Correlates of Overweight and Obesity among American Indian/Alaskan Native and Non-Hispanic White

Children and AdolescentsMaria N. Ness, M.P.H.

Office of Family Health, Oregon Health Authority, Portland, OR

Danielle T. Barradas, Ph.D.Division of Reproductive Health, Centers for Disease Control and Prevention, Atlanta, GA

Jennifer Irving, M.P.H.Great Plains Tribal Chairmen's Health Board, Northern Plains Tribal Epidemiology Center, Rapid City, SD

Susan E. Manning, M.D., M.P.H.Career Epidemiology Field Officer Program, Centers for Disease Control and Prevention, Atlanta, GA

Council of State and Territorial Epidemiologists Annual ConferenceJune 13, 2011

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Background• Nationally, prevalence of overweight and

obese children is rising at an alarming rate• Studies have shown rates of overweight and

obesity to be consistently higher among American Indian/Alaska Native (AI/AN) children than other racial groups*

• The development of overweight and obesity in childhood is a complex process, with many interrelated contributing factors

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* Anderson, S. E., & Whitaker, R. C. (2009). Prevalence of obesity among US preschool children in different racial and ethnic groups. Archives of Pediatric & Adolescent Medicine, 136, 344-348. Zephier, E., Himes, J. H., Story, M., & Zhou, X. (2006). Increasing prevalences of overweight and obesity in Northern Plains American Indian children. Archives of Pediatric & Adolescent Medicine, 160, 34-39.

Aim & Research Question

• Aim: To contribute to the understanding of the risk factors for childhood overweight and obesity among AI/AN children, so that effective prevention and treatment strategies can be developed

• Research Question: Do risk factors for overweight and obesity differ among AI/AN children compared to non-Hispanic (NH) white children?

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Methods• Secondary data analysis of the 2007 National

Survey of Children’s Health• Telephone survey conducted in English and

Spanish of parents with child under 18 years• Provides a broad range of information about

children’s health and well-being• Survey results are weighted to represent the

population of non-institutionalized children ages 0-17 nationally and in each state

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Sample

• Analysis limited to:– Seven states that report AI/AN race as a distinct

category (AK, AZ, MT, NM, ND, OK, SD)– Children aged 10-17 years because parent report

of child’s height and weight not reliable for children < 10 years

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Measures Examined

• Dependent variable: Overweight and obesity combined into one variable (referent group = normal weight)

• Independent variables:– Weight-related behaviors (e.g. physical activity)– Household environment– Neighborhood environment– Demographic and socioeconomic characteristics

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Independent Variables

Variable Survey QuestionSports Team Participation During the past 12 months, was [CHILD’S NAME] on a sports

team or did he/she take sports lessons after school or on the weekends?

Vigorous Physical Activity During the past week, on how many days did [CHILD’S NAME] exercise or participate in physical activity for at least 20 minutes that made him/her sweat and breathe hard, such as basketball, soccer, running, swimming laps, fast bicycling, fast dancing, or similar aerobic activities?

Computer Use On an average school day, about how many hours does [CHILD’S NAME] use a computer for purposes other than homework?

TV/Video Watching On an average school day, about how many hours does [CHILD’S NAME] usually watch TV, watch videos, or play video games?

TV in Bedroom Is there a television in the child’s bedroom?

TV Rules Are there family rules about what television programs [he/she] is allowed to watch?

Screen Time Addition of Computer Use and TV/Video Watching variables

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Table 1: Weight Related Behaviors

Independent Variables, cont.

Variable Survey Question

Family Meals During the past week, on how many days did all the family members who line in the household eat a meal together?

Parent’s Physical Activity During the past week, on how many days did you exercise, play a sport, or participate in physical activity for at least 20 minutes that made (you/her) sweat and breathe hard?

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Table 2: Household Environment

Independent Variables, cont.

Variable Survey QuestionCommunity Safety How often do you feel [CHILD'S NAME] is safe in your community

or neighborhood?

School Safety How often do you feel [he/she] is safe at school?

Sidewalks, parks or recreation center in neighborhood

Please tell me if the following places and things are available to children in your neighborhood, even if [CHILD'S NAME] does not actually use them:

•Sidewalks or walking paths?•A park or playground area?•A recreation center, community center, or boys' or girls' club?

Neighborhood Support/Social Capital

Now, for the next four questions, I am going to ask you how much you agree or disagree with each of these statements about your neighborhood or community:

•"People in my neighborhood help each other out."•"We watch out for each other's children in this neighborhood."•"There are people I can count on in this neighborhood."•"If my child were outside playing and got hurt or scared, there are adults nearby who I trust to help my child."

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Table 3: Neighborhood Environment

Independent Variables, cont.

Variable Survey QuestionChild’s age The interviewer begins by asking how many children live in the

household and the age of each person under 18 years old living in the household. After the initial screening is completed, a single child is randomly selected from households with one or more children, ages 0-17.

Child’s Sex Is [CHILD] male or female?

Household Structure/Composition

What is your relationship to [CHILD]? Are you [CHILD'S NAME]'s biological, adoptive, step, or foster [MOTHER/FATHER]? Does [CHILD’S NAME] have any (other) parents, or people who act as [his/her] parents, living here? What is there relationship to [CHILD'S NAME]?

Household Income Please think about your total combined FAMILY income during (LAST CALENDAR YEAR) for all members of the family. Can you tell me that amount before taxes?

