Is a blood sample for hemoglobins in the transfusional range reliable?

OBJECTIVE

To evaluate the correlation and agreement in our unit and population of hemoglobin in gasometry versus hematology analyzer, to evaluate errors in transfusion or lack thereof.

RESULTS

strong association between Point-of-care (POC) and hematimetry, with P<.001, with a coefficient of determination r² of 0.56, an intraclass correlation coefficient of 0.63 and a Lin's concordance correlation coefficient of 0.65. For hemoglobins less than 7g/dL, a success rate of 29.41% was obtained.

CONCLUSIONS

Low-moderate agreement of POC hemoglobin with standard haemothymetry. High probability of errors in the indication of transfusion based on gasometer hemoglobins, especially in low hemoglobins.

Mitigated clinical disease in water buffaloes experimentally infected with Babesia bovis

Water buffaloes (Bubalus bubalis) are raised in tropical and subtropical regions of the world, and act as hosts of Babesia bovis parasites and the tick vector Rhipicephalus microplus. As no clinical cases of B. bovis-infection have been reported, we hypothesized that, unlike bovines, water buffaloes respond asymptomatically to an acute infection. To test this hypothesis, we inoculated two groups of 24-month-old Mediterranean breed water buffaloes with 10⁸ erythrocytes infected with two Argentine B. bovis isolates: BboM2P (n = 5) or BboS2P (n = 5). These strains displayed mild (BboM2P) or high (BboS2P) pathogenicity in Bos taurus calves of the same age (n = 5 and n = 1, respectively), when tested in parallel. In water buffaloes, no changes in body temperature were observed with both strains, and no hematocrit changes were detected in BboM2P-inoculated animals. In contrast, in the BboS2P-inoculated water buffalo group significant but relatively minor reductions in haematocrit values were noted compared to the infected bovine. The parasitemia attained in water buffaloes was considerably lower than in bovines and could only be detected by nested PCR, or indirectly via serology, whereas in most bovines, it could also be detected in Giemsa-stained smears under the light microscope. Our results show that water buffaloes present no or significantly mitigated clinical symptoms to B. bovis infections and suggest that they are able to substantially reduce and/or eliminate B. bovis parasites from circulation by an efficient innate immune mechanism.

Development of a hematocrit-insensitive device to collect accurate volumes of dried blood spots without specialized skills for measuring clozapine and its metabolites as model analytes

Dried blood spots have been used as alternatives to traditional plasma and serum samples. We have now developed new devices, named volumetric absorptive paper disc (VAPD) and mini-disc (VAPDmini), to collect accurate volumes of dried blood spots in a simple manner and without the need for additional instruments. VAPD consists of a filter paper disc and a filter paper sheet with holes slightly larger than the disc. The disc is fixed in one such hole without direct contact with the filter sheet. VAPDmini is a scaled-down version of the same device. When several drops of whole blood are applied, the disc becomes saturated and any excess sample is absorbed by the surrounding filter sheet. Accuracy and precision of sampling were assessed by determining the levels of clozapine and its metabolites as target analytes by liquid-liquid extraction and high-performance liquid chromatography with coulometric detection. In addition, differences in analyte recovery were within ±15% for all analytes in samples with 30-60% hematocrit, suggesting that VAPD and VAPDmini are insensitive to hematocrit for the analytes tested. The devices were also validated for analyte concentrations in the range 50-1000 ng/mL, and the limit of detection and lower limit of quantification were 5-17 ng/mL and 15-51 ng/mL, respectively. Intra- and inter-day precision ranged from 3% to 13%, whereas accuracy ranged from a -14% to 12% bias. Analytes were stable in the devices for at least 2 weeks at room temperature. Collectively, these results indicate that sampling using VAPD and VAPDmini is comparable to conventional hole punch sampling of entire dried blood spots, even for samples obtained from patients treated with clozapine. Importantly, the devices were also found to be suitable for sample self-collection.

Noninvasive hematocrit assessment for cardiovascular magnetic resonance extracellular volume quantification using a point-of-care device and synthetic derivation

BACKGROUND

Calculation of cardiovascular magnetic resonance (CMR) extracellular volume (ECV) requires input of hematocrit, which may not be readily available. The purpose of this study was to evaluate the diagnostic accuracy of ECV calculated using various noninvasive measures of hematocrit compared to ECV calculated with input of laboratory hematocrit as the reference standard.

METHODS

One hundred twenty three subjects (47.7 ± 14.1 years; 42% male) were prospectively recruited for CMR T1 mapping between August 2016 and April 2017. Laboratory hematocrit was assessed by venipuncture. Noninvasive hematocrit was assessed with a point-of-care (POC) device (Pronto-7® Pulse CO-Oximeter®, Masimo Personal Health, Irvine, California, USA) and by synthetic derivation based on the relationship with blood pool T1 values. Left ventricular ECV was calculated with input of laboratory hematocrit (Lab-ECV), POC hematocrit (POC-ECV), and synthetic hematocrit (synthetic-ECV), respectively. Statistical analysis included Wilcoxon signed-rank test, Bland-Altman analysis, receiver-operating curve analysis and intra-class correlation (ICC).

