February 2008: Metabolic Syndrome and Its Association with Diet and Physical Activity in US Adolescents

Article Summary

Metabolic syndrome has been associated as a co-morbid condition in relation to specifically cardiovascular disease and type 2 diabetes. While there is a plethora of information pertaining to adults; there is recent interest in learning more about the prevalence of metabolic syndrome in adolescents. Particularly research related to physical activity and diet quality given the little research yet conducted with this age group.

The purpose of this study was to examine the relationship between physical activity, diet quality and prevalence of metabolic syndrome in US adolescents. For the purposes of this study, metabolic syndrome was defined as presence of at least three of the following five conditions: waist circumference greater than or equal to 90^th percentile for age/sex, fasting blood glucose greater than or equal to 100mg/dL, triglycerides greater than or equal to 110mg/dL, HDL cholesterol less than or equal to 35mg/dL, and systolic or diastolic blood pressure greater than 90^th percentile for age/sex or the presence of taking anti-hypertensive medications.

The present study examined a sample of 4,450 12-19 year olds from information obtained by NHANES 1999-2000. Diet quality was assessed using a 24 hour recall measured by the Healthy Eating Index. Physical activity was measured by using an average of the past 30 days of weighted minutes spent doing moderate to physical activity. The weighted minutes were categorized into three levels: low(<30%),>30% and <60%),>60^th percentile). The incidence of metabolic syndrome was then evaluated according to those three categories.

Overall there was a 3.5% incidence of metabolic syndrome in the sample 12-19 yr olds. The prevalence was significantly higher for males versus females. It was also significantly more prevalent in White males versus Black males and Mexican American males. When broken down into age brackets the incidence was greater in adolescents age 15-19 compared with those aged 12-14yrs. Of the five categories chosen to determine metabolic syndrome, high triglyceride levels and elevated blood pressure were the most common and low HDL cholesterol levels was the least common factor. However, the prevalence of the factors varied based on gender and race with no major commonality. Adolescents who were overweight (BMI for age/sex greater than 95%) were much more likely to also be present with metabolic syndrome compared to adolescents of normal BMI.

From the information obtained by the Healthy Eating Index, diet patterns varied among the various groups yet low fruit intake and high cholesterol intake was observed as a trend overall. No apparent association was found between metabolic syndrome and specific nutrient intake, still there was a decrease in presence of the syndrome when diet improved overall and physical activity was increased.

The findings of this study indicate a first insight into metabolic syndrome and adolescents in regard to diet and physical activity particularly as intervention means. It emphasizes the importance of weight management and strengthens the relationship between obesity and metabolic syndrome. This also demonstrates the important role of dietitians in means to promote prevention of chronic diseases like obesity and metabolic syndrome. Prevention of these disorders may also contribute to a lower incidence of cardiovascular disease and type two diabetes for which they are commonly associated.

Additional article references the increased incidence of metabolic syndrome diagnoses in the pediatric population and attributes diet and physical activity as fundamental to prevention efforts.

JADA Continuing Education Article

Pan, Y, Pratt, CA. Metabolic Syndrome and Its Association with Diet and Physical Activity in US Adolescents.
J Am Diet Assoc. 2008;108:276-286.

Additional Reference Article

Lottenberg, SA, Glezer, A, Turatti, LA. Metabolic Syndrome: Identifying the Risk Factors. Jornal de Pediatria.
2007 Nov; 83(5):S204-8.