Does First-Trimester Screening Modify the Natural History of Congenital Heart Disease? Analysis of Outcome of Regional Cardiac Screening at 2 Different Time Periods.

BACKGROUND: The study analyzed the impact of first-trimester screening on the spectrum of congenital heart defects (CHDs) later in pregnancy and on the outcome of fetuses and children born alive with a CHD. METHODS: The spectrum of CHDs, associated comorbidities, and outcome of fetuses, either diagnosed with a CHD in the first trimester (Group I, 127 fetuses) or only in the second-trimester screening (Group II, 344 fetuses), were analyzed retrospectively between 2007 and 2013. Second-trimester fetuses diagnosed with a CHD between 2007 and 2013 were also compared with Group III (532 fetuses diagnosed with a CHD in the second trimester from 1996 to 2001, the period before first-trimester screening was introduced). RESULTS: The spectrum of CHDs diagnosed in the first and second trimesters in the same time period differed significantly, with a greater number of comorbidities (P<0.0001), CHDs with univentricular outcome (P<0.0001), intrauterine deaths (P=0.01), and terminations of pregnancy (P<0.0001) in Group I compared with Group II. In Group III, significantly more cases of CHDs with univentricular outcome (P<0.0001), intrauterine demise (P=0.036), and early termination (P<0.0001) were identified compared with fetuses diagnosed with CHDs in the second trimester between 2007 and 2013. The spectrum of CHDs seen in the second-trimester groups differed after first-trimester screening was implemented. CONCLUSIONS: First-trimester screening had a significant impact on the spectrum of CHDs and the outcomes of pregnancies with CHDs diagnosed in the second trimester. Early detection of severe forms of CHDs and significant comorbidities resulted in an increased pregnancy termination rate in the first trimester.

Individual-level exposure to disaster, neighborhood environmental characteristics, and their independent and combined associations with depressive symptoms in women.

PURPOSE: The severity of the stress response to experiencing disaster depends on individual exposure and background stress prior to the event. To date, there is limited research on the interaction between neighborhood environmental stress and experiencing an oil spill, and their effects on depression. The objective of the current study was to assess if the association between exposure to the Deepwater Horizon Oil Spill (DHOS) and depressive symptoms varied by neighborhood characteristics. METHODS: US Census data (2010) and longitudinal data collected in two waves (2012-2014 and 2014-2016) from female residents [N = 889 (Wave I), 737 (Wave II)] of an area highly affected by the DHOS were analyzed. Multilevel and individual-level negative binomial regressions were performed to estimate associations with depressive symptoms in both waves. An interaction term was included to estimate effect modification of the association between DHOS exposure and depressive symptoms by neighborhood characteristics. Generalized estimating equations were applied to the negative binomial regression testing longitudinal associations. RESULTS: Census tract-level neighborhood characteristics were not associated with depressive symptoms. Exposure to the DHOS and neighborhood physical disorder were associated with depressive symptoms cross-sectionally. There was no evidence of effect modification; however, physical/environmental exposure to the DHOS was associated with increased depressive symptoms only among women living in areas with physical disorder. Exposure to the DHOS remained associated with depressive symptoms over time. CONCLUSIONS: Findings support the enduring consequences of disaster exposure on depressive symptoms in women and identify potential targets for post-disaster intervention based on residential characteristics.

Permanent cardiac pacing in children: choosing the optimal pacing site: a multicenter study.

