Utilization of Healthcare Resources by HIV-Positive Children in the United States: A National Perspective

OBJECTIVE

We characterized and estimated the cost of inpatient hospital utilization by US pediatric patients who tested positive for the human immunodeficiency virus (HIV).

METHODS

The 2012 Kids' Inpatient Database was analyzed to provide a descriptive assessment of national inpatient hospital utilization. We analyzed a stratified probability sampling of 3.2 million pediatric hospital discharges weighted to 6.7 million national discharges. Descriptive statistics for hospital and patient characteristics were identified and binary variables were analyzed using the Student t test. The Kids' Inpatient Database is the largest available all-payer pediatric (20 years old and younger) inpatient care database in the United States, yielding national estimates of hospital inpatient stays. Children aged 17 years and younger were included in the study and conditions related to pregnancy and delivery.

RESULTS

We estimated that 1344 pediatric discharges were associated with an HIV diagnosis, totaling 10,704 inpatient days at a cost of $91 million. Among pediatric patients with HIV, 55% were African American, 20% were white, 15% were Asian/Pacific Islander, 8% were other races (including Hispanics and Native Americans), and 51% were female. Children who were HIV positive were more likely to have longer mean hospital stays, have higher mean hospital charges, be of a higher median age (8 years and older), have Medicaid insurance, come from lower-income families, be treated in urban teaching hospitals, and be more likely to die during hospitalization (P < 0.01 for all). Among non-HIV-related pediatric discharges, 20% occurred in households with a mean annual income >$63,000 compared with only 12% for children who were HIV positive. During hospitalization, at least one procedure was performed in 56.6% of children with HIV compared with 45.65% of hospitalized children without HIV. The most frequently observed diagnoses associated with children infected with HIV were gastrointestinal disorders, mental disorders, and bacterial infections and sepsis.

CONCLUSIONS

The results suggest that pediatric patients who were HIV positive were significantly older, from lower-income areas, and members of minority groups. They underwent more procedures during hospitalization, incurred more than twice the total cost, stayed in the hospital twice as long, and had statistically higher in-hospital mortality than children who were HIV negative. As we continue to explore effective and judicious treatment options for patients who are HIV positive, our national estimates of resource utilization can be used to conduct a more detailed examination of current medical practices and specific patterns of diagnoses associated with HIV infection in the US pediatric population.

Food Addiction: A Barrier for Effective Weight Management for Obese Adolescents

BACKGROUND

Findings from studies of food addiction in adults suggest those with food addiction are less successful in weight-loss interventions. Little is known about food addiction in obesity treatment-seeking adolescents; therefore, the purpose of this study was to explore the prevalence of food addiction and correlates of food addiction symptoms in obese adolescents entering an outpatient, weight management program.

METHODS

Obese adolescents (n = 26) were administered the Yale Food Addiction Scale for Children (YFAS-C), measures of appetitive responsiveness, and health-related quality of life (HRQOL) before and following a 12-week, outpatient, behavioral weight management program. Descriptive statistics and correlations between YFAS-C symptoms and study variables were performed and further examined with linear regression. Baseline differences were compared between those meeting criteria for food addiction to those who did not (independent t-tests) and pre-postweight management program changes were examined (paired t-tests).

RESULTS

30.7% met criteria for food addiction and 50% reported ≥3 symptoms. Number of YFAS-C symptoms was correlated with appetitive responsiveness (r = 0.57, p < 0.05) and inversely correlated with all domains of HRQOL (r = 0.47-0.53, p < 0.05). Attrition rate was higher in adolescents with food addiction compared to those without (62.5% vs. 44.4%, p < 0.05).

CONCLUSIONS

Adolescents with food addiction or with a higher number of food addiction symptoms may warrant additional resources to support adherence to and retention with a weight management program. Implementing screening measures for food addiction before enrolling in a weight management program may be an effective strategy to identify adolescents who may benefit from adjunct modalities.

Resting energy expenditure and systolic blood pressure relationships in women across 4.5 years

Recent studies have reported a strong association between blood pressure (BP) and resting energy expenditure (REE). However, it is not known whether this relationship persists over time. Therefore, the authors examined the temporal relationship between REE and systolic BP. In addition, the impact of sympathetic tone and anthropometric variables on this relationship was examined. All testing was performed on healthy, overweight African American and European American women aged 25 to 45 years over 4.5 years in the University of Alabama at Birmingham General Clinical Research Center. Repeated-measures mixed-models revealed REE as a significant determinant of systolic BP (β=0.0155, P<.0001), independent of catecholamines, leg fat, visceral fat, fat-free mass, fat mass, height, relative skeletal muscle index, and resting heart rate. Observations that REE is predictive of systolic BP across 4.5 years support previous findings that REE may potentially mediate resting BP, independent of anthropometric variables and a marker for sympathetic tone.

The effect of an unstructured, moderate to vigorous, before-school physical activity program in elementary school children on academics, behavior, and health

Background

Physical inactivity has been deemed a significant, contributing factor to childhood overweight and obesity. In recent years, many school systems removed recess and/or physical education from their curriculum due to growing pressure to increase academic scores. With the vast majority of children’s time spent in school, alternative strategies to re-introduce physical activity back into schools are necessary. A creative yet underutilized solution to engage children in physical activity may be in before-school programs. The objective of the proposed study is to examine the effect of an unstructured, moderate to vigorous, before-school physical activity program on academic performance, classroom behavior, emotions, and other health related measures.

