The influence of blood glucose on neutrophil function in individuals without diabetes

Identifying Predictive Biomarkers of Subclinical Mastitis in Dairy Cows through Urinary Metabotyping

Mastitis is a significant infectious disease in dairy cows, resulting in milk yield loss and culling. Early detection of mastitis-prone cows is crucial for implementing effective preventive measures before disease onset. Current diagnosis of subclinical mastitis (SCM) relies on somatic cell count assessment post-calving, lacking predictive capabilities. This study aimed to identify metabolic changes in pre-SCM cows through targeted metabolomic analysis of urine samples collected 8 wks and 4 wks before calving, using mass spectrometry. A nested case-control design was employed, involving a total of 145 multiparous dairy cows, with disease occurrence monitored pre- and postpartum. Among them, 15 disease-free cows served as healthy controls (CON), while 10 cows exclusively had SCM, excluding those with additional diseases. Urinary metabolite profiling revealed multiple alterations in acylcarnitines, amino acids, and organic acids in pre-SCM cows. Metabotyping identified 27 metabolites that distinguished pre-SCM cows from healthy CON cows at both 8 and 4 wks before parturition. However, only four metabolites per week showed significant alterations (p < 0.005). Notably, a panel of four serum metabolites (asymmetric dimethylarginine, proline, leucine, and homovanillate) at 8 wks prepartum, and another panel (asymmetric dimethylarginine, methylmalonate, citrate, and spermidine) at 4 wks prepartum, demonstrated predictive ability as urinary biomarkers for SCM risk (AUC = 0.88; p = 0.02 and AUC = 0.88; p = 0.03, respectively). In conclusion, our findings indicate that metabolite testing can identify cows at risk of SCM as early as 8 and 4 wks before parturition. Validation of the two identified metabolite panels is warranted to implement these predictive biomarkers, facilitate early intervention strategies, and improve dairy cow management to mitigate the impact of SCM. Further research is needed to confirm the efficacy and applicability of these biomarkers in practical farm settings.

Use of pre-operative hemoglobin a1c to predict early post-operative renal failure and infection risks in patients who are not diabetics and undergoing elective off pump coronary artery bypass graft surgery

Background

Recent studies have indicated that patients, both with and without diabetes with an increased HbA1c, have a higher rate of adverse outcomes following cardiac surgeries. Our study is focused on to evaluate the prognostic impact of admission value of HbA1c in non-diabetic patients for postoperative renal failure and infections.

Materials and Methods

Plasma HbA1c levels were collected from 200 consecutive nondiabetic patients who got admitted for elective off pump coronary artery bypass graft (CABG) procedure over a 2-year period under two groups, Group A whose HbA1c was < 6% at admission and Group B whose HbA1c was ≥6% and ≤6.4% at admission. After surgery, patients were followed up to see if they have got infection or renal failure as postoperative complication. Student's unpaired t test was used to test the significance of difference between the quantitative variables, Yate's and Fisher's chi square tests were used for qualitative variables.

Results

We found early postoperative renal failure in 14 (3/96 in Group A and 11/104 in Group B) out of 200 patients (7%) and infection in 21 (8/96 in Group A and 13/104 in Group B) out of 200 patients (10.5%). After data analysis, it was noted that there is a positive correlation between HbA1c and postoperative renal failure (P = 0.0213) whereas no association was found between HbA1c and postoperative infections (P = 0.175) in patients undergoing off-pump CABG surgery.

Conclusion

In patients without diabetes, a plasma HbA1c ≥6% was a significant independent predictor for early postoperative renal failure.

