triglyceride variables were found to be significant risk factors together. Fasting blood glucose values of 22 out of 86 patients with hyperglycemia returned to normal after six months of follow-up. Undiagnosed-preexisting DM in 4 out of 17 patients diagnosed with T2DM at their first visit and in 7 out of 8 hyperglycemia patients diagnosed with T2DM at the end of six-month follow-up.

CONCLUSION

COVID-19, may directly/indirectly, predispose to hyperglycemia. Obesity and hyperlipidemia are risk factors for newly diagnosed T2DM/hyperglycemia in post-COVID-19 syndrome patients. Since that some metabolic variables were found to be significantly higher in the group with high AIP values, we suggest that AIP might be used as a reference to predict the development of obesity and T2DM.

Long COVID exhibits clinically distinct phenotypes at 3-6 months post-SARS-CoV-2 infection: results from the P4O2 consortium

BACKGROUND

Four months after SARS-CoV-2 infection, 22%-50% of COVID-19 patients still experience complaints. Long COVID is a heterogeneous disease and finding subtypes could aid in optimising and developing treatment for the individual patient.

METHODS

Data were collected from 95 patients in the P4O2 COVID-19 cohort at 3-6 months after infection. Unsupervised hierarchical clustering was performed on patient characteristics, characteristics from acute SARS-CoV-2 infection, long COVID symptom data, lung function and questionnaires describing the impact and severity of long COVID. To assess robustness, partitioning around medoids was used as alternative clustering.

RESULTS

Three distinct clusters of patients with long COVID were revealed. Cluster 1 (44%) represented predominantly female patients (93%) with pre-existing asthma and suffered from a median of four symptom categories, including fatigue and respiratory and neurological symptoms. They showed a milder SARS-CoV-2 infection. Cluster 2 (38%) consisted of predominantly male patients (83%) with cardiovascular disease (CVD) and suffered from a median of three symptom categories, most commonly respiratory and neurological symptoms. This cluster also showed a significantly lower forced expiratory volume within 1 s and diffusion capacity of the lung for carbon monoxide. Cluster 3 (18%) was predominantly male (88%) with pre-existing CVD and diabetes. This cluster showed the mildest long COVID, and suffered from symptoms in a median of one symptom category.

CONCLUSIONS

Long COVID patients can be clustered into three distinct phenotypes based on their clinical presentation and easily obtainable information. These clusters show distinction in patient characteristics, lung function, long COVID severity and acute SARS-CoV-2 infection severity. This clustering can help in selecting the most beneficial monitoring and/or treatment strategies for patients suffering from long COVID. Follow-up research is needed to reveal the underlying molecular mechanisms implicated in the different phenotypes and determine the efficacy of treatment.

Triglicerydes/high-density lipoprotein ratio as a risk factor of post-Covid-19 sinus tachycardia: A retrospective study

Inappropriate sinus tachycardia (IST) is one of the manifestations of the post-COVID-19 syndrome (PCS), which pathogenesis remains largely unknown. This study aimed to identify potential risk factors for IST in individuals with PCS. The 1349 patients with PCS were included into the study. Clinical examination, 24H Holter ECG, 24H ambulatory blood pressure monitoring and biochemical tests were performed 12-16 weeks after the COVID-19 in all participants. IST was found in 69 (3.5%) individuals. In the clinical assessment IST patients were characterized by a higher age (p < 0.001) and lower prevalence of the diagnosed hypertension (p = 0.012), compared to remaining patients. Biochemical testing showed higher serum triglycerides (1.66 vs. 1.31 pmol/L, p = 0.007) and higher prevalence of a low high-density lipoprotein (HDL) cholesterol (24.6% vs. 15.2%, p = 0.035) in the IST group. Subsequently, the triglicerydes (TG)/HDL ratio, an indicator of insulin resistance, was significantly higher in the IST individuals (3.2 vs. 2.4, p = 0.005). 24H monitoring revealed a significantly higher minimum diastolic, maximum systolic and mean arterial blood pressure values in the IST group (p < 0.001 for all), suggesting a high prevalence of undiagnosed hypertension. A multivariate analysis confirmed the predictive value TG/HDL ratio >3 (OR 2.67, p < 0.001) as predictors of IST development. A receiver operating characteristic curve analysis of the relationship between the TG/HDL ratio and the IST risk showed that the predictive cut-off point for this parameter was 2.46 (area under the ROC curve = 0.600, p = 0.004). Based on these findings, one can conclude that insulin resistance seems to be a risk factor of IST, a common component of PCS.