RESULTS

There was no significant difference between Lab-ECV and POC-ECV (27.1 ± 4.7% vs. 27.3 ± 4.8%, p = 0.106), with minimal bias and modest precision (bias - 0.18%, 95%CI [- 2.85, 2.49]). There was no significant difference between Lab-ECV and synthetic-ECV (26.7 ± 4.4% vs. 26.5 ± 4.3%, p = 0.084) in subjects imaged at 1.5 T, although bias was slightly higher and limits of agreement were wider (bias 0.23%, 95%CI [- 2.82, 3.27]). For discrimination of abnormal Lab-ECV ≥30%, POC-ECV had good diagnostic performance (sensitivity 85%, specificity 96%, accuracy 94%, and AUC 0.902) and synthetic-ECV had moderate diagnostic performance (sensitivity 71%, specificity 98%, accuracy 93%, and AUC 0.849). POC-ECV had excellent test-retest (ICC 0.994, 95%CI[0.987, 0.997]) and inter-observer agreement (ICC 0.974, 95%CI[0.929, 0.991]).

CONCLUSIONS

Myocardial ECV can be accurately and reproducibly calculated with input of hematocrit measured using a noninvasive POC device, potentially overcoming an important barrier to implementation of ECV. Further evaluation of synthetic ECV is required prior to clinical implementation.

The role of the peritrophic matrix and red blood cell concentration in Plasmodium vivax infection of Anopheles aquasalis

Background

Plasmodium vivax is predominant in the Amazon region, and enhanced knowledge of its development inside a natural vector, Anopheles aquasalis, is critical for future strategies aimed at blocking parasite development. The peritrophic matrix (PM), a chitinous layer produced by the mosquito midgut in response to blood ingestion, is a protective barrier against pathogens. Plasmodium can only complete its life-cycle, and consequently be transmitted to a new host, after successfully passing this barrier. Interestingly, fully engorged mosquitoes that had a complete blood meal form a thicker, well-developed PM than ones that feed in small amounts. The amount of red blood cells (RBC) in the blood meal directly influences the production of digestive enzymes and can protect parasites from being killed during the meal digestion. A specific study interrupting the development of the PM associated with the proteolytic activity inhibition, and distinct RBC concentrations, during the P. vivax infection of the New World malaria vector An. aquasalis is expected to clarify whether these factors affect the parasite development.

Results

Absence of PM in the vector caused a significant reduction in P. vivax infection. However, the association of chitinase with trypsin inhibitor restored infection rates to those of mosquitoes with a structured PM. Also, only the ingestion of trypsin inhibitor by non-chitinase treated mosquitoes increased the infection intensity. Moreover, the RBC concentration in the infected P. vivax blood meal directly influenced the infection rate and its intensity. A straight correlation was observed between RBC concentrations and infection intensity.

Conclusions

This study established that there is a balance between the PM role, RBC concentration and digestive enzyme activity influencing the establishment and development of P. vivax infection inside An. aquasalis. Our results indicate that the absence of PM in the midgut facilitates digestive enzyme dispersion throughout the blood meal, causing direct damage to P. vivax. On the other hand, high RBC concentrations support a better and thick, well-developed PM and protect P. vivax from being killed. Further studies of this complex system may provide insights into other details of the malaria vector response to P. vivax infection.

Bright light and oxygen therapies decrease delirium risk in critically ill surgical patients by targeting sleep and acid-base disturbances

This study examined the effects of bright light therapy (BLT) on the incidence of delirium in post-operative patients admitted to a surgical intensive care unit (SICU) and delineates risk and protective factors. We included 62 patients in a single-blind, randomized controlled study. The intervention group was treated with care as usual plus BLT for three consecutive days. Delirium was diagnosed by DSM-5 criteria with the Confusion Assessment Method-Intensive Care Unit (CAM-ICU). Risk factors for delirium were measured, including the APACHE II score, Insomnia Severity Index (ISI), as well as hematocrit and bicarbonate levels. Results were adjusted for treatment with nasal cannula oxygen and medications. Thirteen patients developed delirium within the three days following surgery. Generalized estimating equations analysis showed a significant preventive effect of BLT on delirium, which was independent of risk or treatment factors. Higher APACHE-II and ISI scores, lower hematocrit and lower bicarbonate levels increased the risk of developing delirium. BLT plus nasal cannula oxygen significantly reduced the likelihood of delirium. BLT significantly lowered ISI scores, while nasal cannula oxygen significantly enhanced bicarbonate levels. The results indicate that BLT and supplementary oxygen therapy may protect against delirium by targeting sleep-wake and deficits in the bicarbonate buffer system.

