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K J Ellis

Publications and source records attributed to K J Ellis.

At least 55 records · Page 3Linked to original sources
PubMed1998

Bone mineral and body composition measurements: cross-calibration of pencil-beam and fan-beam dual-energy X-ray absorptiometers.

Pencil-beam dual-energy X-ray absorptiometers (DXA) are being replaced with instruments that rely solely on fan-beam technology. However, information has been lacking regarding the translation of bone mineral and body composition data between the two devices. We have compared total body scans using pencil-beam (Hologic QDR-2000W) and fan-beam (Hologic QDR-4500A) instruments for 33 children (ages 3-18 years) and 14 adults. Bone mineral content (BMC), bone mineral density (BMD), fat, lean, and body fatness (%fat) values were highly correlated (r2 = 0.984-0.998) between the two DXA instruments. The mean differences between the paired measurements were: deltaBMC = 7.5 +/- 73.6 g, deltaBMD = 0.0074 +/- 0.0252 g/cm2, delta lean = 1.05 +/- 1.8 kg, delta fat = -0.77 +/- 1.7 kg, and delta%fat = -0.94% +/- 2.5%. The BMC and BMD values were not statistically different, whereas the differences for the body composition values were significant (p < 0.02-0.005). Regression equations are provided for conversion of bone and body composition data between pencil-beam and fan-beam values for the whole body. To test the performance of these equations for a second group (23 subjects), predicted values were compared with the measured data obtained using the fan-beam instrument. The mean differences were -1.0% to 1.4%, except for body fat mass, where the difference was 6.4%. For cross-sectional studies, the two DXA technologies can be considered equivalent after using the translational equations provided. For longitudinal studies in which small changes in body composition for the individual are to be detected, we recommend that the same DXA instrument be used whenever possible. For example, transition from a pencil-beam to a fan-beam instrument could, in extreme cases, result in differences as large as 19% for the estimate of body fat mass.

Absorptiometry, Photon↗
PubMed1998

Bone turnover response to changes in calcium intake is altered in girls and adult women in families with histories of osteoporosis.

Heredity and environmental factors contribute to the development of osteoporosis. Because calcium is the major mineral in bone and adolescence is a key period in bone acquisition, we hypothesized that bone turnover would be less responsive to alterations in dietary calcium intake in both girls and adult women from families with histories of osteoporosis. To address this issue, we studied calcium kinetics in the maternal grandmother (age range 56-81 years), mother (age range 32-47 years), and granddaughter (age range 8-15 years) in 10 multigenerational families. In five families, the mother and/or grandmother had osteoporosis (bone mineral density > or = 2 SD below the age-specific mean). To examine both active and passive calcium absorption, families consumed low- (279 +/- 64 mg/day) and high- (1580 +/- 385) calcium diets for 10 days prior to administration of oral (46Ca) and intravenous (42Ca) stable isotopes. Using repeated measures analysis of variance, fractional calcium absorption, true calcium absorption, bone calcium deposition, and the balance in bone calcium turnover were all significantly affected by diet (p < 0.01). Females from nonosteoporotic families had decreased bone calcium resorption with little change in bone calcium deposition during the high-calcium study. In contrast, girls and adult women from osteoporotic families had increased both bone calcium deposition and resorption during the high-calcium period, leading to a less positive balance in bone calcium turnover. A significant interaction between bone status and diet was found for bone calcium resorption (p < 0.05) and approached significance for bone calcium deposition (p < 0.07), effects which were independent of generation. We conclude that girls and women from osteoporotic families have a significantly altered bone turnover response to acute changes in calcium intake.

Absorptiometry, Photon↗
PubMed1998

Multicompartmental analysis of magnesium and calcium kinetics during growth: relationships with body composition.

Stable isotope techniques permit a unique approach to the assessment of magnesium metabolism, including absorption, excretion, pool sizes, and turnover. Findings from our recent studies on magnesium and calcium kinetics indicate close relationships between the mass of the magnesium exchangeable pool, efflux from this pool, and body weight. In this report, we further evaluate these data by relating the kinetic values with other measures of body composition. We found that fat-free mass represents the single body composition parameter that most closely correlates with magnesium kinetic data. Body composition has a stronger relationship with magnesium kinetics than with calcium kinetics. These relationships provide justification for basing dietary magnesium requirements in children on body composition measures such as body weight or, where available, fat-free mass. Further studies to evaluate these relationships are indicated in situations where either magnesium status or body composition is abnormal.

