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Biomedical subjects

J T Dwyer

Publications and source records attributed to J T Dwyer.

At least 19 recordsLinked to original sources

Registered dietitian time requirements in the Modification of Diet in Renal Disease Study.

OBJECTIVE: To assess time expended by registered dietitians to conduct clinical and research activities during the Modification of Diet in Renal Disease (MDRD) Study. DESIGN: Two randomized, controlled clinical trials among persons with diminished levels of renal function using a factorial design to evaluate effects of dietary protein restriction and blood pressure control on progression of renal disease. In study A, subjects with moderate renal insufficiency were randomly assigned to a diet of usual protein (1.30 g/kg per day) or low protein (0.58 g/kg per day) and to either a usual or low blood pressure level. Study B involved subjects with advanced renal insufficiency who were randomly assigned to the low-protein diet or a very-low-protein prescription (0.28 g/kg per day) with a ketoacid-amino acid supplement (0.28 g/kg per day) and to either the usual or low blood pressure level. A time-log form designed by MDRD Study dietitians was completed for each participant at 36 monthly follow-up visits. SETTING: Fifteen clinical centers throughout the continental United States. SUBJECTS: Eight hundred forty adults aged 18 to 70 years with chronic renal diseases participated in the MDRD Study--585 in study A and 255 in study B. STATISTICAL ANALYSES: One-way analyses of variance and t tests were used to evaluate significant time requirement differences by diet groups, diagnosis, and sociodemographics. RESULTS: Mean total time for all participant visits declined from 183 +/- 1 minutes per visit during months 1 through 4 to 116 +/- 41 minutes per visit during months 25 through 36. Significantly more dietitian time was required for participants consuming the low-protein and very-low-protein diets than for those consuming the usual-protein diet. Age, gender, race, marital status, and renal diagnosis did not influence time requirements. A significant inverse association between education level and dietitian time was apparent. APPLICATIONS: The MDRD Study time-log data should be useful when determining staffing patterns for nutrition management in clinical and research settings.

Adolescent

Dietary fiber for children: how much?

BACKGROUND: Dietary fiber intakes of most American children are lower than current American Academy of Pediatrics recommendations. Intakes of vegetarian children come closer to these levels. RESULTS: We summarize dietary fiber recommendations for children based on existing evidence. The general public needs guidance on appropriate fiber intake levels for children and adolescents. It is important to ensure that energy intakes are adequate by monitoring child weight, growth, and size, especially when fiber intakes are very high. At levels of "age plus 5 g" there seem to be few problems. CONCLUSIONS: Age plus 5 g is a reasonable recommendation and is easier to remember than others by weight or energy level, although it never exceeds them. Age plus 15 g is clearly excessive; there is less evidence about ill effects arising with age plus 10 g. Delivery of dietary fiber in food rather than by supplements is suggested to ensure intakes of other nutrients and to avoid medicalizing dietary intake. In addition to dietary fiber recommendations for the general population of healthy children, individualized recommendations may be necessary for some high-risk groups. Practical steps to increase child fiber intakes from food sources are provided. The article concludes with suggestions for further research. Age plus 5 g is a reasonable minimum recommendation for dietary fiber intakes for children older than 3 years of age.

Adolescent

Body mass index from childhood to middle age: a 50-y follow-up.

The tracking of body mass index (BMI) over a 50-y period in a longitudinal study was examined by using both correlation coefficients and the Foulkes-Davis tracking index. Over the long term, BMIs before maturity were poor predictors of middle-aged BMI status in females but were good predictors in males. The correlation between females' BMI in childhood and their BMIs at two points during middle age (40 and 50 y) was zero; in males it was r = 0.36 and 0.41, respectively. Between-age correlations were high (P less than 0.0001) for both sexes, reflecting stability in BMI over the shorter term (less than or equal to 10 y). The tracking of BMI (with the Foulkes-Davis tracking index) from childhood to middle age was better for males than for females (P less than 0.1). Linear-regression analysis was also used to assess the predictability of relative body size in middle age from earlier measures; BMI in childhood accounted for 0% of the variance in females and 17% in males. We conclude that the prediction of ponderosity in middle age from BMIs early in life is more reliable for males than for females.

Adolescent

Long-term memory of body weight and past weight satisfaction: a longitudinal follow-up study.

Recalled body weight and self-reported current weight were validated in a longitudinal study population by comparing recalls at 50 y to actual measures taken at ages 18, 30, 40, and 50 y. Recalled body weights were also compared with reported desired weights at these same ages. Self-reported weights at 50 y were equally accurate for both males and females; the mean reporting underestimate was -1.98 kg for males and -1.86 kg for females. Males' self reports at age 50 y were influenced by years of education (P less than 0.005) and current body size (P less than 0.0001) whereas females' were not. Correlations between recall of past weights and measured weights ranged from r = 0.87 at 18 y to 0.95 at 40 y. Recalls of past body weight were not significantly influenced by the passage of time, the number of years of education, or the accuracy of current weight reports. Current body size (wt/ht2) was significantly associated with life-time weight dissatisfaction in both sexes (P less than 0.0005).

Body Image

Nutritional support in treatment of oral carcinomas.

Two young adults, one lean and one obese, with squamous cell carcinomas of the oral cavity received aggressive antitumor therapies with comprehensive nutritional support in an effort to minimize the secondary malnutrition that often accompanies cancer treatments.