Evaluation of Hemoglobin Concentration and Hematocrit Values in Temporomandibular Joint Ankylosis Patients in Comparison to Nonankylosed Patients

AIM

The aim of this study is to find if there is any correlation between the hematological parameters and temporomandibular joint (TMJ) ankylosis and severity of the disease in such patients when compared with the nonankylosed patients.

MATERIALS AND METHODS

A total of 70 patients with age ranging from 10 to 40 years were included in the study after excluding the subjects according to the inclusion criteria. We categorized the subjects into two major groups: group I: control (nonankylosed/ healthy subjects) and group II: study group (ankylosed subjects) with each group containing 35 subjects (n = 35) respectively. A detailed personal and medical history was obtained. The pharynx diameter was also recorded for each patient, and blood investigations using venous blood were done, which included hemoglobin concentration and hematocrit values.

RESULTS

The results of study population showed a mean age of 22 ± 2.2 years. The most common etiology reported was trauma (65.7%) followed by infections, in which Noma was the most common one (80%). The difference of the mean values for hemoglobin and hematocrit concentration, between both the groups, was found to be statistically significant (p < 0.0001). Furthermore, a positive correlation was observed between the hemoglobin concentration and duration of ankylosis.

CONCLUSION

This study was an attempt to find a relation between the hemoglobin and hematocrit values in TMJ ankylosis patients so that the clinical treatment and management of such patients during surgeries be improved and may be beneficial for the patient.

CLINICAL SIGNIFICANCE

Temporomandibular joint ankylosis patients have to undergo complex surgical treatment, where the risk of excessive blood loss is high. Therefore, considering the complications of blood transfusions, such as infections and other risk factors, these patients can be good subjects for autologous blood transfusions, which help in improvement of the overall well-being of the patient.

Higher plasma corticosterone is associated with reduced costs of infection in red-winged blackbirds

Glucocorticoid hormones allow individuals to rapidly adjust their physiology and behavior to meet the challenges of a variable environment. An individual's baseline concentration of glucocorticoids can reflect shifts in life history stage and resource demands while mediating a suite of physiological and behavioral changes that include immune modulation and resource allocation. Thus, glucocorticoids could facilitate a response to parasites that is optimized for an individual's specific challenges and life history stage. We investigated the relationship between endogenous circulating glucocorticoids and measures of resistance and tolerance to Haemosporidian parasites (including those that cause avian malaria) in red-winged blackbirds (Agelaius phoeniceus). We found that higher endogenous concentrations of circulating glucocorticoids were associated with reduced costs of parasite infection, which is indicative of higher tolerance, but were unrelated to parasite burden in free ranging, breeding male birds. Post-breeding, both males and females with higher glucocorticoid concentrations had higher measures of tolerance to Haemosporidian infection. Our findings suggest a potentially adaptive role for glucocorticoids in shifting the response to parasites to align with an individual's current physiological state and the challenges they face.

Alterations of Hematological Parameters, Hemoglobin and Hematocrit With Liver Enzymes, Aspartate Transaminase and Alanine Transaminase Among Patients With Chronic Kidney Disease Undergoing Hemodialysis in Aljouf Region, Saudi Arabia

Background

Anemia results from low kidney production of the erythropoiesis-stimulant erythropoietin. Good liver function is crucial to patients with chronic kidney disease (CKD). This study analyzed two hematological parameters (hemoglobin (Hb) and hematocrit (Ht)) and two liver enzymes, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in patients with CKD undergoing hemodialysis (HD).

Methods

Three hundred and thirty individuals participated in this study. Of them, 159 patients with CKD undergoing HD and 171 healthy individuals as a control group were recruited between January and October 2017. Blood was collected into EDTA containers for complete blood count (CBC) and into additive plain containers for ALT and AST. Relevant case history data were also taken.

Results

Obtained results for first and second month of Hb, Ht, AST and ALT of CKD patients undergoing HD were lower (10.2 g/dL and 8.9 for Hb; 27.2% and 24.8% for Ht; 17.8 IU/L and 15.6 IU/L for ALT; 13.9 IU/L and 12.0 IU/L for AST, respectively) (P < 0.05) compared to healthy individuals (15.1 g/dL for Hb; 44.6% for Ht; 28.3 IU/L for ALT and 23.0 IU/L for AST). Furthermore, Hb, Ht, AST and ALT levels were significantly lower (P < 0.05) in their second month compared to the first month.

Conclusions

Anemia might emerge in CKD patients because of low Hb concentration and consequent low Ht. Advanced stage CKD causes decreased AST and ALT, as a result of lipid metabolism disturbances. Therefore, anemia and liver diseases are recommended to be treated in CKD patients to alleviate related complications. Renal transplantation must be performed earlier for them to avoid further complications.