BACKGROUND: We evaluated the effects of the site of ventricular pacing on left ventricular (LV) synchrony and function in children requiring permanent pacing. METHODS AND RESULTS: One hundred seventy-eight children (aged <18 years) from 21 centers with atrioventricular block and a structurally normal heart undergoing permanent pacing were studied cross-sectionally. Median age at evaluation was 11.2 (interquartile range, 6.3-15.0) years. Median pacing duration was 5.4 (interquartile range, 3.1-8.8) years. Pacing sites were the free wall of the right ventricular (RV) outflow tract (n=8), lateral RV (n=44), RV apex (n=61), RV septum (n=29), LV apex (n=12), LV midlateral wall (n=17), and LV base (n=7). LV synchrony, pump function, and contraction efficiency were significantly affected by pacing site and were superior in children paced at the LV apex/LV midlateral wall. LV dyssynchrony correlated inversely with LV ejection fraction (R=0.80, P=0.031). Pacing from the RV outflow tract/lateral RV predicted significantly decreased LV function (LV ejection fraction <45%; odds ratio, 10.72; confidence interval, 2.07-55.60; P=0.005), whereas LV apex/LV midlateral wall pacing was associated with preserved LV function (LV ejection fraction ≥55%; odds ratio, 8.26; confidence interval, 1.46-47.62; P=0.018). Presence of maternal autoantibodies, gender, age at implantation, duration of pacing, DDD mode, and QRS duration had no significant impact on LV ejection fraction. CONCLUSIONS: The site of ventricular pacing has a major impact on LV mechanical synchrony, efficiency, and pump function in children who require lifelong pacing. Of the sites studied, LV apex/LV midlateral wall pacing has the greatest potential to prevent pacing-induced reduction of cardiac pump function.

Interaction between dietary fat and exercise on excess postexercise oxygen consumption.

The objective of this study was to determine the effect of increased physical activity on subsequent sleeping energy expenditure (SEE) measured in a whole room calorimeter under differing levels of dietary fat. We hypothesized that increased physical activity would increase SEE. Six healthy young men participated in a randomized, single-blind, crossover study. Subjects repeated an 8-day protocol under four conditions separated by at least 7 days. During each condition, subjects consumed an isoenergetic diet consisting of 37% fat, 15% protein, and 48% carbohydrate for the first 4 days, and for the following 4 days SEE and energy balance were measured in a respiration chamber. The first chamber day served as a baseline measurement, and for the remaining 3 days diet and activity were randomly assigned as high-fat/exercise, high-fat/sedentary, low-fat/exercise, or low-fat/sedentary. Energy balance was not different between conditions. When the dietary fat was increased to 50%, SEE increased by 7.4% during exercise (P < 0.05) relative to being sedentary (baseline day), but SEE did not increase with exercise when fat was lowered to 20%. SEE did not change when dietary fat was manipulated under sedentary conditions. Physical activity causes an increase in SEE when dietary fat is high (50%) but not when dietary fat is low (20%). Dietary fat content influences the impact of postexercise-induced increases in SEE. This finding may help explain the conflicting data regarding the effect of exercise on energy expenditure.

Chronic binge alcohol consumption does not diminish effectiveness of continuous antiretroviral suppression of viral load in simian immunodeficiency virus-infected macaques.

BACKGROUND: Alcohol use disorders (AUDs) are a frequent comorbidity in a large percentage of people living with HIV/AIDS (PLWHA). PLWHA with comorbid AUDs are consistently found to perform poorly at most levels of the HIV treatment cascade, resulting in a higher likelihood of virologic nonsuppression. This has been partly attributed to lower rates of persistence with and adherence to antiretroviral therapies (ART). Focus groups of in-care PLWHA identify the need to suspend ART on drinking days because of the potential for toxicity and/or lack of therapeutic effectiveness. The aim of this study was to examine whether chronic binge alcohol (CBA) consumption decreases the effectiveness of uninterrupted ART, specifically that of nucleoside reverse-transcriptase inhibitors (NRTI) tenofovir and emtricitabine in suppressing viral replication, or results in drug toxicity in simian immunodeficiency virus (SIV)-infected rhesus macaques. METHODS: Daily CBA or isocaloric sucrose (SUC) administration was initiated 3 months prior to intrarectal SIVmac251 inoculation and continued throughout the study period. ART was initiated 2.5 months after SIV infection and continued through the study period. RESULTS: CBA administration did not prevent or delay the ART-mediated reduction in viral load. Following ART, circulating levels of total protein and creatinine were significantly higher than baseline values in both SUC- and CBA-treated animals, but still within a normal range. No evidence of ART toxicity was observed in either CBA- or SUC-administered macaques. CONCLUSIONS: These findings indicate that CBA does not attenuate effectiveness of NRTI suppression of viral load, nor does it appear to interact with NRTI to produce toxicity during the initial 2 months of treatment. We conclude that while efforts to reduce AUD in PLWHA should be a priority, counseling on the importance of adherence to ART even on drinking days should also be promoted.