Circulating haematopoietic stem cells and long-term outcomes of COVID-19

BACKGROUND AND AIMS

An acute depletion of circulating haematopoietic stem/progenitor cells (HSPCs) occurs during COVID-19, especially among patients with a poorer disease course. We herein examined whether HSPCs levels at hospital admission for COVID-19 predict 1-year mortality and the long-COVID syndrome.

MATERIALS AND METHODS

Patients hospitalized for COVID-19 in an infectious disease ward were consecutively enrolled. Circulating HSPC levels were assessed by flow cytometry as cells expressing CD34 and/or CD133. Follow-up was performed for 12 months after hospitalization through the review of electronic medical records and demographic local registers.

RESULTS

The study included 100 patients, 36 of whom reported symptoms of long-COVID and 20 died during follow-up. The reduction of 1-SD of HSPCs was associated with a 3- to 5-fold increase in the risk of 1-year mortality. Age, admission hyperglycaemia, C-reactive protein peak, liver enzymes, the need of high-flow oxygen and/or invasive ventilation were predictors of mortality at univariate analysis. Among pre-existing comorbidities, coronary heart disease and chronic kidney disease, but not diabetes, were associated with 1-year mortality. In multivariate analyses, HSPCs remained significantly associated with 1-year mortality independently of confounders. The development of pneumonia an in-hospital treatment with glucocorticoids and convalescent plasma were associated with long-COVID symptoms at follow-up. HSPCs, diabetes and other comorbidities were not predictors of long-COVID.

CONCLUSIONS

In a cohort of patients hospitalized for COVID-19, lower HSPC levels at the time of admission were independent predictors of 1-year mortality. However, COVID-19 severity, but not HSPC level, was significantly associated with the development of long-COVID symptoms.

Hereditary Connective Tissue Diseases and Risk of Post-Acute SARS-CoV-2

We completed a retrospective review of data collected by the JH-CROWN consortium based on ICD10 codes for a hospitalized cohort. The severity and prevalence of COVID-19 and development of PASC within heritable connective tissue diseases were unknown; however, clinical observation suggested a thorough examination was necessary. We compared rates of disease severity, death, and PASC in connective tissue diseases versus the entire cohort as well as in diabetes and hypertension to determine if connective tissue disease was a risk factor. Of the 15,676 patients in the database, 63 (0.40%) had a connective tissue disease, which is elevated relative to the distribution in the population, suggesting a higher risk of severe disease. Within these 63 patients, 9.52% developed PASC compared to 2.54% in the entire cohort (p < 0.005). Elucidation of populations at high risk for severe disease and development of PASC is integral to improving treatment approaches. Further, no other study to date has examined the risk in those with connective tissue diseases and these data support a need for enhanced awareness among physicians, patients, and the community.

A Critical Review on the Long-Term COVID-19 Impacts on Patients With Diabetes

BACKGROUND

The world is currently grappling with the potentially life-threatening coronavirus disease 2019 (COVID-19), marking it as the most severe health crisis in the modern era. COVID-19 has led to a pandemic, with the World Health Organization (WHO) predicting that individuals with diabetes are at a higher risk of contracting the virus compared to the general population. This review aims to provide a practical summary of the long-term impacts of COVID-19 on patients with diabetes. Specifically, it focuses on the effects of SARS-CoV-2 on different types of diabetic patients, the associated mortality rate, the underlying mechanisms, related complications, and the role of vitamin D and zinc in therapeutic and preventive approaches.

METHODS

Relevant literature was identified through searches on PubMed, Web of Science, and Science Direct in English, up to April 2023.

RESULTS

COVID-19 can lead to distressing symptoms and pose a significant challenge for individuals living with diabetes. Older individuals and those with pre-existing conditions such as diabetes, coronary illness, and asthma are more susceptible to COVID-19 infection. Managing COVID-19 in individuals with diabetes presents challenges, as it not only complicates the fight against the infection but also potentially prolongs the recovery time. Moreover, the virus may thrive in individuals with high blood glucose levels. Various therapeutic approaches, including antidiabetic drugs, are available to help prevent COVID-19 in diabetic patients.

CONCLUSIONS

Diabetes increases the morbidity and mortality risk for patients with COVID-19. Efforts are globally underway to explore therapeutic interventions aimed at reducing the impact of diabetes on COVID-19.