Inflammatory signature in acute-on-chronic liver failure includes increased expression of granulocyte genes ELANE, MPO and CD177

Acute-on-Chronic Liver Failure (ACLF) is associated with innate immune dysfunction and high short-term mortality. Neutrophils have been identified to influence prognosis in ACLF. Neutrophil biology is under-evaluated in ACLF. Therefore, we investigated neutrophil-specific genes and their association with ACLF outcomes. This is an observational study. Enriched granulocytes, containing neutrophils, isolated from study participants in three groups- ACLF(n = 10), chronic liver disease (CLD, n = 4) and healthy controls (HC, n = 4), were analysed by microarray. Differentially expressed genes were identified and validated by qRT-PCR in an independent cohort of ACLF, CLD and HC (n = 30, 15 and 15 respectively). The association of confirmed overexpressed genes with ACLF 28-day non-survivors was investigated. The protein expression of selected neutrophil genes was confirmed using flow cytometry and IHC. Differential gene expression analysis showed 1140 downregulated and 928 upregulated genes for ACLF versus CLD and 2086 downregulated and 1091 upregulated genes for ACLF versus HC. Significant upregulation of neutrophilic inflammatory signatures were found in ACLF compared to CLD and HC. Neutrophil enriched genes ELANE, MPO and CD177 were highly upregulated in ACLF and their expression was higher in ACLF 28-day non-survivors. Elevated expression of CD177 protein on neutrophil surface in ACLF was confirmed by flow cytometry. IHC analysis in archival post mortem liver biopsies showed the presence of CD177+ neutrophils in the liver tissue of ACLF patients. Granulocyte genes ELANE, MPO and CD177 are highly overexpressed in ACLF neutrophils as compared to CLD or HC. Further, this three-gene signature is highly overexpressed in ACLF 28-day non-survivors.

Rejuvenation of Neutrophil Functions in Association With Reduced Diabetes Risk Following Ten Weeks of Low-Volume High Intensity Interval Walking in Older Adults With Prediabetes - A Pilot Study

Neutrophil dysfunction is a common feature of aging, and is associated with the pathogenesis of many age-related diseases, including type 2 diabetes mellitus (T2DM). Although exercise training improves metabolic health, decreases risk of T2DM, and is associated with improving neutrophil functions, involvement in regular physical activity declines with age. The aim of this study was to determine if neutrophil functions could be improved in association with changes in fitness and metabolic parameters in older adults at risk for T2DM using 10-weeks of low volume high-intensity interval exercise training (HIIT). Ten older (71 ± 5 years) sedentary adults with prediabetes (HbA1c: 6.1 ± 0.3%) completed 10 weeks of a supervised HIIT program. Three 30 min sessions/week consisted of ten 60 s intervals of low intensity [50-60% heart rate reserve (HRR)] separated with similar durations of high intensity intervals (80-90% HRR). Before and after training, glucose and insulin sensitivity, neutrophil chemotaxis, bacterial phagocytosis, reactive oxygen species (ROS) production, and mitochondrial functions were assessed. Exercise-mediated changes in cardiorespiratory fitness (VO2peak) and neutrophil functions were compared to six young (23 ± 1 years) healthy adults. Following training, significant reductions in fasting glucose and insulin were accompanied by improved glucose control and insulin sensitivity (all p < 0.05). Before exercise training, VO2peak in the old participants was significantly less than that of the young controls (p < 0.001), but increased by 16 ± 11% following training (p = 0.002) resulting in a 6% improvement of the deficit. Neutrophil chemotaxis, phagocytosis and stimulated ROS production were significantly less than that of the young controls, while basal ROS were higher before training (all p < 0.05). Following training, chemotaxis, phagocytosis and stimulated ROS increased while basal ROS decreased, similar to levels observed in the young controls (all p < 0.05) and reducing the deficit of the young controls between 2 and 154%. In five of the adults with prediabetes, neutrophil mitochondrial functions were significantly poorer than the six young controls before training. Following training, mitochondrial functions improved toward those observed in young controls (all p < 0.05), reducing the deficit of the young controls between 14.3 and 451%. Ten weeks of HIIT in older adults at risk for T2DM reduced disease risk accompanied by improved primary and bioenergetic neutrophil functions. Our results are consistent with a reduced risk of infections mediated by relationships in exercise induced systemic and cellular metabolic features. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT02441205, registered on May 12th, 2015.

Preoperative hemoglobin A1c levels and increased risk of adverse limb events in diabetic patients undergoing infrainguinal lower extremity bypass surgery in the Vascular Quality Initiative

BACKGROUND

The impact of preoperative glycemic control on the risk of adverse perioperative outcomes in diabetic patients undergoing lower extremity bypass (LEB) surgery is not well-understood. We determined whether higher preoperative hemoglobin A1c (HbA1c) levels are associated with an increased risk of major adverse limb events, major adverse cardiovascular events, and mortality in diabetic patients undergoing infrainguinal LEB.

