Biomedical subjects

R B Harrist

Publications and source records attributed to R B Harrist.

At least 19 recordsLinked to original sources

PubMed2001

Nutrient intake of obese female binge eaters.

OBJECTIVE: To compare the 6-month change in selected nutrients and number of binge days (from 7-day food records) between obese binge eaters randomly assigned to either a behavioral self-management (BSM) or waiting list control (WLC) group. Within each of the 2 groups, the average intake of selected nutrients on binge and nonbinge days at baseline and at 6 months were compared. DESIGN: A randomized, controlled, intervention study with assessments at entry and 6 months later. SUBJECTS: Forty-six women in the BSM group and 36 in the WLC group completed the 6-month measurement. Participants were 25 to 50 years of age, 30 to 90 pounds overweight, did not have a history of physical or psychological illnesses, and scored 20 or greater on the binge eating scale. INTERVENTION: Participants in the BSM intervention received 6 months of weekly, 1-hour classes taught by registered dietitians. Participants in the WLC group were not contacted during the 6 months. OUTCOME MEASURES: The main outcome measures were change in energy consumed (kilocalories); percentage of energy from fat, protein, and carbohydrate; grams of fiber/1,000 kcal; and change in the number of self-reported binge days. STATISTICAL ANALYSES: Weight at 6 months was compared using a 2-sample t test. The change in the number of binge days at 6 months and the amount of change in selected nutrients by group was compared using the 2-sample t test. The paired t test was used to compare the average nutrient intakes on binge and nonbinge days within groups. RESULTS: No significant difference was found in the 6-month change between groups in any of the selected nutrients. The BSM group reported a greater reduction in binge days between baseline and 6 months compared with the WLC group (mean 1.0 vs 1.7, P < 0.03). Within the BSM group at 6 months, energy intake and percentage of energy from fat on nonbinge days were significantly reduced compared with binge days. At baseline within the WLC group, energy intake increased and percentage of energy from protein decreased significantly on nonbinge days compared with binge days. Within the WLC group at 6 months, energy intake and percentage of energy from fat significantly decreased and percentage of energy from protein significantly increased on nonbinge days. CONCLUSIONS: Our results suggest that collecting dietary information from participants identified with binge eating disorder is challenging. Dietitians who conduct behavioral weight management programs may require additional training in identifying and understanding the psychological characteristics of participants with binge-eating disorder.

Adult↗

PubMed2000

Factors influencing success of monovision contact lens fitting: survey of contact lens diplomates.

BACKGROUND: Contact lenses are frequently fitted so that one eye is focused for distance and the other for near (monovision) in order to reduce the dependence of presbyopic patients on bifocal spectacle correction. METHODS: We surveyed Diplomates in the Cornea and Contact Lens section of the American Academy of Optometry (N = 179) regarding their estimates of success with monovision fitting and factors influencing their perception of success. Results were statistically analyzed to determine the fitting philosophies of responders estimating that they achieve high success rates (HSRs) and low success rates (LSRs), respectively. RESULTS: Completed surveys were returned by 98 Diplomates (54.8%), who estimated an overall success rate of approximately 71.7% with monovision; 50.5% "totally successful" (wear monovision correction full-time without problems or need for additional correction) and 21.2% "successful" (wear monovision full-time, but experience some symptoms of blur or other discomfort, may wear over-correction at times for driving or detailed near work). Sighting dominance was the most frequently used method to determine the distant eye, followed by the plus-lens test. The HSR group tended to be more likely to take occupational factors into account when deciding which eye to use for the distance lens, and they used more flexibility in determining the near-add power. The LSR group discontinued monovision sooner than the HSR group, who continued treatment for longer than 4 weeks during the adaptation period much more often for all add ranges. CONCLUSIONS: Practitioners who regard monovision treatment as very successful have somewhat different fitting philosophies than those who regard monovision as unsuccessful. Implementation of highly successful practitioners' fitting techniques may increase success with monovision contact lens fitting.

Adaptation, Ocular↗

PubMed1999

Validity of echocardiographic measurement in an epidemiological study. Project HeartBeat!