Diabetes Mellitus, Energy Metabolism, and COVID-19

Obesity, diabetes mellitus (mostly type 2), and COVID-19 show mutual interactions because they are not only risk factors for both acute and chronic COVID-19 manifestations, but also because COVID-19 alters energy metabolism. Such metabolic alterations can lead to dysglycemia and long-lasting effects. Thus, the COVID-19 pandemic has the potential for a further rise of the diabetes pandemic. This review outlines how preexisting metabolic alterations spanning from excess visceral adipose tissue to hyperglycemia and overt diabetes may exacerbate COVID-19 severity. We also summarize the different effects of SARS-CoV-2 infection on the key organs and tissues orchestrating energy metabolism, including adipose tissue, liver, skeletal muscle, and pancreas. Last, we provide an integrative view of the metabolic derangements that occur during COVID-19. Altogether, this review allows for better understanding of the metabolic derangements occurring when a fire starts from a small flame, and thereby help reducing the impact of the COVID-19 pandemic.

The knowns and unknowns of long COVID-19: from mechanisms to therapeutical approaches

The coronavirus disease 2019 (COVID-19) pandemic caused by SARS-CoV-2 has been defined as the greatest global health and socioeconomic crisis of modern times. While most people recover after being infected with the virus, a significant proportion of them continue to experience health issues weeks, months and even years after acute infection with SARS-CoV-2. This persistence of clinical symptoms in infected individuals for at least three months after the onset of the disease or the emergence of new symptoms lasting more than two months, without any other explanation and alternative diagnosis have been named long COVID, long-haul COVID, post-COVID-19 conditions, chronic COVID, or post-acute sequelae of SARS-CoV-2 (PASC). Long COVID has been characterized as a constellation of symptoms and disorders that vary widely in their manifestations. Further, the mechanisms underlying long COVID are not fully understood, which hamper efficient treatment options. This review describes predictors and the most common symptoms related to long COVID's effects on the central and peripheral nervous system and other organs and tissues. Furthermore, the transcriptional markers, molecular signaling pathways and risk factors for long COVID, such as sex, age, pre-existing condition, hospitalization during acute phase of COVID-19, vaccination, and lifestyle are presented. Finally, recommendations for patient rehabilitation and disease management, as well as alternative therapeutical approaches to long COVID sequelae are discussed. Understanding the complexity of this disease, its symptoms across multiple organ systems and overlapping pathologies and its possible mechanisms are paramount in developing diagnostic tools and treatments.

Low-dose naltrexone and NAD+ for the treatment of patients with persistent fatigue symptoms after COVID-19

A subset of patients experiences persistent fatigue symptoms after COVID-19, and patients may develop long COVID, which is characterized by lasting systemic symptoms. No treatments for this condition have been validated and are urgently warranted. In this pilot study, we assessed whether treatment with low-dose naltrexone (LDN, 4.5 mg/day) and supplementation with NAD + through iontophoresis patches could improve fatigue symptoms and quality of life in 36 patients with persistent moderate/severe fatigue after COVID-19. We detected a significant increase from baseline in SF-36 survey scores after 12 weeks of treatment (mean total SF-36 score 36.5 [SD: 15.6] vs. 52.1 [24.8]; p < 0.0001), suggestive of improvement of quality of life. Furthermore, participants scored significantly lower on the Chalder fatigue scale after 12 weeks of treatment (baseline: 25.9 [4.6], 12 weeks: 17.4 [9.7]; p < 0.0001). We found a subset of 52 % of patients to be responders after 12 weeks of treatment. Treatment was generally safe, with mild adverse events previously reported for LDN, which could be managed with dose adjustments. The iontophoresis patches were associated with mild, short-lived skin irritation in 25 % of patients. Our data suggest treatment with LDN and NAD+ is safe and may be beneficial in a subset of patients with persistent fatigue after COVID-19. Larger randomized controlled trials will have to confirm our data and determine which patient subpopulations might benefit most from this strategy.

Mechanisms of endothelial activation, hypercoagulation and thrombosis in COVID-19: a link with diabetes mellitus

Early since the onset of the COVID-19 pandemic, the medical and scientific community were aware of extra respiratory actions of SARS-CoV-2 infection. Endothelitis, hypercoagulation, and hypofibrinolysis were identified in COVID-19 patients as subsequent responses of endothelial dysfunction. Activation of the endothelial barrier may increase the severity of the disease and contribute to long-COVID syndrome and post-COVID sequelae. Besides, it may cause alterations in primary, secondary, and tertiary hemostasis. Importantly, these responses have been highly decisive in the evolution of infected patients also diagnosed with diabetes mellitus (DM), who showed previous endothelial dysfunction. In this review, we provide an overview of the potential triggers of endothelial activation related to COVID-19 and COVID-19 under diabetic milieu. Several mechanisms are induced by both the viral particle itself and by the subsequent immune-defensive response (i.e., NF-κB/NLRP3 inflammasome pathway, vasoactive peptides, cytokine storm, NETosis, activation of the complement system). Alterations in coagulation mediators such as factor VIII, fibrin, tissue factor, the von Willebrand factor: ADAMST-13 ratio, and the kallikrein-kinin or plasminogen-plasmin systems have been reported. Moreover, an imbalance of thrombotic and thrombolytic (tPA, PAI-I, fibrinogen) factors favors hypercoagulation and hypofibrinolysis. In the context of DM, these mechanisms can be exacerbated leading to higher loss of hemostasis. However, a series of therapeutic strategies targeting the activated endothelium such as specific antibodies or inhibitors against thrombin, key cytokines, factor X, complement system, the kallikrein-kinin system or NETosis, might represent new opportunities to address this hypercoagulable state present in COVID-19 and DM. Antidiabetics may also ameliorate endothelial dysfunction, inflammation, and platelet aggregation. By improving the microvascular pathology in COVID-19 and post-COVID subjects, the associated comorbidities and the risk of mortality could be reduced.