METHODS

A retrospective review of all infrainguinal LEB surgeries in the Vascular Quality Initiative registry from January 2012 to February 2017 was performed. Only surgeries performed on diabetic patients with complete demographic and clinical data, including HbA1c value at the time of LEB, were included for analysis (n = 7727). Entries were stratified according to the following HbA1c levels: 6 or less (n = 1087), greater than 6 to 7 or less (n = 2137), greater than 7 to 8 or less (n = 1657), and greater than 8 (n = 2846). Multivariate logistic regression was used to determine the association of preoperative HbA1c levels on the risk of in-hospital major adverse limb events (above ankle amputation, loss of primary graft patency), major adverse cardiovascular events (myocardial infarction, stroke, congestive heart failure, cardiac arrhythmia), and mortality.

RESULTS

The number of surgeries complicated by adverse limb and cardiovascular events were 356 (4.6%) and 1314 (17.0%), respectively. There were 72 in-hospital deaths (0.9%). After adjustment for clinical and demographic variables, patients with high HbA1c values (≥8%) were at an increased risk of adverse limb events (odds ratio [OR], 1.37; 95% confidence interval [CI], 1.01-1.86) compared with those with a normal HbA1c (>6% to ≤7%). High HbA1c values were not associated with an increased risk of cardiovascular events (OR, 1.07; 95% CI, 0.81-1.43) or mortality (OR, 1.57; 95% CI, 0.83-3.03). Patients with low HbA1c values (≤6%) did not experience a significantly higher risk for any of the three outcomes. In a stratified analysis, the association of high HbA1c values with adverse limb events was only present in those presenting without critical limb ischemia (OR 1.82; 95% CI, 1.05-3.16).

CONCLUSIONS

Poor preoperative glycemic control in diabetic individuals undergoing infrainguinal LEB, particularly in those without critical limb ischemia, is associated with an increased risk of in-hospital limb events. Further study should evaluate whether improved efforts to identify individuals with poorly controlled diabetes and subsequent interventions to better optimize glycemic control during the preoperative period improve limb outcomes after LEB.

Perioperative Management of Diabetes Mellitus: Novel Approaches

PURPOSE OF REVIEW

Several studies have demonstrated the benefits of glycemic control in the perioperative period and there is ongoing interest in development of systematic approaches to achieving glycemic control. This review discusses currently available data and proposes a new approach to the management of hyperglycemia in the perioperative period.

RECENT FINDINGS

In a recent study, we demonstrated that early preoperative identification of patients with poorly controlled diabetes and proactive treatment through various phases of surgery improves glycemic control, lowers the risk of surgical complications, and decreases the length of hospital stay. Implementation of a perioperative diabetes program that systematically identifies and treats patients with poor glycemic control early in the preoperative period is feasible and improves clinical care of patients undergoing elective surgery.

Effects of glycosylated hemoglobin levels on neutrophilic phagocytic functions

It is well established that diabetic patients with poor glycemic control have increased susceptibility to infections, but glucose levels have not been directly associated with this increase. The assessment of the effects of glycosylated hemoglobin (A₁ c) on the body’s ability to fight infections may be useful directly in establishing a link between elevated blood sugar and the risk of infections. A total of 127 subjects in Heart Pilot Study (HPS), sub-study of the Adventist Health Study 2 (AHS-2) completed a lifestyle, medical and food frequency questionnaire (FFQ) at baseline between 2013 and 2014. The A₁ c and phagocytic index (PI) were measured in the same blood sample and their associations were assessed using linear regression. Mean blood glucose (MBG) was estimated based on A₁ c levels using a standard formula. Three levels of MBG were used to compare prediabetic and diabetic ranges to the normal range. The PI is the average number of bacteria in the cytoplasm of 50 neutrophils, manually counted under a light microscope after the whole blood was briefly exposed to a standard dose of bacteria and stained. In multivariable analysis, we found that MBG in the prediabetic (117 to137 mg/dL) and diabetic (>137 mg/dL) ranges were associated with 12.9% (β= −0.129, 95% Cl: −0.30, 0.05) and 20.4% decrease in PI (β= −0.204, 95% Cl: −0.592, 0.184) compared to that, observed among those with normal MBG (p for trend=0.119). Elevated MBG levels contribute a decrease in the PI among those in the prediabetic and diabetic range compared to the normal range. Although our findings were not quite statistically significant due to low power which are clinically relevant in line with observations of an increased infections among diabetics. Further research on larger populations is needed.