Working memory in the oldest-old: evidence from output serial position curves.

In the present study, we examined adult age differences in short-term and working memory performance in middle-aged (45-64 years), young-old (65-74 years), old-old (75-89 years), and oldest-old adults (90 years and over) in the Louisiana Healthy Aging Study. Previous research suggests that measures of working memory are more sensitive to age effects than are simple tests of short-term memory Bopp and Verhaeghen (Journal of Gerontology: Psychological Sciences 60:223-233, 2005), Myerson, Emery, White, and Hale, (Aging, Neuropsychology, and Cognition 10:20-27, 2003). To test this hypothesis, we examined output serial position curves of recall data from three span tasks: forward and backward digit span and size judgment span. Participants' recall patterns in the size judgment span task revealed that the two oldest groups of adults showed the largest decreases in recall performance across output serial positions, but did not differ significantly from each other. Correlation analyses indicated the strongest negative correlation with age occurred with the size judgment span task. Implications of these findings for understanding strategic processing abilities in late life are discussed.

Longitudinal Assessment of Cognitive and Psychosocial Functioning After Hurricanes Katrina and Rita: Exploring Disaster Impact on Middle-Aged, Older, and Oldest-Old Adults.

The authors examined the effects of Hurricanes Katrina and Rita (HKR) on cognitive and psychosocial functioning in a lifespan sample of adults 6 to 14 months after the storms. Participants were recruited from the Louisiana Healthy Aging Study (LHAS). Most were assessed during the immediate impact period and retested for this study. Analyses of pre-and post-disaster cognitive data confirmed that storm-related decrements in working memory for middle-aged and older adults observed in the immediate impact period had returned to pre-hurricane levels in the post-disaster recovery period. Middle-aged adults reported more storm-related stressors and greater levels of stress than the two older groups at both waves of testing. These results are consistent with a burden perspective on post-disaster psychological reactions.

Increased physical activity cosegregates with higher intake of carbohydrate and total calories in a subcongenic mouse strain.

C57BL/6 J (B6) and CAST/EiJ (CAST), the inbred strain derived from M. musculus castaneus, differ in nutrient intake behaviors, including dietary fat and carbohydrate consumption in a two-diet-choice paradigm. Significant quantitative trait loci (QTLs) for carbohydrate (Mnic1) and total energy intake (Kcal2) are present between these strains on chromosome (Chr) 17. Here we report the refinement of the Chr 17 QTL in a subcongenic strain of the B6.CAST-( D17Mit19-D17Mit91 ) congenic mice described previously. This new subcongenic strain possesses CAST Chr 17 donor alleles from 4.8 to 45.4 Mb on a B6 background. Similar to CAST, the subcongenic mice exhibit increased carbohydrate and total calorie intake per body weight, while fat intake remains equivalent. Unexpectedly, this CAST genomic segment also confers two new physical activity phenotypes: 22% higher spontaneous physical activity levels and significantly increased voluntary wheel-running activity compared with the parental B6 strain. Overall, these data suggest that gene(s) involved in carbohydrate preference and increased physical activity are contained within the proximal region of Chr 17. Interval-specific microarray analysis in hypothalamus and skeletal muscle revealed differentially expressed genes within the subcongenic region, including neuropeptide W (Npw); glyoxalase I (Glo1); cytochrome P450, family 4, subfamily f, polypeptide 1 (Cyp4f15); phospholipase A2, group VII (Pla2g7); and phosphodiesterase 9a (Pde9a). This subcongenic strain offers a unique model for dissecting the contributions and possible interactions among genes controlling food intake and physical activity, key components of energy balance.

