Long-term effect of weight loss on obstructive sleep apnea severity in obese patients with type 2 diabetes.

STUDY OBJECTIVES: To examine whether the initial benefit of weight loss on obstructive sleep apnea (OSA) severity at 1 year is maintained at 4 years. DESIGN: Randomized controlled trial with follow-up at 1, 2, and 4 years. SETTING: 4 Look AHEAD clinical centers. PARTICIPANTS: Two hundred sixty-four obese adults with type 2 diabetes and OSA. INTERVENTIONS: Intensive lifestyle intervention with a behavioral weight loss program or diabetes support and education. MEASUREMENTS: Change in apnea-hypopnea index on polysomnogram. RESULTS: The intensive lifestyle intervention group's mean weight loss was 10.7 ± 0.7 (standard error), 7.4 ± 0.7, and 5.2 ± 0.7 kg at 1, 2, and 4 years respectively, compared to a less than 1-kg weight loss for the control group at each time (P < 0.001). Apnea-hypopnea index difference between groups was 9.7 ± 2.0, 8.0 ± 2.0, and 7.7 ± 2.3 events/h at 1, 2 and 4 years respectively (P < 0.001). Change in apnea-hypopnea index over time was related to the amount of weight loss (P < 0.0001) and intervention, independent of weight loss (P = 0.001). Remission of OSA at 4 years was 5 times more common with intensive lifestyle intervention (20.7%) than diabetes support and education (3.6%). CONCLUSIONS: Among obese adults with type 2 diabetes and OSA, intensive lifestyle intervention produced greater reductions in weight and apnea-hypopnea index over a 4 year period than did diabetes support and education. Beneficial effects of intensive lifestyle intervention on apneahypopnea index at 1 year persisted at 4 years, despite an almost 50% weight regain. Effect of intensive lifestyle intervention on apnea-hypopnea index was largely, but not entirely, due to weight loss.

Relationship between treatment preference and weight loss in the context of a randomized controlled trial.

Randomized controlled trials (RCTs) are considered the gold standard used to assess the efficacy of treatment. While a well implemented RCT can produce an unbiased estimate of the relative difference between treatment groups, the generalizability of these findings may be limited. Specific threats to the external validity include treatment preference. The purposes of this study were to: (i) assess whether receiving one's treatment preference was associated with weight loss and retention and (ii) whether receiving one's treatment preference modified the relationship between the treatments and weight loss. Treatment preference was assessed in 250 subjects prior to but independent of randomization into either low-carbohydrate or low-fat diets. Treatment preference was a predictor of weight loss (P = 0.002) but not retention (P = 0.90). Participants who received their preference lost less weight (-7.7 kg, 95% confidence interval (CI): -9.3 to -6.1) than participants who did not receive their preference (-9.7 kg, 95% CI: -11.4 to -8.1) and participants who did not report a strong preference at baseline (-11.2 kg, 95% CI: -12.6 to -9.7) (P = 0.04 and P = 0.0004, respectively). Treatment preference did not modify the effect of the treatment on weight loss. Contrary to conceptual predictions, this study failed to identify an interaction between treatment preference and weight loss in the setting of a randomized trial. Until treatment preference effects are definitively ruled out in this domain, future studies might consider stratifying their randomization procedure by treatment preference rather than excluding participants with strong treatment preferences.

The individual and combined effects of glycemic index and protein on glycemic response, hunger, and energy intake.