Evaluating Otherwise-Discarded Umbilical Cord Blood as a Source for a Neonate's Complete Blood Cell Count at Various Time Points

BACKGROUND

Previous studies have reported the use of cord blood for admission laboratory complete blood counts (CBCs). However, no studies have investigated its stability for the first 30 min after delivery.

OBJECTIVES

We quantified blood cells drawn from the umbilical vein to determine the effect of (1) the time after placental delivery, and (2) the site of blood sampling (umbilical vein on an isolated cord segment vs. umbilical vein on the placental surface).

METHODS

Timed phlebotomies were drawn at 2, 10, and 30 min from (1) the umbilical vein on an isolated, double-clamped cord segment, and (2) the umbilical vein near or on the placental surface. Leukocyte count, hemoglobin, platelet count, and fibrinogen were measured on each phlebotomy sample.

RESULTS

Blood drawn from the isolated umbilical cord segments had leukocyte count, hemoglobin, platelet count, and fibrinogen that remained unchanged between the phlebotomies at 2, 10, and 30 min after delivery. However, blood drawn from the umbilical vein on the placental surface had, at 30 min, a leukocyte count (p = 0.002), hemoglobin (p = 0.01), and platelet count (p = 0.001) that were statistically different from the values at 2 and 10 min after delivery. There was no difference in fibrinogen at 2, 10, or 30 min.

CONCLUSIONS

If cord blood is used for a neonate's initial CBC, the blood should be drawn within 10 min of the placental delivery when it is taken from the umbilical vein on or near the placenta. If an umbilical cord segment is obtained, the phlebotomy can be delayed for up to 30 min.

Measuring Hematocrit in Mice Injected with In Vitro-Transcribed Erythropoietin mRNA

In vitro-transcribed (IVT) mRNA encoding therapeutic protein has the potential to treat a variety of diseases by serving as template for translation in the patient. To optimize conditions for such therapy, reporter protein-encoding mRNAs are usually used. One preferred reporter is erythropoietin (EPO), which stimulates erythropoiesis and leads to an increase in hematocrit. Measurement of hematocrit is a fast and reliable method to determine the potency of the in vitro-transcribed EPO mRNA. However, frequent blood draw from mice can increase hematocrit due to blood loss. Therefore, instead of using conventional hematocrit capillary tubes, we adapted glass microcapillaries for hematocrit measurement. Daily monitoring of mice can be accomplished by drawing less than 20 μL of blood, thus avoiding blood loss-related hematocrit increase. Due to the small volume of the withdrawn blood the hematocrit remains the same for mice injected with control mRNA, whereas significant hematocrit increase is measured between day 4 and 20 postinjection for those injected with pseudouridine-modified EPO mRNA. Following hematocrit measurement the microcapillaries are snapped easily to recover plasma for further analyses, including EPO measurement by ELISA.

Impact of maternal iron deficiency on the auditory functions in the young and adult guinea pig

OBJECTIVES

The aim of this study was to evaluate the hearing function in the guinea pig offspring at post-natal day (PNd) 24 and PNd84 born from dams suffering from iron deficiency during pregnancy and lactation by using the auditory brainstem response (ABR).

METHOD

Female guinea pigs (n = 24 per dietary group) were fed an iron sufficient (IS) diet (114 mg/kg) or an iron deficient (ID) diet (11.7 mg/kg) during the gestation and lactation periods. Pups in both groups were weaned at PNd9 and given the IS diet. The hematocrit level was measured at every trimester of pregnancy and at the day of sacrifice in dams and at PNd24 and PNd84 in pups. The animal body weight was measured on every second day until the day of sacrifice. The ABR was used in pups to measure the hearing threshold using a broad range of stimulus intensities and latency at 100 and 80 dB in response to 2, 4, 8, 16, and 32 kHz tone pips at PNd24 and 84.

RESULTS AND DISCUSSION

No significant difference between dietary groups was measured in hearing threshold and absolute latencies in pups at PNd24 and PNd84. Although the ID offspring (n = 16) did not differ in brainstem transmission times (BTTs) at 80 dB compare to the IS siblings (n = 25) at PNd24, they showed significant delayed inter-peak latency (IPL) I-IV at 100 dB suggesting a delayed BTT. At PNd84, the latency of all peaks including IPL I-IV at 80 and 100 dB significantly decreased and was also similar in pups from both dietary groups suggesting a better brain maturation. This is the first study investigating the long-term impact of maternal iron deficiency on the auditory functions in the guinea pig offspring during early development to adulthood.