Body mass index changes and their association with SARS-CoV-2 infection: a real-world analysis

Objective

To study body mass index (BMI) changes among individuals aged 18-99 years with and without SARS-CoV-2 infection.

Subjects/Methods

Using real-world data from the OneFlorida+ Clinical Research Network of the National Patient-Centered Clinical Research Network, we compared changes over time in BMI in an Exposed cohort (positive SARS-CoV-2 test between March 2020 - January 2022), to a contemporary Unexposed cohort (negative SARS-CoV-2 tests), and an age/sex-matched Historical control cohort (March 2018 - January 2020). Body mass index (kg/m2) was retrieved from objective measures of height and weight in electronic health records. We used target trial approaches to estimate BMI at baseline and change per 100 days of follow-up for Unexposed and Historical cohorts relative to the Exposed cohort by categories of sex, race-ethnicity, age, and hospitalization status.

Results

The study sample consisted of 44,436 (Exposed cohort), 164,118 (Unexposed cohort), and 41,189 (Historical cohort). Cumulatively, 62% were women, 21.5% Non-Hispanic Black, 21.4% Hispanic and 5.6% Non-Hispanic Other. Patients had an average age of 51.9 years (SD: 18.9). At baseline, relative to the Exposed cohort (mean BMI: 29.3 kg/m2 [95%CI: 29.0, 29.7]), the Unexposed (-0.07 kg/m2 [95%CI; -0.12, -0.01]) and Historical controls (-0.27 kg/m2 [95%CI; -0.34, -0.20]) had lower BMI. Relative to no change in the Exposed over 100 days (0.00 kg/m2 [95%CI; -0.03,0.03]), the BMI of those Unexposed decreased (-0.04 kg/m2 [95%CI; -0.06, -0.01]) while the Historical cohort's BMI increased (+0.03 kg/m2 [95%CI;0.00,0.06]). BMI changes were consistent between Exposed and Unexposed cohorts for most population groups, except at start of follow-up period among Males and those 65 years or older, and in changes over 100 days among Males and Hispanics.

Conclusions

In a diverse real-world cohort of adults, mean BMI of those with and without SARS-CoV2 infection varied in their trajectories. The mechanisms and implications of weight retention following SARS-CoV-2 infection remain unclear.

Single-cell RNA sequencing reveals characteristics of myeloid cells in post-acute sequelae of SARS-CoV-2 patients with persistent respiratory symptoms

Background

Although our understanding of the immunopathology and subsequent risk and severity of COVID-19 disease is evolving, a detailed account of immune responses that contribute to the long-term consequences of pulmonary complications in COVID-19 infection remains unclear. Few studies have detailed the immune and cytokine profiles associated with post-acute sequelae of SARS-CoV-2 infection (PASC) with persistent pulmonary symptoms. The dysregulation of the immune system that drives pulmonary sequelae in COVID-19 survivors and PASC sufferers remains largely unknown.