Adolescent↗
PubMed1997

Changes in fat-free mass and fat mass in postpartum women: a comparison of body composition models.

OBJECTIVES: (1) To compare 2-, 3- and 4-component models of body composition based on total body water (TBW), underwater weighing (UWW), skinfold thicknesses (SF), total body potassium (TBK), dual-energy X-ray absorptiometry (DXA) and total body electrical conductivity (TOBEC); (2) to compare postpartum changes in body composition estimated by the 2-, 3- and 4-component models and (3) to test for an effect of pregnancy or lactation on the hydration, density and potassium content of fat free mass (FFM) in postpartum women. DESIGN: Longitudinal measurements of body composition at 3, 6 and 12 months postpartum. SUBJECTS: Thirty-five healthy postpartum women, aged 30.2 +/- 3.5 y. MEASUREMENTS: Body composition was estimated by 2-component models based on TBW, UWW, SF, TBK, DXA or TOBEC; 3-component models based on TBW and UWW (Fuller 3, Siri 3); and a 4-component model (Fuller 4) based on TBW, UWW and bone mineral content. RESULTS: Systematic differences were seen among the various body composition models, with the following ranking from lowest to highest estimate of fat mass (FM): TOBEC, TBW, Fuller 3, Siri 3, Fuller 4, UWW, SF, TBK, and DXA. Estimated changes in FFM and FM were not significantly different among methods, except for the 3-6 months FFM and FM changes estimated from TBW, which differed from SF, DXA, and TOBEC. Pregnancy-induced changes in the hydration, density and potassium content of FFM were not evident by 3 months postpartum (0.73 +/- 0.02, 1.099 +/- 0.015 kg/l and 2.31 +/- 0.10 g/kg, respectively). CONCLUSION: In spite of systematic differences among body composition models for the measurement of FFM and FM, changes in FFM and FM did not differ significantly among the models. Since there was no apparent effect of pregnancy or lactation on the postpartum composition of FFM, 2-component models of body composition are acceptable for use in postpartum women beyond the puerperium.

Adult↗
PubMed1997

Body fat estimation in late pregnancy and early postpartum: comparison of two-, three-, and four-component models.

Accurate methods for determining body fat mass during reproduction are necessary to evaluate energy balance. However, determination of fat mass is complicated during pregnancy by the accretion of water, which invalidates assumptions underlying standard two-compartment models. The extent to which the variability in body water during pregnancy invalidates use of pregnancy-corrected two-compartment models for determination of fat mass in individual women is unknown. Moreover, it is unclear whether body water returns to nonpregnant values by 2 wk postpartum, which is frequently used as the baseline in studies of postpartum women. The present study uses a four-component model as a criterion for evaluating two- and three-component models. Fifty-six healthy, normotensive women between the ages of 19 and 35 y were studied at 36 +/- 1 wk gestation and 15 +/- 2 d postpartum. Total body water (TBW), total body potassium (TBK), body density, and bone mineral content were measured by deuterium dilution, whole-body potassium counting, hydrodensitometry, and dual-energy X-ray absorptiometry (postpartum only), respectively. At 2 wk postpartum, hydration and density of fat-free mass (FFM) had not returned to nonpregnant values, and differed between lactating and nonlactating women (P < 0.05). Accordingly, standard TBW and body density estimates of fat mass differed from four-component estimates at both time points (P < 0.005). Moreover, our data indicate that even when pregnancy-specific values for hydration or density of FFM are used in TBW and body density models, individual fat mass estimates may differ by > 3 kg from the four-component value. Fat mass by TBK may differ by > 10 kg from fat mass by the four-component model during pregnancy, and by 6 kg postpartum. Use of standard two-compartment models to estimate fat mass results in significant error both during pregnancy and at 2 wk postpartum. Pregnancy-corrected two-compartment models produce reliable mean fat mass estimates during pregnancy, but individual fat mass estimates may vary widely from four-component values.

Absorptiometry, Photon↗
PubMed1997

Body composition of a young, multiethnic female population.

