Prognostic impact of hyperglycemia at onset of methicillin-sensitive Staphylococcus aureus bacteraemia

The impact of type 2 diabetes and glycaemic control on mortality and clinical outcomes in hospitalized patients with COVID-19 in the capital region of Denmark

AIM

To explore the impact of type 2 diabetes (T2D), glycaemic control and use of glucose-lowering medication on clinical outcomes in hospitalized patients with COVID-19.

MATERIALS AND METHODS

For all patients admitted to a hospital in the Capital Region of Denmark (1 March 2020 to 1 December 2021) with confirmed COVID-19, we extracted data on mortality, admission to intensive care unit (ICU), demographics, comorbidities, medication use and laboratory tests from the electronic health record system. We compared patients with T2D to patients without diabetes using Cox proportional hazards models adjusted for available confounding variables. Outcomes were 30-day mortality and admission to an ICU. For patients with T2D, we also analysed the association of baseline haemoglobin A1c (HbA1c) levels and use of specific glucose-lowering medications with the outcomes.

RESULTS

In total, 4430 patients were analysed, 1236 with T2D and 2194 without diabetes. The overall 30-day mortality was 19% (n = 850) and 10% (n = 421) were admitted to an ICU. Crude analyses showed that patients with T2D both had increased mortality [hazard ratio (HR) 1.37; 95% CI 1.19-1.58] and increased risk of ICU admission (HR 1.28; 95% CI 1.04-1.57). When adjusted for available confounders, this discrepancy was attenuated for both mortality (adjusted HR 1.13; 95% CI 0.95-1.33) and risk of ICU admission (adjusted HR 1.01; 95% CI 0.79-1.29). Neither baseline haemoglobin A1c nor specific glucose-lowering medication use were significantly associated with the outcomes.

CONCLUSION

Among those hospitalized for COVID-19, patients with T2D did not have a higher risk of death and ICU admission, when adjusting for confounders.

Hyperglycemia Increases Severity of Staphylococcus aureus Osteomyelitis and Influences Bacterial Genes Required for Survival in Bone

Hyperglycemia, or elevated blood glucose, renders individuals more prone to developing severe Staphylococcus aureus infections. S. aureus is the most common etiological agent of musculoskeletal infection, which is a common manifestation of disease in hyperglycemic patients. However, the mechanisms by which S. aureus causes severe musculoskeletal infection during hyperglycemia are incompletely characterized. To examine the influence of hyperglycemia on S. aureus virulence during invasive infection, we used a murine model of osteomyelitis and induced hyperglycemia with streptozotocin. We discovered that hyperglycemic mice exhibited increased bacterial burdens in bone and enhanced dissemination compared to control mice. Furthermore, infected hyperglycemic mice sustained increased bone destruction relative to euglycemic controls, suggesting that hyperglycemia exacerbates infection-associated bone loss. To identify genes contributing to S. aureus pathogenesis during osteomyelitis in hyperglycemic animals relative to euglycemic controls, we used transposon sequencing (TnSeq). We identified 71 genes uniquely essential for S. aureus survival in osteomyelitis in hyperglycemic mice and another 61 mutants with compromised fitness. Among the genes essential for S. aureus survival in hyperglycemic mice was the gene encoding superoxide dismutase A (sodA), one of two S. aureus superoxide dismutases involved in detoxifying reactive oxygen species (ROS). We determined that a sodA mutant exhibits attenuated survival in vitro in high glucose and in vivo during osteomyelitis in hyperglycemic mice. SodA therefore plays an important role during growth in high glucose and promotes S. aureus survival in bone. Collectively, these studies demonstrate that hyperglycemia increases the severity of osteomyelitis and identify genes contributing to S. aureus survival during hyperglycemic infection.

Hospital related hyperglycemia as a predictor of mortality in non-diabetes patients: A systematic review

BACKGROUND AND AIMS

Hyperglycemia is a condition often found in hospitalized patients due to stress injury, parenteral nutrition or medications administered during hospitalization. According to previous studies, hyperglycemia could be an independent predictor of mortality. The objective of the study is to assess the risk of mortality in non-diabetic patients with hyperglycemia during hospitalization.

METHODS

In this systematic review, we conducted literature reviews on several databases. Twelve studies were retrieved and critically reviewed using NOS.

RESULTS

A majority of the studies reported that hospital related hyperglycemia increased the mortality rate.

CONCLUSIONS

Hospital related hyperglycemia is an independent predictor factor for both in-hospital and long-term mortality.

Increased risk of diabetes mellitus five years after an episode of Staphylococcus aureus bacteraemia

Background: Diabetes mellitus is a risk factor for infection with Staphylococcus aureus, but it is unclear whether S. aureus infection is a prediabetic condition. Methods: Nationwide population-based matched cohort study. Incidence rate and ratio with 95% confidence interval of diabetes were estimated by negative binomial regression. Results: Of 19,988 individuals with S. aureus bacteraemia and 185,579 population comparators, 667 and 4974 had a primary diagnose of diabetes within five years after discharge of S. aureus bacteraemia corresponding to a more than double risk of diabetes (adjusted incidence rate ratio 2.28 (95% confidence interval: 2.10-2.46)). Other factors associated with an increased risk of diabetes during follow-up were male sex, increasing age and level of comorbidity. Of the S. aureus bacteraemia and population cohort, 422 (2.11%) and 4048 (2.18%), respectively, developed diabetes without complications, while 245 (1.23%) and 926 (0.50%), respectively, developed diabetes with complications. Rates of diabetes without complication were increased for individuals in the S. aureus bacteraemia cohort compared to the population cohort within the first two years after which rates were comparable while rates of diabetes with complications remained higher throughout the five year follow-up period compared to the population cohort. Conclusions: The risk of diabetes was markedly increased up to five years after S. aureus bacteraemia compared to a population cohort. In addition to screening for diabetes during hospital admittance, screening cases of S. aureus bacteraemia for diabetes in the years following S. aureus bacteraemia may allow for earlier detection of diabetes.

Bloodstream infection caused by S. aureus in patients with cancer: a 10-year longitudinal single-center study

BACKGROUND

Staphylococcus aureus bloodstream infections (SABIs) represent a significant cause of morbidity and mortality in cancer patients. In this study, we compared infection characteristics and evaluated epidemiology and risk factors associated to SABIs and 30-day attributable mortality in cancer patients.

METHODS

Clinical and microbiological data from patients with cancer and positive blood cultures for S. aureus were retrieved during a 10-year period at an oncology reference center. Analyses were performed according to type of malignancy and infection with methicillin-resistant S. aureus (MRSA). Data was evaluated using competing risk analyses to identify risk factors associated to 30-day mortality and used to create a point system for mortality risk stratification.

RESULTS

We included 450 patients and MRSA was documented in 21.1%. Hospital-acquired infection, healthcare-associated pneumonia, and type-2 diabetes were associated to MRSA. In patients with hematologic malignancies, MRSA was more frequent if hospital-acquired, but less likely in primary bacteremia. Variables associated to mortality included abdominal source of infection, hematologic malignancy, MRSA, glucose levels > 140 mg/dL, and infectious endocarditis; catheter removal and initiation of adequate treatment within 48 h of positive blood culture were protective factors. From our designed mortality prediction scale, patients with a score > 3 had a 70.23% (95%CI 47.2-85.3%) probability of infection-related death at 30 days.

CONCLUSION

SABIs are a significant health burden for cancer patients. Risk factors for SABI-related mortality in this population are varied and impose a challenge for management to improve patient's outcomes. Risk stratification might be useful to evaluate 30-day mortality risk.