Although high protein and low glycemic index (GI) foods are thought to promote satiety, little is known about the effects of GI, protein, and their interaction on hunger and energy intake several hours following a mixed meal. This study investigated the long term effects of GI, protein, and their combined effects on glucose, insulin, hunger, and energy intake in healthy, sedentary, overweight, and obese adults (BMI of 30.9 ± 3.7 kg/m(2)). Sixteen individuals participated separately in four testing sessions after an overnight fast. The majority (75%) were non-Hispanic Blacks. Each consumed one of four breakfast meals (high GI/low protein, high GI/high protein, low GI/low protein, low GI/high protein) in random order. Visual analog scales (VAS) and blood samples were taken at baseline, 15 min, and at 30 min intervals over 4 h following the meal. After 4 h, participants were given the opportunity to consume food ad libitum from a buffet style lunch. Meals containing low GI foods produced a smaller glucose (P < 0.002) and insulin (P = 0.0001) response than meals containing high GI foods. No main effects for protein or interactions between GI and protein were observed in glucose or insulin responses, respectively. The four meals had no differential effect on observed energy intake or self-reported hunger, satiety, and prospective energy intake. Low GI meals produced the smallest postprandial increases in glucose and insulin. There were no effects for GI, protein, or their interaction on appetite or energy intake 4 h after breakfast.

The impact of weight, sex, and race/ethnicity on body dissatisfaction among urban children.

The purpose of the current study was to examine the relative contributions of weight status, race/ethnicity, sex, and age on body dissatisfaction in a large group of diverse children. Participants were 4th-6th graders (N=1212) in ten inner-city schools who participated in an obesity prevention study previously published. Children completed the body dissatisfaction subscale of the Eating Disorder Inventory-2 (EDI-2), and weight status was assessed by measured weights and heights. Multiple regression analyses were conducted. Relative weight status was the strongest predictor of body dissatisfaction, followed by race/ethnicity, and sex. Body dissatisfaction was greatest in obese, Asian, and female children. Overall, results indicated that children's body dissatisfaction varies based on relative weight status, as well as race/ethnicity and sex among urban children. Results highlight the strong need for additional research so that more definitive conclusions may be drawn regarding the development of body image among diverse groups of children.

Effects of weight status and barriers on physical activity adoption among previously inactive women.

This study examined self-reported physical activity (PA) barriers, and their effects on PA behavior change at 3 and 12 months among 280 previously inactive women enrolled in a PA promotion trial. Effect modification of baseline barriers by baseline weight status on PA behavior change was also examined. At baseline and month 12, obese women reported significantly greater PA barriers compared with normal and overweight women (P < 0.05). Individual barriers that were more likely to be elevated for obese vs. normal and overweight participants at baseline were feeling too overweight, feeling self-conscious, reporting minor aches and pains, and lack of self-discipline. Also, weight status moderated the effect of PA barriers on PA behavior change from baseline to month 3 (P < 0.05), but not to month 12 (P = 0.637), with obese participants reporting high barriers achieving 70 min/week fewer than those with low barriers (P < 0.05). Finally, the interaction between barriers (high vs. low) and weight status (obese vs. normal), shows PA barriers had a detrimental PA effect among obese participants that was 122.5 min/week (95% confidence interval (CI) = 15.7, 229.4; P < 0.05) lower than their effect on normal-weight participants. These results suggest that for obese women, PA barriers have quantifiable effects on PA behavior change. This study has implications for the design of future weight loss and PA interventions, suggesting that a comprehensive assessment of PA barriers is a prerequisite for appropriate tailoring of behavioral PA interventions.

Accelerometer use in a physical activity intervention trial.

This paper describes the application of best practice recommendations for using accelerometers in a physical activity (PA) intervention trial, and the concordance of different methods for measuring PA. A subsample (n = 63; 26%) of the 239 healthy, sedentary adults participating in a PA trial (mean age = 47.5; 82% women) wore the ActiGraph monitor at all 3 assessment time points. ActiGraph data were compared with self-report (i.e., PA weekly recall and monthly log) and fitness variables. Correlations between the PA recall and ActiGraph for moderate intensity activity ranged from 0.16-0.48 and from 0.28-0.42 for vigorous intensity activity. ActiGraph and fitness [estimated VO(2)(ml/kg/min)] had correlations of 0.15-0.45. The ActiGraph and weekly self-report were significantly correlated at all time points (correlations ranged from 0.23 to 0.44). In terms of detecting intervention effects, intervention groups recorded more minutes of at least moderate-intensity PA on the ActiGraph than the control group at 6 months (min = 46.47, 95% CI = 14.36-78.58), but not at 12 months. Limitations of the study include a small sample size and only 3 days of ActiGraph monitoring. To obtain optimal results with accelerometers in clinical trials, the authors recommend following best practice recommendations: detailed protocols for monitor use, calibration of monitors and validation of data quality, and use of validated equations for analysis. The ActiGraph has modest concordance with other assessment tools and is sensitive to change over time. However, until more information validating the use of accelerometry in clinical trials becomes available, properly administered self-report measures of PA should remain part of the assessment battery.