After Hurricanes Katrina and Rita: gender differences in health and religiosity in middle-aged and older adults.

We examined health-related quality of life in adults in the Louisiana Health Aging Study (LHAS) after Hurricanes Katrina and Rita (HK/R) that made landfall on the U.S. Gulf Coast region in 2005. Analyses of pre- and post-disaster SF-36 scores yielded changes in physical function and bodily pain. Mental health scores were lower for women than men. Gender differences were observed in religious beliefs and religious coping, favoring women. Religious beliefs and religious coping were negatively correlated with physical function, implying that stronger reliance on religiosity as a coping mechanism may be more likely among those who are less physically capable.

Pictorial superiority effects in oldest-old people.

We examined memory for pictures and words in middle-age (45-59 years), young-old (60-74 years), old-old (75-89 years), and the oldest-old adults (90-97 years) in the Louisiana Healthy Aging Study. Stimulus items were presented and retention was tested in a blocked order where half of the participants studied 16 simple line drawings and the other half studied matching words during acquisition. Free recall and recognition followed. In the next acquisition/test block a new set of items was used where the stimulus format was changed relative to the first block. Results yielded pictorial superiority effects in both retention measures for all age groups. Follow-up analyses of clustering in free recall revealed that a greater number of categories were accessed (which reflects participants' retrieval plan) and more items were recalled per category (which reflects participants' encoding strategy) when pictures served as stimuli compared to words. Cognitive status and working memory span were correlated with picture and word recall. Regression analyses confirmed that these individual difference variables accounted for significant age-related variance in recall. These data strongly suggest that the oldest-old can utilise nonverbal memory codes to support long-term retention as effectively as do younger adults.

Chromium picolinate supplementation attenuates body weight gain and increases insulin sensitivity in subjects with type 2 diabetes.

OBJECTIVE: Chromium picolinate (CrPic) supplementation has been suggested to improve glycemia, but there are conflicting reports on efficacy. We sought to determine the effect of CrPic on insulin sensitivity, glycemic control, and body composition in subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: Thirty-seven subjects with type 2 diabetes were evaluated. After baseline, subjects were placed on a sulfonylurea (glipizide gastrointestinal therapeutic system 5 mg/day) with placebo for 3 months. Subjects were then randomized in a double-blind fashion to receive either the sulfonylurea plus placebo (n = 12) or the sulfonylurea plus 1,000 microg Cr as CrPic (n = 17) for 6 months. Body composition, insulin sensitivity, and glycemic control were determined at baseline, end of the 3-month single-blind placebo phase, and end of study. RESULTS: Subjects randomized to sulfonylurea/placebo, as opposed to those randomized to sulfonylurea/CrPic, had a significant increase in body weight (2.2 kg, P < 0.001 vs. 0.9 kg, P = 0.11), percent body fat (1.17%, P < 0.001 vs. 0.12%, P = 0.7), and total abdominal fat (32.5 cm(2), P < 0.05 vs. 12.2 cm(2), P < 0.10) from baseline. Subjects randomized to sulfonylurea/CrPic had significant improvements in insulin sensitivity corrected for fat-free mass (28.8, P < 0.05 vs. 15.9, P = 0.4), GHb (-1.16%, P < 0.005 vs. -0.4%, P = 0.3), and free fatty acids (-0.2 mmol/l, P < 0.001 vs. -0.12 mmol/l, P < 0.03) as opposed to sulfonylurea/placebo. CONCLUSIONS: This study demonstrates that CrPic supplementation in subjects with type 2 diabetes who are taking sulfonylurea agents significantly improves insulin sensitivity and glucose control. Further, CrPic supplementation significantly attenuated body weight gain and visceral fat accumulation compared with the placebo group.

Energy expenditure and substrate oxidation predict changes in body fat in children.