The study objective was to establish the range of body-composition values for a multiethnic female population (aged 3-18 y) by using dual-energy X-ray absorptiometry (DXA). Results for 313 females in three ethnic groups [European American (white), n = 141; African American (black), n = 104; and Mexican American (Hispanic), n = 68] are reported. Changes in the bone mineral content (BMC), lean tissue mass (LTM), fat mass, and percentage fat are presented as functions of age. Analysis of variance with age, weight, and height as covariates was used to evaluate differences among the three ethnic groups. BMC and LTM were higher in the black than the white females, but no significant difference in BMC or LTM was evident between the white and Hispanic groups. The relation between the BMC and LTM compartments was linear (r = 0.963, P < 0.0005) and independent of age or ethnic classification. The Hispanic and black females had higher percentage fat values than the white group. When adjusted for body size, the Hispanic females continued to have significantly higher fat mass and percentage fat than the white females in this study. Ethnic-specific equations for body composition as a function of age, weight, and height are given. In addition, the results for the white females in the present study were compared with DXA-derived body-composition data for reference populations in other countries. We conclude that reference values of total body composition for young females need to be ethnic-specific.

Adolescent↗
PubMed1997

Body composition of a young, multiethnic, male population.

The study objective was to establish the range of total body-composition values for a young, multiethnic, healthy male population (aged 3-18 y) by using dual-energy X-ray absorptiometry (DXA). Results for 297 males in three ethnic groups [European American (white), n = 145; African American (black), n = 78; and Mexican American (Hispanic), n = 74] are reported. Bone mineral content (BMC), lean tissue mass (LTM), body fat mass, and percentage fat are presented as functions of age. Analysis of variance with age, weight, and height as covariates was used to evaluate differences among the three ethnic groups. BMC and LTM were higher in black than in white males, but no difference in BMC or LTM was evident between the white and Hispanic groups. The relation between total-body BMC and LTM was linear (r = 0.985, P < 0.0001) and independent of age or ethnic classification. The Hispanic males had higher body fat values than the white group, whereas the black males generally had lower values than the white group. When adjusted for body size, the Hispanic males continued to have significantly higher body fat and percentage fat than the white or black males. Ethnic-specific equations for the prediction of body composition as a function of age, weight, and height were derived. The results for the white males in the present study were compared with DXA-derived reference data reported in other countries for young white males. We conclude that reference values of total body composition for young healthy males need to be ethnic specific.

Absorptiometry, Photon↗
PubMed1997

Oxidative metabolism in insulin-treated gestational diabetes mellitus.

To investigate whether protein, carbohydrate, and fat metabolism was normalized in insulin-treated gestational diabetes mellitus (GDM), eight Hispanic women with GDM and eight healthy controls were studied at 32-36 wk of gestation and 6 wk postpartum. Net substrate utilization was measured using room respiration calorimetry. Exogenous substrate oxidation was determined by 13C recovered in breath CO2 from 13C-labeled leucine, glucose, and Hiolein. Women with GDM had higher 24-h oxygen consumption, carbon dioxide production, total energy expenditure, and basal metabolic rates than controls due to larger body mass. Adjusted for weight or fat-free mass, total energy expenditure, basal metabolic rate, and basal and 24-h whole body net protein, carbohydrate, and fat utilization did not differ between insulin-treated GDM subjects and controls in pregnancy or postpartum. Oxidation of [13C]leucine and [13C]glucose did not differ by group or pregnancy status. Recovery of exogenously administered [13C]Hiolein, a biosynthetic triglyceride, as breath 13CO2 was significantly lower in the GDM group antepartum and postpartum (P = 0.02), indicating lower oxidation of exogenous triglycerides in GDM.

Adipose Tissue↗
PubMed1997

Leptin levels and body fatness in children: effects of gender, ethnicity, and sexual development.

Leptin, a hormone secreted by adipocytes, is elevated in blood of obese adults. It is unknown whether the concentration is affected by gender, ethnicity, age, or stage of sexual maturation in children. We measured serum leptin levels in 183 children and 27 young adults using a double-antibody ELISA assay. Body fat mass (FM) and percent body fatness (%Fat) were determined by dual-energy x-ray absorptiometry. Correlations for serum leptin with FM, %Fat, and a body mass index were examined. Analyses of covariance were used to determine the effects of gender, ethnicity, and sexual maturation (Tanner stage). We found strong positive correlations (r = 0.56-0.88, p < 0.001) for serum leptin with body mass index. %Fat, and FM, which were gender-dependent (p < 0.001), but unaffected by ethnicity. At each Tanner stage, female subjects had higher serum leptin than male subjects (p < 0.001), and this difference remained significant (p < 0.001) when leptin was normalized for FM. For each gender, the mean leptin/FM ratios were relatively invariant during sexual maturation and no differences were observed between the oldest children (Tanner stage 5) and the young adults. The observation that female subjects have higher mean serum leptin and leptin/FM levels than male subjects at prepubertal ages may suggest that there are gender differences in leptin synthesis, clearance rates, bioactivity, and/or leptin transport.