Healthy food availability in small urban food stores: a comparison of four US cities.

OBJECTIVE: Given that small food stores may be important retail food sources in low-income urban communities, our objective was to examine cross-city comparative data documenting healthy food availability within such facilities, particularly those located in low-income areas and nearby schools. DESIGN: Food stores in Baltimore, Maryland; Minneapolis/St. Paul, Minnesota; Oakland, California; and Philadelphia, Pennsylvania were selected for assessment based on proximity to low-income schools. Stores were defined as: (i) single-aisle (n 45); (ii) small (2-5 aisles; n 52); and (iii) large (> or = 6 aisles; n 8). Staff conducted in-store audits to assess the presence/absence of twenty-eight healthy items, organized within five categories: (i) fresh fruits/vegetables, (ii) processed fruits/vegetables, (iii) healthy beverages/low-fat dairy, (iv) healthy snacks and (v) other healthy staple foods. RESULTS: The availability of healthy food items was low, particularly in single-aisle and small stores, and there was significant cross-site variability in the availability of healthy snacks (P < 0.0001) and other healthy staple foods (P < 0.0001). No cross-site differences existed for fruits/vegetables or healthy beverages/low-fat dairy availability. Healthy food availability scores increased significantly with store size for nearly all food/beverage categories (P < 0.01). CONCLUSIONS: Overall, healthy food availability in these venues was limited. Region-specific factors may be important to consider in understanding factors influencing healthy food availability in small urban markets. Data suggest that efforts to promote healthy diets in low-income communities may be compromised by a lack of available healthy foods. Interventions targeting small stores need to be developed and tailored for use in urban areas across the USA.

The effects of a commercially available weight loss program among obese patients with type 2 diabetes: a randomized study.

The purpose of this study was to assess the effects of a commercially available weight loss program on weight and glycemic control among obese patients with type 2 diabetes. Participants included 69 patients (49 females, 20 males) with type 2 diabetes who had a mean +/- SD age of 52.2 +/- 9.5 years, a body mass index of 39.0 +/- 6.2 kg/m(2), and hemoglobin A1c (HbA1c) of 7.5 +/- 1.6%. Over half (52.2%) of the participants were African American. Participants were randomly assigned to: 1) a portion-controlled diet (NutriSystem D) (PCD) or 2) a diabetes support and education (DSE) program. After the initial 3 months, the PCD group continued on the PCD for the remaining 3 months, and the DSE group crossed over to PCD for the remaining 3 months. The primary comparison for this study was at 3 months. At 3 months, the PCD group lost significantly more weight (7.1 +/- 4%) than the DSE group (0.4 +/- 2.3%) (P < 0.0001). From 3 to 6 months the change in weight for both groups was statistically significant. After 3 months, the PCD group had greater reductions in HbA1c than the DSE group (-0.88 +/- 1.1 vs 0.03 +/- 1.09; P < 0.001). From 3 to 6 months the PCD group had no further change in HbA1c, while the DSE group showed a significant reduction. These data suggest that obese patients with type 2 diabetes will experience significant improvements in weight, glycemic control, and cardiovascular disease risk factors after the use of a commercially available weight management program.

Snacking in children: the role of urban corner stores.