Acoustofluidic hematocrit determination

Hematocrit (HCT) measurements of blood from patients, blood donors and athletes are routinely performed on a daily basis. These measurements are often performed in centralized hospital labs by whole blood analyzers, which leads to long time-to-result. On site measurements, based on centrifugation can be done, but these assays require manual handling, are slow and can just measure HCT in contrast to the central lab whole blood analyzers. In this work, we present a microfluidic based method to measure HCT in blood samples by acoustic separation of whole blood into discrete regions of plasma and red blood cells. Comparison of the areas of the red blood cell and plasma regions gives an accurate HCT value, with a linear correlation to the centrifugation-based reference method. A readout can be performed within 2 s of acoustic actuation providing a readout accuracy of approximately 3% points (pp) HCT. Additional accuracy can be achieved by extending the acoustic actuation to 20 s, yielding an error of less than 1 pp HCT. This acoustic tool is optimal for integration into a lab-on-a-chip device with in-line measurements of different clinical parameters.

Investigation of the effect of blood hematocrit and lipid content on the blood volume deposited by a disposable dried blood spot collection device

When using dried blood spot (DBS) sampling for the quantitative bioanalysis of circulating concentrations of drugs, metabolites and endogenous analytes, it is important that a fixed volume of blood is deposited to overcome the issues associated with blood hematocrit (HCT) and homogeneity. The volumetric performance of the KTH DBS collection device was tested with radiolabelled [¹⁴C]-diclofenac. It was demonstrated that the device deposits a fixed volume of blood (13.5μL) regardless of the HCT (25-65%), or lipid content of the blood sample. Further, it was found that the precision and accuracy of the derived dried blood samples were at least as good as those of a positive displacement pipette. The device was found to be easy to use and gave acceptable dried samples for 92.9% of the tests performed (n=42).

The top tertile of hematocrit change during hospitalization is associated with lower risk of mortality in acute heart failure patients

BACKGROUND

Hemoconcentration has been proposed as surrogate for changes in volume status among patients hospitalized with acute heart failure (AHF) and is associated with a favorable outcome. However, there is a dearth of research assessing the clinical outcomes of hospitalized patients with hemoconcentration, hemodilution and unchanged volume status.

METHODS

We enrolled 510 consecutive patients hospitalized for AHF from April 2011 to July 2015. Hematocrit (HCT) levels were measured at admission and either at discharge or on approximately the seventh day of admission. Patients were stratified by delta HCT tertitles into hemodilution (ΔHCT ≤ - 1.6%), no change (NC, -1.6% < ΔHCT ≤1.5%) and hemoconcentration (ΔHCT >1.5%) groups. The endpoint was all-cause death, with a median follow-up duration of 18.9 months.

RESULTS

Hemoconcentration was associated with lower left ventricle ejection fraction, as compared with NC and hemodilution groups, while renal function at entry, New York Heart Association class IV, and in-hospital worsening renal function (WRF) were not significantly different across the three groups. After multivariable adjustment, hemoconcentration had a lower risk of mortality as compared with hemodilution [hazard ratio (HR) 0.39, 95% confidence interval (CI) 0.24-0.63, P < 0.001], or NC (HR 0.54, 95% CI 0.33-0.88, P = 0.015], while hemodilution and NC did not have significantly differ in mortality (HR 0.72, 95% CI 0.48-1.10, P = 0.130).

CONCLUSIONS

In patients hospitalized with AHF, an increased HCT during hospitalization is associated with a lower risk of all-cause mortality than a decreased or unchanged HCT. Furthermore, all-cause mortality does not differ significantly between patients with unchanged and decreased HCT values.

Postoperative Haematocrit and Outcome in Critically Ill Surgical Patients

INTRODUCTION

Haematocrit has been studied as an outcome predictor. The aim of this study was to evaluate the correlation between low haematocrit at surgical intensive care unit admission and high disease scoring system score and early outcomes.

MATERIAL AND METHODS

This retrospective study included 4398 patients admitted to the surgical intensive care unit between January 2006 and July 2013. Acute physiology and chronic health evaluation and simplified acute physiology score II values were calculated and all variables entered as parameters were evaluated independently. Patients were classified as haematocrit if they had a haematocrit < 30% at surgical intensive care unit admission. The correlation between admission haematocrit and outcome was evaluated by univariate analysis and linear regression.

RESULTS

A total of 1126 (25.6%) patients had haematocrit. These patients had higher rates of major cardiac events (4% vs 1.9%, p < 0.001), acute renal failure (11.5% vs 4.7%, p < 0.001), and mortality during surgical intensive care unit stay (3% vs 0.8%, p < 0.001) and hospital stay (12% vs 5.9%, p < 0.001).

DISCUSSION

A haematocrit level < 30% at surgical intensive care unit admission was frequent and appears to be a predictor for poorer outcome in critical surgical patients.

CONCLUSION

Patients with haematocrit had longer surgical intensive care unit and hospital stay lengths, more postoperative complications, and higher surgical intensive care unit and hospital mortality rates.