Adipose Tissue↗
PubMed1996

Total body calcium and bone mineral content: comparison of dual-energy X-ray absorptiometry with neutron activation analysis.

The aim of this study was to compare the dual-energy X-ray absorptiometry (DXA) measurement of bone mass with an independent measure of body calcium obtained by neutron activation analysis (NAA). Total body bone mineral content (BMC) was measured using DXA in 46 subjects in the age range 5-47 years (17 children, 28 young women, and 1 adult male). Total body calcium (TBCa) was measured in the same subjects by in vivo NAA. The correlation between the two measures of bone mass was highly significant (BMC[g] = 3.22 x TBCa[g] - 51.4, r > 0.98, p < 0.0001, SEEBMC = 122.7 g). When BMC was the independent parameter, the SEETBCa was 37.5 g. Bland-Altman analysis indicated a mean difference of 2.8 g with a standard error +/- 4.7 g for TBCaNAA versus TBCaDXA when the BMC values were converted to TBCa. The relative change in bone mass (delta TBCa/delta BMC) for DXA was higher than that reported for dual-photon absorptiometry versus NAA. The findings presented in this study provide translational equations among the DXA and NAA measurements and for the conversion of total body BMC to TBCa in children and young adults.

Absorptiometry, Photon↗
PubMed1996

Increased efficiency of calcium absorption during short periods of inadequate calcium intake in girls.

Adequate calcium intake is essential for skeletal integrity, particularly during the period of peak bone mass acquisition from 9 to 17 y of age. Currently, the calcium intake of many adolescent girls is below the recommended dietary allowance. The purpose of this study was to evaluate the ability of girls to respond to acute periods of inadequate dietary calcium intake. Calcium absorption was evaluated in 11 girls aged 11.6 +/- 2.4 y after 10 d on both a low-calcium (7.05 +/- 2.03 mmol/d) and a high-calcium (35.30 +/- 2.28 mmol/d) diet. Fractional calcium absorption was determined by using oral (46Ca) and intravenous (42Ca) stable isotopes of calcium. During a low calcium intake, fractional calcium absorption was significantly greater (0.582 +/- 0.087 compared with 0.260 +/- 0.068, P < 0.0001) and urinary calcium excretion was significantly lower (1.30 +/- 0.83 compared with 3.08 +/- 1.98 mmol/d, P < 0.004) than values obtained during a high calcium intake. Concentrations of 1,25-dihydroxyvitamin D (combination of cholecalciferol and ergocalciferol) were greater during the low calcium intake, although the difference was not significant (108.7 +/- 30.6 compared with 90.0 +/- 25.1 pmol/L, P < 0.1; n = 9). Excretion of N-telopeptide was significantly greater during the low calcium intake (761 +/- 508 compared with 413 +/- 341 nmol bone collagen equivalent (BCM)/mmol creatinine, P < 0.02; n = 9), indicating that bone resorption was increased. These results suggest that during short periods of inadequate calcium intake, girls are able to significantly increase the efficiency of calcium absorption and decrease urinary calcium losses to conserve calcium required for bone mineral acquisition.

Absorption↗
PubMed1996

Severe protein deficiency and repletion alter body and brain composition and organ weights in infant pigs.

Three-wk-old genetically lean or obese pigs were used in two experiments to determine the changes in body composition, visceral organs and brain in response to severe protein deficiency. In Experiment 1, 16 obese pigs were fed an adequate (A, 21% protein, 3% fat) or a protein-deficient (D, 5% protein, 23% fat) diet for 7 wk. One-half of each group was killed at 7 wk, and the remainder of each group was fed the A diet for an additional 8 wk. At 7 wk, pigs fed D contained a higher percentage of fat than those fed A (P < 0.01); after 8-wk of repletion, body composition of the two groups was similar. Duodenum, jejunum, and ileum of the protein-deficient pigs had severely atrophic villi, submucosal edema, and atrophic muscle layers; after 8 wk of repletion, however, microscopic architecture of the gastrointestinal tract was restored to normal. Absolute cerebrum weight at 7 wk, but not after 8 wk repletion, in the pigs fed D were significantly less than in pigs fed A, indicating reduced brain cellularity after 7 wk of protein restriction, but not after 8 wk repletion. In Experiment 2, genetically obese (O, n = 8) and lean (L, n = 8) pigs consumed the A or D diet ad libitum for 10 wk. L and O pigs responded similarly to protein deficiency; D pigs were fatter than A pigs and plasma constituents, bone mineral content, bone mineral density and most organ weights revealed no interactions between diet and genotype. The pig model system used in these experiments enabled the isolation of protein deficiency from infectious disease, parasites and social environmental stimulation that may confound interpretation of human infant malnutrition experiments. The data suggest that genetically controlled body fatness is not a major determinant in the response of the infant pig to severe protein deficiency.

