Increasing Protein Intake to Help Older Adults Increase Muscle Strength and Function: A Pilot, Single-Arm Investigation Using Coaching and a Per-Meal Protein Prescription.

Objective: To evaluate the effects of nutrition education, diet coaching, and a protein prescription (PP) on protein intake, and associations with muscle strength and function. Design: Prospective pretest posttest single-arm study. Setting: Urban area, East coast of South Florida. Participants: 20 white, non-Hispanic adults, aged 73.3 + 10.4 years. Intervention: 10-week telephone-based diet coaching, nutrition education and a per-meal PP. Measurements: Protein and energy intakes, weight, grip strength (GS), and 5-chair-rise (5CR), timed up and go (TUG), 3-meter walk (3mW) tests at baseline and 10 weeks. Results: Pre to 10-week post values significantly improved (p<0.05) for protein intake/kg body weight (0.8 + 0.3 to 1.2 + 0.3g), protein intake/meal (17.2 ± 4.8g to 26.4 ± 6.g), protein intake/100 kcal (3.74 + 1.16 to 5.97 + 0.98g), GS (22.4 to 23.4kg), and times for TUG (10 to 8sec), 3mW (4 to 3sec), and 5CR (13 to 11sec). Conclusions: Given the positive findings of this unique pilot investigation, additional studies, which include a larger more diverse group of participants and provide for control group(s), are needed to better investigate the effectiveness of this approach and its effects on muscle strength and function.

Hyperthermia increases exercise-induced oxidative stress.

The purpose of this investigation was to examine oxidative markers after exercise in a hyperthermic environment (35 degrees C, 70 % RH) (Hot) versus a neutral environment (25 degrees C, 40 % RH) (Con). Hyperthermia may exacerbate oxidative stress by uncoupling the mitochondrial respiratory chain or by inhibiting antioxidant defense mechanisms, but this has not been assessed in vivo. Six male subjects performed low-intensity exercise (50 % VO(2max)) on a treadmill in Hot until a core temperature of 39.5 degrees C was reached, and for an equivalent time in Con. Blood samples were drawn before and immediately after exercise and at 8 min and 15 min following exercise. Samples were analyzed for F2 isoprostanes (FIP), lipid hydroperoxides (LPO), and lactate. A 2 x 4 repeated measures ANOVA was used to test for treatment, time, and interaction effects for FIP, LPO, and lactate. Differences in VO(2) were tested with Student's t-test. Significance was set at p < 0.05. Oxygen consumption was not significantly different between Hot and Con. The pattern of change of FIP and lactate in Hot was significant versus exercise in Con. LPO was significantly elevated over time in both Hot and Con, but the pattern of change was not significantly different. Ending core temperatures and heart rates were significantly elevated in Hot versus Con. These data indicate that hyperthermia increases oxidative stress and selectively affects specific lipid markers, independent of oxygen consumption.

Energy expenditure and intake in children with sickle cell disease during acute illness.

BACKGROUND: Children with sickle cell disease have frequent bouts of pain and infection which may increase energy expenditure, decrease energy intake and lead to a subsequent energy deficit. METHODS: Two groups of African-American children with sickle cell disease-SS genotype were enrolled in this study upon hospital admission for a sickle cell disease related illness: a younger (<6 years, n=14, 7 M) and older group (> or =6 years, n=17, 8 M). Body composition and dietary intake were assessed, and sleeping (younger) or resting energy expenditure (older) were measured by indirect calorimetry at admission and one month later at steady state. RESULTS: Energy expenditure was not different between the two timepoints for younger children, but was slightly elevated at steady state (+50 kcal/d, P=0.049) in the older group. After controlling for gender, changes in fat-free mass and dietary intake, the significance disappeared. Energy intake in both groups was significantly depressed at admission compared to follow-up (P<0.01). CONCLUSIONS: These children and adolescents did not expend excess energy during their acute illness, however, an energy deficit was observed secondary to poor energy intake. Since 20% of patients with sickle cell disease have multiple hospitalizations per year, these results provide justification for the development and evaluation of nutrition care protocols to maintain adequate caloric intake during hospitalization and recovery.

