CHIC II was funded through 1998 when the students were in 8th through 11th
grades. Continuation funding was awarded to follow Cohort 3 students until high
school graduation. In addition, a younger cohort of elementary students and
an older cohort of high school students will be followed in order to examine
the development of CVD and Type 2 diabetes.
of the Cardiovascular Health in Children and Youth Study
(CHIC III) is investigating the childhood development of several risk factors for cardiovascular disease (CVD) and the aggregation of those risk factors over time. One recognized aggregation, or cluster, of risk factors is commonly linked to
Type 2 diabetes and CVD in adults. This aggregation is called the insulin resistance syndrome and consists of related metabolic abnormalities including dyslipidemia (high triglyceride and low high density lipoprotein cholesterol [HDL-C]), hypertension, hyperinsulinemia, and glucose intolerance. Obesity is thought by some to also be a part of the syndrome. At this time, little is known about the prevalence or development of the insulin resistance syndrome during childhood and adolescence. In addition, no studies have examined insulin resistance in youth with regard to eating habits, physical activity and maturational level, all of which can affect various risk factors, particularly those in the insulin resistance syndrome.
Using an accelerated, longitudinal
(cohort-sequential) design, CHIC II subjects
and additional adolescent and preadolescent children are being followed through
all stages of puberty. CVD risk factors as well as aggregation of specific factors into the insulin resistance syndrome are being studied. The contribution of obesity, heredity and environmental factors (broadly defined), as well as a newer risk factor (lipid particle subclass profiles), are also being examined to determine their effects on the emergence, aggregation and developmental course of risk factors for CVD.
Youth in three cohorts, aged 8 - 18, are being evaluated annually for risk factors of CVD for 4 years or until they graduate from high school. We are measuring blood pressure; body mass index; skinfolds; waist and other circumferences; insulin, glucose, and lipids via venipuncture; CV fitness; eating habits; physical activity; and smoking to examine the emergence, aggregation and development of risk factors across all stages of puberty. We are also storing all blood for possible future genetic studies as well as gathering data from parents on the family history of CVD and their personal health habits. This is a cost effective way to obtain these data, as we will be able to capitalize on the data already collected for CHIC II subjects. Major analysis will include general linear models and latent class models.
The ultimate goal of the project is to evaluate the importance of appropriate physical education and health classes in reducing the incidence of heart disease risk factors.