Hemoglobin Concentration In Children Research Articles

Demographic Characteristics and Low Iron Status Markers Are Associated with Hemoglobin Levels and Anemia among Children Living at High Elevation in Cusco, Peru.

Anemia is a complex condition associated with diet, chronic infections, and blood loss. Children living at high altitudes have higher absolute hemoglobin levels due to hypoxemia. However, they are exposed to repeated infections and dietary limitations. We conducted a cross-sectional study to identify factors affecting the hemoglobin concentration in children living in high-altitude rural communities in the Anta province of Peru. All children 3-16 years of age attending public schools were invited to participate. We enrolled children 3-16 years old in schools and visited their homes to collect demographic, socioeconomic, medical history, and anthropometric data. Children provided blood and stool samples for complete blood counts, iron status markers, and helminth infection testing. Among the 2,000 children enrolled, the mean age was 9.9 (±3.4) years, 1,004 (50.2%) were female, and the median residence altitude was 3,398 (interquartile range 3,35-3,497) meters. The mean hemoglobin level was 15 (±1.15) mg/dL; 320 (16%) had anemia as defined by WHO. Children with anemia were more likely to have lower serum iron levels (odds ratio [OR] 2.8 [95% CI 2.2-3.6], P <0.001) and serum transferrin saturation (OR 2.8 [95% CI 2-3.9], P <0.001). Younger age (OR 0.85 [95% CI 0.82-0.89], P <0.001), stunting (OR 0.68 [95% CI 0.59-0.79], P <0.001), education of the mother (OR 0.94 [95% CI 0.91-0.98], P <0.005), and low eosinophils (OR 0.49 [95% CI 0.26-0.9], P = 0.022) were associated with anemia. Helminth infections were not associated with anemia. Anemia among children at high altitude is multifactorial, but iron deficiency is a contributing factor. Further studies are needed to evaluate iron status and anemia in children living at high altitudes.

Erythrocyte Indices Variations In Under Five Children As A Result Of High Plasmodium Falciparum Parasitaemia

Nigeria accounts for 31% of the 619,000 malaria-related deaths recorded worldwide, according to the World Malaria Report 2022. Malaria caused by Plasmodium falciparum causes significant changes in haematological parameters and indices. The study aimed to observe erythrocyte indices and haemoglobin concentration variations in children with Plasmodium falciparum parasitaemia, evaluate the correlation between parasite count and indices, and assess their predictive roles. We analysed 194 children (≤ 5 years old) suspected of malaria and collected 5 ml of whole blood samples for analysis. The samples were used to prepare thin and thick blood films for qualitative and quantitative assays. A CBC was carried out to estimate HGB concentration and erythrocyte indices. The case and control group had a mean difference statistically significant at (P&lt;0.001). MCV [case group (72.26±4.83), control group (85.00±4.48)]; MCH [case group (23.82±2.51), control group (28.85±2.02)] and HGB [case group (100.78±14.84), control group (135.65±9.95). Pearson correlation showed weak negative statistical significance at (P&lt;0.05) for MCV, MCH, MCHC and HGB in the range of (-0.38) – (-0.218). Regression analysis indicated that parasite count predicted MCV, MCH, MCHC and HGB at (P&lt;0.05); R values at (0.283, 0.272, 0.326 and 0.308, respectively). When considering age and parasite count as predictive variables, we obtained R values of 0.285, 0.282, 0.326, and 0.328 for MCV, MCH, MCHC, and HGB, respectively. Research results show a significant relationship between Plasmodium falciparum parasitaemia and variations in erythrocyte indices with haemoglobin concentration in children at significant levels.

Association of women's empowerment with anaemia and haemoglobin concentration in children in sub-Saharan Africa: A multilevel analysis.

