Transitory hematologic effects of moderate exercise are not influenced by iron supplementation

A young women's exercise/fitness class tested the idea that administration of supplemental iron would prevent "sports anemia" that may develop during exercise and training and improve iron status of exercising females of menstrual age. Fifteen women (aged 18-37) were selected for each of three treatment groups: (1) no supplemental iron; (2) 9 mg X d-1 of Fe; and (3) 18 mg X d-1 of Fe (1 US Recommended Daily Allowance). Women exercised at approximately 85% of maximal heartrate for progressively increasing lengths of time in a jogging program and worked up to 45 min of exercise 4 d X week-1 for 8 weeks. Hematologic analysis was performed in weeks 1, 5, and 8. A significant decline in hemoglobin (Hb) concentration and hematocrit (Hct) was observed at week 5 when all data were examined without regard for iron intake; these red cell indices returned to pre-exercise levels by week 8. Reduction of mean cell hemoglobin concentration (MCHC) indicated that the midpoint decline was not caused by simple hemodilution during exercise. Serum ferritin (SF) concentration changed in parallel with Hb and Hct. Although the midpoint decline in SF was not statistically significant, it ruled out the possibility that turnover of red cell iron was directed to storage. Lowered MCHC and SF suggested lower availability of iron during the synthesis of a new generation of red cells. Few iron treatment effects of magnitude were observed. Iron did not prevent the midpoint decline in Hb concentration. Iron intake did not affect SF, serum iron, transferrin saturation, or final Hb, and Hct.(ABSTRACT TRUNCATED AT 250 WORDS)     

城市人群血清营养水平指标与膳食习惯关系的分析

目的:分析血清营养状态指标与膳食习惯的关联关系与意义。方法:采用横断面调查的数据,用标准问卷询问1694人相关信息,内容包括人口学资料、自报疾病现患史、膳食习惯、健康自评、认知功能信息;同时采集被调查人群血样本;测定血红蛋白、白蛋白、叶酸和维生素B12水平。采用R 3.2.5和SPSS 20.0软件进行相关和显著性差异分析。结果:人体血红蛋白、白蛋白、叶酸和维生素B12水平与被调查个体进食水果和鸡蛋习惯有密切关联;天天进食水果、鸡蛋的个体上述指标水平明显高于不进食此类食物的个体,且血红蛋白、白蛋白水平随增龄下降程度减低;天天进食水果习惯的个体同时具有天天进食蛋、奶、菜习惯;有进食水果习惯的人群表现为受教育程度高;自评健康状态好和相对自报患病率低等特点。结论:合理膳食习惯可保持较高的血营养状态指标水平;且延缓相关指标水平随增龄下降的程度。天天进食水果习惯可被视为合理膳食的指标,为膳食评估提供简易、可行、有效的指标。     

Changes in body mass index and smoking habits have a different impact on hemoglobin concentration in men and women: A longitudinal follow-up of the tromsø study, 1994–2002

Background: Body mass index (BMI) and smoking have been positively associated with hemoglobin concentration, and both are risk factors for cardiovascular disease.Objective: The aim of this study was to assess whether there were sex differences in how changes in BMI and smoking habits influenced hemoglobin concentration.Methods: In 1994–95 and 2001–02, a longitudinal, population-based study was conducted in the municipality of Tromsø, in northern Norway. Inhabitants aged ≥25 years were invited to participate. Participants replied to a questionnaire regarding health, physical activity, coffee and alcohol consumption, and smoking habits. Blood samples were drawn to analyze hemoglobin concentration.All analyses were performed separately for each sex. Differences between 1994–95 and 2001–02 were examined with t or χ² (McNemar) tests for paired data. Cross-sectional comparisons were made using 2-sample t tests. Different models of univariate and multiple linear regression analyses were used to investigate the impact of the various variables on hemoglobin change.Results: Data from a total of 2105 men and 2945 women were examined. At baseline, mean age was 58.9 years for men (range, 25–78 years) and 57.8 years for women (range, 25–82 years); mean BMI was 26.1 kg/m² for men and 25.8 kg/m² for women. In men, hemoglobin decreased with age, on average from 147.5 to 145.1 g/L. In women, hemoglobin decreased from 135.6 to 134.7 g/L, but increased with increasing age up to 54 years, and thereafter decreased gradually. Mean BMI increased 0.8 kg/m² in men and 1.2 kg/m² in women. In total, 394 of 2057 men (19%) and 499 of 2889 women (17%) stopped smoking or smoked fewer cigarettes per day. In a univariate regression model, an increase of 1 kg/m² in BMI was associated with an increase in hemoglobin of 1.1 g/L (95% CI, 0.84 to 1.27) in men and 0.4 g/L (95% CI, 0.30 to 0.56) in women. In another univariate model, smoking cessation was associated with a decrease in hemoglobin of 1.9 g/L (95% CI, ?3.32 to ?0.56) in men and 1.7 g/L (95% CI, ?2.93 to ?0.56) in women. In men who smoked less and had a BMI increase of >2.5 kg/m², hemoglobin decreased 0.3 g/L. In contrast, hemoglobin decreased 3.4 g/L in men who smoked less and lost weight (P for trend, < 0.001 by changing BMI). Women who smoked less had a decrease in hemoglobin independent of BMI changes.Conclusions: The positive association between an increase in BMI and hemoglobin was stronger in men than in women. The effect of smoking reduction on hemoglobin was attenuated with increasing BMI in men, but not in women.     