Methods/Design

Children in 3rd–5th grade will participate in a before-school (7:30–8:15 a.m.), physical activity program for 12 weeks, 3 days a week. Children will be able to choose their preferred activity and asked to sustain physical activity of moderate to vigorous intensity with individual heart rate monitored during each session.

Discussion

The proposed study explores an innovative method of engaging and increasing physical activity in children. The results of this study will provide evidence to support the feasibility of an unstructured, moderate to vigorous, before-school physical activity program in children and provide insight regarding the ideal physical activity intensity and duration necessary to achieve a positive increase in academic performance.

Trial registration

ClinicalTrials.gov Identifier: NCT01505244

Influence of resting energy expenditure on blood pressure is independent of body mass and a marker of sympathetic tone

Two recent examinations reported a strong association between blood pressure (BP) and resting energy expenditure (REE), independent of body mass and body composition. Both reports postulate that neurohumoral processes that contribute to variation in REE may partly mediate the body mass effect on BP. Therefore, we examined the relationship of REE and BP in 108 asymptomatic women (a) to confirm previous findings in a novel population and (b) to examine the impact of a marker of sympathetic tone on this relationship, as this was indicated as a potentially salient intermediary in previous reports. All testing was performed during a 4-day admission to the General Clinical Research Center. Resting energy expenditure was measured by indirect calorimetry, body composition was determined by dual-energy x-ray absorptiometry, and 24-hour fractionated urinary norepinephrine was determined by high-performance liquid chromatography. Multiple linear regression revealed REE as a significant predictor of systolic BP (β = 0.30, P = .04), independent of race (β = 0. 28, P = .01), age (β = -0.02, P = .80), height (β = -0.38, P = .08), fat mass (β = 0.22, P = .20), fat-free mass (β = 0.08, P = .65), and 24-hour fractionated urinary norepinephrine (β = 0.06, P = .57); and the same model using diastolic BP as the dependent variable approached significance (β = 0.24, P = .09). This study affirms previous findings that REE may be a potential mediator in resting BP, independent of many well-cited factors and, additionally, a marker of sympathetic tone.

Physical activity-induced improvements in markers of insulin resistance in overweight and obese children and adolescents

Childhood obesity is a significant, worldwide, public health problem. Coinciding with the increasing prevalence of obesity in youth, Type 2 diabetes has emerged as a critical health condition in this population. In the U.S. alone, approximately 215,000 U.S. youth under the age of 20 were diagnosed with diabetes, with the majority of 10-19 years old diagnosed with Type 2 diabetes. Additionally, the exact number of youth that may have Type 2 diabetes yet remain undiagnosed is unknown. Increasing physical activity to encourage weight loss among youth may reduce the incidence of Type 2 diabetes in youth; however, several recent studies reported positive associations between physical activity and components of Type 2 diabetes without weight loss in youth. These findings support previous studies in adults which observed physical activity-induced improvements in insulin dynamics without changes in body fat. The purpose of this review was to identify studies which examined the effect of physical activity without dietary intervention on markers of insulin resistance in overweight and obese youth. These studies provide strong evidence that physical activity alone, without dietary intervention, can have a positive, significant impact on insulin resistance risk and potentially prevent the development of type 2 diabetes in overweight and obese youth. The studies reviewed provide support for future interventions to shift the focus from reducing obesity to increasing physical activity for the prevention of type 2 diabetes in obese youth.

Differences emerge in visceral adipose tissue accumulation after selection for innate cardiovascular fitness

Cardiorespiratory fitness (CRF) has been reported to be inversely associated with visceral adipose tissue (VAT) accumulation, independent of body weight. However, the confounding effect of physical activity on the association between CRF and VAT remains inadequately addressed. On the basis of maximal oxygen uptake (VO(2 max)), 143 sedentary, overweight women were dichotomized into high-fit (HF) and low-fit (LF) groups. Body composition and VAT were measured using dual-energy X-ray absorptiometry and computed tomography, respectively, and activity-related energy expenditure (AEE) was calculated using the doubly labeled water technique. No differences were observed between HF and LF for body mass index (HF 28.2 ± 1.3; LF 28.3 ± 1.31 kg m(-2)), total body weight (HF 77.5 ± 6.8; LF 77.9 ± 7.3 kg), total fat mass (HF 33.5 ± 5.1; LF 33.9 ± 4.4 kg) or AEE (HF 439.9 ± 375.4; LF 517.9 ± 298.7 kcal day(-1)). Significant differences in visceral adiposity (HF 68.5 ± 30.4; LF 91.2 ± 31.8 cm(2); P<0.001) and insulin sensitivity (HF 5.1 ± 1.8; LF 3.1 ± 2.4 S(I) × 10(-4) min(-1) μIU(-1) ml(-1); P<0.01) were observed between the HF and LF groups, independent of age, race and AEE. This study affirms previous findings that CRF is an important determinant of the accumulation of VAT, and this relationship is independent of physical activity.

Perception of exercise difficulty predicts weight regain in formerly overweight women

It has been previously reported that overweight and obese individuals perceive exercise as more difficult than their lean counterparts, and this difference may not be solely attributed to physiological differences. Therefore, we tested the hypothesis that individual differences in the perception of exercise difficulty during exercise, independent of concurrently measured physiological markers of exertion, are predictive of weight regain, after completion of a weight loss program. A total of 113 formerly overweight women who had previously completed a weight-loss program to achieve a normal body weight (BMI <25 kg/m(2)) underwent a submaximal aerobic exercise task while measures of physiological and perceived exertion (rating of perceived exertion (RPE)) were recorded. Weight gain was assessed following a subsequent 1-year free-living period. Average weight regain 1 year following the intervention was 5.46 +/- 3.95 kg. In regression modeling, RPE (beta = 0.21, P = 0.01), but not physiological exertion (beta = 0.02, P = 0.81), during the submaximal exercise task was positively associated with 1-year weight regain following weight loss in premenopausal women, independent of measured confounding variables. The association between RPE and weight regain suggests that perception of exercise difficulty is an important predictor of weight regain following a weight-loss intervention.