We assessed the associations between women's empowerment and anaemia and haemoglobin concentration among children (6-59 months) in 31 sub-Saharan African (SSA) countries. We included 72,032 mother-child pairs from Demographic and Health Surveys conducted between 2006 and 2019. A three-dimensional women's empowerment index (attitude towards violence, decision makingand social independence) was constructed using principal components analysis, and associations between the index and any anaemia and Hb concentration were assessed using multilevel regression.The mean (standard deviation) haemoglobin concentration was 102.3 (16.0 g/L) and 65.8% of the children were anaemic. The odds of anaemia reduced with increasing empowerment in the dimensions of attitude towards violence [quintile (Q5) versus Q1, OR 0.77; 95% confidence interval [CI] 0.65-0.89, ptrend = 0.006], decision making (Q5 vs. Q1, OR 0.72; 95% CI 0.61-0.84, ptrend < 0.001)and social independence (Q5 vs. Q1, OR 0.86; 95% CI 0.76-0.97, ptrend = 0.015). The mean Hb concentration increased with increasing women's empowerment in the dimensions of attitude towards violence (Q5 vs. Q1, mean difference [MD] 1.40 g/L; 95% CI 0.63-2.17, ptrend < 0.001) and social independence (Q5 vs. Q1, MD 1.32 g/L; 95% CI 0.36-2.28, ptrend = 0.001). There was no evidence for a linear trend in the association between decision making and haemoglobin concentration (ptrend = 0.051).Women's empowerment was associated with reduced odds of any anaemia and higher haemoglobin concentration in children. The promotion of women's empowerment may play a role in reducing the burden of childhood anaemia in SSA.

Efecto de una intervención educativa en la hemoglobina capilar en una comunidad indígena de la Huasteca Potosina. Estudio piloto

Introducción: El objetivo de esta investigación fue evaluar el efecto de una intervención educativa contextualizada a los alimentos disponibles en una comunidad indígena de la Huasteca Potosina, sobre la hemoglobina capilar.Material y métodos: Se llevó a cabo un estudio cuasiexperimental pretest-postest de un solo grupo, de diciembre de 2014 a diciembre de 2015 en niños indígenas de 0 a 5 años, de la comunidad de Tocoy, San Antonio, San Luis Potosí, México. Se realizó una intervención de 6 meses y constó de talleres de educación nutricional los cuales incluían pláticas informativas, talleres de cocina y retroalimentación de los conocimientos impartidos. Se realizó una evaluación previa a la intervención y 4 meses posteriores a esta, en la que se valoró el estado nutricio (medidas antropométricas y concentración de hemoglobina capilar) y la ingesta de macro y micronutrimentos (recordatorios de 24 horas). Resultados: Se encontró un aumento en la concentración de hemoglobina capilar de 11,3±1,3 a 12,0±1,4 mg/dl (p=0,025) y la prevalencia de anemia disminuyó de 37 a 25.9%.Conclusiones: Una intervención educativa contextualizada a los alimentos disponibles en una comunidad puede contribuir a mejorar las concentraciones de hemoglobina capilar en niños menores de 5 años en una comunidad indígena de la Huasteca potosina.

Efficacy of Different Doses of Multiple Micronutrient Powder on Haemoglobin Concentration in Children Aged 6-59 Months in Arusha District.

In Tanzania's Arusha District, anaemia is a significant public health problem. Recently, home fortification with multiple micronutrient powder was recommended, and daily use of one sachet has shown to be effective. However, it is a challenge for deprived families with low income to afford the daily sachet. The aim of this study was to compare the efficacy of different administration frequencies of micronutrient powder in reducing anaemia in children aged 6–59 months. This research used a community-based, randomized longitudinal trial design with the intent to treat anaemia. Children aged 6 to 59 months (n=369) were randomly assigned to one of four intervention groups which received, on a weekly basis, either five sachets (n=60), three sachets (n=80), two sachets (n=105), or one sachet (n=124) for six months; 310 children completed the study. Using the HemoCue technique, a finger-prick blood was taken at baseline, middle, and end points of the intervention to determine haemoglobin levels. The effect of treatment on haemoglobin was assessed with analysis of covariates with Bonferroni post hoc to test group difference (p > 0.05) from each other. At the end, haemoglobin levels were significantly higher in participants who received three or five sachets of micronutrient powder per week compared to those who received one or two micronutrient powder sachets per week (p < 0.05). The prevalence of illnesses was reduced from 65% to 30.5% in all groups. This finding indicates that economically challenged families may opt for three times per week sachet administration rather than a more costly daily administration. This trial is registered with PACTR201607001693286.

Hemoglobin Concentration in Children at Different Altitudes in Peru: Proposal for [Hb] Correction for Altitude to Diagnose Anemia and Polycythemia.