BACKGROUND: The hypothesis that alterations in energy metabolism predict body fat gain is controversial. OBJECTIVE: The aim of this study was to determine which components of energy metabolism were most important in predicting fat gain in children aged 10.8 +/- 0.6 y. DESIGN: A 2-y longitudinal study to examine whether components of energy metabolism are predictors of body fat gain was conducted in 114 preadolescent African American and white children aged 9-11 y by measuring total daily energy expenditure on the basis of doubly labeled water (DLW), resting metabolic rate, the thermic effect of food, energy expended in physical activity, and substrate oxidation after a meal. The primary endpoint was the 2-y change in percentage body fat (%BF). RESULTS: Individual variables of energy metabolism predicted up to 7% of the variance in changes in %BF over the 2-y interval in the whole group. Predictors of change in body fatness tended to be sex and race specific. Protein oxidation during a test meal explained a significant portion of the variance in change in %BF in the overall group and in nearly all of the subgroups. Multivariate prediction models accounted for 10-41% of the variance in change in %BF. Tanner stage at 2-y follow-up was highly predictive of change in body fatness and improved the overall prediction, accounting for 24-62% of the variance in change in %BF in those groups in which Tanner entered the model. CONCLUSION: This study provides evidence that total daily energy expenditure, resting metabolic rate, substrate oxidation, and total energy intake are predictors of gain in body fatness during late childhood in boys and girls.

Effect of 6-month calorie restriction on biomarkers of longevity, metabolic adaptation, and oxidative stress in overweight individuals: a randomized controlled trial.

CONTEXT: Prolonged calorie restriction increases life span in rodents. Whether prolonged calorie restriction affects biomarkers of longevity or markers of oxidative stress, or reduces metabolic rate beyond that expected from reduced metabolic mass, has not been investigated in humans. OBJECTIVE: To examine the effects of 6 months of calorie restriction, with or without exercise, in overweight, nonobese (body mass index, 25 to <30) men and women. DESIGN, SETTING, AND PARTICIPANTS: Randomized controlled trial of healthy, sedentary men and women (N = 48) conducted between March 2002 and August 2004 at a research center in Baton Rouge, La. INTERVENTION: Participants were randomized to 1 of 4 groups for 6 months: control (weight maintenance diet); calorie restriction (25% calorie restriction of baseline energy requirements); calorie restriction with exercise (12.5% calorie restriction plus 12.5% increase in energy expenditure by structured exercise); very low-calorie diet (890 kcal/d until 15% weight reduction, followed by a weight maintenance diet). MAIN OUTCOME MEASURES: Body composition; dehydroepiandrosterone sulfate (DHEAS), glucose, and insulin levels; protein carbonyls; DNA damage; 24-hour energy expenditure; and core body temperature. RESULTS: Mean (SEM) weight change at 6 months in the 4 groups was as follows: controls, -1.0% (1.1%); calorie restriction, -10.4% (0.9%); calorie restriction with exercise, -10.0% (0.8%); and very low-calorie diet, -13.9% (0.7%). At 6 months, fasting insulin levels were significantly reduced from baseline in the intervention groups (all P<.01), whereas DHEAS and glucose levels were unchanged. Core body temperature was reduced in the calorie restriction and calorie restriction with exercise groups (both P<.05). After adjustment for changes in body composition, sedentary 24-hour energy expenditure was unchanged in controls, but decreased in the calorie restriction (-135 kcal/d [42 kcal/d]), calorie restriction with exercise (-117 kcal/d [52 kcal/d]), and very low-calorie diet (-125 kcal/d [35 kcal/d]) groups (all P<.008). These "metabolic adaptations" (~ 6% more than expected based on loss of metabolic mass) were statistically different from controls (P<.05). Protein carbonyl concentrations were not changed from baseline to month 6 in any group, whereas DNA damage was also reduced from baseline in all intervention groups (P <.005). CONCLUSIONS: Our findings suggest that 2 biomarkers of longevity (fasting insulin level and body temperature) are decreased by prolonged calorie restriction in humans and support the theory that metabolic rate is reduced beyond the level expected from reduced metabolic body mass. Studies of longer duration are required to determine if calorie restriction attenuates the aging process in humans. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00099151.