In Project HeartBeat!, a longitudinal study of cardiovascular disease risk factors in healthy children and adolescents, 3 samples of 40, 80, and 182 echocardiograms, respectively, were randomly selected and reread to evaluate intraobserver and interobserver variabilities and comparability between measurements of field echocardiographic technicians and reference readings at Texas Children's Hospital. Included in the evaluation were 8 M-mode echocardiographic measurements, ie, aortic root diameter, left atrial diameter, and end-diastolic and end-systolic measurements of interventricular septal thickness, left ventricular (LV) diameter, and LV posterior wall thickness; 8 Doppler measurements; and a calculated LV mass. Means and SDs of the differences of the paired measurements were used to assess the relative bias and random error of the measurements. For the intraobserver comparison, means and SDs of the differences were very small, indicating that the echo measurements were performed consistently by each project echo technician. Interobserver comparison showed statistically but not clinically significant differences between the paired readings of end-diastolic septal thickness, end-systolic LV posterior wall thickness, and 5 Doppler measurements. Comparison with reference readings at Texas Children's Hospital showed significant differences in diastolic LV diameter, systolic septal thickness, and right ventricular ejection time. These differences, however, were minimal with limited clinical significance. Mean differences in LV mass for the corresponding comparisons were -1.82, 4.50, and 0.0013 g, and the SDs were 18.79, 24.16, and 12.35 g, respectively. We conclude that the echocardiographic measurements taken from healthy children in a longitudinal study can be made accurately with acceptable reproducibility.

Adolescent↗

PubMed1997

Development of cardiovascular risk factors from ages 8 to 18 in Project HeartBeat! Study design and patterns of change in plasma total cholesterol concentration.

BACKGROUND: Project HeartBeat! is a longitudinal study of the development of cardiovascular risk factors as growth processes. Patterns of serial change, or trajectories, from ages 8 to 18 years for plasma total cholesterol concentration (TC) and percent body fat illustrate the design and synthetic cohort approach of the study. METHODS AND RESULTS: Six hundred seventy-eight children (49.1% female, 20.1% black) entered the study at ages 8, 11, and 14 years and were followed up with examinations every 4 months for < or = 4 years. Multilevel analysis demonstrated trajectories for population mean values of TC and percent body fat in sex-specific synthetic cohorts from ages 8 to 18 years. Polyphasic patterns of change in TC were confirmed, with notable sex differences in age patterns and with minimum mean values of TC of 3.85 mmol/L for females and 3.59 for males. As illustrated by data for males, the approximate 75th percentile values of mean TC ranged from 4.78 mmol/L at its early peak to 4.06 at its late-teen nadir. Percent body fat exhibited a trajectory closely parallel with that for TC only for males and appeared to be unrelated for females. CONCLUSIONS: The polyphasic trajectory for TC from ages 8 to 18 years differs between females and males, indicates marked age variation in 75th percentile values and, in males only, closely parallels the trajectory for percent body fat. These and other results indicate the value of both follow-up every 4 months across age intervals to detect rapid risk factor change and the synthetic cohort approach for gaining new insights into the dynamics and possible determinants of this change from ages 8 to 18 years.

Adipose Tissue↗

PubMed1997

Low birth weight and blood pressure at age 7-11 years in a biracial sample.

The hypothesis that birth weight predicts blood pressure inversely at age 7 through 11 years was examined in 1,446 white children and black children in Washington Parish, Louisiana. Two data sets of the Bogalusa Heart Study were merged: 1) newborn cohort participants (n = 233), initially examined at birth, 1973-1974, and reexamined in 1984-1985 at ages 9 through 11 years; and 2) subjects examined at ages 7 through 11 years in 1987-1988 (n = 1,213) whose birth weight was collected from birth certificates in 1991. The prevalence ratios for being in the race-, sex-, and age-specific upper decile of diastolic blood pressure in children born with low birth weight (< 2,500 g) versus those with birth weight > or = 2,500 g were 0.85 (95% confidence interval 0.28-2.56) for white boys, 2.66 (95% confidence interval 1.24-5.70, p < 0.05) for black boys, 1.38 (95% confidence interval 0.63-3.03) for white girls, and 1.05 (95% confidence interval 0.40-2.75) for black girls. For systolic blood pressure, the corresponding prevalence ratio for each race-sex group did not differ from one. When the analyses were restricted to full-term births, prevalence ratios in any race-sex group did not differ from one for systolic and diastolic blood pressure. In multiple linear regression analyses, the concurrently determined Quetelet index (p < 0.001) was a much stronger correlate of systolic and diastolic blood pressure after appropriate adjustment than was birth weight (p > 0.05). From this study, there is some evidence that low birth weight may determine a risk for subsequent high blood pressure in black boys in the age group 7 through 11 years, but the inconsistency of the results for other race-sex groups was unexpected and remains unexplained, if the underlying hypothesis is true.

Black or African American↗

PubMed1997

Low birth weight and serum lipid concentrations at age 7-11 years in a biracial sample.