The present study was designed to define the hemoglobin [Hb] increase with altitude in Peruvian children. We suggest the normal range of [Hb] as means ±2 standard deviations (SD), with a value less than - 2 SD as a possible threshold to detect anemia. The prevalence of anemia was calculated. These values were compared to the World Health Organization (WHO) altitude correction parameter and the threshold for anemia of 11 g/dL. Likewise, polycythemia is suggested as [Hb] greater than 2 SD. 2,028,701 children aged 6-59 months were analyzed. The quadratic regression analysis shows that [Hb] is constant between sea level and 999 m. Thereafter, [Hb] increases from 11.32 g/dL (1000 m) up to ∼14.54 g/dL at 4000 m. Applying the threshold for anemia defined by WHO (11 g/dL) results in a prevalence of ∼35% for children living at altitudes <1000 m, and prevalence decreases to ∼4.5% at >4000 m. After [Hb] altitude correction, the prevalence was ∼36% (1000 m) and increases to ∼66% above 4000 m. With our proposed threshold for anemia, the prevalence was ∼15% below 1000 m and ∼5% above 4000 m. For polycythemia ([Hb] >14.5 g/dL), increases were from 1.2% at <1000 m to 39.4% at 4000 m. After [Hb] correction for altitude, the prevalence of polycythemia decreases with altitude. Excessive erythrocytosis defined as [Hb] >19 g/dL shows the highest values at 4000 m, while polycythemia defined as [Hb] greater than 2 SD was reduced at high altitude (HA). In conclusion, using WHO thresholds for anemia and [Hb] correction by altitude most likely overestimates the prevalence of anemia and may underestimate polycythemia in Peruvian children living at HA. Therefore, new threshold values for anemia and polycythemia as mean [Hb] less than 2 SD and greater than 2 SD for populations living at a specific altitude are suggested.

The effect of iron versus iron plus zinc supplementation in children with malaria

Introduction Little is known about the potential interaction of ironand zinc given to increase hemoglobin and serum ferritin in chil-dren with malaria.Objective To study the effect of iron compared with a combination ofiron and zinc supplementation on children with falciparum malaria.Method Children with positive Plasmodium falciparum (n=86) wererandomly assigned to a daily supplementation of 6 mg iron/kg perday plus placebo or plus 10 mg zinc per day for 30 days. All childrenwere treated with the same regimen for the treatment of P. falciparum.Venous blood samples were collected at the start and end of thestudy. After 30 days of supplementation, the baseline and follow-upblood samples were analyzed.Results The increase of hemoglobin concentration in the ironplus placebo group was 0.58 g/dl, while in the iron plus zinc groupwas 0.09 g/dl (P&lt;0.05). Serum ferritin concentration was high inboth groups before trial, yet there was no significant differenceafter iron supplementation.Conclusions Iron supplementation showed significant increasein hemoglobin concentration in children with positive P. falciparumtreated with the same regimen of treatment. Supplementation ofiron alone as well as iron plus zinc had been proven ineffective toiincrease serum ferritin in children with malaria.

Supplementation of vitamin B12 or folic acid on hemoglobin concentration in children 6–36 months of age: A randomized placebo controlled trial

The main objective of this report is to measure to what extent folate or vitamin B12 given daily for 6 months to young North Indian Children improves hemoglobin (Hb) concentration. In a randomized placebo controlled trial in low-to-middle income neighborhoods in New Delhi, India, children were randomized into four groups in a 1:1:1:1 ratio and supplemented daily for 6 months with 2 RDAs of vitamin B12, folic acid, both, or placebo. All children with anemia at baseline were given iron supplementation daily for 2 months. We measured the plasma concentrations of soluble transferrin receptor (sTfR), folate, vitamin B12, total homocysteine (tHcy) and Hb in 262 children. Mean Hb concentration decreased in all four study groups during the six months of follow up and supplementation of either or both of the vitamins did not improve the Hb concentration. Iron supplements for the initial 2mo had limited effect on anemia at 6mo as almost 90% were still anemic at study end. Supplementation of folic acid and/or vitamin B12 for 6 months does not improve Hb concentration in young children. Our findings do not argue for widespread vitamin B12 or folic acid supplementation to combat anemia. Our results also call for alternative strategies to improve iron status and treat iron deficiency anemia. NCT00717730 at www.clinicaltrials.gov, CTRI No.: CTRI/2010/091/001090 at www.ctri.nic.in.