Adult

Nutrition support of HIV+ patients.

Case management strategies for the nutritional support of patients infected with the human immunodeficiency virus (HIV) are evolving as the disease becomes less rapidly fatal and more chronic. Nutritional status changes in advanced HIV infection are similar in many respects to protein-calorie malnutrition. Current clinical effort and research focuses on the beneficial effects of preserving lean body mass and keeping asymptomatic patients in good nutritional status by preventing micronutrient deficiencies and by treating preexisting nutritional problems rather than attempting to intervene late in the disease's course, after secondary malnutrition has already developed. Nutrition support and intervention trials only late in the disease process have not been promising in reversing weight loss once it has occurred. Special diets, such as lactose- or gluten-free diets, may be helpful in some cases as asymptomatic treatment of some opportunistic infections, and such measures may slow additional losses. However, secretory diarrhea, which often seems to be inherent to the disease itself, is not ameliorated by such measures. Current research is focusing on the potential role of glutamine in slowing malabsorption and on combinations of diet and drug treatments. Asymptomatic patients are now the focus of concern. Preserving good nutritional status by attention to preventing weight loss and loss of lean body mass and assuring food safety are primary. Symptomatic patients require specific assistance depending on the presence of opportunistic infections and the drugs required. Specific nutrition support measures depend on whether or not the gut is functional.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome

Consensus of the Nutrition Screening Initiative: risk factors and indicators of poor nutritional status in older Americans.

Dietetics professionals must become even more proactive in taking the lead in the nutritional screening and assessment of older Americans. They can do so by encouraging all health care providers to become familiar with each older American's circumstances and needs. In addition, as individuals and as a professional health care association, we should urge our colleagues and institutions to establish regular longitudinal surveillance and continuity of care in nutrition services delivery. The timely, appropriate, and cost-effective delivery of nutritional screening, assessment, and care will improve the health and well-being of this valued segment of the US population. Dietetics professionals are a vital part of this process.

Activities of Daily Living

An approach to protein restriction in children with renal insufficiency.

Children with mild to moderate renal insufficiency may be at an increased risk for developing glomerulosclerosis and subsequent renal failure. Low protein diets (LPD) have been shown to delay the progression of renal insufficiency in laboratory animals and may be of benefit in adult humans. The nutritional costs of a LPD in adults are reportedly minimal. We review the protein and caloric requirements of growing children and discuss the potential harmful effects and benefits of an LPD in this population. We also discuss dietary adherence and the difficulty of designing an LPD for children. We conclude that the protein content of a typical American diet can safely be reduced to, but not below, the recommended daily allowance for protein if diets are carefully planned, patients and their parents extensively counseled, and if dietary supplements are given to help meet the caloric and vitamin-mineral nutrient needs of growing children. In addition, ongoing nutritional assessment, counseling, and frequent monitoring of growth, diet and biochemical indicators of protein status are essential for maintaining the health of these children.

Adolescent

Changes in food patterns during a low-fat dietary intervention in women.

The Women's Health Trial was initiated by the National Cancer Institute to study the effects of a low-fat diet on the incidence of breast cancer in women at elevated risk for the disease. The purpose of this article is to examine the specific dietary changes that 173 women made while participating in a feasibility intervention program to reduce their fat intake to approximately 20% of total calories over a 12-month period. The intervention program used group sessions to teach nutrition information and behavioral skills necessary to make a life-style dietary change. Four-day food records were collected from participants at the beginning of the study and again at 12 months. Women in the intervention group reduced their total fat intake from a mean of 76 gm (39% of total energy) to 31 gm (22% of total energy), mainly by decreasing their fat intake from milk products, red meats, and fats/oils. These women used cheddar cheese, American cheese, whole milk, butter, mayonnaise, salad dressing, bacon, and hamburgers less frequently, and used diet American cheese, low-fat cottage cheese, and skim milk more frequently. They consumed less fat in their vegetable dishes, and their total caloric intake from fruit increased slightly. In addition, the overall quality of the diets improved, since there was a 20% to 50% increase in the energy-adjusted intake of vitamins and minerals from food sources.

Aged

Plasma lipoprotein cholesterol and endogenous sex hormones in healthy young women.

Relationships between plasma levels of lipoproteins and sex hormones were studied in 24 healthy premenopausal women with no risk factors for coronary heart disease. The women were carefully selected to remove the effects of other environmental factors, such as smoking, drugs, alcohol, and exercise, which are known to influence lipid metabolism. They all ate precisely the same Western-style diet for 1 to 2 weeks before blood samples were obtained in the follicular phase of their menstrual cycle. After adjusting for other hormones by multiple regression, significant positive partial correlations were seen between high density lipoprotein cholesterol (HDL-C) and protein bound estradiol (r = .57, P = .02), as well as between very low density lipoprotein cholesterol (VLDL-C) and protein bound estradiol (r = .63, p = .01). A significant negative partial correlation was seen between VLDL-C and free estradiol (r = -.65 P = .01). Conversely, low density lipoprotein cholesterol (LDL-C) levels were negatively correlated with protein bound estradiol (r = -.77, P less than .001) and positively correlated with free estradiol (r = .71, P less than .001). No associations between plasma lipoproteins and testosterone were seen; however, androstenedione was positively correlated with VLDL-C (r = .59, P = .01). These findings show a close link between plasma lipoproteins and sex hormones, and may help to explain the lower risk of coronary heart disease in women.

Adult