Results

To characterize the immunological features of pulmonary PASC (PPASC), we performed droplet-based single-cell RNA sequencing (scRNA-seq) to study the transcriptomic profiles of peripheral blood mononuclear cells (PBMCs) from a participant naïve to SARS-CoV-2 (Control) (n=1) and infected with SARS-CoV-2 with chronic pulmonary symptoms (PPASC) (n=2). After integrating scRNA-seq data with a naïve participant from a published dataset, 11 distinct cell populations were identified based on the expression of canonical markers. The proportion of myeloid-lineage cells ([MLCs]; CD14+/CD16+monocytes, and dendritic cells) was increased in PPASC (n=2) compared to controls (n=2). MLCs from PPASC displayed up-regulation of genes associated with pulmonary symptoms/fibrosis, while glycolysis metabolism-related genes were downregulated. Similarly, pathway analysis showed that fibrosis-related (VEGF, WNT, and SMAD) and cell death pathways were up-regulated, but immune pathways were down-regulated in PPASC. Further comparison of PPASC with scRNA-seq data with Severe COVID-19 (n=4) data demonstrated enrichment of fibrotic transcriptional signatures. In PPASC, we observed interactive VEGF ligand-receptor pairs among MLCs, and network modules in CD14+ (cluster 4) and CD16+ (Cluster 5) monocytes displayed a significant enrichment for biological pathways linked to adverse COVID-19 outcomes, fibrosis, and angiogenesis. Further analysis revealed a distinct metabolic alteration in MLCs with a down-regulation of glycolysis/gluconeogenesis in PPASC compared to SARS-CoV-2 naïve samples.

Conclusion

Analysis of a small scRNA-seq dataset demonstrated alterations in the immune response and cellular landscape in PPASC. The presence of elevated MLC levels and their corresponding gene signatures associated with fibrosis, immune response suppression, and altered metabolic states suggests a potential role in PPASC development.

SGLT2 Inhibitors in Long COVID Syndrome: Is There a Potential Role?

The coronavirus disease (COVID)-19 has turned into a pandemic causing a global public health crisis. While acute COVID-19 mainly affects the respiratory system and can cause acute respiratory distress syndrome, an association with persistent inflammatory stress affecting different organ systems has been elucidated in long COVID syndrome (LCS). Increased severity and mortality rates have been reported due to cardiophysiological and metabolic systemic disorders as well as multiorgan failure in COVID-19, additionally accompanied by chronic dyspnea and fatigue in LCS. Hence, novel therapies have been tested to improve the outcomes of LCS of which one potential candidate might be sodium-glucose cotransporter 2 (SGLT2) inhibitors. The aim of this narrative review was to discuss rationales for investigating SGLT2 inhibitor therapy in people suffering from LCS. In this regard, we discuss their potential positive effects-next to the well described "cardio-renal-metabolic" conditions-with a focus on potential anti-inflammatory and beneficial systemic effects in LCS. However, potential beneficial as well as potential disadvantageous effects of SGLT2 inhibitors on the prevalence and long-term outcomes of COVID-19 will need to be established in ongoing research.

Prevalence and risk of new-onset diabetes mellitus after COVID-19: a systematic review and meta-analysis

Aims

After the acute phase of SARS-CoV-2 infection, the onset of glycemic impairment and diabetes have been reported. Nevertheless, the exact burden of glycemic impairment and diabetes after COVID-19 has not been clearly described.

Materials and methods

Electronic search was run in Pubmed (MEDLINE), Web of Science, Scopus, and ClinicalTrial.org for reports published from database inception to September 2022. We included observational studies reporting quantitative data on diabetes prevalence or its onset in subjects with a history of SARS-CoV-2 infection from at least 60 days. Risk of bias was assessed by the JBI's critical appraisal checklist. Random effect model was used to calculate pooled data. The review protocol was registered on PROSPERO (CRD42022310722).

Results

Among 1,630 records screened, 20 studies were included in the analysis. The mean or median age of participants ranged from ~ 35 to 64 years, with a percentage of males ranging from 28% to 80%. Only two studies were considered at low risk of bias. The estimate of diabetes prevalence, calculated on a total of 320,948 participants pooled with 38,731 cases, was 16% (95%CI: 11-22%). The estimate of proportion of incident cases of diabetes was 1.6% (95%CI: 0.8-2.7%). Subgroup analysis showed that previous hospitalization increased the prevalence of diabetes and the proportion of incident cases.

Conclusion

Diabetes is common in individuals who have experienced SARS-CoV-2 infection, especially if they required hospitalization. This data may be helpful to screen for diabetes and manage its complications in individuals who experienced COVID-19.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022310722, identifier CRD42022310722.

Mechanisms and clinical relevance of the bidirectional relationship of viral infections with metabolic diseases

Viruses have been present during all evolutionary steps on earth and have had a major effect on human history. Viral infections are still among the leading causes of death. Another public health concern is the increase of non-communicable metabolic diseases in the last four decades. In this Review, we revisit the scientific evidence supporting the presence of a strong bidirectional feedback loop between several viral infections and metabolic diseases. We discuss how viruses might lead to the development or progression of metabolic diseases and conversely, how metabolic diseases might increase the severity of a viral infection. Furthermore, we discuss the clinical relevance of the current evidence on the relationship between viral infections and metabolic disease and the present and future challenges that should be addressed by the scientific community and health authorities.