Effect of Deworming on Hemoglobin Concentration in Children from 2 to 15 Years from the Bengo Province, Angola

Objectives: The most common causes of anemia are micronutrient deficiencies, but other factors may influence namely inflammation, parasitic infections and inherited disorders. One strategy to combat micronutrient deficiencies is supplementation, yet, in zones with high prevalence of Schistosomiasis or Soil Transmitted Helminthes (STH), supplementation could be not sufficient. The aim of this study was to evaluate the effects of deworming, on hemoglobin concentration, in children from 2 to 15 years, from Bengo. Methods: A total of 429 children between 2 to 15 years were involved. Nutritional status and anemia were evaluated. Urine and feces samples were collected for diagnosis of Schistosoma haematobium and STH. Praziquantel (40 mg/Kg) and Albendazol (400 mg) were administrated. All parameters were determined at baseline and after 6 months. Results: The prevalence at baseline of S. hematobium was 61,9%, Trichuris trichuria 15,3%, Ascaris lumbricoides 11,8 %, Hymenolepis nana 7,8%, and hookworm 3,8%. Anemia was detected in 71,2% of the children (mild 11,7%, moderate 57,1% and severe 2,3%). Average hemoglobin concentration was 106,8 g/L. 6 months after treatment the prevalence of S. hematobium decreased to 44,5%, Trichuris trichuria to 10,9%, Ascaris lumbricoides to 5,0 %, Conference Abstract Brito et al.; EJNFS, 5(5): 1007-1008, 2015; Article no.EJNFS.2015.401 1008 Hymenolepis nana to 6,7%, and hookworm to 0,8%.The average hemoglobin concentration increased by 7,9 g/L and the prevalence of anemia declined to 49,5% (mild 17,1%, moderate 32,2% and severe 0,2%). Conclusions: These results confirm the benefit of deworming on hemoglobin concentration, even with a single intervention. However it should be clear that integrated intervention aiming nutritional education water treatment, hygiene and sanitation are needed to reduce micronutrient deficiency. © 2015 Brito et al.; This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Critical evaluation of peripheral smear in cases of anemia with high mean corpuscular hemoglobin concentration in children: A series of four cases

Mean corpuscular hemoglobin concentration (MCHC), a parameter that is reported as a part of a standard complete blood count by automated analyzer, is a measure of the concentration of hemoglobin in a given volume of packed red blood cell. Values of MCHC significantly above reference range are not physiologically possible due to limitations on solubility of hemoglobin. The high MCHC can give us a clue to certain type of hemolytic anemia and necessitate critical evaluation of peripheral smear to reach a definitive diagnosis. Here we are presenting a series of four cases with raised MCHC, emphasizing the importance of systematic and meticulous examination of the peripheral smear to render a definitive diagnosis.

Seasonal prevalence of malaria in West Sumba district, Indonesia

BackgroundAccurate information about the burden of malaria infection at the district or provincial level is required both to plan and assess local malaria control efforts. Although many studies of malaria epidemiology, immunology, and drug resistance have been conducted at many sites in Indonesia, there is little published literature describing malaria prevalence at the district, provincial, or national level.MethodsTwo stage cluster sampling malaria prevalence surveys were conducted in the wet season and dry season across West Sumba, Nusa Tenggara Province, Indonesia.ResultsEight thousand eight hundred seventy samples were collected from 45 sub-villages in the surveys. The overall prevalence of malaria infection in the West Sumba District was 6.83% (95% CI, 4.40, 9.26) in the wet season and 4.95% (95% CI, 3.01, 6.90) in the dry. In the wet season Plasmodium falciparum accounted for 70% of infections; in the dry season P. falciparum and Plasmodium vivax were present in equal proportion. Malaria prevalence varied substantially across the district; prevalences in individual sub-villages ranged from 0–34%. The greatest malaria prevalence was in children and teenagers; the geometric mean parasitaemia in infected individuals decreased with age. Malaria infection was clearly associated with decreased haemoglobin concentration in children under 10 years of age, but it is not clear whether this association is causal.ConclusionMalaria is hypoendemic to mesoendemic in West Sumba, Indonesia. The age distribution of parasitaemia suggests that transmission has been stable enough to induce some clinical immunity. These prevalence data will aid the design of future malaria control efforts and will serve as a baseline against which the results of current and future control efforts can be assessed.