Percutaneous freezing of sensory nerves prior to total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is a common procedure resulting in significant post-operative pain. Percutaneous cryoneurolysis targeting the infrapatellar branch of the saphenous nerve and anterior femoral cutaneous nerve could relieve post-operative knee pain by temporarily blocking sensory nerve conduction. METHODS: A retrospective chart review of 100 patients who underwent TKA was conducted to assess the value of adding perioperative cryoneurolysis to a multimodal pain management program. The treatment group consisted of the first 50 patients consecutively treated after the practice introduced perioperative (five days prior to surgery) cryoneurolysis as part of its standard pain management protocol. The control group consisted of the 50 patients treated before cryoneurolysis was introduced. Outcomes included hospital length of stay (LOS), post-operative opioid requirements, and patient-reported outcomes of pain and function. RESULTS: A significantly lower proportion of patients in the treatment group had a LOS of ≥2days compared with the control group (6% vs. 67%, p<0.0001) and required 45% less opioids during the first 12weeks after surgery. The treatment group reported a statistically significant reduction in symptoms at the six- and 12-week follow-up compared with the control group and within-group significant reductions in pain intensity and pain interference at two- and six-week follow-up, respectively. CONCLUSIONS: Perioperative cryoneurolysis in combination with multimodal pain management may significantly improve outcomes in patients undergoing TKA. Promising results from this preliminary retrospective study warrant further investigation of this novel treatment in prospective, randomized trials. LEVEL OF EVIDENCE: III.

Effect of pioglitazone on body composition and energy expenditure: a randomized controlled trial.

BACKGROUND: Several clinical studies have demonstrated that body weight increases after treatment with thiazolidinediones (TZDs). Prior studies have demonstrated an increase in insulin-stimulated lipid storage in adipose tissue. Some, but not all, studies demonstrate reductions in visceral adipose tissue. Changes in body weight are the result of changes in energy intake, energy expenditure, or both. OBJECTIVES: Based on these findings, the primary aim of this study was to evaluate the effect of TZDs on visceral, subcutaneous, and total body fat. Secondary aims were to determine the effects of pioglitazone on (a) energy expenditure, (b) hunger and satiety, (c) blood lipids, and (d) the role of insulinemia/sulfonylurea usage on weight gain in patients with type 2 diabetes. SUBJECTS AND METHODS: We performed a randomized, double-blind, placebo-controlled trial in 48 men and women with type 2 diabetes who had not previously received treatment with TZDs. Patients were treated for 24 weeks with 45 mg/d of pioglitazone or a matching placebo. Body composition was measured by dual-energy x-ray absorptiometry. Visceral and subcutaneous fat were measured by computed tomography. Resting metabolic rate and thermogenic response to a test meal were measured by indirect calorimetry before and after a standardized meal. Hunger and satiety were measured with visual analog scales before and after the same test meal. Blood was collected for the measurement of fasting glucose and insulin levels, hemoglobin A 1c levels, and lipid content. RESULTS: Pioglitazone treatment resulted in a decrease in hemoglobin A(1c) level by 0.96 +/- 1.1% vs 0.11 +/- 0.8% in the placebo group (P < .005). Body weight and fat increased steadily in the patients treated with pioglitazone during the 6 months of the study (+3.9 +/- 3.1 kg at 6 months in pioglitazone-treated patients vs -0.8 +/- 3.4 kg in the placebo-treated patients). Subcutaneous fat in the trunk, arms, and legs were all increased in the pioglitazone-treated group. Visceral fat did not change significantly in either group. Neither resting metabolic rate nor the thermogenic responses to a meal were altered by pioglitazone. Subjective measures of hunger (visual analog scale) did not change with pioglitazone treatment. Triglycerides fell in the pioglitazone-treated group (-58.5 +/- 124 mg/dL, P < .003). Neither the prior use of sulfonylureas nor the level of insulinemia before treatment was a predictor of weight or fat change. CONCLUSION: Pioglitazone increased subcutaneous body fat, but not visceral fat. There was no measurable effect on energy expenditure or hunger/satiety. In contrast to the placebo-treated patient with diabetes, weight gain occurs in the face of falling hemoglobin A(1c) and triglyceride levels.

