• Diabetes Mellitus
• Prevention & Screening
• Obesity
• Pediatric Nutrition

The HEALTHY study, a name that was selected by the targeted middle school student population, was initiated after a pilot investigation in 2003 documented a high prevalence of risk factors for diabetes in 8th grade students in the United States [Diabetes Care 2006]. Indeed, of the 1740 subjects who were observed, 49% had a body mass index (BMI) ≥ the 85^th percentile (the cutoff for overweightness and obesity); 40.5% had fasting blood glucose (FPG) ≥100 mg/dl; and 36.2% had fasting insulin ≥30 μU/ml, suggesting that middle schools could be logical venues for population-based efforts to prevent or delay the onset of type 2 diabetes mellitus (T2DM).

As described by Kathryn Hirst, PhD, George Washington University Biostatistics Center, Rockville, MD, the HEALTHY study enrolled 6^th grade students from 42 middle schools and followed them through 8^th grade (n=4603). School eligibility required a ≥50% minority student body and/or ≥50% of students who were eligible for free/reduced rate lunch. Schools were randomized 1:1 to either control (observation only) or a comprehensive intervention program that was conducted by teachers and school officials that targeted nutrition, physical activity, and personal behavior [The HEALTHY Study Group. Internatl J Obesity 2009].

At baseline, subjects were assessed for physical measurements and fasting blood was drawn to determine FBG, insulin, HbA1C, and lipids; self-reports of diet, exercise, and quality of life were also collected. The same data were collected at the end of study following two and a half years of HEALTHY intervention delivery. Primary endpoints for the study included measures of adiposity, glucose, and insulin.

Gary D. Foster, PhD, Temple University, Philadelphia, PA, reported the primary results of the study [The HEALTHY Study Group. N Engl J Med 2010]. For BMI ≥85^th percentile (defined as overweight and obese categories), the changes that were observed for the intervention versus control group were not statistically significant, though significance was seen for BMI z-scores (p=0.04; Table 1). Average waist circumference and FBG were not significantly different; however, significant differences were observed for fasting insulin levels (p=0.04) as well as for reductions in measures for the most at-risk individuals: BMI ≥95^th percentile (− 5.5% vs −3.8%; p=0.05) and waist circumference > 90^th percentile (−8.1% vs −5.9%; p=0.04) for intervention versus control, respectively.

In reporting the HEALTHY secondary endpoints for cardiovascular disease risk factors and fitness, Marsha D. Marcus, PhD, University of Pittsburgh, Pittsburgh, PA, referenced data from 2003, which determined that roughly 4% of all adolescents and nearly 30% of overweight adolescents in the United States meet the criteria for metabolic syndrome – the constellation of metabolic dysfunctions that are associated with obesity [Cook et al. Arch Pediatr Adolesc Med 2003].

There were no significant differences in abnormal lipids in intervention versus control. Overall, there was no difference in level of hypertension; however, the intervention showed significant improvements in measures of hypertension for male African-American (p=0.002) and male Caucasian students (p=0.045) but not for male Hispanics.

Levels of physical activity were low at baseline and remained so at the end of the study, suggesting that the HEALTHY intervention had a negligible effect in this population.

HEALTHY investigators commented that while the intervention did not meet its primary endpoint of altering the combined prevalence of being overweight or obese, it did have moderate effects on obesity and other important risk factors for T2DM.

For further details and access to the intervention program materials that were used in the HEALTHY study, go to http://www.healthystudy.org.

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The editors would like to thank the many members of the American Diabetes Association presenting faculty who generously gave their time to ensure the accuracy and quality of the articles in this publication.

• © 2010 MD Conference Express