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Table 4: Demographic & Socioeconomic Characteristics

Statistical Analysis• Descriptive Analysis: Differences in variable

distributions between NH white and AI/AN children were tested using Chi-square statistics

• Bivariate Analysis: Bivariate associations between overweight/obesity and each independent variable were assessed

• Multivariable Analysis: A multivariable logistic regression model was created including interaction terms in addition to all variables with significant odds ratios among any race in the bivariate regressions*

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*Kleinbaum DG and Klein M. Modeling Strategy Guidelines. In Logistic Regression: A Self-Learning Text (2nd ed). New York: Springer, 2005

Descriptive Results

• Characteristics which were statistically significantly differently distributed between NH white and AI/AN children:– Parental physical activity (p = 0.04)– Family meals/week (p < 0.001)– School safety (p = 0.001)– Parks in neighborhood (p = 0.007)– Household poverty status (p < 0.001)– Household structure (p = 0.002)

• Of these, only household poverty status and household structure made it into the final multivariable model

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Bivariate Results

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Figure 1. Percent of overweight/obese children by risk factor

Bivariate Results, cont.

All

(n=5342)Crude OR (95% CI)

Non-Hispanic White

(n=4956)Crude OR (95% CI)

American Indian/ Alaska Native

(n=386)Crude OR (95% CI)

No Sports Team Participation(Ref = Sports Team Participation)

1.3 (1.0-1.7) 1.2 (0.9-1.6) 2.0 (1.0-4.3)

> 2 Hours TV Viewing/Day(Ref = 0 - 2 Hours TV Viewing/Day)

2.3 (1.7-3.1) 2.4 (1.7-3.4) 1.5 (0.7-3.4)

No Neighborhood Support(Ref= Moderate/High Neighborhood Support)

2.4 (1.4-4.3) 2.4 (1.3-4.4) 2.8 (0.7-12.3)

< 100% Federal Poverty Level(Ref = ≥ 400 FPL)

3.9 (2.4-6.2) 3.5 (2.0-6.0) 3.0 (0.9-9.6)

“Other” Household Structure(Ref = Two Parents)

1.9 (1.2-2.9) 1.5 (0.9-2.5) 2.8 (1.1-7.3)

Age 10 - 11(Ref = Age 15 – 17)

2.2 (1.6-3.1) 2.2 (1.6-3.2) 2.5 (0.7-8.6)

Male Sex(Ref = Female Sex)

1.5 (1.2-2.0) 1.6 (1.2-2.0) 1.9 (0.8-4.2)14

Table 5: Unadjusted risk factors for childhood overweight and obesity among 10 – 17 year old NH white & AI/AN children, NSCH 2007

Multivariable Results

Risk Factor Adjusted Odds Ratio

95% Confidence Interval

Child’s Sports Team Participation1

No, among Non-Hispanic white 1.8 0.8-4.2

Yes, among Non-Hispanic white 1.0 Ref

No, among American Indian/Alaskan Native 2.7 1.3-5.2

Yes, among American Indian/Alaskan Native 1.0 Ref

Child’s TV Viewing, hours/day

0-2 1.0 Ref

>2 2.0 1.5-2.8

Neighborhood Support/Social Capital

None 1.9 1.1-3.5

Low 0.9 0.6-1.3

Moderate/High 1.0 Ref15

1p for interaction term= 0.18

Table 6: Adjusted risk factors for childhood overweight and obesity among 10 – 17 year old NH white & AI/AN children, NSCH 2007

Multivariable Results, cont.

Risk Factor Adjusted Odds Ratio

95% Confidence Interval

Household Poverty Status, %FPL <100 2.9 1.7-5.1

100-399 1.6 1.2-2.1 ≥400 1.0 Ref

Household Structure Two parents 1.0 Ref

Single mom 1.4 0.9-2.0

Other 1.9 1.2-2.8Age

10-11 2.5 1.7-3.5 12-14 1.2 0.9-1.6

15-17 1.0 Ref

Sex Male 1.6 1.2-2.1

Female 1.0 Ref 16n= 4743; Adjusted for all variables simultaneously

Table 6 continued: Adjusted risk factors for childhood overweight and obesity among 10 – 17 year old NH white & AI/AN children, NSCH 2007

Conclusions / Discussion• In general, correlates of overweight/obesity did

not differ between non-Hispanic white and AI/AN children

• Sports team participation was differentially related to overweight/obesity between racial groups (AI/AN children who did not participate on a sports team had a statistically significant 2.7 times increased odds of being overweight or obese)

• Our findings also support TV viewing and neighborhood social support as potential areas for intervention among AI/AN children

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Limitations• Cross-sectional design of the NSCH means that temporality

cannot be established; therefore cannot infer causality• No direct measurements of children’s height and weight;

data is all parental report• Results can only be generalized to 7 states that report

AI/AN race, and only to 10-17 year old children• Small sample size of AI/AN children– Overweight and obesity combined into a single variable,

unable to examine risk factors for each separately– Potential significance of independent variables may not

have been detected

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Public Health Implications• Increased sports participation may be a key area

for targeted interventions among AI/AN children• Interventions could consist of increasing safe and

easily accessible sports facilities, in school or an external setting

• Funding could be sought from programs with aligned goals, such as the Special Diabetes Program for Indians

• Alternatively, focus could be targeted towards improving AI/AN children’s access to sports facilities

• Interventions to increase sports participation may be more effective among boys

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Acknowledgments

• Deborah Rosenberg, Ph.D. & Kristin Rankin, Ph.D.– Division of Epidemiology and Biostatistics, School

of Public Health, University of Illinois at Chicago• Kenneth D. Rosenberg, M.D., M.P.H. & Kathleen

A. Anger, Ph.D.– Oregon Public Health Division, Office of Family

Health, Portland OR

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Thank you!Questions?

Please contact Maria Ness CDC/CSTE Applied Epidemiology Fellow

Oregon Public Health DivisionOffice of Family Health

800 NE Oregon Street, Suite 825Portland OR 97232

maria.n.ness@state.or.us(971) 673-1564

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