Short communication: Alteration in blood parameters by enrofloxacin in juvenile lesser spotted dogfish (Scyliorhinus canicula, Linnaeus, 1758) after intramuscular injection

Enrofloxacin (EF) is a veterinary drug for respiratory, gastrointestinal and urinary tract infections. Parenteral administration at doses higher than the manufacturer recommended dosage has induced cartilage lesions in juvenile mammals and poultry. In elasmobranchs EF is commonly used for the treatment of infectious diseases, however only one study has been performed previously to evaluate pharmacokinetics and the potential chondrotoxicity of a fluoroquinolone in adult skates. In present study juvenile lesser spotted dogfish (Scyliorhinus canicula, Linnaeus, 1758) were treated with low (LD, 5mg/kg) and high dose (HD, 10mg/kg) of EF daily via intramuscular injection for 15 consecutive days, as indicated in a recognized treatment. Hematological parameters, oxidative stress and histology of vertebral cartilage were evaluated. No cartilage damage was observed. Hematological parameters evaluation underlined a significant (p=0.035), dose-dependent reduction in red blood cell count and in hematocrit (40% and 6%, respectively). Anyway, the biological significance of this reduction is doubtful, due to limited decrease observed. The evaluation of oxidative stress parameters underlined that glutathione levels, as well as glutathione S-transferase and catalase activities, were significantly increased in HD group animals, with respect to untreated and solvent control groups. Obtained data do not support a toxic effect of EF on dogfish cartilage, while concern arises from hematological and oxidative stress data.

Elevated 1-h post-challenge plasma glucose levels in subjects with normal glucose tolerance or impaired glucose tolerance are associated with whole blood viscosity

AIM

It has been suggested that glucose levels ≥155 mg/dl at 1-h during an oral glucose tolerance test (OGTT) may predict development of type 2 diabetes and cardiovascular events among adults with normal glucose tolerance (NGT 1 h-high). Studies showed a link between increased blood viscosity and type 2 diabetes. However, whether blood viscosity is associated with dysglycemic conditions such as NGT 1 h-high, impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) is unsettled.

METHODS

1723 non-diabetic adults underwent biochemical evaluation and OGTT. A validated formula based on hematocrit and total plasma proteins was employed to estimate whole blood viscosity. Subjects were categorized into NGT with 1 h glucose <155 mg/dL (NGT-1 h-low), NGT-1 h-high, IFG and/or IGT.

RESULTS

Hematocrit and blood viscosity values appeared significantly higher in individuals with NGT 1 h-high, IFG and/or IGT as compared to NGT 1 h-low subjects. Blood viscosity was significantly correlated with age, waist circumference, blood pressure, HbA1c, fasting, 1- and 2-h post-challenge insulin levels, total cholesterol and low-density lipoprotein, triglycerides, fibrinogen, white blood cell, and inversely correlated with high-density lipoprotein and insulin sensitivity. Of the four glycemic parameters, 1-h post-challenge glucose showed the strongest correlation with blood viscosity (β = 0.158, P < 0.0001) in a multivariate regression analysis model including several atherosclerosis risk factors.

CONCLUSIONS

Our results demonstrate a positive relationship between blood viscosity and 1-h post-challenge plasma glucose. They also suggest that a subgroup of NGT individuals with 1-h post-challenge plasma >155 mg/dl have increased blood viscosity comparable to that observed in subjects with IFG and/or IGT.

Hematocrit of mammals (Artiodactyla, Carnivora, Primates) at 1500m and 2100m altitudes

The rise in hematocrit (Hct) is one of the hallmarks of human acclimatization to high altitude and, in chronic conditions, reflects the hypoxia-induced polycythemia. However, it is not a uniform response among domestic species and it is not found in Andean camelids, species long adapted to high altitudes. Hence, we asked to what extent the polycythemia of humans is common among mammals. Hct data were collected from captive mammals of three orders (Primates, Artiodactyla, Carnivora), 70 specimens of 33 species at ∼1500m altitude (barometric pressure Pb=635mmHg) and 296 specimens of 64 species at ∼2100m (Pb=596mmHg), long-term residents at those altitudes. Sea level values and data in men and women at the corresponding altitudes were from a compilation of literature sources. At either altitude Hct was significantly higher than at sea level both in men and women; the increase (ΔHct) for genders combined averaged 3.4% (±0.7 SEM) at 1500m and 5.4% (±0.3) at 2100m. Differently, among the three mammalian orders studied a significant increase in Hct occurred only in females of Carnivora (at 1500m) and in males of Primates (at 2100m). The average ΔHct of all species combined was 0.8% (±0.7) at 1500m and 1.5% (±0.4) at 2100m, both significantly less than in humans (P<0.001). At 2100m the average ΔHct of nine species long adapted to high altitude was 0.4% (±1), significantly less than in non-adapted species (P<0.001). A polycythemic response like that of men and women at 2100m occurred in less than 10% of the mammals examined. We conclude that, at least for the altitudes studied, a minimal polycythemia is a general feature of both high-altitude adapted and non-adapted species, and the magnitude of the human response is exceptional among mammals.