Sickle cell disease in the People's Republic of Angola. 2. Behavior of laboratory parameters

In 819 children the Hb concentration, its dependence on the course of disease, the impact of various crises on Hb values and the behaviour of MCHC were evaluated. In the mean there was an anemia of 4.65 +/- 0.5 Hb mmol/l. In the course of 6 years a significant decline anemia of 4.65 +/- 0.5 Hb mmol/l. In the course of 6 years a significant decline of the Hb concentration could be observed. Only those crises connected with severe clinical symptoms (third degree) coincide with a significant Hb decrease. Every second child with a mean Hb value of 2.3 mml/l was transfused. In nearly half the cases there is a normochromic anemia, in 45.7% a hypochromic one. The mean serum bilirubin concentration lay at 31.6 mumol/l and increased with growing age of disease. The anemia has negative effects on the cardio-circulating system. The thorax-heart quotient shows a positive correlation to the degree of anemia.     

Age Related Changes in Metabolite Concentrations in the Normal Spinal Cord

Magnetic resonance spectroscopy (MRS) studies have previously described metabolite changes associated with aging of the healthy brain and provided insights into normal brain aging that can assist us in differentiating age-related changes from those associated with neurological disease. The present study investigates whether age-related changes in metabolite concentrations occur in the healthy cervical spinal cord. 25 healthy volunteers, aged 23–65 years, underwent conventional imaging and single-voxel MRS of the upper cervical cord using an optimised point resolved spectroscopy sequence on a 3T Achieva system. Metabolite concentrations normalised to unsuppressed water were quantified using LCModel and associations between age and spinal cord metabolite concentrations were examined using multiple regressions. A linear decline in total N-Acetyl-aspartate concentration (0.049 mmol/L lower per additional year of age, p = 0.010) and Glutamate-Glutamine concentration (0.054 mmol/L lower per additional year of age, p = 0.002) was seen within our sample age range, starting in the early twenties. The findings suggest that neuroaxonal loss and/or metabolic neuronal dysfunction, and decline in glutamate-glutamine neurotransmitter pool progress with aging.     

Hepatic uptake of indocyanine green and perfusion rate in rats: effect of age and albumin concentration

Liver blood flow and hepatic uptake of some indicator substances have been reported to fall with age in both rats and humans. We used an isolated liver system, which was perfused in one pass with hemoglobin free buffer, to investigate the effect of albumin concentration, buffer flow rate, and age upon hepatic clearance of the dye, indocyanine green. We measured the half-life of a bolus of indocyanine green given intravenously to male Sprague-Dawley rats aged 10 and 24 months and then examined its clearance in vitro using their isolated perfused livers. After perfusion, the livers were homogenized and separated into subcellular fractions. The mean liver weight declined significantly (young, 19.7 +/- 2.9 g vs. old, 13.9 +/- 2.6 g; p less than 0.02). In vivo the indocyanine green clearance was reduced in the aged rats (3.2 +/- 1.0 vs. 5.1 +/- 1.7 mL/min; p less than 0.05). In the isolated perfused liver system, extraction ratio showed an inverse curvilinear correlation with albumin concentration and buffer flow rate, but did not differ with age. Hepatic protein content and dye subcellular localization did not differ between the two groups. In conclusion, the fall in indocyanine green clearance in vivo is not paralleled by the ability of the organs to extract the dye in vitro, and likely reflects a decline in hepatic mass and blood flow.     