OBJECTIVE: Childhood obesity is higher among ethnic minorities. One reason may be the limited access to affordable, healthy options. The disparate prevalence of urban corner stores in low-income and high-minority communities has been well documented. There are no data, however, on what children purchase in these environments before and after school. The purpose of this study was to document the nature of children's purchases in corner stores proximal to their schools. METHODS: This was an observational study from January to June 2008. Participants were children in grades 4 through 6 from 10 urban K-8 schools with >or=50% of students eligible for free or reduced-price meals. A total of 833 intercept surveys of children's purchases were conducted outside 24 corner stores before and after school. The main outcomes were type and energy content of items purchased. RESULTS: The most frequently purchased items were energy-dense, low-nutritive foods and beverages, such as chips, candy, and sugar-sweetened beverages. Students spent $1.07 +/- 0.93 on 2.1 +/- 1.3 items (1.6 +/- 1.1 food items and 0.5 +/- 0.6 beverage items) per purchase. The total number of calories purchased per trip was 1497.7 +/- 1219.3 kJ (356.6 +/- 290.3 kcal). More calories came from foods than from beverages. CONCLUSIONS: Purchases made in corner stores contribute significantly to energy intake among urban school children. Obesity prevention efforts, as well as broader efforts to enhance dietary quality among children in urban settings, should include corner store environments proximal to schools.

A randomized study on the effect of weight loss on obstructive sleep apnea among obese patients with type 2 diabetes: the Sleep AHEAD study.

BACKGROUND: The belief that weight loss improves obstructive sleep apnea (OSA) has limited empirical support. The purpose of this 4-center study was to assess the effects of weight loss on OSA over a 1-year period. METHODS: The study included 264 participants with type 2 diabetes and a mean (SD) age of 61.2 (6.5) years, weight of 102.4 (18.3) kg, body mass index (BMI) (calculated as weight in kilograms divided by height in meters squared) of 36.7 (5.7), and an apnea-hypopnea index (AHI) of 23.2 (16.5) events per hour. The participants were randomly assigned to either a behavioral weight loss program developed specifically for obese patients with type 2 diabetes (intensive lifestyle intervention [ILI]) or 3 group sessions related to effective diabetes management (diabetes support and education [DSE]). RESULTS: The ILI participants lost more weight at 1 year than did DSE participants (10.8 kg vs 0.6 kg; P < .001). Relative to the DSE group, the ILI intervention was associated with an adjusted (SE) decrease in AHI of 9.7 (2.0) events per hour (P < .001). At 1 year, more than 3 times as many participants in the ILI group than in the DSE group had total remission of their OSA, and the prevalence of severe OSA among ILI participants was half that of the DSE group. Initial AHI and weight loss were the strongest predictors of changes in AHI at 1 year (P < .01). Participants with a weight loss of 10 kg or more had the greatest reductions in AHI. CONCLUSIONS: Physicians and their patients can expect that weight loss will result in significant and clinically relevant improvements in OSA among obese patients with type 2 diabetes. Trial Registration clinicaltrials.gov Identifier: NCT00194259.

Obstructive sleep apnea among obese patients with type 2 diabetes.

OBJECTIVE: To assess the risk factors for the presence and severity of obstructive sleep apnea (OSA) among obese patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: Unattended polysomnography was performed in 306 participants. RESULTS: Over 86% of participants had OSA with an apnea-hypopnea index (AHI) >or=5 events/h. The mean AHI was 20.5 +/- 16.8 events/h. A total of 30.5% of the participants had moderate OSA (15 or=30). Waist circumference (odds ratio 1.1; 95% CI 1.0-1.1; P = 0.03) was significantly related to the presence of OSA. Severe OSA was most likely in individuals with a higher BMI (odds ratio 1.1; 95% CI 1.0-1.2; P = 0.03). CONCLUSIONS: Physicians should be particularly cognizant of the likelihood of OSA in obese patients with type 2 diabetes, especially among individuals with higher waist circumference and BMI.

Associations between the Youth/Adolescent Questionnaire, the Youth/Adolescent Activity Questionnaire, and body mass index z score in low-income inner-city fourth through sixth grade children.