Exercise training prevents regain of visceral fat for 1 year following weight loss

The purpose of this study was to determine what effect aerobic and resistance exercise training has on gain of visceral fat during the year following weight loss. After being randomly assigned to aerobic training, resistance training, or no exercise training, 45 European-American (EA) and 52 African-American (AA) women lost 12.3 +/- 2.5 kg on a 800 kcal/day diet. Computed tomography was used to measure abdominal subcutaneous and visceral adipose tissue, whereas total fat and regional fat (leg, arm, and trunk) were measured by dual energy X-ray absorptiometry after weight loss and 1 year following the weight loss. Because not all the subjects adhered to the 2 time/week 40 min/day exercise training during the 1-year follow-up, subjects were divided into five groups for analysis: aerobic adherers, aerobic nonadherers, resistance adherers, resistance nonadherers, and no exercise. No significant differences were observed between the aerobic training and resistance training adherers for any variable. However, the aerobic (3.1 kg) and resistance (3.9 kg) exercise adherers gained less weight than any of the other three groups (all >6.2 kg). In addition, the two exercise adherence groups did not significantly increase visceral fat (<0.8%) as compared with the 38% increase for the two nonadhering exercise groups and the 25% for the nonexercise group. In conclusion, as little as 80 min/week aerobic or resistance training had modest positive effects on preventing weight regain following a diet-induced weight loss. More importantly, both aerobic and resistance training prevented regain of potentially harmful visceral fat.

Fat distribution, aerobic fitness, blood lipids, and insulin sensitivity in African-American and European-American women

The purpose of this study was to determine independent relationships of intra-abdominal adipose tissue (IAAT), leg fat, and aerobic fitness with blood lipids and insulin sensitivity (S(i)) in European-American (EA) and African-American (AA) premenopausal women. Ninety-three EA and ninety-four AA with BMI between 27 and 30 kg/m(2) had IAAT by computed tomography, total fat and leg fat by dual-energy X-ray absorptiometry, aerobic fitness by a graded exercise test, African admixture (AFADM) by ancestry informative markers, blood lipids by the Ektachem DT system, and S(i) by glucose tolerance test. Independent of age, aerobic fitness, AFADM, and leg fat, IAAT was positively related to low-density lipoprotein-cholesterol (LDL-C), cholesterol-high-density lipoprotein (HDL) ratio, triglycerides (TGs), and fasting insulin (standardized beta varying 0.16-0.34) and negatively related to HDL-cholesterol (HDL-C) and S(i) (standardized beta -0.15 and -0.25, respectively). In contrast, independent of age, aerobic fitness, AFADM, and IAAT, leg fat was negatively related to total cholesterol, LDL-C, cholesterol-HDL ratio, TGs, and fasting insulin (standardized beta varying -0.15 to -0.21) and positively related to HDL-C and S(i) (standardized beta 0.16 and 0.23). Age was not independently related to worsening of any blood lipid but was related to increased S(i) (standardized beta for S(i) 0.25, insulin -0.31). With the exception of total cholesterol and LDL-C, aerobic fitness was independently related to worsened blood lipid profile and increased S(i) (standardized beta varying 0.17 to -0.21). Maintenance of favorable fat distribution and aerobic fitness may be important strategies for healthy aging, at least in premenopausal EA and AA women.

Self-reported low vitality, poor mental health, and low dietary restraint are associated with overperception of physical exertion

Objective. We investigated whether perceived exertion, in comparison to the physiological response to exercise, was associated with self-reported vitality, mental health, and physical function during daily activities, or weight control behaviors. Design. Weight-reduced, formerly overweight women (n = 126, aged 22-46 years), completed health and dietary control questionnaires, and underwent a treadmill-walking task while heart rate, ventilation, respiratory exchange ratio, and ratings of perceived exertion were recorded. Results. Overperception of exertion (perceived exertion physiological exertion) was inversely associated with vitality (r = -0.190, P < .05), mental health (r = -0.188, P < .05), and dietary control (r values range -0.231 to -0.317, P < .05). In linear regression modeling, vitality or mental health, and cognitive dietary restraint were independently associated with accuracy of perceived exertion, independent of age, ethnicity, and engagement in exercise during weight loss. Each model explained 7%-8% of the variance in accuracy of perceived exertion. Conclusion. Women with low vitality or poor mental health, and poor dietary control may overperceive exertion. Such overperception may be a barrier to engage in physical activity and thus increase susceptibility to weight gain.