Hematologic reference values for the fetal long-tailed macaque (Macaca fascicularis)

Complete blood counts (CBCs) were performed on 68 fetal macaque blood samples collected from 31 fetuses by repeat ultrasound-guided cardiocentesis (gestational day [GD] 80–150; term ～ GD 165) with the goal of defining normative hematologic reference values during prenatal life. Lymphocytes were the primary white blood cells (WBCs) observed throughout gestation. Segmented neutrophils were the second highest percent of WBCs and were noted to rise significantly during GD 130–140. Overall, WBCs increased progressively throughout gestation with a transient decline at the beginning of the third trimester (～ GD 110). A steady linear rise in red blood cells (RBCs), hemoglobin, and hematocrit was observed with a marginal decline close to term; mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV) showed a consistent linear decline throughout gestation whereas mean corpuscular hemoglobin concentration (MCHC) remained relatively stable. Nucleated RBCs (NRBCs per 100 WBCs) were present on GD 80, showed a sharp decline mid-second trimester (～ GD 90), and were significantly diminished by the beginning of the third trimester (～ GD 110). No quantitative changes in platelets were noted throughout the study period. Evaluations of erythrocyte morphology indicated polychromasia and anisocytosis as typical characteristics throughout gestation with rare occurrence of hypochromasia and poikilocytosis. Howell-Jolly bodies were intermittently observed. These data reveal distinct similarities when compared to prenatal hematologic characteristics for human fetuses and provide baseline data which can be applied to experimental studies where prenatal hematopoietic/hematologic toxicity may be anticipated. © 1993 Wiley-Liss, Inc.     

The relationship between psychosocial stress, age, BMI, CRP, lifestyle, and the metabolic syndrome in apparently healthy subjects

The aim of this cross-sectional study was to examine the factors which may be associated with the metabolic syndrome by exploring the relationship between psychosocial stress, age, body mass index (BMI), C-reactive protein (CRP), lifestyle factors, and the components of the metabolic syndrome, such as glycated hemoglobin (HbA1c), fasting blood sugar (FBS), body fat percentage, and triglyceride concentration, among apparently healthy subjects. Psychosocial stress was measured by the use of the inventory to measure psychosocial stress (IMPS). One thousand four hundred and ninety-nine people out of 1,941 public school workers admitted to a hospital for a medical check-up responded to the IMPS, yielding a response rate of 77.2%. A total of 1,201 workers excluding 298 who were taking medication for various diseases were analyzed with the use of hierarchical multiple regression models. It was found that IMPS-measured stress score, age, BMI, and smoking habit were associated with an increase in glycated hemoglobin among men, while alcohol consumption was associated with a decrease in glycated hemoglobin. Stress score, age, BMI, and alcohol consumption were found to be associated with an increase in FBS among men, while smoking and exercise habits were associated with a decrease in FBS. CRP was found to be associated with an increase in body fat percentage among men, though stress score was not associated with an increase in body fat percentage. Stress score, age, and BMI were associated with an increase in triglyceride concentration among women. The findings of the present study seem to be in line with the hypothesis that psychosocial stress plays an important role in developing the metabolic syndrome, which may be associated with inflammatory processes in the vascular wall, resulting in atherosclerosis and cardiovascular disease.     

Aggregation of normal and sickle hemoglobin in high concentration phosphate buffer

Sickle cell disease is caused by a mutant form of hemoglobin, hemoglobin S, that polymerizes under hypoxic conditions. The extent and mechanism of polymerization are thus the subject of many studies of the pathophysiology of the disease and potential treatment strategies. To facilitate such studies, a model system using high concentration phosphate buffer (1.5 M-1.8 M) has been developed. To properly interpret results from studies using this model it is important to understand the similarities and differences in hemoglobin S polymerization in the model compared to polymerization under physiological conditions. In this article, we show that hemoglobin S and normal adult hemoglobin, hemoglobin A, aggregate in high concentration phosphate buffer even when the concentration of hemoglobin is below the solubility defined for polymerization. This phenomenon was not observed using 0.05 M phosphate buffer or in another model system we studied that uses dextran to enhance polymerization. We have used static light scattering, dynamic light scattering, and differential interference contrast microscopy to confirm aggregation of deoxygenated and oxygenated hemoglobins below their solubility and have shown that this aggregation is not observable using turbidity measurements, a common technique for assessing polymerization. We have also shown that the aggregation increases with increasing temperature in the range of 15 degrees -37 degrees C and that it increases as the concentration of phosphate increases. These studies contribute to the working knowledge of how to properly apply studies of hemoglobin S polymerization that are conducted using the high phosphate model.     