QTL analysis of self-selected macronutrient diet intake: fat, carbohydrate, and total kilocalories.

The present study investigated the inheritance of dietary fat, carbohydrate, and kilocalorie intake traits in an F(2) population derived from an intercross between C57BL/6J (fat-preferring) and CAST/EiJ (carbohydrate-preferring) mice. Mice were phenotyped for self-selected food intake in a paradigm which provided for 10 days a choice between two macronutrient diets containing 78/22% of energy as a composite of either fat/protein or carbohydrate/protein. Quantitative trait locus (QTL) analysis identified six significant loci for macronutrient intake: three for fat intake on chromosomes (Chrs) 8 (Mnif1), 18 (Mnif2), and X (Mnif3), and three for carbohydrate intake on Chrs 17 (Mnic1), 6 (Mnic2), and X (Mnic3). An absence of interactions among these QTL suggests the existence of separate mechanisms controlling the intake of fat and carbohydrate. Two significant QTL for cumulative kilocalorie intake, adjusted for baseline body weight, were found on Chrs 17 (Kcal1) and 18 (Kcal2). Without body weight adjustment, another significant kcal locus appeared on distal Chr 2 (Kcal3). These macronutrient and kilocalorie QTL, with the exception of loci on Chrs 8 and X, encompassed chromosomal regions influencing body weight gain and adiposity in this F2 population. These results provide new insight into the genetic basis of naturally occurring variation in nutrient intake phenotypes.

Energy expenditure in African American and white boys and girls in a 2-y follow-up of the Baton Rouge Children's Study.

BACKGROUND: Previously reported race and sex differences in energy expenditure (EE) may play a role in body fat gain. OBJECTIVE: The purpose of the study was to determine the relations between race, sex, Tanner stage, and EE. DESIGN: We conducted a 2-y follow-up study of EE in 114 African American (AA) and white girls and boys aged 12.7 +/- 0.1 y ( +/- SE), who were stratified as obese or lean and were part of the Baton Rouge Children's Study. Total daily EE (TDEE) was measured by using doubly labeled water. Resting metabolic rate (RMR) and thermic effect of food were measured by using indirect calorimetry. RESULTS: White children had significantly higher TDEE and RMR than did AA children when fat-free mass was considered. Boys had significantly higher TDEE and RMR than did girls, even after adjustment for differences in size. TDEE and RMR were significantly higher in obese children, as a result of their greater fat-free mass and body fat, than in lean children. Activity-related EE did not differ significantly between obese and lean children. There was a strong relation between initial and 2-y TDEE and RMR. There was a significant decrease in activity-related EE in both racial groups. AA children had significantly more lean limb mass than did white children. CONCLUSIONS: Average TDEE did not change over 2 y, but RMR increased significantly, and activity-related EE decreased significantly. Differences in trunk and limb lean mass of white and AA children may explain some of the ethnic differences in EE. The decrease in physical activity over 2 y may contribute to the risk of obesity.

Energy expenditure in preadolescent African American and white boys and girls: the Baton Rouge Children's Study.

BACKGROUND: Low energy expenditure has been identified as a potential risk factor for body fat gain. OBJECTIVE: The objective was to determine the relations between race, sex, body fat, and energy expenditure. DESIGN: As part of the Baton Rouge Children's Study, energy expenditure was examined in 131 preadolescent African American and white girls and boys, further stratified as obese or lean. Total daily energy expenditure (TDEE) was measured by the doubly labeled water method. Resting metabolic rate (RMR) and the thermic effect of food were measured by indirect calorimetry. Fat-free mass and fat mass were measured by dual-energy X-ray absorptiometry. To account for differences in body size, energy expenditure variables were adjusted with the use of fat-free mass or fat-free mass and fat mass as covariates. RESULTS: The African American children had lower TDEE and RMR than did the white children. A lower level of energy expended in physical activity by the African American girls and a lower RMR in the African American boys accounted for the racial differences in TDEE. The white boys had a higher RMR than did the white girls. The girls had a lower TDEE and expended less energy in activity than did the boys. Energy expended in activity was lower in the obese children. CONCLUSIONS: The African American children expended less energy than did the white children. The obese children spent less time engaged in activity or engaged in lower-intensity activity. Obese children may maintain their obese state by spending less time in physical activity, but they do not have a reduced RMR or thermic effect of food.