Aleitamento materno e níveis de hemoglobina em crianças menores de 2 anos em município do estado de São Paulo, Brasil

OBJETIVO: Avaliar a relação entre aleitamento materno e níveis de hemoglobina em crianças menores de 2 anos residentes na cidade de Itupeva, SP, Brasil. MÉTODOS: Estudo transversal de base populacional, realizado em amostra representativa de 254 crianças menores de 2 anos, selecionadas aleatoriamente na área urbana de Itupeva, SP, por procedimento de amostragem por conglomerados em 3 etapas. O aleitamento materno foi classificado utilizando-se as recomendações da Organização Mundial da Saúde e a hemoglobina foi determinada em hemoglobinômetro portátil (HemoCue). Para o diagnóstico, utilizou-se o ponto de corte de 11,0g/dL. RESULTADOS: A prevalência de anemia foi de 41,7%. Anemia foi mais freqüente entre os menores de 6 meses que não se encontravam em aleitamento materno (p&lt;0,05). As médias de hemoglobina das crianças em aleitamento materno também se mostraram significantemente mais elevadas entre os menores de 6 meses (p&lt;0,05). Nessa mesma faixa etária, a média de hemoglobina das crianças em aleitamento materno exclusivo e predominante foi significantemente maior do que a observada nas crianças em alimentação artificial (12,30g/dL versus 10,99g/dL; p=0,022). CONCLUSÃO: Os resultados encontrados sugeriram que a substituição parcial ou total do leite materno antes dos seis meses de idade associa-se com diminuição dos níveis médios de hemoglobina. A alta prevalência de anemia e o baixo percentual de crianças em aleitamento materno exclusivo chamam atenção para a necessidade do controle dessa deficiência nutricional no município e para a promoção do aleitamento materno exclusivo até os seis meses.

Effects of haemoglobin and serum ferritin on cognitive function in school children

The association between iron deficiency anaemia and cognitive function impairment has been widely reported in young children, but whether the impairment is a result of iron deficiency per se or a combination of iron deficiency and anaemia, and how these conditions interact, is still questionable. Four hundred and twenty-seven school children from two schools in socioeconomically deprived communities were selected in southern Thailand. Iron status was determined by haemoglobin and serum ferritin concentrations. Cognitive function in this study was measured by IQ test and school performance, including Thai language and mathematics scores, using z-scores based on distributions within the same grade and school. Data on demography and socioeconomic status were collected by questionnaire answered by the parents. Linear regression models were used to investigate the effect of anaemia and iron deficiency, reflected by haemoglobin and serum ferritin concentration, on cognitive function and school performance. We found that cognitive function increased with increased haemoglobin concentration in children with iron deficiency, but did not change with haemoglobin concentration in children with normal serum ferritin level. Children with iron deficiency anaemia had consistently the poorest cognitive function (IQ, 74.6 points; Thai language score, 0.3 SD below average; and mathematics score, 0.5 SD below average). Children with non-anaemic iron deficiency but with high haemoglobin levels had significantly high cognitive function (IQ, 86.5 points; Thai language score, 0.8 SD above average; and mathematics score, 1.1 SD above average). This study found a dose-response relationship between haemoglobin and cognitive function in children with iron deficiency, whereas no similar evidence was found in iron sufficient children.