Phosphate binders do not compromise the copper status of adult renal disease patients on hemodialysis.

The effects of phosphate binder therapies (calcium carbonate, calcium acetate, or aluminum hydroxide) on copper status were assessed in 88 adult patients with end-stage renal disease on hemodialysis. Subjects were divided into two groups based on binder therapy compliance as specified by medical criteria established by the Health Care Financing Administration. Binder compliant subjects (n = 62), aged 59.7+/-12.2 yr, maintained serum phosphorus concentrations of 3.5-6.0 mg/dL. Noncompliant subjects (n = 26), aged 54.2+/-13.8 yr, had serum phosphorus concentrations > 6.0 mg/dL. Mean plasma and red blood cell (RBC) copper, serum ceruloplasmin, and erythrocyte superoxide dismutase activity did not differ between binder compliant and noncompliant subjects. Mean RBC copper, plasma copper, and serum ceruloplasmin concentrations of hemodialysis subjects were within normal limits, despite copper intakes of less than two-thirds of the lower limit of the Estimated Safe and Adequate Daily Dietary Intakes for copper. The phosphate binder therapies (calcium carbonate, calcium acetate, and/or aluminum hydroxide) had no effect on the copper status of patients with end-stage renal disease on hemodialysis.

Impact of acute illness on nutritional status of infants and young children with sickle cell disease.

OBJECTIVE: To evaluate changes in growth, nutritional status, body composition, and energy and nutrient intakes during illness and usual state of health in infants and young children with sickle cell disease. DESIGN: Sixteen children, aged 0.4 to 5.6 years, with SS type sickle cell disease (SCD-SS) were assessed at the time of hospital admission for an acute illness episode and during an 18-hour overnight follow-up visit 2 to 6 weeks after the acute illness episode when in a state of usual health. Main outcome measures included growth in height and weight compared with reference standards, body composition determined by the skinfold thickness technique and total body electrical conductivity, and dietary intake determined by 24-hour recall during hospital admission and at follow-up. RESULTS: Height, weight, and weight-for-height z scores did not differ from national reference data; triceps skinfold thickness and arm fat area z scores were less. Mean +/- standard error body fat was 15.6 +/- 2.1% at the time of hospital admission, as measured by total body electrical conductivity, and was not significantly different from the follow-up value (16.2 +/- 2.2%). Mean energy intake was 44 +/- 9% of Recommended Dietary Allowances at the time of admission and differed significantly from the follow-up value of 90 +/- 9% (P < .05). APPLICATIONS: Infants and children with sickle cell disease appear to be at nutritional risk during an acute illness episode, as indicated by body fat measures and inadequate intakes of energy and macronutrients. Energy intake may be suboptimal for several days surrounding an admission for an acute illness in children with sickle cell disease. Physicians and other health practitioners should be alert to inadequate nutrient intakes of their patients during this time period and may consider supplemental energy to avoid a potential net negative energy balance.

Effect of chromium nicotinic acid supplementation on selected cardiovascular disease risk factors.

The effects of daily supplemental chromium (200 micrograms) complexed with 1.8 mg nicotinic acid on plasma glucose and lipids, including total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides, were assessed in 14 healthy adults and 5 adults with noninsulin-dependent diabetes mellitus (NIDDM) using a double-blind crossover study with 8-wk experimental periods. Eight of the 14 healthy subjects and all 5 subjects with NIDDM also underwent an oral glucose tolerance test with assessment of 90 min postprandial plasma glucose and insulin concentrations. No statistically significant effects of chromium nicotinic acid supplementation were found on plasma insulin, glucose, or lipid concentrations, although chromium nicotinic acid supplementation slightly lowered fasting plasma total and LDL cholesterol, triglycerides, and glucose concentrations, and 90-min postprandial glucose concentrations in individuals with NIDDM.

Immune status of children with phenylketonuria.