Ethnicity-specific anthropometric predictors of metabolic risk in women

OBJECTIVE: The objective of this study was to determine associations of anthropometric measures of thigh and abdominal adipose tissue with metabolic risk factors, and whether these associations differed with ethnicity. We hypothesized that thigh circumference (ThC) would have an independent favorable association with insulin sensitivity, lipids, and blood pressure, whereas waist circumference (WC) would have an independent deleterious association with these variables in both African Americans (AA) and European Americans (EA). METHODS: Subjects were 228 healthy, overweight, premenopausal AA and EA women. Insulin sensitivity was assessed by intravenous glucose tolerance test and minimal modeling. Simple relationships between anthropometric measures and risk factors were determined by Pearson correlation analysis. Partial correlation coefficients were determined for circumference measures adjusted for thigh and abdominal skinfolds to differentiate relationships between thigh and abdominal subcutaneous fat from thigh muscle and deeper abdominal fat, respectively. RESULTS: In EA but not AA, ThC was positively associated with insulin sensitivity, independent of thigh skinfold. In both EA and AA, ThC was associated with a desirable lipid profile. In AA but not EA, WC was associated with lower insulin sensitivity and a less desirable metabolic profile. CONCLUSION: Results suggest that thigh muscle (ThC adjusted for thigh skinfold) may be metabolically protective in EA but not AA. In contrast, WC was a better indicator of insulin sensitivity and metabolic health in AA. Further investigation is needed to verify the association between thigh muscle and metabolic health, and to probe the reason for the observed ethnic specificity of the associations between anthropometric measures and metabolic risk factors.

Missing data in randomized clinical trials for weight loss: scope of the problem, state of the field, and performance of statistical methods

Background

Dropouts and missing data are nearly-ubiquitous in obesity randomized controlled trails, threatening validity and generalizability of conclusions. Herein, we meta-analytically evaluate the extent of missing data, the frequency with which various analytic methods are employed to accommodate dropouts, and the performance of multiple statistical methods.

Methodology/Principal Findings

We searched PubMed and Cochrane databases (2000–2006) for articles published in English and manually searched bibliographic references. Articles of pharmaceutical randomized controlled trials with weight loss or weight gain prevention as major endpoints were included. Two authors independently reviewed each publication for inclusion. 121 articles met the inclusion criteria. Two authors independently extracted treatment, sample size, drop-out rates, study duration, and statistical method used to handle missing data from all articles and resolved disagreements by consensus. In the meta-analysis, drop-out rates were substantial with the survival (non-dropout) rates being approximated by an exponential decay curve (e^−λt) where λ was estimated to be .0088 (95% bootstrap confidence interval: .0076 to .0100) and t represents time in weeks. The estimated drop-out rate at 1 year was 37%. Most studies used last observation carried forward as the primary analytic method to handle missing data. We also obtained 12 raw obesity randomized controlled trial datasets for empirical analyses. Analyses of raw randomized controlled trial data suggested that both mixed models and multiple imputation performed well, but that multiple imputation may be more robust when missing data are extensive.

Conclusion/Significance

Our analysis offers an equation for predictions of dropout rates useful for future study planning. Our raw data analyses suggests that multiple imputation is better than other methods for handling missing data in obesity randomized controlled trials, followed closely by mixed models. We suggest these methods supplant last observation carried forward as the primary method of analysis.

Sample size in obesity trials: patient perspective versus current practice

OBJECTIVE

To evaluate patient opinions on acceptable risks in exchange for a given degree of weight loss and their implications for sample size determination in obesity randomized clinical trials (RCTs).

DESIGN

. Survey of patients entering RCTs for weight loss in a university-based clinical research setting and power calculations based on their responses. Participants. Men (n = 8) and women (n = 66) between 24 and 73 years of age with body mass indices ranging from 26.8 to 40.5 kg/m(2). Measurements. Survey responses to questions assessing the added risk of serious adverse events (SAEs) or death one is willing to assume for a given degree of weight loss.

RESULTS

For 5% and 10% weight loss against risk for death per se, the mean acceptable risk tended to be about 3.5%, but the median (0.00) and mode (0.00) suggested that for most individuals, only a risk of < or = 1% would be acceptable. Figures, estimated dropout rates, and base rates of SAEs (including deaths) from recent obesity trials indicate that 1-year 2-group obesity RCTs would need tens of thousands of participants per group to have 80% power to detect risks that are meaningful to patients at the 2-tailed 0.05 alpha level.

CONCLUSION

Patient education is needed to explain which risks are realistically detectable in RCTs so that patients may provide truly informed consent, or RCT standards should be modified to meet patients' implicit expectations.

Effect of exercise training intensity on abdominal visceral fat and body composition

The metabolic syndrome is a complex clustering of metabolic defects associated with physical inactivity, abdominal adiposity, and aging.

PURPOSE

To examine the effects of exercise training intensity on abdominal visceral fat (AVF) and body composition in obese women with the metabolic syndrome.

METHODS

Twenty-seven middle-aged obese women (mean +/- SD; age = 51 +/- 9 yr and body mass index = 34 +/- 6 kg x m(-2)) with the metabolic syndrome completed one of three 16-wk aerobic exercise interventions: (i) no-exercise training (Control): seven participants maintained their existing levels of physical activity; (ii) low-intensity exercise training (LIET): 11 participants exercised 5 d x wk(-1) at an intensity < or = lactate threshold (LT); and (iii) high-intensity exercise training (HIET): nine participants exercised 3 d x wk(-1) at an intensity > LT and 2 d x wk(-1) < or = LT. Exercise time was adjusted to maintain caloric expenditure (400 kcal per session). Single-slice computed tomography scans obtained at the L4-L5 disc space and midthigh were used to determine abdominal fat and thigh muscle cross-sectional areas. Percent body fat was assessed by air displacement plethysmography.

RESULTS

HIET significantly reduced total abdominal fat (P < 0.001), abdominal subcutaneous fat (P = 0.034), and AVF (P = 0.010). There were no significant changes observed in any of these parameters within the Control or the LIET conditions.

CONCLUSIONS

The present data indicate that body composition changes are affected by the intensity of exercise training with HIET more effectively for reducing total abdominal fat, subcutaneous abdominal fat, and AVF in obese women with the metabolic syndrome.