Animals↗
PubMed1996

A randomized, placebo-controlled trial of combined insulin-like growth factor I and low dose growth hormone therapy for wasting associated with human immunodeficiency virus infection.

Loss of body mass, or wasting, is a major cause of morbidity and a contributor to mortality in human immunodeficiency virus-1 (HIV-1) infection. Dietary supplements and appetite adjuvants have had limited effectiveness in treating this condition. GH and insulin-like growth factor I (IGF-I) have been shown to be anabolic in many catabolic conditions, and limited data suggest similar efficacy in HIV wasting. In addition, it appears that GH and IGF-I may have complementary anabolic effects with opposing glucoregulatory effects. We report results from a 12-week randomized, placebo-controlled trial of combination recombinant human GH (rhGH; Nutropin; 0.34 mg, sc, twice daily) and rhIGF-I (5.0 mg, sc, twice daily) in individuals with HIV wasting and without active opportunistic infection, cancer, or gastrointestinal disease. A total of 142 subjects (140 males and 2 females) were randomized using a 2:1, double blind treatment scheme and assigned to receive either active treatment or placebo injections. Eighty subjects completed the 12-week protocol. Nutritional intake and demographic and clinical characteristics did not differ between the groups at any study time point. At 3 weeks, the treatment group had a significantly larger weight increase (P = 0.0003), but this difference was not observed at any later time point. Similarly, fat-free mass, calculated from skinfold measurements, increased transiently in the treatment group at 6 weeks (P = 0.002). No significant differences in isokinetic muscle strength or endurance testing or in quality of life were observed between the groups. Resting heart rate was significantly higher in the treatment group at each time point post-baseline. GH and IGF-binding protein-3 levels did not change; however, IGF-I levels were higher in the treatment group at 6 and 12 weeks. There were no significant between-group differences in any of the measured biochemical or immunological parameters. rhGH plus rhIGF-I treatment was associated with an increased incidence of peripheral edema and other side-effects, possibly related to fluid retention. We conclude that the combination of rhIGF-I and low dose rhGH used in this study had no significant anabolic effect in HIV wasting.

Acquired Immunodeficiency Syndrome↗
PubMed1996

Changes in body composition of human immunodeficiency virus-infected males receiving insulin-like growth factor I and growth hormone.

Weight loss is a common, persistent characteristic of long term human immunodeficiency virus (HIV-1) infection; its full etiology remains unknown. Because treatment with GH has induced nitrogen retention in various catabolic conditions, we designed this study to determine whether a moderate dose of insulin-like growth factor I (IGF-I) combined with a low GH dose could impede the catabolic response seen in HIV-1 infection. A double blind, placebo-controlled study design was used. Subjects in the GH/IGF-I treatment group (n = 44) and control group (n = 22) continued to receive their routine stable antiretroviral therapy. No patient had a recent history of opportunistic infection, malignancy, or Kaposi's sarcoma and had dietary intakes of at least 25 Cal/kg weight.day at study entry. During the 12-week study period, dietary instruction was given, and subjects were encouraged to maintain an intake of 35 Cal/kg and 1 g protein/kg. All subjects had a body mass index of 19.8 kg/m2 or less at the time of study entry or a weight loss of 10% or more of their premorbid weight and a body mass index below 26.1 kg/m2. The treatment group received 0.34 mg (0.68 mg/day) GH, twice daily, and 5.0 mg (10 mg/day) IGF-I, twice daily. Changes in body composition of total body potassium (TBK), total body nitrogen (TBN), fat-free mass (FFM), and body fat (Fat) were examined at 6 and 12 weeks during the treatment period. TBK, TBN, FFM, and Fat for the treatment and placebo groups were, on the average, below normal at study entry. At 6 weeks, the GH/IGF-I group showed a significant increase in FFM (P < 0.0001), a minimal increase in TBK (P < 0.05), and a substantial decrease in Fat (P < 0.01) compared with baseline values. The loss of body fat continued to be significant (P < 0.01) in the GH/IGF-I group treatment at 12 weeks, whereas the increase in FFM was minimal (P < 0.05). No significant changes in the mean body composition occurred at 6 or 12 weeks in the placebo group. By 12 weeks, neither TBK (body cell mass) nor TBN (total protein mass) had significantly increased relative to the values at baseline, although the FFM remained elevated. Thus, the combined GH and IGF-I doses used in this study in adult males with HIV-associated weight loss were ineffective in producing a sustained anabolic response and, in fact, resulted primarily in a significant loss of body fat.