Prediction of body fat in 12-y-old African American and white children: evaluation of methods.

BACKGROUND: The prevalence of obesity is increasing in children. Validation of methods of predicting fatness in African American and white children could help to identify children at high risk. OBJECTIVE: We assessed published methods for determining body fat in 12-y-old male and female white and African American schoolchildren. DESIGN: The body fat of 114 children was measured with the use of dual-energy X-ray absorptiometry, underwater weighing (densitometry), measurement of skinfold thicknesses, isotope dilution (H(2)(18)O), and bioelectrical impedance analysis. Formulas derived from these data and from published reports were compared by using the Bland-Altman approach. RESULTS: Calculation of percentage of body fat by using an equation predicting body fat in kg and dividing by the current weight was the criterion method against which the other methods were compared. Four-compartment models had the smallest variability across the range of body fat, and 2 of these models differed from the criterion method by 1-2%. Six methods (the Pennington 4-compartment model, the Wells et al 4-compartment model, the isotope dilution model, dual-energy X-ray absorptiometry, the Pennington skinfold thickness model, and the Pennington density model) provided specificity > 90%, an estimate of body fat that was within the 95% CI of the criterion method, and a difference from the criterion method that was < +/- 2%. Bioelectrical impedance analysis was the least acceptable method. CONCLUSIONS: A 4-compartment model in which body fat in kg is divided by current body weight and multiplied by 100 provides the best estimate of percentage of body fat. The isotope dilution and body density models provide estimates within 2% of the estimate provided by the 4-compartment model. Other models do less well.

A 9-mo randomized clinical trial comparing fat-substituted and fat-reduced diets in healthy obese men: the Ole Study.

BACKGROUND: Dietary fat has been implicated as a risk factor for cardiovascular disease and obesity. OBJECTIVE: We evaluated the effect on body weight, body fat, lipids, glucose, and insulin of replacing dietary fat with olestra in moderately obese men. DESIGN: Forty-five healthy overweight men were randomly assigned to 1 of 3 diets: control diet (33% fat), fat-reduced diet (25% fat), or fat-substituted diet (one-third of dietary fat replaced by olestra to achieve a diet containing 25% metabolizable fat). Body fat was measured by dual-energy X-ray absorptiometry and visceral and subcutaneous abdominal fat by computed tomography. RESULTS: Thirty-six men completed the 9-mo study. Body weight and body fat in the fat-substituted group declined by a mean (+/- SEM) of 6.27 +/- 1.66 and 5.85 +/- 1.34 kg, respectively, over 9 mo compared with 3.8 +/- 1.34 and 3.45 +/- 1.0 kg in the control group and 1.79 +/- 0.81 and 1.68 +/- 0.75 kg in the fat-reduced diet group. At 9 mo, the mean difference in body fat between the fat-reduced and fat-substituted groups was -4.19 +/- 1.19 kg (95% CI: -6.57, -1.81), that between the control and fat-substituted groups was -2.55 +/- 1.21 kg (-0.13, -4.97), and that between the control and fat-reduced groups was 1.63 +/- 1.18 kg (3.96, -0.70). The men eating the fat-reduced diet asked for almost no extra foods, in contrast with the significantly higher requests (P < 0.05) from both of the other 2 groups. CONCLUSION: Replacement of dietary fat with olestra reduces body weight and total body fat when compared with a 25%-fat diet or a control diet containing 33% fat.