Delia Smith West

Cardiovascular effects of intensive lifestyle intervention in type 2 diabetes

BACKGROUND Weight loss is recommended for overweight or obese patients with type 2 diabetes on the basis of short-term studies, but long-term effects on cardiovascular disease remain unknown. We examined whether an intensive lifestyle intervention for weight loss would decrease cardiovascular morbidity and mortality among such patients. METHODS In 16 study centers in the United States, we randomly assigned 5145 overweight or obese patients with type 2 diabetes to participate in an intensive lifestyle intervention that promoted weight loss through decreased caloric intake and increased physical activity (intervention group) or to receive diabetes support and education (control group). The primary outcome was a composite of death from cardiovascular causes, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for angina during a maximum follow-up of 13.5 years. RESULTS The trial was stopped early on the basis of a futility analysis when the median follow-up was 9.6 years. Weight loss was greater in the intervention group than in the control group throughout the study (8.6% vs. 0.7% at 1 year; 6.0% vs. 3.5% at study end). The intensive lifestyle intervention also produced greater reductions in glycated hemoglobin and greater initial improvements in fitness and all cardiovascular risk factors, except for low-density-lipoprotein cholesterol levels. The primary outcome occurred in 403 patients in the intervention group and in 418 in the control group (1.83 and 1.92 events per 100 person-years, respectively; hazard ratio in the intervention group, 0.95; 95% confidence interval, 0.83 to 1.09; P=0.51). CONCLUSIONS An intensive lifestyle intervention focusing on weight loss did not reduce the rate of cardiovascular events in overweight or obese adults with type 2 diabetes. (Funded by the National Institutes of Health and others; Look AHEAD ClinicalTrials.gov number, NCT00017953.).

Long-Term Weight Loss and Changes in Blood Pressure: Results of the Trials of Hypertension Prevention, Phase II

