Community Intervention to Improve CVD Risk Factor Control in Young American Indians (CIRCLE)


University of Oklahoma (OU)


Begins enrollment in 2 months


Cholesterol, Elevated
Diabetes Mellitus


Other: Guided management
Other: Self management

Study type


Funder types




Details and patient eligibility


American Indians are more likely to die from heart disease compared to other people in the United States. High levels of fat (lipids) and sugar (glucose) in the blood are related to heart disease. Young American Indians who are 15 to 39 years old have high lipid and glucose levels. This has led to heart disease later in life. This means they are likely to benefit from a program to lower these levels. In this project, researchers will work with American Indians in rural southwestern Oklahoma. The researchers will start by asking American Indians how they would like to design a program for younger members of their community. After getting permission, the researchers will take a small amount of blood from young community members. The researchers will measure lipid and glucose levels and ask those with high levels to be in the study. Then the researchers will do several measurements. These will include blood pressure, height, weight, diet, physical activity, tobacco and alcohol use, access to health care, and social support. The researchers will compare these measurements to similar measurements taken from young American Indians 20 years ago, collected through the Strong Heart Study, which is the longest running study measuring heart disease in American Indians. Next, the researchers want to know if the program they developed with the American Indian communities will work. To do this, they will put people in one of two groups. They will decide which group each person will be in using a process that is like flipping a coin (heads for one group, tails for the other group). One group will receive educational booklets about how to avoid getting heart disease. The other group will receive help from a community health worker. The community health worker will help participants to get to the doctor for treatment. They will also help participants change their diet and exercise routines and provide education about heart disease risk factors. After 9 and 18 months, the researchers will repeat the measurements to see if one of the groups has lower lipid or glucose levels. This program will support the National Heart, Lung, and Blood Institute's mission to "reduce human disease" by lowering lipid and glucose levels, which are related to getting heart disease. This will be done by using the community health worker model to help people go to the doctor and improve their lifestyle related to diet and exercise. The researchers will also be able to advance heart health in American Indians in rural Oklahoma by lowering factors related to heart disease.