Assessing the Risk of Stroke in the Elderly in the Context of Long-COVID, Followed Through the Lens of Family Medicine

BACKGROUND/AIM

Patients infected with COVID-19 may experience a range of acute and chronic neurological disorders. While severe neurological complications like strokes and seizures were less common during the acute or post-COVID period, the long-term effects of COVID-19, known as long COVID, have received limited attention. This study aimed to examine the lasting consequences of SARS-CoV-2 infection and establish potential connections with related diseases.

PATIENTS AND METHODS

We followed a group of 157 patients for one year, predominantly from urban areas (61.8%), divided into three groups based on the presence of associated diseases that pose health risks: the control (43 patients), low-risk (67 patients), and high-risk (47 patients) groups.

RESULTS

We observed an inverse relationship between oxygen saturation and erythrocyte sedimentation rate, as well as a direct relationship between varicose disease and dyslipidemia, and gastrointestinal disease. Additionally, we noticed a less significant improvement in oxygen saturation and increased prevalence of psychoanxiety disorders in individuals undergoing anticoagulant treatment.

CONCLUSION

The impact of long COVID and its secondary effects, which persist for an extended period and are influenced by associated diseases, can be effectively monitored and addressed by primary care physicians. These findings can serve as a basis for developing more efficient approaches to managing the long-term consequences of COVID-19.

Reduced Exercise Capacity, Chronotropic Incompetence, and Early Systemic Inflammation in Cardiopulmonary Phenotype Long Coronavirus Disease 2019

BACKGROUND

Mechanisms underlying persistent cardiopulmonary symptoms after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (postacute sequelae of coronavirus disease 2019 [COVID-19; PASC] or "long COVID") remain unclear. This study sought to elucidate mechanisms of cardiopulmonary symptoms and reduced exercise capacity.

METHODS

We conducted cardiopulmonary exercise testing (CPET), cardiac magnetic resonance imaging (CMR) and ambulatory rhythm monitoring among adults >1 year after SARS-CoV-2 infection, compared those with and those without symptoms, and correlated findings with previously measured biomarkers.

RESULTS

Sixty participants (median age, 53 years; 42% female; 87% nonhospitalized; median 17.6 months after infection) were studied. At CPET, 18/37 (49%) with symptoms had reduced exercise capacity (<85% predicted), compared with 3/19 (16%) without symptoms (P = .02). The adjusted peak oxygen consumption (VO2) was 5.2 mL/kg/min lower (95% confidence interval, 2.1-8.3; P = .001) or 16.9% lower percent predicted (4.3%-29.6%; P = .02) among those with symptoms. Chronotropic incompetence was common. Inflammatory markers and antibody levels early in PASC were negatively correlated with peak VO2. Late-gadolinium enhancement on CMR and arrhythmias were absent.

CONCLUSIONS

Cardiopulmonary symptoms >1 year after COVID-19 were associated with reduced exercise capacity, which was associated with earlier inflammatory markers. Chronotropic incompetence may explain exercise intolerance among some with "long COVID."

Risk phenotypes of diabetes and association with COVID-19 severity and death: an update of a living systematic review and meta-analysis

AIMS/HYPOTHESIS

To provide a systematic overview of the current body of evidence on high-risk phenotypes of diabetes associated with COVID-19 severity and death.

METHODS

This is the first update of our recently published living systematic review and meta-analysis. Observational studies investigating phenotypes in individuals with diabetes and confirmed SARS-CoV-2 infection with regard to COVID-19-related death and severity were included. The literature search was conducted from inception up to 14 February 2022 in PubMed, Epistemonikos, Web of Science and the COVID-19 Research Database and updated using PubMed alert to 1 December 2022. A random-effects meta-analysis was used to calculate summary relative risks (SRRs) with 95% CIs. The risk of bias was evaluated using the Quality in Prognosis Studies (QUIPS) tool and the certainty of evidence using the GRADE approach.