OBJECTIVE: To determine the effect of differences in plasma phenylalanine (Phe) concentrations (< 363 umol/L, 363 to 605 umol/L, and > 605 umol/L) on hematological and immunological parameters in 22 children with phenylketonuria (PKU). METHODS: Children with PKU were divided into one of three groups based on fasting plasma Phe levels. Hematologic and immunologic parameters of the children with PKU were compared between the groups and also compared with published values from age-matched children without PKU. RESULTS: Hematologic and immunologic parameters did not differ among children with different plasma Phe concentrations. Specifically, no significant differences between groups of PKU children with differing plasma Phe levels were found for plasma levels of albumin, hemoglobin, amino acids, IgM, complement C3, interleukins 1 and 2, erythrocyte, leukocyte and differential cell counts, hematocrit, percentages and numbers of CD4+, CD8+, CD3+ and total lymphocytes, or CD4 to CD8 ratio. Mean plasma IgG and IgA concentrations of the PKU children were, however, significantly lower than values from similar aged children. Moreover, positive correlations were obtained between plasma albumin and percentages and numbers of CD3+ and CD4+, between plasma IgG and interleukins 1 and 2, and between intakes of energy, protein, iron and plasma IgG levels. No correlations were found between plasma Phe and immunological parameters. CONCLUSION: While differences in plasma Phe concentrations up to concentrations of 866 umol/L do not appear to affect selected immune system parameters, further studies are needed to investigate the relationship between dietary nutrient intake, nutritional status, antibody biosynthesis and cytokine production. Assessment of plasma and cell membrane lipids and trace mineral status of PKU children would be helpful to determine if relationships exist between these nutrients and antibody production.

Plasma molybdenum concentrations in children with and without phenylketonuria.

Plasma molybdenum concentrations were determined in children, ages two to 12 yr, with and without phenylketonuria (PKU). Mean plasma molybdenum concentrations did not differ significantly between the children with PKU (1.33 +/- 0.5 microgram/L) and without PKU (1.75 +/- 0.8 microgram/L). Plasma molybdenum concentrations in both groups of children ranged from < 1 to 3 micrograms/L. When data from all children were combined and then separated based on gender, mean plasma molybdenum levels did not differ significantly between 9 females (1.56 +/- 0.68 microgram/L) and 12 males (1.58 +/- 0.76 microgram/L). Data were also combined and mean (+/- SD) plasma molybdenum concentrations calculated for age groups. Two children aged 1 to < 4 yr had plasma molybdenum concentrations of 1.0 micrograms/L, and six children aged 4 to < 7 yr had mean (+/- SD) plasma molybdenum concentrations of 1.5 +/- 0.8 microgram/L. Eleven children aged 7 to < 11 yr had a mean plasma molybdenum concentration of 1.7 +/- 0.7 microgram/L, and two children 11 to < 14 yr had plasma molybdenum of 1 microgram/L and 2 micrograms/L. Plasma molybdenum concentrations did not differ significantly among children in the age groups.

Nutrient intakes of adolescents with phenylketonuria and infants and children with maple syrup urine disease on semisynthetic diets.

Adequacy of nutrient intakes of adolescents with and without phenylketonuria (PKU) and infants and children with and without maple syrup urine disease (MSUD) were assessed using 3-day diet records sorted by disease and by age of the subject. Mean intakes of all nutrients were greater than two-thirds of the Recommended Dietary Allowances (RDA) or Estimated Safe and Adequate Daily Dietary Intakes (ESADDI) for all adolescents studied, with the exception of selenium (Se) in PKU adolescents, which averaged 27.8 micrograms. For adolescents with PKU, > 50% of the RDA or ESADDI for all nutrients was provided by elemental or modified protein hydrolysate medical foods, except for vitamin A in children aged 11-15 years and Se in children 11-18 years. Mean nutrient intakes of all infants and children were greater than two-thirds of the RDA or ESADDI for all nutrients except Se in MSUD children aged 1-11 years, where intakes ranged from 6.4 to 13.2 micrograms (21-66% of the RDA). The medical foods provided for most of the RDA and ESADDI recommendations, with the exception of Se in MSUD children.

Plasma amino acid response to ingestion of L-amino acids and whole protein.