The relation between birth weight and serum lipid concentrations at age 7 through 11 years was examined in a sample of 1,411 black children and white children in Washington Parish, Louisiana. Two data sets of the Bogalusa Heart Study were merged: 1) newborn cohort participants (n = 225) initially examined at birth, 1973-1974, and reexamined in 1984-1985 at age 9 through 11 years; and 2) subjects examined at ages 7 through 11 years in 1987-1988 (n = 1,186) whose birth weight was collected from birth certificates in 1991. The prevalence ratios for being in the race-, sex-, and age-specific upper decile of serum lipid concentrations in children born with low birth weight (< 2,500 g) versus those with birth weight > or = 2,500 g were calculated per race-sex group. Among white boys with low birth weight, higher than expected percentages of subjects were in the highest decile group of triglyceride concentrations (0.01 < p < 0.05). The prevalence ratio was 2.42 (95% confidence interval 1.19-4.91). When premature infants were excluded, only for white girls was a greater than expected percentage of subjects with low birth weight found to be in the highest decile group of triglyceride concentrations. The corresponding prevalence ratio for white girls was 3.23 (95% confidence interval 1.16-9.00). In analyses that either included or excluded premature infants, prevalence infants, prevalence ratios for triglyceride concentrations in black boys and black girls and for the low density lipoprotein cholesterol/high density lipoprotein cholesterol ratio, total cholesterol concentration, and very low density lipoprotein cholesterol concentration in all race-sex groups were not significantly different from one. To our knowledge, this is the first study finding associations between low birth weight and elevated triglyceride concentrations in later childhood. A follow-up study among adults is recommended.

Black or African American↗

PubMed1995

Diffusion of an effective tobacco prevention program. Part II: Evaluation of the adoption phase.

This paper presents the results of theory-based intervention strategies to increase the adoption of a tobacco prevention program. The adoption intervention followed a series of dissemination intervention strategies targeted at 128 school districts in Texas. Informed by Social Cognitive Theory, the intervention provided opportunities for districts to learn about and model themselves after 'successful' school districts that had adopted the program, and to see the potential for social reinforcement through the knowledge that the program had the potential to have an important influence on students' lives. The proportion of districts in the Intervention condition that adopted the program was significantly greater than in the Comparison condition (P < 0.001). Stepwise logistic regression indicated that the variables most closely related to adoption among intervention districts were teacher attitudes toward the innovation and organizational considerations of administrators. Recommendations for the development of effective strategies for the diffusion of innovations are presented.

Administrative Personnel↗

PubMed1993

Factors associated with serum cholesterol level in a pediatric practice. Cholesterol screening in a pediatric practice.

The associations between age, sex, height, Quetelet index, blood pressure, and serum cholesterol level were examined among 1406 routinely screened children, aged 4 to 19 years, in a pediatric practice. After adjustment for sex and age, height and Quetelet index were associated with serum cholesterol levels. Quetelet index was shown by multiple linear regression to be positively related to cholesterol levels (b = 0.780, P < 0.01), but the predictive value of screening based on an elevated Quetelet index was marginal. Clustering of elevated serum cholesterol level, Quetelet index, and systolic blood pressure was observed. Familial aggregation of cholesterol levels was demonstrated using analysis of variance for 742 children from 342 families included in the regression analysis (F341,400 = 1.56, P < 0.0001). The intraclass correlation coefficient, a measure of familial aggregation, was 0.205 (P < 0.0001). Age, sex, height, Quetelet index, and familial aggregation accounted for 10.6% of the variance in serum cholesterol levels. Siblings of children with high cholesterol levels are a high-yield group in cholesterol screening.

Adolescent↗

PubMed1992

Fetal body ratios in second trimester: a useful tool for identifying chromosomal abnormalities?

This study was carried out to determine if second trimester fetal body ratios are useful in detecting chromosomally abnormal fetuses. As a reference population, normative data for five fetal body ratios (femur length/biparietal diameter, biparietal diameter/fetal length, femur length/head circumference, head circumference/abdominal circumference, and femur length/abdominal circumference) were derived using regression analysis from a population of chromosomally normal fetuses (n = 1770) who underwent genetic amniocentesis at our institution between 14 and 21 menstrual weeks. During the same time period, 37 chromosomally abnormal fetuses were identified by amniocentesis. In comparing the two groups using the 10th and 90th percentiles as cutoffs between normal and abnormal, approximately 25% of chromosomally abnormal fetuses were identified, whereas approximately 20% of the normal fetuses were incorrectly classified as abnormal. Moreover, the use of 1.5 standard deviations above the mean for BPD/FL identified only 19% of Down syndrome fetuses. Our data, and those from a comprehensive review of the literature, suggest that the sensitivity of these ratios in detecting chromosomally abnormal fetuses is too low to recommend them for routine screening.