The Microrheology of Sickle Hemoglobin Gels

Sickle cell disease is a rheological disease, yet no quantitative rheological data exist on microscopic samples at physiological concentrations. We have developed a novel method for measuring the microrheology of sickle hemoglobin gels, based on magnetically driven compression of 5- to 8-μm-thick emulsions containing hemoglobin droplets ∼80 μm in diameter. Using our method, by observing the expansion of the droplet area as the emulsion is compressed, we were able to resolve changes in thickness of a few nanometers with temporal resolution of milliseconds. Gels were formed at various initial concentrations and temperatures and with different internal domain structure. All behaved as Hookean springs with Young's modulus from 300 to 1500 kPa for gels with polymerized hemoglobin concentration from 6 g/dl to 12 g/dl. For uniform, multidomain gels, Young's modulus mainly depended on the terminal concentration of the gel rather than the conditions of formation. A simple model reproduced the quadratic dependence of the Young's modulus on the concentration of polymerized hemoglobin. Partially desaturated samples also displayed quadratic concentration dependence but with a smaller proportionality coefficient, as did samples that were desaturated in steps; such samples were significantly less rigid than gels formed all at once. The magnitude of the Young's modulus provides quantitative support for the dominant models of sickle pathophysiology.     

A theoretical model to predict the behavior of glycosylated hemoglobin levels

The measurement of glycosylated hemoglobin as a percentage of total hemoglobin is rapidly becoming the standard method of monitoring the average blood sugar level in diabetics for research purposes and may soon become the standard for clinical care and diagnosis. Much speculation exists in the literature about the nature of the glycosylation reaction. Most experimenters expect a linear relationship between the plasma glucose level and percent glycosylated hemoglobin in whole blood; however, a curve of decreasing slope with increasing glucose concentration is found.Here, a reaction model including simple first order kinetics between glucose and hemoglobin and a finite erythrocyte life of 120 days is considered. By carrying out the integration for each erythrocyte cohort followed by an integration combining all cohorts, a curve corresponding to the experimental result is found. In addition, results on expected glycosylated hemoglobin percent as a function of erythrocyte age and plasma glucose concentration are presented as well as a plot of glucose concentration versus glycosylated hemoglobin percent for the 40-day erythrocyte life in mice. All of the results correlate with experimental values in the literature if a rate constant of k = 1·0 × 10^?5dlmg^?1 day is used.The evaluation of a radioactive iron-transferrin experiment in the literature reveals the possibility that the glycosylation reaction begins during erythropoiesis.Finally, a curve is displayed which shows the expected 120-day decay during normoglycemia, of an elevated glycosylated hemoglobin level resulting from a preceding period of constant hyperglycemia.     

Health status of young Alaska Steller sea lion pups (Eumetopias jubatus) as indicated by blood chemistry and hematology

Blood chemistry and hematology were examined in 238 Steller sea lion pups (Eumetopias jubatus) to assess the health status of pups <1 month of age. Failure of juvenile recruitment (possibly due to nutritionally or physiologically compromised pups) into breeding populations has been proposed as a cause of recent declines of this endangered species in Alaska. To identify potential correlations with areas of high population decline, blood chemistry data were considered for three areas: eastern Aleutian Islands (low rates of population decline to stable populations), Gulf of Alaska (high rates of decline), and Southeast Alaska (stable to increasing population). Southeast Alaska pups showed elevated ketone body concentrations (beta-hydroxybutyrate,(beta-HBA)) and depressed glucose levels than pups in the Gulf of Alaska. Over 40% of the pups from Southeast Alaska had elevated beta-HBA concentrations suggesting they underwent longer periods of fasting than seen in pups from other areas. Hematocrit (Hct), hemoglobin concentration (Hb) and water content of the blood exhibited typical mammalian relationships. In summary, blood chemistry and hematology data showed no indication that Steller sea lion pups <1 month old from areas of population decline were nutritionally compromised.     

