Lifestyle Intervention for Type 2 Diabetes Risk Reduction: Using the Diabetes Prevention Program to Inform New Directions in Pediatric Research

Theoretical Mediators of Diabetes Risk and Quality of Life Following a Diabetes Prevention Program for Latino Youth With Obesity

PURPOSE

This study tested self-efficacy and social support for activity and dietary changes as mediators of changes in type 2 diabetes related outcomes following a lifestyle intervention among Latino youth.

SETTING AND INTERVENTION

Latino adolescents (14-16 years) with obesity (BMI% = 98.1 ± 1.4) were randomized to a 3-month intervention (n = 67) that fostered self-efficacy and social support through weekly, family-centered sessions or a comparison condition (n = 69).

MEASURES

Primary outcomes included insulin sensitivity and weight specific quality of life. Mediators included self-efficacy, friend, and family social support for health behaviors. Data was collected at baseline, 3-months, 6-months, and 12-months.

ANALYSIS

Sequential path analysis was used to examine mediators as mechanisms by which the intervention influenced primary outcomes.

RESULTS

The intervention had a direct effect on family (β = 0.33, P < .01) and friend social support (β = 0.22, P < .001) immediately following the intervention (3-months). Increased family social support mediated the intervention's effect on self-efficacy at 6-months (β = 0.09, P < .01). However, social support and self-efficacy did not mediate long-term changes in primary outcomes (P > .05) at 12-months.

CONCLUSIONS

Family social support may improve self-efficacy for health behaviors in high-risk Latino youth, highlighting the important role of family diabetes prevention. Fostering family social support is a critical intervention target and more research is needed to understand family-level factors that have the potential to lead to long-term metabolic and psychosocial outcome in vulnerable youth.

Effects of a Community-Based Diabetes Prevention Program for Latino Youth with Obesity: A Randomized Controlled Trial

OBJECTIVE

This study examined the short- and long-term effects of a community-based lifestyle intervention among Latino youth with obesity.

METHODS

Latino adolescents (14-16 years old) were randomized to a 3-month lifestyle intervention (n = 67) or comparison control (n = 69) and followed for 12 months. The intervention included weekly nutrition and health classes delivered to groups of families and exercise sessions (3 days/week) delivered to groups of adolescents. Comparison youth received laboratory results and general health information. Primary outcomes included insulin sensitivity and weight-specific quality of life (QoL) with secondary outcomes of BMI percentile (BMI%), waist circumference, and percent body fat.

RESULTS

At 3 months, youth in the intervention group exhibited significant increases in insulin sensitivity (P < 0.05) and weight-specific QoL (P < 0.001), as well as reductions in BMI%, waist circumference, and percent body fat compared with controls. Increases in weight-specific QoL and reductions in BMI% and percent body fat remained significant at 12 months (P < 0.001), while changes in insulin sensitivity did not. In a subsample of youth with prediabetes at baseline, insulin sensitivity (P = 0.01), weight-specific QoL (P < 0.001), and BMI% (P < 0.001) significantly improved at 3 months.

CONCLUSIONS

Lifestyle intervention can improve cardiometabolic and psychosocial health in a vulnerable population of Latino adolescents at high risk for developing type 2 diabetes.

Development, implementation, and effects of community-based diabetes prevention program for obese latino youth

OBJECTIVE

Obesity and type 2 diabetes have emerged as critical health issues among Latino youth. Although both conditions manifest early in life, very few diabetes prevention programs have been developed to specifically meet the needs of this population. The authors describe the development, implementation, and metabolic impact of a culturally informed, community-based diabetes prevention program for obese Latino youth.

METHODS

A lifestyle education program was developed to address the health needs of Latino youth served by a community-based medical clinic. The program consisted of group education sessions delivered to children and their families to address nutrition, physical activity, family roles and responsibilities, and self-esteem. The metabolic impact of the program was evaluated by assessing body mass index (BMI), high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, total cholesterol, triglycerides, glucose, and insulin.