Association between systemic oxidative stress and insulin resistance/sensitivity indices - the PREDIAS study

OBJECTIVE

Systemic oxidative stress has been causally related to insulin resistance and the subsequent development of type 2 diabetes mellitus (T2D). We investigated associations between circulating oxidative stress markers and different surrogate indexes of insulin sensitivity/resistance.

PATIENTS

Cross-sectional data were obtained from 1183 subjects with normal glucose tolerance (NGT), 280 subjects with impaired glucose tolerance (IGT) and 69 newly detected T2D individuals entering the PREDIAS (prevention of diabetes) study.

MEASUREMENTS

Following oral glucose tolerance test, five different insulin sensitivity/resistance indices were estimated: homoeostasis model of insulin resistance (HOMA-IR), quantitative insulin sensitivity check index (QUICKI), early phase insulin release (EPIR), insulin sensitivity index (ISI) and disposition index (DI). Additionally, circulating phagocyte generation of reactive oxygen species (ROS) and plasma total antioxidant capacity (TAC) was measured.

RESULTS

After adjustment for five covariates, HOMA-IR was significantly increased in IGT and T2D subjects when compared to NGT subjects (P = 0·000). QUICKI (P = 0·000), ISI (P = 0·000), EPIR (0·005/0·012) and DI (P = 0·000) were significantly attenuated in IGT and T2D. The prevalence of IGT and T2D individuals increased with increasing ROS generation and TAC tertiles. Increased systemic ROS generation was paralleled by increased HOMA-IR (P < 0·001, tertile 1/T1/vs tertile 3/T3/), decreased QUICKI (P < 0·001, T1 vs T3) and decreased ISI (P < 0·05, T1 vs T3). A similar tendency for indices was observed when comparing TAC tertiles: increase in HOMA-IR, decrease in QUICKI and ISI (P < 0·001, T1 vs T3 each). EPIR and DI did not differ significantly across ROS generation and TAC tertiles.

CONCLUSIONS

Systemic oxidative stress is associated with elevated insulin resistance index HOMA-IR, and decreased insulin sensitivity surrogates QUICKI and ISI.

Effect of host factors on neutrophil functions in response to Burkholderia pseudomallei in healthy Thai subjects

Burkholderia pseudomallei is an intracellular pathogenic bacterium that causes melioidosis in humans. On infection, neutrophils eliminate the majority of intracellular B. pseudomallei. Previous reports on the risk factors for melioidosis have shown that host factors, particularly age and diabetes mellitus, increase susceptibility to B. pseudomallei; however, whether these factors influence neutrophil functions in response to infection remains unknown. In this study, whole blood samples were collected from healthy Thai blood donors and co-cultured with B. pseudomallei, and phagocytic and respiratory burst functions of neutrophils were then measured by flow cytometry. The results show reduced neutrophil functions in older donors or those with poor glycemic control. Furthermore, the levels of antibody against B. pseudomallei showed a positive correlation with neutrophil functions. This study therefore indicated the importance of age, glycemic control, and antibody levels in the activity of neutrophils in melioidosis.

Relationship between glycemic control and histochemical myeloperoxidase activity in neutrophils in patients with type 2 diabetes

BACKGROUND

Myeloperoxidase (MPO) is a lysosomal hemoprotein found in the azurophilic granules in neutrophils. Myeloperoxidase plays an important role in oxygen-dependent killing of bacteria, fungi, virus and malignant cells. Diabetes mellitus (DM) is listed among conditions that may lead to secondary MPO deficiency in neutrophils but inconsistent results concerning MPO activity in diabetic patients have been reported in the literature. In this study, we aimed to evaluate the relationship between glycemic control in patients with type 2 DM and MPO activity in neutrophils from a histochemical perspective.