BACKGROUND: Diet and physical activity are important factors in the etiology, prevention, and treatment of chronic diseases such as obesity and its associated comorbidities. Accurate measures of diet and activity are critical in understanding how these lifestyle and behavioral factors covary to affect health status. OBJECTIVE: The purpose of this study was to investigate the relation between body mass index (BMI) z score and self-report measures of diet and activity, the Youth/Adolescent Questionnaire (YAQ) and the Youth/Adolescent Activity Questionnaire (YAAQ), respectively. DESIGN: Participants were 1092 students in grades 4 through 6 from 10 schools in a US city in the middle Atlantic region with >or=50% of students eligible for free or reduced-price meals. Students were assessed at baseline and again after 2 y. The relation between self-reported energy intake (YAQ) and activity (physical and sedentary) (YAAQ) and BMI z score was explored from both a cross-sectional and longitudinal perspective. RESULTS: The YAQ (energy intake) and YAAQ (physical and sedentary activity) did not relate to BMI z score in the expected directions from either a cross-sectional or longitudinal perspective. CONCLUSION: In this large, racially diverse sample, the YAQ and the YAAQ were not significantly associated with BMI z score or changes in BMI z score.

A policy-based school intervention to prevent overweight and obesity.

BACKGROUND: The prevalence and seriousness of childhood obesity has prompted calls for broad public health solutions that reach beyond clinic settings. Schools are ideal settings for population-based interventions to address obesity. OBJECTIVE: The purpose of this work was to examine the effects of a multicomponent, School Nutrition Policy Initiative on the prevention of overweight (85.0th to 94.9th percentile) and obesity (> 95.0th percentile) among children in grades 4 through 6 over a 2-year period. METHODS: Participants were 1349 students in grades 4 through 6 from 10 schools in a US city in the Mid-Atlantic region with > or = 50% of students eligible for free or reduced-price meals. Schools were matched on school size and type of food service and randomly assigned to intervention or control. Students were assessed at baseline and again after 2 years. The School Nutrition Policy Initiative included the following components: school self-assessment, nutrition education, nutrition policy, social marketing, and parent outreach. RESULTS: The incidences of overweight and obesity after 2 years were primary outcomes. The prevalence and remission of overweight and obesity, BMI z score, total energy and fat intake, fruit and vegetable consumption, body dissatisfaction, and hours of activity and inactivity were secondary outcomes. The intervention resulted in a 50% reduction in the incidence of overweight. Significantly fewer children in the intervention schools (7.5%) than in the control schools (14.9%) became overweight after 2 years. The prevalence of overweight was lower in the intervention schools. No differences were observed in the incidence or prevalence of obesity or in the remission of overweight or obesity at 2 years. CONCLUSION: A multicomponent school-based intervention can be effective in preventing the development of overweight among children in grades 4 through 6 in urban public schools with a high proportion of children eligible for free and reduced-priced school meals.

The relationship between relative weight and school attendance among elementary schoolchildren.

OBJECTIVE: To determine the relationship between relative weight and school attendance among elementary schoolchildren. RESEARCH METHODS AND PROCEDURES: A total of 1069 fourth to sixth graders from nine elementary schools in the inner city of Philadelphia, PA, were part of an ongoing randomized control trial to assess prevention strategies for obesity. The mean rate of students eligible for free/reduced meals was 82.9 +/- 11.5%. Weight was measured in the second semester of the academic year. Absentee data for the entire academic year were recorded by homeroom teachers. Participants were classified into relative weight categories described by the Institute of Medicine: underweight, normal-weight, overweight, and obese. RESULTS: ANOVA showed that overweight children were absent significantly more than normal-weight children (12.2 +/- 11.7 days vs.10.1 +/- 10.5 days) (p < 0.05). Linear regression showed that the obese category remained a significant contributor to the number of days absent even after adjusting for age, race/ethnicity, and gender. DISCUSSION: These data suggest that in addition to the medical and psychosocial consequences of being overweight, heavier children have greater risk for school absenteeism than their normal-weight peers. As the rate of childhood obesity increases, parallel increases in school absenteeism should be expected.