The effect of whole protein and L-amino acid ingestion on plasma amino acid concentrations was investigated in 10 men. Each subject ingested equivalent amounts of amino acids as cottage cheese (session 1), an L-amino acid mixture (session 2), and cottage cheese and L-amino acids (session 3). Postprandial changes from baseline were larger for essential versus nonessential amino acids in each session. Higher and more rapid rises followed by more rapid declines in individual plasma amino acid concentrations were observed after ingestion of L-amino acids alone or with whole protein than after ingestion of an equivalent amount of amino acids as whole protein. Individuals receiving the majority of their essential amino acid and nitrogen needs from elemental products may need, for example, to consume them more frequently or after consumption of other foods in an effort to slow down absorption rates.

Effect of simultaneous ingestion of L-amino acids and whole protein on plasma amino acid and urea nitrogen concentrations in humans.

The effect of whole protein and L-amino acid ingestion on plasma amino acid (PAA) and urea nitrogen (UN) concentrations was investigated. Ten males ingested equivalent amounts of nitrogen as (trial 1) cottage cheese, (trial 2) an L-amino acid mixture, (trial 3) cottage cheese and L-amino acids. Mean changes in total PAA between trials 1 (342 mumol/liter) and 2 (719 mumol/liter) and trials 1 (342 mumol/liter) and 3 (981 mumol/liter) at 30 min and trials 1 (547 mumol/liter) and 3 (143 mumol/liter) at 150 min differed significantly. Mean changes in essential PAA between trials 1 (180 mumol/liter) and 2 (420 mumol/liter) and trials 1 (180 mumol/liter) and 3 (500 mumol/liter) at 30 min differed significantly. Mean changes in essential PAA between trials 1 (247 mumol/liter) and 3 (334 mumol/liter) at 60 min and between trials 1 (252 mumol/liter) and 3 (80 mumol/liter) at 150 min differed significantly. Mean increments in total and essential PAA were higher and peaked faster but decreased more quickly after trials 2 and 3 than after trial 1. Mean changes in plasma UN did not differ between trials. Ingestion of either L-amino acids, whole protein or the mixture of L-amino acids and whole protein was equally effective in increasing total PAA over 4 hr.

Trace element status of children with PKU and normal children.

The trace mineral (chromium, copper, iron, selenium, and zinc) status of 10 children (4 to 13.8 years) with phenylketonuria (PKU) and 9 normal children (6.5 to 15.9 years) was assessed. The children with PKU were treated with a phenylalanine-free L-amino acid mix that supplied the following percentages (mean +/- standard deviation) of total daily intake: energy, 45 +/- 13; protein, 75 +/- 11; copper (Cu), 62 +/- 10; iron (Fe), 82 +/- 7; selenium (Se), 40 +/- 20; and zinc (Zn) 87 +/- 8. Diet records and blood samples were collected from each subject. Children with PKU had significantly greater mean intakes of Cu, Fe, and Zn than normal children. Mean serum Cu, Fe, and Zn concentrations of the children with PKU and normal children were not different despite significantly greater intakes by the children with PKU. Normal children had a significantly greater mean serum Se concentration and a mean blood chromium concentration 1.6 times that of children with PKU. Individuals whose primary source of protein is an elemental diet are especially at risk for multiple trace mineral deficiencies. Manufacturers of chemically defined medical foods should evaluate composition, specifically molar ratios between minerals, as a basis for product formulation.

The therapeutic effect of fiber in treating obesity.

This study provides preliminary data on the influence of ingestion of 15 g of dietary fiber daily for 4 weeks on weight change and serum iron concentrations in obese children. During two consecutive 4-week periods, subjects received either fiber/placebo supplements or placebo/fiber supplements. Initially, and after the fourth and eighth weeks, height, weight, and serum iron concentration were obtained. Diet records were maintained throughout the study. No significant differences (p less than or equal to 0.05) were found in weight change, energy, iron, and crude fiber intakes and serum iron concentrations of the subjects between periods of fiber and placebo supplementation. However, mean weight loss of subjects (336 g) was greater during fiber ingestion than during placebo ingestion (33 g). Due to the small sample size and the subjects' poor compliance, further studies are needed, with a larger sample size, to determine the effectiveness of different fibers in the treatment of obesity.