Hemorheological alterations in adults with prediabetes identified by hemoglobin A1c levels

BACKGROUND AND AIMS

A link between increased blood viscosity and type 2 diabetes has been previously reported. Herein, we investigated the association of blood viscosity with prediabetes, identified by glycated hemoglobin A1c (HbA1c) according to the new American Diabetes Association criteria, and subclinical atherosclerosis.

METHODS AND RESULTS

The study cohort includes 1136 non-diabetic adults submitted to anthropometrical evaluation, an oral glucose tolerance test and ultrasound measurement of carotid intima-media thickness (IMT). Whole blood viscosity was estimated using a validated formula based on hematocrit and total plasma proteins. After adjusting for age, and gender, individuals with HbA1c-defined prediabetes (HbA1c 5.7-6.4% [39-47 mmol/mol]) exhibited significantly higher values of hematocrit, and predicted blood viscosity as compared with controls. Increased levels of IMT were observed in subjects with HbA1c-defined prediabetes in comparison to controls. Predicted blood viscosity was positively correlated with age, waist circumference, blood pressure, cholesterol, triglycerides, fibrinogen, white blood cell, HbA1c, fasting and 2-h post-load glucose levels, fasting insulin, IMT and inversely correlated with HDL and Matsuda index of insulin sensitivity. Of the three glycemic parameters, i.e. HbA1c, fasting and 2-h post-load glucose, only HbA1c showed a significant correlation with predicted blood viscosity (β = 0.054, P = 0.04) in a multivariate regression analysis model including multiple atherosclerosis risk factors.

CONCLUSION

The study shows that individuals with HbA1c-defined prediabetes have increased predicted blood viscosity and IMT. The HbA1c criterion may be helpful to capture individuals with an increased risk of diabetes and cardiovascular disease who may benefit from an intensive lifestyle intervention.

Can we safely decrease intensive care unit admissions for children with high grade isolated solid organ injuries? Using the shock index, pediatric age-adjusted and hematocrit to modify APSA admission guidelines

BACKGROUND

In 2000, the American Pediatric Surgical Association (APSA) disseminated consensus practice guidelines for the management of blunt liver and splenic injury which included intensive care unit (ICU) admission for children with grade IV injuries. We sought to determine if we could better predict which children with isolated solid organ injuries (SOI) underwent an ICU-level intervention, thus necessitating ICU admission.

METHODS

Children with isolated liver, spleen, or kidney injuries admitted to the ICU from November 2003 to August 2015 were identified in our trauma registry, and data were extracted from the medical record. ICU-level interventions were defined as transfusion, vasopressor use, intubation, and operative/procedural intervention. Shock index and pediatric age-adjusted (SIPA) was calculated for all patients. The sensitivity and negative predictive values (NPV) were determined.

RESULTS

133 children met inclusion criteria. 19 (14.3%) required ICU-level intervention, and 114 (85.1%) did not. 95% (n=18) of the intervention group had either an elevated SIPA or a hematocrit <30% on admission compared to 22% (n=25) of patients in the no intervention group. Sensitivity was 95%, and NPV was 99%.

CONCLUSIONS

Limiting ICU admission in children with isolated SOI to those with an elevated SIPA or hematocrit <30% would reduce the ICU admission rate by two-thirds while maintaining patient safety.

TYPE OF STUDY

Diagnostic study.

LEVEL OF EVIDENCE

III.

Life-history dependent relationships between body condition and immunity, between immunity indices in male Eurasian tree sparrows

In free-living animals, recent evidence indicates that innate, and acquired, immunity varies with annual variation in the demand for, and availability of, food resources. However, little is known about how animals adjust the relationships between immunity and body condition, and between innate and acquired immunity to optimize survival over winter and reproductive success during the breeding stage. Here, we measured indices of body condition (size-corrected mass [SCM], and hematocrit [Hct]), constitutive innate immunity (plasma total complement hemolysis activity [CH₅₀]) and acquired immunity (plasma immunoglobulin A [IgA]), plus heterophil/lymphocyte (H/L) ratios, in male Eurasian tree sparrows (Passer montanus) during the wintering and the breeding stages. We found that birds during the wintering stage had higher IgA levels than those from the breeding stage. Two indices of body condition were both negatively correlated with plasma CH₅₀ activities, and positively with IgA levels in wintering birds, but this was not the case in the breeding birds. However, there was no correlation between CH₅₀ activities and IgA levels in both stages. These results suggest that the relationships between body condition and immunity can vary across life-history stage, and there are no correlations between innate and acquired immunity independent of life-history stage, in male Eurasian tree sparrows. Therefore, body condition indices predict immunological state, especially during the non-breeding stage, which can be useful indicators of individual immunocompetences for understanding the variations in innate and acquired immunity in free-living animals.