Anthropometry↗

PubMed1991

In utero analysis of fetal growth: a sonographic weight standard.

Regression analysis was used to develop an in utero fetal weight model from a population of 392 predominantly middle-class white patients with certain menstrual histories. There was a gradual increase in fetal weight from 35 g at 10 weeks to 3,619 g at 40 weeks, with uniform variance of +/- 12.7% (1 standard deviation) throughout gestation. When tested against the estimated weights of 1,771 chromosomally normal fetuses between 14 and 21 weeks, the mean percent difference was 0.8% and the average absolute percent error was 3.3%. When compared with actual delivery data for 163 fetuses in the group, the mean percent difference was 0.8% and the average absolute percent error was 1.1%. These data are compared with other prenatal weight curves obtained at ultrasound and with data from several large postnatal weight studies.

Body Weight↗

PubMed1991

How accurate is second trimester fetal dating?

In this study, the Hadlock models for fetal dating using single and multiple parameters were tested retrospectively in 1770 chromosomally normal singleton fetuses in the second trimester (14 to 21 weeks of fetal development). The 95% confidence interval using measurements of the fetal head and femur individually was approximately +/- 1 week, which is comparable to the results of recently published dating models from other centers designed specifically for use during this time frame. The use of multiple-parameter models results in statistically significant improvement in prediction of age, in terms of both random error and maximum observed errors. We conclude that these models, developed for dating between 14 and 42 weeks of fetal development, provide highly accurate estimates of fetal age in the second trimester of pregnancy.

Cephalometry↗

PubMed1990

Neonatal growth assessment score: a new approach to the detection of intrauterine growth retardation in the newborn.

To develop an improved means for evaluation of the outcome of fetal growth in utero, a growth study of 37 fetuses at risk for intrauterine growth retardation was undertaken. Intrauterine growth was evaluated with ultrasonography at 2- to 3-week intervals beginning at 15 weeks' gestation. Measurements obtained in the second trimester were used to specify Rossavik growth models for various anatomic parameters. Values for weight, head circumference, abdominal circumference, and thigh circumference at birth were predicted with the use of these models. Growth potential realization index values for these four parameters were calculated from actual and predicted birth measurements. The growth potential realization index values were combined to form a neonatal growth assessment score. With the use of cluster analysis and neonatal growth assessment score values, the 37 infants were separated into 24 group I (neonatal growth assessment score values between 3.7 and 18.6) and 13 group II (neonatal growth assessment score values between 19.4 and 50.0) infants. In group I, 66.7% of the infants had no growth abnormalities; a single abnormality, usually borderline, was found in an additional 20.8% (total = 87.5%). In group II all infants had growth abnormalities (range, 2 to 6) although only 46.2% had birth weights below the 10th percentile. No differences in risk factors (except for the incidence of smoking) or second trimester growth were found in these two groups. The neonatal growth assessment score appears to be a sensitive indicator of third trimester growth retardation, is not affected by differences in growth potential, can separate normal infants from those with evidence of intrauterine growth retardation, and provides a quantitative assessment of growth problems in individual fetuses.

Adult↗

PubMed1990

Exercise tolerance and alcohol intake. Blood pressure relation.

The relations of systolic and diastolic blood pressures to alcohol intake and exercise tolerance levels in 15,612 men and 3,855 women were investigated. Alcohol intake was assessed by questionnaire and stratified into seven levels for men and six for women according to the ounces of ethanol consumed per week. Exercise tolerance was determined by maximal treadmill exercise testing and was categorized into six age-specific by sex-specific levels. Both systolic and diastolic blood pressure were significantly related to both alcohol intake and exercise tolerance levels in both men and women. These relations, which were positive for alcohol and negative for exercise tolerance, remained after covariance adjustment for age, body mass index, and cigarette smoking. Alcohol intake was not significantly correlated with exercise tolerance. The relation of blood pressure to alcohol was not linear because the blood pressure of moderate consumers of alcohol tended to be slightly lower than that of nondrinkers. Higher blood pressure was found only in drinkers whose ethanol intake exceeded 9.5 ounces (approximately 285 ml or 19 drinks) per week. However, heavy drinkers in high exercise tolerance categories had no higher blood pressure than nondrinkers in low exercise tolerance groups. Exercise tolerance or physiological fitness appears to be important in quantifying the relation between alcohol intake and blood pressure and should be considered in describing this relation.

Adolescent↗

PubMed1990

Sonographic fetal growth standards. Are current data applicable to a racially mixed population?