Perception of others' body size influences weight loss and regain for European American but not African American women

OBJECTIVE

The authors investigated whether European American (EA) and African American (AA) women took longer to lose weight, and were less likely to maintain weight loss if they perceived others to be overweight.

DESIGN

Overweight EA and AA women completed a Figure Rating Scale and the Three-Factor Eating Questionnaire prior to a weight loss intervention. Body composition was assessed by dual energy X-ray absorptiometry prior to and following weight loss.

MAIN OUTCOME MEASURES

rate of weight loss, % body fat at follow-up.

RESULTS

For EA, but not AA women, perception of others' body size was inversely associated with rate of weight loss and cognitive restraint, and positively associated with body fat gain following intervention. In linear regression modeling, EA, but not AA, women who perceived others as large, subsequently had greater percent body fat 1 year after weight loss than did those who perceived others as lean, independent of age, baseline body fat, and body size deemed "acceptable." Inclusion of cognitive restraint in the model weakened this effect.

CONCLUSION

Among EA but not AA women, perception of others' body size influenced weight loss and maintenance. This effect may have been mediated by cognitive restraint.

Effects of exercise training intensity on nocturnal growth hormone secretion in obese adults with the metabolic syndrome

CONTEXT

Abdominal adiposity is associated with reduced spontaneous GH secretion, and an increased incidence of the metabolic syndrome, type 2 diabetes, and cardiovascular disease. Exercise training increases GH secretion, induces abdominal visceral fat loss, and has been shown to improve the cardiometabolic risk factor profile. However, little is known about the effects of endurance training intensity on spontaneous GH release in obese individuals.

OBJECTIVE

Our objective was to examine the effects of 16 wk endurance training on spontaneous 12-h overnight GH secretion in adults with the metabolic syndrome.

DESIGN AND SETTING

This randomized, controlled exercise intervention was conducted at the University of Virginia.

PARTICIPANTS

A total of 34 adults with the metabolic syndrome (mean +/- sem: age: 49.1 +/- 1.8 yr) participated.

INTERVENTION

Participants were randomized to one of three groups for 16 wk: no exercise training (control), low-intensity exercise training, or high-intensity training.

MAIN OUTCOME MEASURE

Change in nocturnal integrated GH area under the curve (AUC) was calculated.

RESULTS

Both exercise training conditions augmented within-group nocturnal GH AUC pretrain to post-training (low-intensity exercise training approximately (upward arrow) 49%, P < 0.05; and high-intensity training approximately (upward arrow) 65%, P < 0.01), and these changes were also greater than the changes in the control group (P < 0.01). The change in nocturnal GH AUC was inversely associated with the change in fat mass across the entire sample (r = -0.34; P = 0.051; n=34) but was not significantly associated with the change in abdominal visceral fat (r = 0.02; P = 0.920; n = 34).

CONCLUSIONS

Sixteen wk of supervised exercise training in adults with the metabolic syndrome increases spontaneous nocturnal GH secretion independent of exercise training intensity.

Association between insufficiently physically active and the prevalence of obesity in the United States

BACKGROUND

Numerous public health organizations have adopted national physical activity recommendations. Despite these recommendations, over half of the US population does not meet the minimum recommendation for physical activity, with large variations across individual US states.

METHODS

Using the 2005 Behavioral Risk Factor Surveillance System (BRFSS) prevalence data for physical activity and obesity by state, we performed a weighted least squares regression using prevalence of obesity (BMI>or=30 kg/m2) as the dependent variable and insufficiently physically active (included completely sedentary), age, race, gender, and median household income as the independent variables.

RESULTS

The unadjusted weighted least squares regression revealed a strong correlation between a state's prevalence of obesity and the prevalence of insufficiently physically active (R=.76, R2=.58, P<.0001). After adjusting for age, gender, race, and median household income, the prevalence of insufficiently physically active is still a significant predictor of the state prevalence of obesity (partial R=.44, R2=.19 P=.004).

CONCLUSION

Macroenvironmental and sociopolitical disparities between individual US states that transcend simple state-level demographic factors need to be examined more rigorously to identify unique barriers and promoters of physical activity.

Ethnicity and weight status affect the accuracy of proxy indices of insulin sensitivity

This study tested the hypotheses that correlations between direct measures of insulin sensitivity and proxy indices of insulin sensitivity derived from fasting values, (i) would not be affected by ethnicity, and (ii) would be stronger in overweight vs. weight-reduced states. We further hypothesized that associations between proxy indices and fat distribution would be similar to those between directly measured insulin sensitivity and fat distribution. Testing was performed in weight-stable conditions in 59 African-American (AA) and 62 white-American (WA) overweight, premenopausal women before and after a weight loss intervention. Subjects were retested 1 year following weight loss. Proxy indices were correlated against the insulin sensitivity index S(I) determined via minimal modeling. Fat distribution was assessed using computed tomography. Correlations between Si and proxy indices were consistently stronger among overweight women (r = 0.44-0.52) vs. weight-reduced women (r = 0.18-0.32), and among AA (r = 0.49-0.56, baseline; 0.24-0.36, weight-reduced) vs. WA (r = 0.38-0.46, baseline; 0.19-0.31, weight-reduced). Among subjects who regained >3 kg after 1 year, correlations between S(I) and proxy indices were similar to those observed at baseline, whereas correlations were weak among women who maintained their reduced body weight. S(I) and all proxy indices were similarly correlated with intra-abdominal adipose tissue (IAAT) at baseline, but not after weight loss. In conclusion, correlations between S(I) and proxy indices were affected by both ethnicity and weight status. If proxy indices are used in multiethnic populations, or in populations including both lean and overweight/obese subjects, data should be interpreted with caution.