RESULTS

A total of 169 articles (147 new studies) based on approximately 900,000 individuals were included. We conducted 177 meta-analyses (83 on COVID-19-related death and 94 on COVID-19 severity). Certainty of evidence was strengthened for associations between male sex, older age, blood glucose level at admission, chronic insulin use, chronic metformin use (inversely) and pre-existing comorbidities (CVD, chronic kidney disease, chronic obstructive pulmonary disease) and COVID-19-related death. New evidence with moderate to high certainty emerged for the association between obesity (SRR [95% CI] 1.18 [1.04, 1.34], n=21 studies), HbA1c (53-75 mmol/mol [7-9%]: 1.18 [1.06, 1.32], n=8), chronic glucagon-like peptide-1 receptor agonist use (0.83 [0.71, 0.97], n=9), pre-existing heart failure (1.33 [1.21, 1.47], n=14), pre-existing liver disease (1.40 [1.17, 1.67], n=6), the Charlson index (per 1 unit increase: 1.33 [1.13, 1.57], n=2), high levels of C-reactive protein (per 5 mg/l increase: 1.07 [1.02, 1.12], n=10), aspartate aminotransferase level (per 5 U/l increase: 1.28 [1.06, 1.54], n=5), eGFR (per 10 ml/min per 1.73 m2 increase: 0.80 [0.71, 0.90], n=6), lactate dehydrogenase level (per 10 U/l increase: 1.03 [1.01, 1.04], n=7) and lymphocyte count (per 1×109/l increase: 0.59 [0.40, 0.86], n=6) and COVID-19-related death. Similar associations were observed between risk phenotypes of diabetes and severity of COVID-19, with some new evidence on existing COVID-19  vaccination status (0.32 [0.26, 0.38], n=3), pre-existing hypertension (1.23 [1.14, 1.33], n=49), neuropathy and cancer, and high IL-6 levels. A limitation of this study is that the included studies are observational in nature and residual or unmeasured confounding cannot be ruled out.

CONCLUSIONS/INTERPRETATION

Individuals with a more severe course of diabetes and pre-existing comorbidities had a poorer prognosis of COVID-19 than individuals with a milder course of the disease.

REGISTRATION

PROSPERO registration no. CRD42020193692.

PREVIOUS VERSION

This is a living systematic review and meta-analysis. The previous version can be found at https://link.springer.com/article/10.1007/s00125-021-05458-8 FUNDING: The German Diabetes Center (DDZ) is funded by the German Federal Ministry of Health and the Ministry of Culture and Science of the State North Rhine-Westphalia. This study was supported in part by a grant from the German Federal Ministry of Education and Research to the German Center for Diabetes Research (DZD).

Endothelial dysfunction in autoimmune, pulmonary, and kidney systems, and exercise tolerance following SARS-CoV-2 infection

Long COVID is characterized by persistent symptoms beyond 3-months of severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) infection that last for at least 2 months and cannot be explained by an alternative diagnosis. Autonomic, immunologic, endothelial, and hypercoagulation are implicated as possible mechanisms of long COVID symptoms. Despite recognition of the public health challenges posed by long COVID, the current understanding of the pathophysiological underpinnings is still evolving. In this narrative review, we explore the long-term effects of SARS-CoV-2 infection on T cell activation such as autoimmune disorders and endothelial cell dysfunction involving vascular impairments within pulmonary and renal architecture. We have described how endothelial dysfunction and vascular abnormalities may underscore findings of exercise intolerance by way of impaired peripheral oxygen extraction in individuals with long COVID.

Laboratory Findings and Biomarkers in Long COVID: What Do We Know So Far? Insights into Epidemiology, Pathogenesis, Therapeutic Perspectives and Challenges

Long COVID (LC) encompasses a constellation of long-term symptoms experienced by at least 10% of people after the initial SARS-CoV-2 infection, and so far it has affected about 65 million people. The etiology of LC remains unclear; however, many pathophysiological pathways may be involved, including viral persistence; a chronic, low-grade inflammatory response; immune dysregulation and a defective immune response; the reactivation of latent viruses; autoimmunity; persistent endothelial dysfunction and coagulopathy; gut dysbiosis; hormonal and metabolic dysregulation; mitochondrial dysfunction; and autonomic nervous system dysfunction. There are no specific tests for the diagnosis of LC, and clinical features including laboratory findings and biomarkers may not specifically relate to LC. Therefore, it is of paramount importance to develop and validate biomarkers that can be employed for the prediction, diagnosis and prognosis of LC and its therapeutic response, although this effort may be hampered by challenges pertaining to the non-specific nature of the majority of clinical manifestations in the LC spectrum, small sample sizes of relevant studies and other methodological issues. Promising candidate biomarkers that are found in some patients are markers of systemic inflammation, including acute phase proteins, cytokines and chemokines; biomarkers reflecting SARS-CoV-2 persistence, the reactivation of herpesviruses and immune dysregulation; biomarkers of endotheliopathy, coagulation and fibrinolysis; microbiota alterations; diverse proteins and metabolites; hormonal and metabolic biomarkers; and cerebrospinal fluid biomarkers. At present, there are only two reviews summarizing relevant biomarkers; however, they do not cover the entire umbrella of current biomarkers, their link to etiopathogenetic mechanisms or the diagnostic work-up in a comprehensive manner. Herein, we aim to appraise and synopsize the available evidence on the typical laboratory manifestations and candidate biomarkers of LC, their classification based on pathogenetic mechanisms and the main LC symptomatology in the frame of the epidemiological and clinical aspects of the syndrome and furthermore assess limitations and challenges as well as potential implications in candidate therapeutic interventions.