Approximately one fourth of the U.S. adult populationnearly 50 million peoplehas hypertension (1, 2). Taking a broader perspective, more than half of the adult population has higher than optimal blood pressure (1), defined as systolic blood pressure greater than 120 mm Hg and diastolic blood pressure greater than 80 mm Hg (2). These persons are at significantly increased risk for cardiovascular disease and stroke (3). Although pharmacologic treatment for hypertension significantly reduces morbidity and mortality from cardiovascular diseases (4, 5), long-term pharmacologic therapy can have undesirable side effects and requires the expense of continuing medical supervision. Furthermore, pharmacologic therapy is not usually initiated when blood pressure is higher than optimal yet below diagnostic thresholds for hypertension. Thus, lifestyle interventions for primary prevention and initial treatment of high blood pressure remain a vital strategy for controlling this highly prevalent condition (2). Weight loss has been shown to reduce blood pressure in overweight hypertensive patients (6-9) and in overweight persons with high-normal blood pressure (10-12). Two reviews of randomized trials of weight reduction to reduce blood pressure examined the results of nine studies (13, 14). Most of these trials were small, only one had more than 500 participants (11), and most had short-term follow-up (1 year or less). Only three studies had follow-up of 3 to 5 years (8, 10, 11). Compared with controls, weight loss averaged nearly 7 kg in the short-term trials and approximately 3 kg in the three longer-term trials. In almost all trials, systolic blood pressure and diastolic blood pressure were reduced in the intervention groups. Since these reviews were published, the Trials of Hypertension Prevention (TOHP) Phase I reported mean weight reduction of 3.9 kg at 18 months in 564 overweight participants with high-normal blood pressure, resulting in significant decreases in systolic blood pressure and diastolic blood pressure compared with a usual care control group (12, 15). To investigate whether nonpharmacologic interventions can prevent hypertension over the long term, TOHP II was initiated. This was a randomized, controlled trial examining the effects of weight loss and dietary sodium reduction, alone and in combination, in reducing blood pressure in overweight adults with high-normal diastolic blood pressure (16). This target population is at high risk for hypertension as they age. The primary outcome paper from this trial (17) provided only a brief overview of the effects of weight loss on blood pressure. Here, we provide more detailed analysis of weight loss and blood pressure in TOHP II. Of special interest are the long-term effects of weight loss on blood pressure, the magnitude of the doseresponse relationship at 36 months, the effect of patterns of weight loss on blood pressure, and the predictors of weight loss and blood pressure response. Methods Participants Participants in TOHP II were overweight adults with nonmedicated diastolic blood pressure of 83 to 89 mm Hg and systolic blood pressure less than 140 mm Hg. Other eligibility criteria included age 30 to 54 years and a body mass index of 26.1 to 37.4 kg/m2 for men and 24.4 to 37.4 kg/m2 for women, approximately 110% to 165% of ideal weight (18). Principal exclusion criteria were current treatment with medications that might affect blood pressure, clinical or laboratory evidence of cardiovascular disease, diabetes mellitus, renal insufficiency (serum creatinine concentration 150 mol/L [ 1.7 mg/dL] for men and 132 mol/L [ 1.5 mg/dL] for women), and current or planned pregnancy. Detailed descriptions of recruitment and participant characteristics have been published elsewhere (19, 20). The study was reviewed and approved by the institutional review boards at all nine TOHP centers and the coordinating center, and all participants signed informed consent forms. Design Eligible participants were randomly assigned with equal probability to one of four groups: weight loss only, sodium reduction only, combined weight loss and sodium reduction, or usual care (controls). Measurements Age, sex, ethnicity, and years of education were obtained by questionnaire. Baseline blood pressure measurements were taken at three screening visits, each separated by 7 to 45 days. At each visit, three readings of systolic blood pressure and diastolic blood pressure were obtained and averaged. Certified staff obtained measurements in seated participants by using a Hawksley random-zero sphygmomanometer (21). Body weight was measured to the nearest 0.2 kg (0.5 lb) by using a calibrated balance-beam scale; participants wore indoor clothing (without shoes). Blood pressure and weight were measured every 6 months after randomization to the end of follow-up at 36, 42, or 48 months, depending on randomization date. Clinic staff who were blinded to study group assignment made these assessments. Blood pressure measurements were obtained during a single visit at all follow-up points except for 18 and 36 months, when measurements were taken at a series of three visits approximately 1 week apart. Multiple measurements were taken at 18 and 36 months to provide a more precise assessment of average blood pressures at these primary outcome points. Dietary intake was assessed by 24-hour recall, and physical activity was assessed by questionnaire. Intervention Participants assigned to the weight loss intervention group sought to lose at least 4.5 kg (10 lb) during the first 6 months of the intervention and to maintain their weight loss for the remainder of the trial. A brief description of the intervention methods is presented here; a more detailed description has been published elsewhere (22). The intervention started with an individual counseling session, followed by 14 weekly group meetings led by dietitians or health educators. After this 14-week intensive phase, participants attended six biweekly group meetings and then monthly group meetings. Beginning in the 18th month, participants were offered a variety of options to keep them involved in the intervention, including individual counseling sessions and special group sessions focused on selected weight loss topics. The intervention focused on self-directed behavior change (behavioral self-management), nutrition education, information on physical activity, and social support for making and maintaining behavior changes. Specific behavior change techniques included self-monitoring (food diaries and graphs of minutes of physical activity per day), setting explicit short-term goals and developing specific action plans to achieve those objectives, and developing alternative strategies for situations that trigger problem eating. The dietary intervention focused on reducing caloric intake by decreasing consumption of excess fat, sugar, and alcohol. Keeping daily food diaries was emphasized for monitoring intake and assessing progress. With experience, the participants determined the caloric intake that produced moderate weight loss for them. It was suggested that men not consume less than 1500 kcal/d and women not less than 1200 kcal/d. Weight loss of more than 0.9 kg (2 lb) per week was discouraged. The physical activity goal was to gradually increase activity to 30 to 45 minutes per day, four to five days per week. Exercise intensity was moderate, approximately 40% to 55% of heart rate reserve, and consisted primarily of brisk walking. Statistical Analysis Baseline characteristics of the weight loss and usual care groups were compared overall and by sex by using t-tests for means and chi-square tests for proportions. Although weight and blood pressure data were collected every 6 months, special efforts were made to achieve high follow-up rates at 18 and 36 months; at each of these two time points, nine blood pressure readings were collected over three visits and were averaged. For participants prescribed antihypertensive medication, follow-up blood pressure for all subsequent visits was taken to be the last study blood pressure before therapy was started. Participants receiving medications that affect blood pressure for reasons other than hypertension or who became pregnant were treated as missing at that visit. We used two-sample t-tests to compare changes in weight and blood pressure from baseline in the weight loss intervention and usual care groups overall, by sex, by ethnicity, and by sex and ethnicity. The effects of the intervention in terms of changes in weight and blood pressure were examined overall and in subgroups defined by sex, ethnicity, and sex and ethnicity. Subgroup differences were tested by using terms for the interaction of treatment group with sex and with ethnicity in multiple linear regression models. Regression analyses were also used to analyze the doseresponse relationship between change in weight and change in blood pressure, overall and within sex and ethnicity subgroups. Differences in dose response were tested by using interaction terms in linear regression models. All regressions were adjusted for age and baseline weight. We also adjusted for baseline blood pressure in the blood pressure regression models. Change in blood pressure was also examined in relation to quintile of weight loss. Quintiles were computed by using the distribution of weight change in the weight loss intervention group. Additional multiple regression analyses were performed in which weight loss participants were categorized according to patterns of weight loss at 6 and 36 months. The PROC MIXED function of SAS software (SAS Institute, Inc., Cary, North Carolina) was used to perform repeated-measures analyses that tested differences over time by pattern of weight loss. Cox proportional-hazards models were used for survival analyses, with onset of hypertension as the outcome. Results Baseline Findings The baseline characteristics of participants assigned to th

The Look AHEAD study: a description of the lifestyle intervention and the evidence supporting it.