Heart rate recovery does not predict endothelial function in obese women

The purpose of the present study was to examine the relationship between heart rate recovery (HR(REC)) and endothelial function in obese women with the metabolic syndrome. The metabolic syndrome has been associated with increased cardiometabolic risk including endothelial dysfunction. However, measurement of endothelial function via flow-mediated dilation (FMD) requires expensive equipment and qualified medical personnel, and therefore may be impractical in some healthcare settings. Heart rate recovery (HR(REC)) has predictive utility with respect to endothelial function in individuals with suspected coronary artery disease and individuals with the metabolic syndrome also have elevated risk for developing coronary artery disease. Thirty-one obese, sedentary women (age: 47.7±11.2 yr, mean±SD) who met the International Diabetes Federation criteria for the metabolic syndrome underwent a brachial artery ultrasound to determine FMD and nitroglycerine-mediated dilation (NTG). HR(REC) was assessed during 5 min of active recovery following a standardized VO(2 Peak) treadmill protocol. Results revealed that the %FMD was not correlated to HR(REC) when examined across all participants (r= 0.067, p=0.72). However, this relationship was significant in participants with impaired FMD (n=16, %FMD<6%) (r=0.71, p=0.002). Although HR(REC) may be a significant correlate of FMD in women with the metabolic syndrome and with prevalent endothelial dysfunction, it was not a significant correlate across all women with the metabolic syndrome. The present data do not support the use of HR(REC) as a possible screening tool for endothelial dysfunction in obese women with the metabolic syndrome.

The metabolic syndrome, hypertriglyceridemic waist, and cardiometabolic risk factor profile in obese women

The hypertriglyceridemic waist (HTGW) and metabolic syndrome (MS) are associated with increased cardiometabolic risk. We evaluated the impact of the HTGW on cardiometabolic risk factors in obese women diagnosed with the MS. Thirty-six abdominally obese women with the MS as defined by the International Diabetes Federation (IDF) [(mean (SD); age 49 (11) y, ht 165 (6) cm, wt 95 (16) kg] participated. The HTGW was defined as follows: a waist circumference ≥80 cm and triglycerides ≥1.7 mM. Unpaired t-tests and Analysis of Covariance (ANCOVA) were employed to detect mean differences between women with MS plus or minus HTGW. Women with the MS plus HTGW had higher total cholesterol (16%, p=0.015), VLDL-cholesterol (97%, p<0.001), non-HDL-cholesterol (16%, p=0.002), insulin (40%, p=0.043), and abdominal visceral fat (24%, p=0.100), and lower total HDL-cholesterol (6%, p=0.024), HDL(3) (11%, p=0.031) and Quantitative Insulin Sensitivity Check Index (QUICKI) (5%, p=0.068) compared with women with the MS minus HTGW. Thus, the presence of the HTGW was accompanied by a worsened cardiometabolic risk factor profile in these obese women with the MS. In particular, women with the MS plus HTGW were more insulin resistant compared to women with the MS minus HTGW. In conclusion, the presence of the HTGW in obese women with the MS exacerbates insulin resistance and cardiometabolic risk factors.

NIH ImageJ and Slice-O-Matic computed tomography imaging software to quantify soft tissue

OBJECTIVE

To compare reliability and limits of agreement of soft tissue cross-sectional areas obtained using Slice-O-Matic and NIH ImageJ medical imaging software packages.

RESEARCH METHODS AND PROCEDURES

Abdominal and midthigh images were obtained using single-slice computed tomography. Two trained investigators analyzed each computed tomography image in duplicate. Adipose tissue and skeletal muscle cross-sectional areas (centimeters squared) were calculated using standard Hounsfield unit ranges (adipose tissue: -190 to -30 and skeletal muscle: -29 to 150). Regions of interest included abdominal total area, total fat area, subcutaneous fat area, visceral fat area (AVF), and right and left thigh total area, fat area, and skeletal muscle area.

RESULTS

For all images, intra-investigator coefficients of variation ranged from 0.2% to 3.4% and from 0.4% to 5.6% and inter-investigator coefficients of variation ranged from 0.9% to 4.8% and 0.2% to 2.6% for Slice-O-Matic and NIH ImageJ, respectively, with intra- and inter-investigator coefficients of reliability of R(2) = 0.99. Mean AVF values for investigators A and B ranged from 168 to 170 cm(2) using Slice-O-Matic and NIH ImageJ. Bland-Altman analyses revealed that Slice-O-Matic and NIH ImageJ results were comparable. The mean differences (95% confidence intervals) between the AVF cross-sectional areas obtained using the Slice-O-Matic and NIH ImageJ medical imaging software were +2.5 cm(2) (-5.7, +10.8 cm(2)) or +1.4% (-3.4%, +6.4%).

DISCUSSION

These findings show that both the Slice-O-Matic and NIH ImageJ medical imaging software systems provide reliable measurements of adipose tissue and skeletal muscle cross-sectional areas.