Absorptiometry, Photon↗
PubMed1996

Measuring body fatness in children and young adults: comparison of bioelectric impedance analysis, total body electrical conductivity, and dual-energy X-ray absorptiometry.

OBJECTIVE: To determine the level of agreement for body fatness measurements among four body composition measurement techniques. SUBJECTS: 99 healthy children and young adults (63 males, 36 females; ages: 5-22 y) MEASUREMENT: Bioelectrical impedance analysis (BIA), bioelectrical impedance spectroscopy (BIS), total body electrical conductivity (TOBEC), and dual-energy X-ray absorptiometry (DXA) measurements of body fat mass, and its percentage of body weight (% Fat). RESULTS: Estimates for body fat mass and % Fat were highly correlated (r = 0.72-0.97, P < 0.001) among the four methods. However, a Bland-Altman comparison among the estimates indicated significant differences between methods. The mean differences between methods for body fat ranged from -0.30 +/- 6.7 kg to 4.2 +/- 2.7 kg. Differences for % Fat ranged from 0.8% +/- 3.5% to -9.9% +/- 5.2%. Fatness classification of an individual as normal, overweight, or obese on the basis of his/her % Fat was significantly method dependent. CONCLUSIONS: The lack of interchangeability for fatness classification makes it difficult to ensure that similar groups of subjects can be accurately selected for the same true fat content or % Fat range when different methods are used. Furthermore, this limitation may restrict comparison of findings among different studies, such as in weight reduction, exercise, or therapy programs, when the subjects were not originally classified using the same measurement methods. That is, the reported values and changes for body fat or % Fat appear to be highly method dependent.

Absorptiometry, Photon↗
PubMed1995

Acute decreases in serum potassium augment blood pressure.

Potassium depletion is a risk factor for cardiovascular diseases, including hypertension, and frequently is encountered in patients with end-stage renal disease. Since the treatment of end-stage renal disease might result in K+ depletion and postdialysis hypokalemia, we investigated the relationship between acute K+ removal by hemodialysis and changes in blood pressure at the completion of treatment compared with predialysis and 1-hour postdialysis blood pressure. The effects of three different dialysate potassium concentrations ([K+]d; 1.0, 2.0, and 3.0 mmol/L) were investigated in 11 patients. Hemodialysis-induced K+ removal, serum [K+], total body K+, and blood pressure were measured. The use of 1.0, 2.0, or 3.0 mmol/L [K+]d resulted in the removal of 77.0 +/- 6.5, 54.5 +/- 7.9, and 42.5 +/- 9.9 mmol of K+ per treatment, respectively (P < 0.05, [K+]d 1.0 v [K+]d 3.0). Predialysis and postdialysis serum [K+] were 4.9 +/- 0.2 and 3.6 +/- 0.1 mEq/L for 1.0 mmol/L [K+]d, 5.1 +/- 0.3 and 3.9 +/- 0.1 mEq/L for 2.0 mmol/L [K+]d, and 5.3 +/- 0.3 and 4.2 +/- 0.2 mEq/L for 3.0 mmol/L [K+]d, respectively (P < 0.001 for each [K+]d). The baseline total body K+ corrected for gender, age, and race was 92% of predicted normal level and did not change significantly with the use of different [K+]d. Blood pressure decreased during hemodialysis as excess fluid was removed, regardless of [K+]d. Significant increases in blood pressure did occur 1 hour postdialysis compared with levels measured at the completion of treatment ("rebound hypertension") when hemodialysis was performed with 1.0 and 2.0 mmol/L, but not with 3.0 mmol/L [K+]d.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Pressure↗