Hemorrhage following pediatric tonsillectomy before puberty

Objective: Control of postoperative bleeding, considered as the major complication following tonsillectomy, serves as a landmark for the safety of the operation. There is a constant decrease of the concentration of hemoglobin during childhood with lowest values around 6 years of age with normal values at the beginning of puberty accompanied by a constant decrease of the number of platelets after birth. Dehydration, poor oral intake and airway problems are predominant complications in early childhood. A retrospective study was undertaken to evaluate if the incidence of bleeding is associated with certain age groups in pediatric patients. We assessed if there is a questionable higher risk for blood transfusions due to the age-specific lower hemoglobin concentration in children. Methods: Between January 1988 and August 2000, 2330 patients under 12 years of age underwent tonsillectomy, with or without adenoidectomy, in St. Anna Hospital, Duisburg. Group A (age<6 years) consisted of 1467 patients of whom 59.6% were male. Group B (aged 6–12 years) consisted of 863 patients, of whom 48.1% were male. Results: Postoperative bleeding from the tonsillar fossae requiring treatment under general anesthesia occurred in group A (1%) and B (2.3%). Bleeding from the adenoidectomy site was treated in group A (0.3%) and B (0.3%). Primary bleeding occurred in the majority of patients in both groups group A (55%) and group B (75%). The latest bleeding was observed 6 days (group A) and 10 days (group B) following surgery, due to statistical analysis the difference was found to be significant ( P<0.025). In group A there was one 42-month-old boy who died due to massive bleeding despite ligature of the external carotid artery and blood transfusions. Statistical evaluation shows a significant increase of postoperative bleeding with age ( P=0.024). No blood transfusion was required in other patients. Conclusion: Tonsillectomy can be safely performed in children under 6 years of age with no increased risk of postoperative bleeding or risk of receiving blood transfusion. Rare cases of secondary hemorrhage seem to occur more frequently in younger children and should be treated immediately under general anesthesia to avoid severe complications.

Hemoglobin concentration in children in a malaria holoendemic area is determined by cumulated Plasmodium falciparum parasite densities.

In malaria holoendemic areas children are anemic, but the exact influence of falciparum malaria on hemoglobin (Hb) concentration remains largely unsettled. Prospective data were therefore collected in children < 24 months of age during five months in a Tanzanian village. Children with mean asymptomatic parasitemia > or = 400/microl had lower median Hb levels during the study than those with mean density < 400/microl. The difference was 9.7 g/L (95% confidence interval [CI] 2.8-17). In children with one or more clinical malaria episodes, the median Hb was 8.3 g/L (95% CI 0.9-16) lower than those without episode. If early treatment failure was recorded, the immediate effect on Hb was particularly important with a mean drop of 17 g/L. Interestingly, at study-end the Hb concentration represented a function of the area under the parasitemia curve (AUPC) during the previous five months, adjusting for age. In conclusion, stepwise deterioration in median Hb levels was found by asymptomatic parasitemia, clinical malaria episode, and most significantly, treatment failure.

Centile probabilities of hemoglobin levels in children of school age

Hemoglobin indexed are analyzed in 2807 children in Kazan, Nizhnekamsk and in three Arsky) of Tatarstan Republik. Centile probabiagricultural regions (Apastovsky, Aktanyshsky, lities of hemoglobin concentration in children of school age are obtained by means of the nonparametrical statistical analysis. This method may be used to estimate the variations of individual indexes of hemoglobin in dynamics in preventive medicine.

Acute hemodynamic effects of increasing hemoglobin concentration in children with a right to left ventricular shunt and relative anemia

The short-term effects of increasing hemoglobin concentration were evaluated at cardiac catheterization in seven children (aged 0.3 to 7.5 years) with a right to left ventricular shunt and relative anemia. Diagnoses were tetralogy of Fallot in six and L-transposition of the great vessels with ventricular septal defect and pulmonary stenosis in one. Before and 20 minutes after isovolumic partial exchange transfusion with 20 ml/kg packed red cells, the following variables were measured: hemoglobin, partial pressure of oxygen (PO2), oxygen consumption, oxygen saturation and pressure in the aorta, superior vena cava and right and left atria. After partial exchange transfusion, hemoglobin increased from 13.7 +/- 0.5 to 16.4 +/- 0.4 g/100 ml (p less than 0.001, mean +/- SEM). Aortic PO2 increased from 55.0 +/- 3.5 to 62.0 +/- 4.1 mm Hg (p less than 0.01) and aortic oxygen saturation increased from 84.3 +/- 2.3 to 90.9 +/- 1.3% (p less than 0.002). Effective pulmonary blood flow increased by 17% from 2.72 +/- 0.10 to 3.17 +/- 0.10 liters/min per m2 (p less than 0.01), and right to left shunt decreased by 59% from 1.44 +/- 0.29 to 0.59 +/- 0.10 liters/min per m2 (p less than 0.01). Systemic oxygen transport increased from 658 +/- 48 to 738 +/- 46 ml/min per m2 (p less than 0.002). After partial exchange transfusion, systemic vascular resistance increased from 15.9 +/- 1.1 to 20.0 +/- 1.4 units (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)