Heart rate at lactate threshold and cycling time trials

The purpose of this investigation was to relate the heart rate and lactate response during simulated cycling time trials to incremental laboratory tests. Subjects (N = 10) were tested for .V(O2)max (56.1 +/- 2.4 ml.kg(-1).min(-1) ) and lactate threshold during incremental tests to exhaustion. Power output and heart rate (HR) at threshold was assessed by 3 methods: lactate deflection point (LaT), onset of blood lactate accumulation (OBLA), and the point on the lactate curve at maximal distance from a line connecting starting and finishing power output (Dmax). Power output determined at these thresholds was 282.1 +/-4.2, 302.5 +/-1.3, and 296.0 +/- 1.8 W, respectively, whereas HR was determined to be 88.6 +/- 0.01, 92.2 +/- 0.01, and 91.0 +/- 0.01% of maximum, respectively. Power output and HR were significantly lower for LaT than for the other 2 methods (p < 0.05). On separate visits, cyclists were instructed to perform maximum efforts for 30 and 60 minutes (30TT and 60TT). Lactate, HR, perceived exertion (RPE), and metabolic variables were measured during the time trials. During the 30TT, participants sustained a significantly higher lactate level (5.29 +/- 0.3 vs. 3.43 +/- 0.3 mmol.L(-1), p < 0.001), percentage of maximum HR (%HRmax) (90.3 +/- 0.02 vs. 84.6 +/- 0.01, p = 0.009), and overall RPE (15.5 +/- 0.5 vs. 14.4 +/- 0.5, p = 0.009), than during the 60TT. .V(O2) was not significantly different between the time trials; however, .V(CO2) (p = 0.008), ventilation (p = 0.004), and respiratory exchange ratio (p = 0.02) were significantly higher during the 30TT. Correlations were found between HR at LaT (r = 0.78), OBLA (r = 0.78), and Dmax (r = 0.71) for the 60TT, but not for the 30TT. These data suggest that despite a large variability in blood lactate during time trial efforts of 30 and 60 minutes (from 1.8 to 10.8 mmol.L(-1)), HR was consistently 90% of maximum for the 30TT and 85% for the 60TT. HR during the 30TT was approximated by HR corresponding to OBLA and Dmax, whereas HR during 60TT was approximated by LaT.

Comparison of Borg- and OMNI-RPE as Markers of the Blood Lactate Response to Exercise

PURPOSE

To examine the utility of the Borg (6-20) and adult OMNI walk/run (0-10) ratings of perceived exertion (RPE) scales as markers of the blood lactate response to exercise.

METHODS

Thirty-six (26 females and 10 males) individuals with the metabolic syndrome (mean+/-SEM: age, 45.8+/-2.0 yr; height, 168.4+/-1.3 cm; weight, 100.4+/-3.6 kg) completed a continuous peak oxygen uptake (VO2peak)/lactate threshold (LT) treadmill protocol. VO2 (mL.kg.min), blood lactate concentration (BLC, mM), and heart rate (bpm) were measured at the end of each stage. RPE were assessed at 2:15 and 2:45 of each 3-min stage using both RPE scales presented in a counterbalanced order. Participants were read standardized instructions specific to each scale. The LT and BLC of 2.5 and 4.0 mM were determined from the blood lactate-velocity relationship.

RESULTS

The mean Borg, OMNI, and standardized (to the Borg scale) OMNI-RPE values at the LT and BLC of 2.5 mM, 4.0 mM, and peak ranged from 10.1 to 16.9, 3.1 to 8.2, and 9.9 to 17.1, respectively. No differences were observed between Borg and standardized OMNI-RPE at any exercise intensity. The correlation within and between Borg- and OMNI-RPE and the velocities associated with LT, BLC of 2.5 mM, 4.0 mM, and peak ranged from r=0.82 to 0.93 (P<0.01). Mean differences (95% CI) between the Borg- and standardized OMNI-RPE at LT, and BLC of 2.5 mM, 4.0 mM, and peak were 0.27 (-2.26, 2.80), -0.48 (-3.14, 2.18), -0.29 (-2.92, 2.35), and 0.10 (-1.65, 1.84), respectively.

CONCLUSION

Both the Borg and OMNI walk/run scales demonstrate predictive utility as markers of the blood lactate response to incremental exercise in individuals with the metabolic syndrome.

Is a consensus possible on stem cell research? Moral and political obstacles

Neither of the two central moral and political obstacles to human embryonic stem cell research survives critical scrutiny

Reducing diet and/or exercise training decreases the lipid and lipoprotein risk factors of moderately obese women

OBJECTIVE

This study was designed to measure the influence of diet, exercise or both on serum lipids and lipoproteins in obese women.

METHODS

Obese subjects were randomly divided into one of four groups: diet alone (1,200-1,300 kcal/day, NCEP, Step I), exercise alone (five 45 minute sessions per week at 78.4+/-0.5% maximum heart rate), exercise and diet, and controls. Maximal aerobic power, body composition, diet, serum lipids and lipoproteins were measured in all subjects at baseline and after a 12-week intervention period. Subjects included 91 moderately obese (45.6+/-1.1 y, body mass index 33.1+/-0.6 kg/m2) and 30 nonobese (43.2+/-2.3 y, body mass index 21.4+/-0.34 kg/m2) women who were recruited from the surrounding community. Independent t tests were used to compare obese and nonobese subjects at baseline. The 12-week intervention data from the obese groups were analyzed using a 4 x 2 repeated measures ANOVA design.

RESULTS

Cross-sectional comparisons at baseline showed obese subjects had significantly higher total cholesterol, triacylglycerol. total cholesterol/HDL-C and LDL-C values and lower HDL-C values. Prospective results showed that subjects in diet and exercise and diet lost 7.8+/-0.7 and 8.1+/-0.6 kg body mass, with no significant change for exercise relative to control. Serum cholesterol and triacylglycerol improved in both diet and in exercise and diet after 12 weeks of intervention, and was most strongly related to weight loss.

