Obesity, Elevated Blood Pressure and Insulin Resistance among American Indian School-Children: Identifying Family- and Environment-level Determinants

Melissa Nelson, Ph.D.
Division of Epidemiology & Community Health, University of Minnesota

American Indian children and adolescents are at particularly high risk for developing obesity and related sequelae. Little research to date has sought to examine the impact of genetic predisposition in this population alongside the important influence of the poor conditions of the reservation environment. In this proposed research we have the exciting opportunity to examine the determinants of weight status, blood pressure (BP) and insulin resistance risk in a cohort of 5500 school children, from Head Start to grade 12, living on the Pine Ridge Reservation in South Dakota. These data were collected by the Indian Health Service (IHS) from 1998-2002 and include approximately 85% of the schoolchildren attending 13 schools within the reservation.

In addition, detailed familial data (percent Indian heritage) has been collected from extensive tribal records. Using addresses of the schools, we will also be able to integrate these data with US Census-level data characterizing sociodemographic attributes of the environment, and examine the relative familial versus environmental contributions to weight-related health outcomes.

Our specific aims are to:

  1. estimate the prevalence of overweight, elevated BP and acanthosis nigricans (a skin disorder used in type 2 diabetes screening and as an indicator of insulin resistance) in American Indian children,
  2. and explore the etiological roots of these risk factors by comparing the relative contribution of genetic/familial versus contextual characteristics.

By examining the association of these health indicators with percent Indian heritage and environmental sociodemographic composition, this will be the first research to our knowledge that assesses the relative contribution of each of these factors in this high-risk population. In addition to filling important gaps in the scientific literature, this research will also directly service the American Indian community, providing important feedback to IHS to be used in public health programming.

In addition, we will be laying the groundwork for a future large-scale follow-up study, following these children into the critical transition through adolescence and young adulthood. Such an unprecedented longitudinal cohort will allow us to better understand the specific familial, cultural and environmental factors underlying the development and persistence of weight-related health issues among these high risk youth, and would inform effective intervention strategies promoting healthy lifestyles on the reservation and beyond.