Sirtuin1: A Promising Serum Protein Marker for Early Detection of Alzheimer’s Disease

Sirtuin (SIRT) pathway has a crucial role in Alzheimer’s disease (AD). The present study evaluated the alterations in serum sirtuin1 (SIRT1) concentration in healthy individuals (young and old) and patients with AD and mild cognitive impairment (MCI). Blood samples were collected from 40 AD and 9 MCI patients as cases and 22 young healthy adults and 22 healthy elderly individuals as controls. Serum SIRT1 was estimated by Surface Plasmon Resonance (SPR), Western Blot and Enzyme Linked Immunosorbent Assay (ELISA). A significant (p<0.0001) decline in SIRT1 concentration was observed in patients with AD (2.27±0.46 ng/µl) and MCI (3.64±0.15 ng/µl) compared to healthy elderly individuals (4.82±0.4 ng/µl). The serum SIRT1 concentration in healthy elderly was also significantly lower (p<0.0001) compared to young healthy controls (8.16±0.87 ng/µl). This study, first of its kind, has demonstrated, decline in serum concentration of SIRT1 in healthy individuals as they age. In patients with AD and MCI the decline was even more pronounced, which provides an opportunity to develop this protein as a predictive marker of AD in early stages with suitable cut off values.     

Is Obesity Associated With Anemia of Chronic Disease? A Population‐based Study

Obesity is characterized by chronic, low-grade, systemic inflammation, which, in turn, has been associated with anemia of chronic disease. We hypothesized that obesity may be associated with the features of anemia of chronic disease, including low hemoglobin concentration, low serum iron and transferrin saturation (TS), and elevated serum ferritin. We compared normal-weight to overweight and obese adult participants of the third National Health and Nutrition Examination Survey with respect to hemoglobin concentration and levels of serum iron, TS, and ferritin. Measured BMI was used to categorize participants into normal weight (BMI < 25 kg/m(2), n = 6,059), overweight (BMI 25 to <30 kg/m(2), n = 5,108), mildly obese (BMI 30 to <35 kg/m(2), n = 2,366), moderately obese (BMI 35 to <40 kg/m(2), n = 850), and severely obese (BMI > or = 40 kg/m(2), n = 465). After adjustment for age, gender, menstruation, race/ethnicity, education, alcohol consumption, smoking, blood donation, and dietary iron intake, serum ferritin was progressively higher with increasing BMI category, whereas serum iron and TS were progressively lower. However, compared to normal-weight persons, those in all other higher BMI categories did not have a significant change in hemoglobin concentration after adjustment for the above-mentioned confounders. Overweight and obesity were associated with changes in serum iron, TS, and ferritin that would be expected to occur in the setting of chronic, systemic inflammation. However, overweight and obese persons were not more likely to be anemic compared with normal-weight persons.     

Glycated hemoglobin as a marker of cardiovascular risk

PURPOSE OF REVIEW: Diabetes mellitus is an established risk factor for cardiovascular disease. This review examines glycated hemoglobin, an indicator of long-term average blood glucose concentrations, in risk prediction for cardiovascular disease. RECENT FINDINGS: Glycated hemoglobin concentrations predict cardiovascular disease risk in people with diabetes, and trial data suggest that good blood glucose control is associated with reduction in cardiovascular disease. Elevated glycated hemoglobin levels below the thresholds accepted for diabetes are also associated with increasing cardiovascular disease risk independent of classical risk factors in a continuous relationship across the whole normal distribution. A 1% increase in absolute concentrations of glycated hemoglobin is associated with about 10-20% increase in cardiovascular disease risk. The continuous relationship is most evident for coronary heart disease in men; the shape of the risk curve is less clear for women and for other cardiovascular endpoints such as stroke or peripheral vascular disease. SUMMARY: Glycated hemoglobin concentration predicts cardiovascular risk both in people with diabetes and in the general population, and may help identify individuals at higher risk of cardiovascular disease for targeted interventions, including blood pressure or cholesterol reduction. Understanding the nature of this relationship may inform new preventive and therapeutic interventions.     

CD4 and Viral Load Dynamics in Antiretroviral-Na?ve HIV-Infected Adults from Soweto,South Africa: A Prospective Cohort

BackgroundCD4 count is a proxy for the extent of immune deficiency and declines in CD4 count are a measure of disease progression. Decline in CD4 count is an important component: for estimating benefits of ARV treatment; for individual level counselling on the rapidity of untreated disease progression and prognosis; and can be used in planning demand for health services. Our objective is to report CD4 decline and changes in viral load (VL) in a group of HIV-infected adults enrolled in a randomized trial of preventive treatment for TB in South Africa where clade C infection predominates.MethodsHIV-infected, tuberculin skin test positive adults who were not eligible for antiretroviral (ARV) treatment were randomized to a trial of preventive treatment from 2003–2005. VL and CD4 count were assessed at enrollment and CD4 counts repeated at least annually. During follow-up, individuals whose CD4 counts decreased to <200 cells/mm³ were referred for antiretroviral therapy (ART) and were analytically censored.Results1106 ARV naïve adults were enrolled. Their median age was 30 years and male to female ratio was 1∶5. Median baseline CD4 count was 490 cells/mm³ (IQR 351–675). The overall mean decline in CD4 count was 61 cells/mm³ per annum. Adjusting for age, gender, baseline hemoglobin, smoking and alcohol use had little impact on the estimate of CD4 decline. However, VL at baseline had a major impact on CD4 decline. The percent decline in CD4 count was 13.3% (95% CI 12.0%, 14.7%), 10.6% (95% CI 8.8%, 12.4%), and 13.8% (95% CI 12.1%, 15.5%) per annum for baseline VLs of <10,000 (N = 314), 10,001–100,000 (N = 338), >100,000 (N = 122) copies/ml.ConclusionsOur data suggests that six and a half years will elapse for an individual''s CD4 count to decline from 750 to 350 cells/mm³ in the absence of ART.     