Metabolic alterations upon SARS-CoV-2 infection and potential therapeutic targets against coronavirus infection

The coronavirus disease 2019 (COVID-19) caused by coronavirus SARS-CoV-2 infection has become a global pandemic due to the high viral transmissibility and pathogenesis, bringing enormous burden to our society. Most patients infected by SARS-CoV-2 are asymptomatic or have mild symptoms. Although only a small proportion of patients progressed to severe COVID-19 with symptoms including acute respiratory distress syndrome (ARDS), disseminated coagulopathy, and cardiovascular disorders, severe COVID-19 is accompanied by high mortality rates with near 7 million deaths. Nowadays, effective therapeutic patterns for severe COVID-19 are still lacking. It has been extensively reported that host metabolism plays essential roles in various physiological processes during virus infection. Many viruses manipulate host metabolism to avoid immunity, facilitate their own replication, or to initiate pathological response. Targeting the interaction between SARS-CoV-2 and host metabolism holds promise for developing therapeutic strategies. In this review, we summarize and discuss recent studies dedicated to uncovering the role of host metabolism during the life cycle of SARS-CoV-2 in aspects of entry, replication, assembly, and pathogenesis with an emphasis on glucose metabolism and lipid metabolism. Microbiota and long COVID-19 are also discussed. Ultimately, we recapitulate metabolism-modulating drugs repurposed for COVID-19 including statins, ASM inhibitors, NSAIDs, Montelukast, omega-3 fatty acids, 2-DG, and metformin.

Diabetes Mellitus after SARS-CoV-2 Infection: An Epidemiological Review

Diabetes mellitus (DM) is among the major global public health issues. According to recent projections, a continued rise in DM prevalence is expected in the following decades. The research has shown that DM is associated with poorer outcomes of coronavirus disease 2019 (COVID-19). However, there is growing evidence suggesting that COVID-19 is associated with new-onset DM type 1 and type 2. This review aims to summarize the current knowledge about the new onset of DM following COVID-19. All identified studies were longitudinal, and they have predominantly shown a significantly increased risk for new-onset DM (both type 1 and type 2) following a SARS-CoV-2 infection. Increased risk of poorer COVID-19 outcomes (mechanical ventilation, death) was noted in persons with new-onset DM following SARS-CoV-2 infection. Studies investigating risk factors for new-onset DM in COVID-19 patients showed that severe disease, age, ethnicity, ventilation, and smoking habits were associated with DM occurrence. The information summarized in this review presents a valuable source of evidence for healthcare policymakers and healthcare workers in the effort of planning prevention measures for new-onset DM after SARS-CoV-2 infection and the timely identification and appropriate treatment of patients with COVID-19 who could be at greater risk for new-onset DM.

Diabetes, COVID-19, and questions unsolved

Recent evidence suggests a role for Diabetes Mellitus in adverse outcomes from COVID-19 infection; yet the underlying mechanisms are not clear. Moreover, attention has turned to prophylactic vaccination to protect the population from COVID-19-related illness and mortality. We performed a comprehensive peer-reviewed literature search on an array of key terms concerning diabetes and COVID-19 seeking to address the following questions: 1. What role does diabetes play as an accelerator for adverse outcomes in COVID-19?; 2. What mechanisms underlie the differences in outcomes seen in people with diabetes?; 3. Are vaccines against COVID-19 efficacious in people with diabetes? The current literature demonstrates that diabetes is associated with an increased risk of adverse outcomes from COVID-19 infection, and post-COVID sequelae. Potential mechanisms include dysregulation of Angiotensin Converting Enzyme 2, Furin, CD147, and impaired immune cell responses. Hyperglycaemia is a key exacerbator of these mechanisms. Limited studies are available on COVID-19 vaccination in people with diabetes; however, the current literature suggests that vaccination is protective against adverse outcomes for this population. In summary, people with diabetes are a high-risk group that should be prioritised in vaccination efforts. Glycaemic optimisation is paramount to protecting this group from COVID-19-associated risk. Unsolved questions remain as to the molecular mechanisms underlying the adverse outcomes seen in people with diabetes; the functional impact of post-COVID symptoms on people with diabetes, their persistence, and management; how long-term vaccine efficacy is affected by diabetes, and the antibody levels that confer protection from adverse outcomes in COVID-19.