Currently available sonographic growth standards for fetal head size, abdominal size, and limb length are based primarily on studies from white populations. To determine whether these published standards are appropriate for a racially mixed, indigent population, we compared our published data from a middle-class white population with data generated from a black/Hispanic population seen at a county hospital in Houston, Texas. No statistically significant differences were found for any of the following fetal sonographic parameters (20 to 41 weeks): biparietal diameter, head circumference, abdominal circumference, femur length.

Black People↗

PubMed1989

An assessment of peak expiratory flow as a surrogate measurement of FEV1 in stable asthmatic children.

We examined the relationship over 24 hours between percent-predicted values (PPV) of peak expiratory flow (PEF) and forced expiratory volume in one second (FEV1) in a group of 23 stable untreated asthmatic children 6 to 17 years of age by means of regression analysis as well as the percentage difference between the PPV of these two measurements. Although the Pearson correlation coefficient between the PPV was consistently high, ranging between 0.854 and 0.892, the assumption that such a finding substantiates the substitution of PEF for FEV1 is called into question. Over 50 percent of the subjects displayed a 10 percent or greater difference in the PPV between the two measurements, regardless of the time of day the two respiratory variable were determined, while over one-third of all subjects evidenced a 20 percent or greater discrepancy between the PPV of the two measures. While, on a group basis, there was no statistically significant difference in the mean percentage difference over 24 hours between the PPV of FEV1, when compared with the corresponding measurement of PEF, reliance on PEF alone in individual subjects may result in a false impression of the patency of the airways in comparison to the FEV1.

Adolescent↗

PubMed1989

Day-night differences in steady-state theophylline pharmacokinetics in asthmatic children.

Potential day-night differences of theophylline absorption and disposition were examined in day-active asthmatic children. Theophylline was given orally as TheoDur tablets and Somophyllin-CRT capsules (random crossover) every 12 hr (0700 and 1900), and patients were studied during two consecutive dosing intervals. In addition, patients were studied during the last 24 hr of a 48-hr continuous, intravenous aminophylline infusion. Serum theophylline concentrations were essentially constant during the intravenous infusion for the day and night periods. Thus, day and night clearances were nearly identical. Following oral administration of Somophyllin-CRT or TheoDur, areas under the serum concentration-time curves were greater during the day than the night, with Somophyllin-CRT yielding greater areas than TheoDur for both dosing intervals. Theophylline was absorbed more rapidly during the day than the night, as evidenced by a time to maximum concentration that occurred earlier in the daytime dosing interval. We conclude that theophylline clearance is not characterized by a circadian rhythm and that absorption of theophylline from Somophyllin-CRT and TheoDur is more rapid and complete during the day than the night.

Administration, Oral↗

PubMed1988

Development of individual growth curve standards for estimated fetal weight: I. Weight estimation procedure.

In this investigation the weight estimation procedure of Rossavik was reassessed with particular emphasis on parameter estimation and performance over a wide weight range. Using a cross-sectional data set (193 patients), a longitudinal data set (20 patients), and an iterative procedure, parameter estimates were obtained based solely on regression analysis. Comparison of weight estimates obtained using a function based on these parameter values with actual birth weights indicated virtually no systematic errors over a 250-g to 4750-g weight range and random errors (+/- 1 SD) of 10% to 13% below 200 g and 6% to 8% above 2000 g. The weights of small- and large-for-gestational age fetuses were systematically overestimated (4.1%) and underestimated (-3.0%), respectively, but systematic errors were not found in average-for-gestational age fetuses. No differences in random errors were seen in these three growth categories. Comparison with other weight estimation procedures indicated that the Rossavik procedure gives weight estimates that are at least as accurate as those obtained with other methods over a wide range of weight and growth categories. However, the Rossavik procedure can be used to generate individual growth curve standards for weight estimates, a characteristic not shared with other weight estimation procedures.

Birth Weight↗

PubMed1987

Estimating fetal age using multiple parameters: a prospective evaluation in a racially mixed population.

This study was designed to evaluate the accuracy of regression models for menstrual age prediction using single versus multiple fetal ultrasonographic measurements (biparietal diameter, head circumference, abdominal circumference, and femur length). The models tested had been previously developed from a study of middle-class white patients in a private hospital. The current study population consisted of 300 indigent black and Hispanic patients seen in a county hospital. This study demonstrated prospectively that the use of multiple parameters in estimating fetal age offers a significant advantage over any single parameter used alone and that the regression equations developed from a middle-class white population appear to be applicable to fetuses from a population with different socioeconomic and racial characteristics.

Black People↗