CONCLUSION

Weight loss is the most effective means of reducing lipid and lipoprotein risk factors in obese women.

Children's Rights to Health Care

This paper will explore the application of an account of justice in health and health care to the special case of children. It is tempting to hold that children require no special treatment in an account of just health care; justice requires guaranteeing access to at least basic health care services to all persons, whatever their age group, within the constraints of a society's resources. However, I will argue that for a number of reasons we need to address what justice requires specifically for children from the health care system, even if the answer must be embedded within a general account of justice in health and health care.

Misconceived sources of opposition to physician-assisted suicide

This article addresses 2 prominent sources of opposition to physician-assisted suicide (PAS): first, the fear of abuse and, second, common moral distinctions drawn between PAS and other forms of end-of-life decisions and care. Each is grounded in a false assumption that PAS is radically different from other forms of widely accepted end-of-life decisions and care. The experience to date in Oregon gives some reassurance that the practice there permitting PAS has not been significantly abused. Moreover, the author argues that abuse, understood as decisions not in accord with what the patient wants, or would have wanted, is greatest when someone other than the patient is the decisionmaker. On this ground, PAS should be less subject to abuse than other surrogate decisions about life support. Moreover, Oregon's law, like virtually all proposals to legalize PAS, contains numerous safeguards that are not present in decisions about life support generally. Second, it is argued that some prominent conceptualizations of accepted end-of-life decisions and care thought to distinguish them morally from PAS fail on closer analysis to do so.

Palliative options of last resort: a comparison of voluntarily stopping eating and drinking, terminal sedation, physician-assisted suicide, and voluntary active euthanasia

Palliative care is generally agreed to be the standard of care for the dying, but there remain some patients for whom intolerable suffering persists. In the face of ethical and legal controversy about the acceptability of physician-assisted suicide and voluntary active euthanasia, voluntarily stopping eating and drinking and terminal sedation have been proposed as ethically superior responses of last resort that do not require changes in professional standards or the law. The clinical and ethical differences and similarities between these 4 practices are critically compared in light of the doctrine of double effect, the active/passive distinction, patient voluntariness, proportionality between risks and benefits, and the physician's potential conflict of duties. Terminal sedation and voluntarily stopping eating and drinking would allow clinicians to remain responsive to a wide range of patient suffering, but they are ethically and clinically more complex and closer to physician-assisted suicide and voluntary active euthanasia than is ordinarily acknowledged. Safeguards are presented for any medical action that may hasten death, including determining that palliative care is ineffective, obtaining informed consent, ensuring diagnostic and prognostic clarity, obtaining an independent second opinion, and implementing reporting and monitoring processes. Explicit public policy about which of these practices are permissible would reassure the many patients who fear a bad death in their future and allow for a predictable response for the few whose suffering becomes intolerable in spite of optimal palliative care.

Limits of patient autonomy. Physician attitudes and practices regarding life-sustaining treatments and euthanasia

BACKGROUND

In making decisions about life-sustaining medical interventions, respect for patient autonomy has been widely advocated, yet little is known about what variables may compete with a physician's ability to honor patient requests in clinical situations. We investigated physician attitudes and behaviors about end-of-life decisions by means of a questionnaire that posed five hypothetical scenarios in which an elderly, competent, terminally ill patient made a request that, if agreed to by the physician, could result in the patient's death.

METHODS

We surveyed 392 physicians in Rhode Island and asked them to decide (1) whether or not they would comply with a specific patient request, (2) the justifications they used in making their decision, and (3) whether they had been approached with such a request in their clinical practices.

RESULTS

Two hundred fifty-six physicians (65%) responded. Of the respondents, 98% agreed not to intubate the patient in the face of worsening respiratory failure. Eighty-six percent agreed to give the patient a dose of narcotics that could cause respiratory compromise and death to treat his pain adequately. Fifty-nine percent agreed, once the patient was intubated without hope of coming off the respirator, to turn the respirator off. Nine percent agreed to give the patient a prescription for an amount of sleeping pills that would be lethal if taken all at once. Only 1% agreed to give the patient a lethal injection. When they complied with patient requests, physicians cited patient autonomy as the principle most important to their decision making. Physicians who would not comply with patient requests also, paradoxically, often cited this principle but agreed with it less strongly; others cited concerns about the ethical nature of the request, legal questions, and the perception that they were "killing the patient." Sixty-five percent of respondents had been asked by patients to turn off a respirator, and 12% had been asked to administer lethal injections. Twenty-eight percent of respondents indicated that they would comply with requests for lethal injection more frequently if such an action were legal.

CONCLUSIONS

Difficult clinical decisions regarding potentially life-prolonging measures are commonly heard in clinical practice. Physicians value the concept of patient autonomy but place it in the context of other ethical and legal concerns and do not always accept specific actions derived from this principle.

Euthanasia

The principles of self-determination and individual well-being support the use of voluntary euthanasia by those who do not have moral or professional objections to it. Opponents of this posture cite the ethical wrongness of the act itself and the folly of any public or legal policy permitting euthanasia. Positive consequences of making euthanasia legally permissible respect the autonomy of competent patients desiring it, expand the population of patients who can choose the option, and release the dying patient from otherwise prolonged suffering and agony. Potentially bad consequences of permitting euthanasia include the undermining of the "moral center" of medicine by allowing physicians to kill, the weakening of society's commitment to provide optimal care for dying patients, and, of greatest concern, the "slippery slope" argument. The evaluation of the arguments leads to support for euthanasia, with its performance not incompatible with a physician's professional commitment.