METHODS

The study included 40 patients with type 2 DM with poor glycemic control, 30 patients with type 2 DM with good glycemic control and 31 healthy controls. Peripheral blood smears were analyzed for each patient included in the study. Myeloperoxidase dye was used for staining. Myeloperoxidase ratios in neutrophil were evaluated for proportions of staining with MPO in 100 neutrophils in each smear. SPSS 16.0 version was used for statistical analyses.

RESULTS

Myeloperoxidase ratios in neutrophils were 70 (58.5-80) in type 2 DM patients with poor glycemic control compared to 80 (73.75-90) in those with good glycemic control and 88 (78-92) in healthy controls. The DM group with poor glycemic control was statistically significantly different from the other groups (p < 0.001).

CONCLUSIONS

Poor glycemic control in diabetic patients results in decreased MPO activity in neutrophils histochemically.

Investigation of neutrophil lymphocyte ratio and blood glucose regulation in patients with type 2 diabetes mellitus

Objective

Leukocytosis is thought to be directly associated with the pathogenesis of atherosclerosis and metabolic syndrome. Increased white blood cell (WBC) count is related to cardiovascular disease in patients with type 2 diabetes mellitus; raised neutrophil lymphocyte ratio (NLR) is associated with metabolic syndrome. There is little information, however, concerning a correlation between glycosylated haemoglobin (HbA1c) and NLR. The aim of the present study was to investigate the relationship between NLR and blood glucose regulation.

Methods

This retrospective study was conducted in patients with type 2 diabetes mellitus, divided into two groups according to HbA1c levels: group 1, HbA1c levels ≤ 7%; group 2, HbA1c levels > 7%. Venous WBC, neutrophil and lymphocyte counts were determined.

Results

Of 71 patients included, fasting serum glucose, neutrophil and WBC counts were significantly higher in group 2 compared with group 1. NLR had a positive correlation with HbA1c.

Conclusion

There may be a significant relationship between NLR and blood glucose regulation. The authors propose that increased NLR may be associated with elevated HbA1c in patients with type 2 diabetes mellitus.

Preoperative A1C and clinical outcomes in patients with diabetes undergoing major noncardiac surgical procedures

OBJECTIVE

To evaluate the relationship between preoperative A1C and clinical outcomes in individuals with diabetes mellitus undergoing noncardiac surgery.

RESEARCH DESIGN AND METHODS

Data were obtained from the National Surgical Quality Improvement Program database and the Research Patient Data Registry of the Brigham and Women's Hospital. Patients admitted to the hospital for ≥1 day after undergoing noncardiac surgery from 2005 to 2010 were included in the study.

RESULTS

Of 1,775 patients with diabetes, 622 patients (35%) had an A1C value available within 3 months before surgery. After excluding same-day surgeries, patients with diabetes were divided into four groups (A1C ≤6.5% [N = 109]; >6.5-8% [N = 202]; >8-10% [N = 91]; >10% [N = 47]) and compared with age-, sex-, and BMI-matched nondiabetic control subjects (N = 888). Individuals with A1C values between 6.5 and 8% had a hospital length of stay (LOS) similar to the matched control group (P = 0.5). However, in individuals with A1C values ≤6.5 or >8%, the hospital LOS was significantly longer compared with the control group (P < 0.05). Multivariate regression analysis demonstrated that a higher A1C value was associated with increased hospital LOS after adjustments for age, sex, BMI, race, type of surgery, Charlson Comorbidity Index, smoking status, and glucose level on the day of surgery (P = 0.02). There were too few events to meaningfully evaluate for death, infections, or readmission rate.

CONCLUSIONS

Our study suggests that chronic hyperglycemia (A1C >8%) is associated with poor surgical outcomes (longer hospital LOS). Providing a preoperative intervention to improve glycemic control in individuals with A1C values >8% may improve surgical outcomes, but prospective studies are needed.