Ocular Manifestations of Hemoglobin S-C Disease

Three patients with hemoglobin S-C disease, all with ocular lesions, were studied and contrasted with four other patients who had predominantly either hemoglobin S or C but no ocular lesions. Attention is drawn to the diagnostic value of hemoglobin electrophoresis in such cases. With this technique a diagnosis of hemoglobin S-C disease was made in a patient previously thought to the “Eales'' disease”; one sister was found to have asymptomatic hemoglobin S-C disease and unsuspected early ocular lesions. The number of persons in Canada with hemoglobinopathies is increasing. Awareness of an association between abnormal hemoglobins and ocular disease may lead to the recognition of an unsuspected blood disorder or of an unsuspected retinopathy.     

Anemia y fragilidad en ancianos españoles. Estudio FRADEA

IntroductionThe objective was to examine the prevalence of anemia according to the state of frailty and to analyze the relationship between anemia, hemoglobin concentration and frailty in a cohort of Spanish older adults.Material and methodsCross-sectional substudy of the FRADEA (Frailty and Dependency in Albacete) cohort, a population-based concurrent cohort study conducted in people older than 69 years of Albacete (Spain). Of the 993 participants included in the first wave, 790 were selected with valid data on anemia and frailty. Anemia was defined according to the criteria of the World Health Organization (hemoglobin less than 13 g/dL in men and 12 g/dL in women). Frailty was assessed using the Fried's phenotype. The association between anemia, hemoglobin concentration and frailty was determined by binary logistic regression adjusted for age, sex, educational level, institutionalization, comorbidity, cognitive status, body mass index, polypharmacy, creatinine, glucose and total white blood cell count.ResultsThe mean age was 79 years. The prevalence of anemia was 19.6%. The prevalence of anemia was significantly higher in frail subjects (29.6%) compared to prefrail (16.6%) and robust ones (6%), p<0.001. The average hemoglobin concentrations were significantly lower in frail (12.7 g/dL), compared to the prefrail (13.5 g/dL) and robust participants (14.4 g/dL), p < 0.001. In the fully adjusted regression model, anemia was associated with frailty (OR 1.95; 95% CI: 1.02-3.73, p<0.05), and similarly, the average hemoglobin concentrations showed a significant association with frailty (OR 0.79; 95% CI: 0.66-0.96, p < 0.05).ConclusionAnemia in older adults, defined according to WHO criteria, is independently associated with frailty.     

Physiological responses to acute experimental hypoxia in the air-breathing Indian catfish, Clarias batrachus (Linnaeus, 1758)

With an aim to study the mechanism of adaptation to acute hypoxic periods by hypoxia-tolerant catfish, Clarias batrachus, the mass-specific metabolic rate (VO₂) along with its hematological parameters, metabolic response and antioxidant enzyme activities were studied. During progressive hypoxia, C. batrachus was found to be an oxyconformer and showed a steady decline in its aquatic oxygen consumption rate. When C. batrachus was exposed for different periods at experimental hypoxia level (0.98?±?0.1 mg/L, DO), hemoglobin and hematocrit concentrations were increased, along with decrease in mean cellular hemoglobin concentration, which reflected a physiological adaptation to enhance oxygen transport capacity. Significant increase in serum glucose and lactate concentration as well as lactate dehydrogenase activity was observed. Antioxidant enzymes were found to operate independently of one another, while total glutathione concentration was unaffected in any of the tissues across treatments. These observations suggested that hypoxia resulted in the development of oxidative stress and C. batrachus was able to respond through increase in the oxygen carrying capacity, metabolic depression and efficient antioxidant defense system to survive periods of acute hypoxia.