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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
PubMed1995

Changes in plasma lipoprotein concentrations and composition in response to a low-fat, high-fiber diet are associated with changes in serum estrogen concentrations in premenopausal women.

We have investigated the effects of a low-fat, high-fiber diet on plasma lipid and lipoprotein levels and serum sex hormone concentrations in 22 normal premenopausal women (mean age, 25.8 +/- 3.8 years). Participants consumed a baseline diet for 4 weeks (40% of calories as fat, 16% as saturated fatty acids, 8% as polyunsaturated fatty acids, 400 mg/d cholesterol, and 12 g/d dietary fiber) and then a low-fat, high-fiber diet for 8 to 10 weeks (16% to 18% of calories as fat, 4% as saturated fatty acids, 4% as polyunsaturated fatty acids, 150 mg/d cholesterol, and 40 g/d fiber). Blood samples for determination of plasma lipids and serum hormones were obtained during the follicular and luteal phases of the menstrual cycle during both diets. Compared with the baseline diet, the low-fat, high-fiber diet resulted in significant decreases in total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol concentrations during both the follicular and luteal phases (TC, -14% and -16%; LDL cholesterol, -14% and -17%; and HDL cholesterol, -15% and -18%, respectively). During the follicular phase but not the luteal phase on the low-fat, high-fiber diet, women exhibited significant increases in plasma triglyceride ([TG] 22%) and very-low-density lipoprotein (VLDL)-TG (36%) concentrations. During the follicular phase, serum estrone sulfate concentrations decreased by 25% (P < .0001) when subjects were fed the low-fat, high-fiber diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

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↗
PubMed1995

Relationship of diet to root caries.

A Nutrition and Oral Health Study was conducted on 141 middle-aged and elderly adults (54% female and 46% male; aged 47-83 y, mean = 67; 51% college educated; and 89% white). This study reports on the relationship between root caries and diet. Nutritional composition was derived from two 3-d food diaries. Root caries was measured according to the 1985 Adult Survey Diagnostic Criteria of the National Institute of Dental Research. When the individuals were segregated by their root DFS (decayed and filled surfaces) status into highest (> or = 7) and lowest (< or = 1) quartiles, the sucrose consumption was significantly higher in the higher DFS group. Mean energy consumption and mean number of teeth were the same in both groups. When the individuals were segregated by sucrose consumption into highest (> or = 89 g) and lowest (< or = 31 g) quartiles, DFS root status was significantly higher (P < 0.01) in the highest quartile group (7 g) vs the lowest group (4 g). By using data from subjects with two food diaries, a stepwise-linear-regression model for root caries showed that 4.2% of the variance for root caries was explained by sucrose, 2.8% by plaque, 3.8% by total number of teeth, and 5.6% by gingival recession. These data suggest that root caries has a similar dietary etiology to coronal caries.

Aged↗
PubMed1995

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↗
PubMed1992

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

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↗
PubMed1991

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↗