RESULTS

On entry, the prevalence of risk factors among the 102 youth (mean BMI, 30.4 ± 4.9 kg/m(2)) was substantial (68.6% with low HDL cholesterol, 32.1% with elevated triglycerides, 9.4% with impaired fasting glucose, 39.4% with elevated total cholesterol, 43.0% with elevated LDL cholesterol, and 60.6% with hyperinsulinemia). The 50 youth who returned after the program for follow-up measurements exhibited significant health improvements, including a 3.8% reduction in BMI; 5.4% and 8.6% decreases in total and LDL cholesterol, respectively; a 9.3% increase in HDL cholesterol; and a 24.0% decrease in fasting insulin (all P values < .05).

CONCLUSIONS

These promising findings suggest that a community-based diabetes prevention program for obese Latino youth is a feasible strategy for improving health in this high-risk population. Further studies are warranted to examine whether similar programs can be implemented in diverse communities and settings.

Effects of a culturally grounded community-based diabetes prevention program for obese Latino adolescents

PURPOSE

The purpose of this study was to test the feasibility and preliminary effects of a culturally grounded, community-based diabetes prevention program among obese Latino adolescents.

METHODS

Fifteen obese Latino adolescents (body mass index [BMI] percentile = 96.3 ± 1.1, age = 15.0 ± 0.9 years) completed a 12-week intervention that included weekly lifestyle education classes delivered by bilingual/bicultural promotoras and three, 60-minute physical activity sessions per week. Participants were assessed for anthropometrics (height, weight, BMI, and waist circumference), cardiorespiratory fitness, physical activity/inactivity, nutrition behaviors, and insulin sensitivity and glucose tolerance by a 2-hour oral glucose tolerance test.

RESULTS

The intervention resulted in significant decreases in BMI z score, BMI percentile, and waist circumference; increases in cardiorespiratory fitness; and decreases in physical inactivity and dietary fat consumption. In addition to these changes, the intervention led to significant improvements in insulin sensitivity and reductions in 2-hour glucose levels.

CONCLUSIONS

These results support the feasibility and efficacy of a community-based diabetes prevention program for high-risk Latino youth. Translational approaches that are both culturally grounded and biologically meaningful represent a novel and innovative strategy for closing the obesity-related health disparities gap.

A 3-year randomized trial of lifestyle intervention for cardiovascular risk reduction in the primary care setting: the Swedish Björknäs study

BACKGROUND

Successfully transferring the findings of expensive and tightly controlled programmes of intensive lifestyle modification to the primary care setting is necessary if such knowledge is to be of clinical utility. The objective of this study was to test whether intensive lifestyle modification, shown previously in tightly-controlled clinical trials to be efficacious for diabetes risk-reduction among high-risk individuals, can reduce cardiovascular risk factor levels in the primary care setting.

METHODOLOGY / PRINCIPAL FINDINGS

The Swedish Björknäs study was a randomized controlled trial conducted from 2003 to 2006 with follow-up on cardiovascular risk factors at 3, 12, 24 and 36 months. A total of 151 middle-aged men and women at moderate- to high-risk of cardiovascular disease from northern Sweden were randomly assigned to either an intensive lifestyle intervention (n = 75) or control (n = 76) group. The intervention was based broadly on the protocol of the Diabetes Prevention Program. The three-month intervention period was administered in the primary care setting and consisted of supervised exercise sessions and diet counselling, followed by regular group meetings during three years. The control group was given general advice about diet and exercise and received standard clinical care. Outcomes were changes in anthropometrics, aerobic fitness, self-reported physical activity, blood pressure, and metabolic traits. At 36 months post-randomisation, intensive lifestyle modification reduced waist circumference (-2.2 cm: p = 0.001), waist-hip ratio (-0.02: p<0.0001), systolic blood pressure (-4.9 mmHg: p = 0.036), and diastolic blood pressure (-1.6 mmHg: p = 0.005), and improved aerobic fitness (5%; p = 0.038). Changes in lipid or glucose values did not differ statistically between groups. At 36 months, self-reported time spent exercising and total physical activity had increased more in the intervention group than in the control group (p<0.001).

CONCLUSION / SIGNIFICANCE

A program of intensive lifestyle modification undertaken in the primary health care setting can favourably influence cardiovascular risk-factor profiles in high-risk individuals.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00486941.