The Look AHEAD (Action for Health in Diabetes) study is a multicenter, randomized controlled trial designed to determine whether intentional weight loss reduces cardiovascular morbidity and mortality in overweight individuals with type 2 diabetes. The study began in 2001 and is scheduled to conclude in 2012. A total of 5145 participants have been randomly assigned to a lifestyle intervention or to an enhanced usual care condition (i.e., diabetes support and education). This article describes the lifestyle intervention and the empirical evidence to support it. The two principal intervention goals are to induce a mean loss ≥ 7% of initial weight and to increase participants’ moderately intense physical activity to ≥175 min/wk. For the first 6 months, participants attend one individual and three group sessions per month and are encouraged to replace two meals and one snack a day with liquid shakes and meal bars. From months 7 to 12, they attend one individual and two group meetings per month and continue to replace one meal per day (which is recommended for the studys duration). Starting at month 7, more intensive behavioral interventions and weight loss medication are available from a toolbox, designed to help participants with limited weight loss. In Years 2 to 4, treatment is provided mainly on an individual basis and includes at least one on‐site visit per month and a second contact by telephone, mail, or e‐mail. After Year 4, participants are offered monthly individual visits. The intervention is delivered by a multidisciplinary team that includes medical staff who monitor participants at risk of hypoglycemic episodes.

One-year weight losses in the Look AHEAD study: factors associated with success.

This report provides a further analysis of the first year weight losses in the Look AHEAD (Action for Health in Diabetes) study and identifies factors associated with success. Participants were a total of 5,145 men and women with type 2 diabetes who were recruited at 16 sites and randomly assigned to an intensive lifestyle intervention (ILI) or a control condition, Diabetes Support and Education (DSE). During year 1, participants in ILI received comprehensive diet and physical activity counseling in a total of 42 group and individual sessions, compared with three educational sessions for DSE participants. As reported previously, at the end of the year, ILI participants lost 8.6% of initial weight, compared to 0.7% for DSE (P < 0.001). Within the ILI group, all racial/ethnic groups achieved clinically significant weight losses (>5.5%), although there were significant differences among groups. For the year, ILI participants attended an average of 35.4 treatment sessions and reported exercising a mean of 136.6 min/week and consuming a total of 360.9 meal replacement products. Greater self‐reported physical activity was the strongest correlate of weight loss, followed by treatment attendance and consumption of meal replacements. The use of orlistat, during the second half of the year, increased weight loss only marginally in those ILI participants who had lost <5% of initial weight during the first 6 months and chose to take the medication thereafter as a toolbox option. The lifestyle intervention was clinically effective in all subsets of an ethnically and demographically diverse population.

Weight Loss of Black, White, and Hispanic Men and Women in the Diabetes Prevention Program

Objective: To provide the specific weight loss outcomes for African‐American, Hispanic, and white men and women in the lifestyle and metformin treatment arms of the Diabetes Prevention Program (DPP) by race‐gender group to facilitate researchers translating similar interventions to minority populations, as well as provide realistic weight loss expectations for clinicians.

Internet delivered behavioral obesity treatment

OBJECTIVES To evaluate the efficacy of an Internet behavioral weight loss program; and determine if adding periodic in-person sessions to an Internet intervention improves outcomes. METHODS 481 healthy overweight adults (28% minority) were randomized to one of 3 delivery methods of a behavioral weight loss program with weekly meetings: Internet (n=161), InPerson (n=158), or Hybrid (Internet+InPerson, n=162). Outcome variables were weight at baseline and 6 months and percent of subjects achieving a 5 and 7% weight loss. The study took place in two centers in Vermont and Arkansas from 2003 to 2008. RESULTS Conditions differed significantly in mean weight loss [8.0 (6.1) kg vs. 5.5 (5.6) kg vs. 6.0 (5.5) kg], for InPerson, Internet, and Hybrid respectively, p<0.01, n=462). Weight loss for InPerson was significantly greater than the Internet and Hybrid conditions (p<0.05). Although the proportion reaching a 5% weight loss did not differ, the proportion losing 7% did differ significantly (56.3% vs. 37.3% vs. 44.4% for InPerson, Internet, and Hybrid respectively, p<0.01). CONCLUSIONS These results demonstrate that the Internet is a viable alternative to in-person treatment for the delivery and dissemination of a behavioral weight-control intervention. The addition of periodic in-person sessions did not improve outcomes.