Full description

The incidence of cardiovascular disease (CVD) in American Indians is more than two-fold higher than the age-matched United States (US) population. Through systematic surveillance conducted by the Strong Heart Study (SHS), the largest and longest running study of CVD in American Indians, the investigators report elevated serum lipids/lipoproteins and plasma glucose levels in young American Indians that are significantly predictive of developing CVD 20 years later. For participants 15-19, 20-29, and 30-39 years old, dyslipidemia prevalence is 55.2%, 73.6%, and 78.0%, respectively. Although statin therapy is effective for dyslipidemia, the rates of use are low among American Indians, with less than 50% of young SHS participants with primary hypercholesterolemia receiving treatment. In addition, the high diabetes prevalence (8%) contributes to high rates of CVD in young American Indians living in Oklahoma. These elevated lipid/lipoprotein and glucose levels may be due to limited health care access and lifestyle factors such as nutrition, physical activity, sleep hygiene, and social determinants of health (SDOH), including social support. Although the SHS measured these lifestyle factors 20 years ago, it is unclear how they may be changing in young American Indians, and therefore affecting lipid/lipoprotein and glucose control. As a result, there is a critical need to measure these factors and include them in a culturally appropriate intervention to control lipid/lipoprotein and glucose levels and thereby reduce CVD. The long-term goal of this research, which aligns with the NHLBI's strategic goal to "reduce human disease," is to reduce incident CVD risk in younger American Indians. The overall objective is to determine the effectiveness of a culturally appropriate intervention, designed with American Indian involvement, to control lipid/lipoprotein and glucose levels. To achieve this objective, the investigators will determine the effectiveness of a guided intervention. Before the intervention phase, the investigators will use a community-based participatory research (CBPR) approach and conduct focus groups asking participants to offer recommendations for a modified version of the Balance Study that the investigators conducted with older (mean age=52 years) American Indians in Oklahoma, 2008-2012. Subsequently, the investigators will recruit 330 American Indians, 15-39 years old, with elevated lipid/lipoprotein or glucose levels. Among this group, the investigators will assess baseline CVD risk factors and then randomly assign them to either a self-managed control group receiving health care referrals and educational materials or to an 18-month guided intervention group, incorporating: 1) community health workers (CHW) to reduce health care access barriers and 2) a multidimensional educational component focusing on nutrition, physical activity, and CVD risk factor education during at least six (6) quarterly in-person meetings. Based on SHS data, the investigators formulated the central hypothesis that health care access, nutrition, physical activity, and CVD risk factor education jointly contribute to lipid/lipoprotein and glucose control. Therefore, the rationale for the proposed research is to include these components in an intervention targeting lipid/lipoprotein and glucose management. Given the investigator's experience with American Indian communities recruiting and designing interventions for the SHS, the investigators are well-positioned to conduct this research, with the following Specific Aims: Aim 1: To adapt a culturally relevant CVD risk factor intervention with American Indians, 15-39 years old, living in southwestern Oklahoma. Aim 2: To recruit American Indians in southwestern Oklahoma,15-39 years old, with serum LDL-C ≥100 mg/dL, serum triglycerides ≥150 mg/dL, or fasting plasma glucose ≥100 mg/dL and assess: a) CVD risk factors including blood pressure, anthropometrics, tobacco and alcohol use, nutrition, physical activity, and sleep hygiene and b) factors influencing CVD risk including health care access, CVD education, and social determinants of health (SODH), including social support. Hypothesis: CVD risk factor frequencies will be different than those measured 20 years ago in SHS participants. Aim 3: To determine if an 18-month guided intervention is more effective than self-management at lowering lipid/lipoprotein and glucose levels and improving CVD risk factor knowledge, among American Indians recruited for Aim 2. Hypothesis: Young American Indians randomized to the guided intervention will have lower lipid/lipoprotein and glucose levels and better CVD risk factor knowledge after 18 months. The proposed research will determine the effectiveness of an intervention that uses the CHW model to target health care access, nutrition, physical activity, and CVD risk factor education within the pediatric and young adult American Indian population. The expected outcomes include the refinement of a culturally appropriate CVD risk factor reduction intervention, the generation of updated CVD risk factor estimates, the reduction of lipid/lipoprotein and glucose levels, and an increase of CVD risk factor knowledge in young American Indians with elevated CVD risk. This study will decrease the disproportionately high lipid/lipoprotein and glucose levels that are significantly predictive of incident CVD in young American Indians.


330 estimated patients




15 to 39 years old


No Healthy Volunteers

Inclusion criteria

  • American Indians
  • 15-39 years old
  • Members of the tribal communities that participate in the Strong Heart Study in southwestern Oklahoma
  • Only one person per household will be eligible

Exclusion criteria

  • Unwilling or unable to follow the intervention, which includes modifying current diet or participating in the proposed physical activity program
  • Taking lipid-lowering or diabetes medication
  • Already participating in a diabetes or CVD risk factor reduction program
  • Are pregnant or plan to become pregnant in the next 18 months.
  • Underlying disease with an expected life-expectancy of less than 2 years such as cancer or end stage renal disease with dialysis

Trial design

Primary purpose




Interventional model

Parallel Assignment


Single Blind

330 participants in 2 patient groups

Guided management
Experimental group
The intervention will be comprised of four broad components (described below). The focus groups will inform these components and therefore, we propose a community-responsive and ultimately, community-driven intervention. Component on reducing barriers to health care access Nutritional component Activity component CVD risk factor education component
Other: Guided management
Active Comparator group
Self-managed (control group): For participants randomized to the self-managed group, we will employ the standard of care that is currently used by the Strong Heart Study (SHS) and other large cohorts, which is based on a referral program for risk factor control and dissemination of educational pamphlets. Therefore, the risk factor control and education for this group will be self-managed.
Other: Self management

Trial contacts and locations



Central trial contact

Jessica A Reese, PhD

Data sourced from

Clinical trials

Find clinical trialsTrials by location
© Copyright 2024 Veeva Systems