Differential Effects of Dapagliflozin on Cardiovascular Risk Factors at Varying Degrees of Renal Function

BACKGROUND AND OBJECTIVE

Sodium glucose cotransporter 2 inhibition with dapagliflozin decreases hemoglobin A1c (HbA1c), body weight, BP, and albuminuria (urinary albumin-to-creatinine ratio). Dapagliflozin also modestly increases hematocrit, likely related to osmotic diuresis/natriuresis. Prior studies suggest that the HbA1c-lowering effects of dapagliflozin attenuate at lower eGFR. However, effects on other cardiovascular risk factors at different eGFR levels are incompletely understood.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This pooled analysis of 11 phase 3 clinical trials assessed changes in HbA1c, body weight, BP, hematocrit, and urinary albumin-to-creatinine ratio with placebo (n=2178) or dapagliflozin 10 mg (n=2226) over 24 weeks in patients with type 2 diabetes according to baseline eGFR (eGFR≥45 to <60 ml/min per 1.73 m2, eGFR≥60 to <90 ml/min per 1.73 m2, and eGFR≥90 ml/min per 1.73 m2).

RESULTS

Compared with placebo, reductions in HbA1c with dapagliflozin were 0.6%, 0.5%, and 0.3%, respectively, for each consecutive lower eGFR subgroup (P value interaction <0.001). Effects of dapagliflozin on hematocrit, body weight, and BP were similar regardless of baseline eGFR, suggesting that effects potentially related to volume and natriuresis are eGFR independent. Moreover, among individuals with baseline urinary albumin-to-creatinine ratio ≥30 mg/g, placebo-adjusted reductions in urinary albumin-to-creatinine ratio were larger in the lowest eGFR subgroup (P value interaction <0.001). Adverse events occurred more frequently in the lowest eGFR subgroup; this was true for both dapagliflozin- and placebo-treated patients.

CONCLUSIONS

The HbA1c-lowering effects of dapagliflozin decrease as renal function declines. However, dapagliflozin consistently decreases body weight, BP, and urinary albumin-to-creatinine ratio regardless of eGFR. These effects in conjunction with the finding of similar effects on hematocrit, a proxy for volume contraction, suggest that the effects of dapagliflozin are partly mediated via nonglucosuric-dependent mechanisms.

Effects of Quercetin and Mannitol on Erythropoietin Levels in Rats Following Acute Severe Traumatic Brain Injury

Objective

The aim of this study to investigate the normal values of erythropoietin (EPO) and neuroprotective effects of quercetin and mannitol on EPO and hematocrit levels after acute severe traumatic brain injury (TBI) in rat model.

Methods

A weight-drop impact acceleration model of TBI was used on 40 male Wistar rats. The animals were divided into sham (group I), TBI (group II), TBI+quercetin (50 mg/kg intravenously) (group III), and TBI+mannitol (1 mg/kg intravenously) (group IV) groups. The malondialdehyde, glutathione peroxidase, catalase, EPO, and hematocrit levels were measured 1 and 4 hour after injury. Two-way repeated measures analysis of variance and Tukey’s test were used for statistical analysis.

Results

The malondialdehyde levels decreased significantly after administration of quercetin and mannitol compared with those in group II. Catalase and glutathione peroxidase levels increased significantly in groups III and IV. Serum EPO levels decreased significantly after mannitol but not after quercetin administration. Serum hematocrit levels did not change significantly after quercetin and mannitol administration 1 hour after trauma. However, mannitol administration decreased serum hematocrit levels significantly after 4 hour.

Conclusion

This study suggests that quercetin may be a good alternative treatment for TBI, as it did not decrease the EPO levels.

On the association analysis of CNV data: a fast and robust family-based association method

BACKGROUND

Copy number variation (CNV) is known to play an important role in the genetics of complex diseases and several methods have been proposed to detect association of CNV with phenotypes of interest. Statistical methods for CNV association analysis can be categorized into two different strategies. First, the copy number is estimated by maximum likelihood and association of the expected copy number with the phenotype is tested. Second, the observed probe intensity measurements can be directly used to detect association of CNV with the phenotypes of interest.

RESULTS

For each strategy we provide a statistic that can be applied to extended families. The computational efficiency of the proposed methods enables genome-wide association analysis and we show with simulation studies that the proposed methods outperform other existing approaches. In particular, we found that the first strategy is always more efficient than the second strategy no matter whether copy numbers for each individual are well identified or not. With the proposed methods, we performed genome-wide CNV association analyses of hematological trait, hematocrit, on 521 Korean family samples.

CONCLUSIONS

We found that statistical analysis with the expected copy number is more powerful than the statistic with the probe intensity measurements regardless of the accuracy of the estimation of copy numbers.