Weight loss treatment influences untreated spouses and the home environment: evidence of a ripple effect

Objectives:To examine whether a weight loss program delivered to one spouse has beneficial effects on the untreated spouse and the home environment.Methods:We assessed untreated spouses of participants in three sites of Look AHEAD, a multicenter randomized controlled trial evaluating the impact of intentional weight loss on cardiovascular outcomes in overweight individuals with type 2 diabetes. Participants and spouses (n=357 pairs) were weighed and completed measures of diet and physical activity at 0 and 12 months. Spouses completed household food and exercise environment inventories. We examined differences between spouses of participants assigned to the intensive lifestyle intervention (ILI) or to the enhanced usual care (DSE; diabetes support and education).Results:Spouses of ILI participants lost −2.2±4.5 kg vs −0.2±3.3 kg in spouses of DSE participants (P<0.001). In addition, more ILI spouses lost ⩾5% of their body weight than DSE spouses (26 vs 9%, P<0.001). Spouses of ILI participants also had greater reductions in reported energy intake (P=0.007) and percent of energy from fat (P=0.012) than DSE spouses. Spouse weight loss was associated with participant weight loss (P<0.001) and decreases in high-fat foods in the home (P=0.05).Conclusion:The reach of behavioral weight loss treatment can extend to a spouse, suggesting that social networks can be utilized to promote the spread of weight loss, thus creating a ripple effect.

Neighbourhood characteristics, individual level socioeconomic factors, and depressive symptoms in young adults: the CARDIA study

Study objective: To investigate the relation between neighbourhood socioeconomic and ethnic characteristics with depressive symptoms in a population based sample. Design: Cross sectional data from the CARDIA study, including the Center for Epidemiological Studies depression scale score (CES-D). Neighbourhoods were 1990 US census blocks of 1000 people; six census variables reflecting wealth/income, education, and occupation investigated separately and as a summary score; neighbourhood racial composition (percentage white and black) and individual level income and education were also examined. Setting: Participants recruited in 1985/86 from community lists in Birmingham, AL; Chicago, IL; Minneapolis MN; from a health plan in Oakland, CA. Participants: 3437 adults aged 28–40 years in 1995/96: 24% white men, 27% white women, 20% black men, 29% black women. Main results: For each race-sex group, CES-D was inversely related to neighbourhood score and individual income and education. Associations of neighbourhood score with CES-D became weak and inconsistent after adjusting for individual level factors; personal income remained strongly and inversely associated with CES-D. Age adjusted mean differences (standard errors) in CES-D between the lowest and highest income categories were 3.41 (0.62) for white men, 4.57 (0.64) for white women, 5.80 (0.87) for black men, and 5.74 (0.83) for black women. For both black and white participants, CES-D was associated negatively with percentage of white people and positively with percentage of black people in their census block, before, but not after, adjustment for individual and neighbourhood socioeconomic variables. Conclusions: Neither neighbourhood socioeconomic characteristics nor ethnic density were consistently related to depressive symptoms once individual socioeconomic characteristics were taken into account.

Overweight children, weight-based teasing and academic performance

BACKGROUND School performance of overweight children has been found to be inferior to normal weight children; however, the reason(s) for this link between overweight and academic performance remain unclear. Psychosocial factors, such as weight-based teasing, have been proposed as having a possible mediating role, although they remain largely unexplored. METHODS Random parental telephone survey data (N=1 071) of public school students collected as part of the statewide evaluation of Arkansas Act 1220, a law to reduce childhood obesity, were used. Overweight status (body mass index > 85th percentile for gender and age) and weight-based teasing were examined as predictors of poorer school performance. RESULTS Overweight status was a significant predictor of poorer school performance (OR=1.51; 95% CI=1.01, 2.25), after adjustment for gender, school level, free and reduced lunch participation, and race. However, the addition of weight-based teasing to the model (with weight category and covariates) reduced the weight category parameter estimate by 24%, becoming non-significant (OR=1.40; 95% CI=0.93, 2.10) and indicating a possible mediating effect of weight-based teasing on the relationship between weight category and school performance. Weight-based teasing was significantly associated with school performance, with lower odds of strong school performance among weight-based teased children (OR=0.44; 95% CI=0.27, 0.74). CONCLUSION Psychosocial variables, such as weight-based teasing, should be considered in future research examining the impact of childhood obesity on school performance and in future intervention studies.

Binge Eating Disorder and Night Eating Syndrome in Adults with Type 2 Diabetes

Objective: To determine the prevalence of binge eating disorder (BED) and night eating syndrome (NES) among applicants to the Look AHEAD (Action for Health in Diabetes) study.