Presentation on theme: "Associations between Obesity and Depression by Race/Ethnicity and Education among Women: Results from the National Health and Nutrition Examination Survey,"— Presentation transcript:
Associations between Obesity and Depression by Race/Ethnicity and Education among Women: Results from the National Health and Nutrition Examination Survey, Arlene Keddie, Ph.D. Northern Illinois University and Marine Nalbandyan, M.D., M.P.H. October 31, 2011 APHA 139 th Annual Meeting
Presenter Disclosure Arlene Keddie No relationships to disclose
Background: Depression and Obesity Evidence for associations between depression and obesity is inconsistent. Depression increases risk of Cardiovascular Disease (CVD) and Non-Insulin Dependent Diabetes Mellitus (NIDDM), especially in women. Obesity is an established risk factor for both CVD and NIDDM. If obesity is associated with depression, this might help to explain why depression is linked to these other conditions.
Background: Race/Ethnicity, Obesity and Depression Inconsistent results from studies of the association between depression and obesity may indicate that only some subgroups are affected. Studies of obesity and depression by race/ethnicity have been few. Prevalence of obesity is high among Non-Hispanic Blacks and Hispanics. If the association varies by race/ethnicity, it may only occur under specific social conditions. Degree of stigma associated with obesity may be culturally determined.
Background: Education, Obesity and Depression Recent studies testing education as a modifier of the obesity – depression association are even more rare. Obesity is inversely related to socioeconomic status among women in developed countries. Depression is also inversely related to education. The effect of education on the obesity- depression association may vary by race/ethnicity.
Objectives 1. To examine associations between large waist circumference and depression within Non-Hispanic Whites, Non-Hispanic Blacks and Hispanics of different levels of education 2. To examine associations between obesity, as indicated by body mass index category, and depression within the same racial/ethnic and educational categories 3. To examine the effect of adjustment for demographic, behavioral and health factors, known to be associated with both depression and obesity, on the original associations found
National Health and Nutrition Examination Survey (NHANES), Combined 2 cycles of Continuous NHANES ( and ) Both cycles oversampled: – African Americans – People with low income – People over cycle – Oversampled Mexican Americans cycle – Oversampled all Hispanics – Increase in proportion aged 40-59
Sample Used for Analyses Final Sample of 3,774 Women 4,760 Eligible Women with BMI ≥18.5 Removed 920 Women with Incomplete Data 4,858 Non-Hispanic White, Non-Hispanic Black and Hispanic Women Removed 98 Underweight Women (BMI <18.5) 5,065 Not Pregnant Women Aged ≥20 Removed 207 Women in “Other” Racial Category 5,617 Females ≥20 Years Old Removed 552 Pregnant Women or With Unknown Pregnancy Status Initial NHANES Sample Included 10,321 Females Removed 4,704 Children Aged <20 Years Old
Depression: Dependent Variable Measured by Patient Health Questionnaire (PHQ-9) PHQ-9 = Nine 4-point Likert questions based on the 9 signs or symptoms from the Diagnostic and Statistical Manual of Mental Disorders, 4 th edition (DSM-IV) Scale of 0-27 for these 9 questions Score ≥10 indicates moderate or severe level of depressive symptoms 88% sensitivity and specificity for Major Depressive Disorder Compared to those scoring <10
Body Mass Index (BMI) Independent Variable National Heart, Lung and Blood Institute criteria: Underweight: <18.5 (deleted) Normal Weight: (referent) Overweight: Obese: ≥30
Waist Circumference (WC) Independent Variable National Institutes of Health cut-points for women <88 centimeters (or <35 inches) = Small WC (referent) ≥88 centimeters (or ≥35 inches) = Large WC
Statistical Analysis Logistic Regression Models Stratified into Six Groups – Non-Hispanic Whites with ≥12 Years of Education – Non-Hispanic Whites with <12 Years of Education – Non-Hispanic Blacks with ≥12 Years of Education – Non-Hispanic Blacks with <12 Years of Education – Hispanics with ≥12 Years of Education – Hispanics with <12 Years of Education Unadjusted and adjusted for all covariates
Covariates Adjusted for: – Age – Annual family income – Marital status – Smoking – Alcohol consumption – Number of chronic conditions
Prevalence of Depression among Women by Race/Ethnicity, Education, Waist Circumference and BMI TotalNon-Hispanic White (N=1,913) Non-Hispanic Black (N=865) Hispanic (N=996) P-Value 8.7%7.7%12.1%11.5% Education <12 Years14.3%13.4%17.7%13.8% Years10.1%9.7%11.3%11.8% ≥13 Years6.4%5.8%9.9%8.1% Waist Circumference <88 cm5.5%4.4%11.7%9.4% ≥88 cm10.4%9.7%12.2%12.5% Body Mass Index %4.5%14.4%10.8% %8.7%12.2%10.2% ≥3010.8%10.4%11.1%12.9%0.6275
Associations between Waist Circumference ≥88 cm and Depression by Race/Ethnicity and Education in Women Race/Ethnicity and EducationNUnadjusted Model Odds Ratios (95% CI) Adjusted Model Odds Ratios (95% CI) Non-Hispanic Whites <12 Years of Education ( )0.84 ( ) ≥12 Years of Education1, ( )2.15 ( ) Non-Hispanic Blacks <12 Years of Education ( )0.79 ( ) ≥12 Years of Education ( )0.76 ( ) Hispanics <12 Years of Education ( )1.79 ( ) ≥12 Years of Education ( )0.67 ( )
Summary of Results I Prevalence of depression is higher in Non- Hispanic Black and Hispanic women compared to Non-Hispanic White women. These ethnic differences only existed among the best educated, and those with small waist circumferences, and normal BMI.
Summary of Results II In unadjusted and adjusted models, Non-Hispanic White women with ≥12 years of education were more likely to be depressed if they had either high BMI or large WC versus normal BMI or small WC. In unadjusted and adjusted models, Non-Hispanic Black women with <12 years of education were less likely to be depressed if their BMI ≥30 versus In the unadjusted model only, Hispanic women with <12 years of education were more likely to be depressed if their WC was ≥88 cm, but this association became insignificant after adjusting for demographic, behavioral and health variables.
Limitations 1. Cross-sectional studies cannot establish causality. 2. Possible Selection Bias – Those with missing data (20.7% of the eligible) Older Less Educated Physically Inactive Lower Income Non-Hispanic Black or Hispanic Widowed or Never Married Abstain from Alcohol Three or More Chronic Conditions
Strengths 1. One of very few studies to examine both the effect of race/ethnicity and education together on obesity- depression association 2. Recent national sample with wide age range, and several racial/ethnic groups 3. PHQ-9 has both high degree of sensitivity and specificity for clinical depression (88% for both). 4. BMI and Waist Circumference measured by trained examiners – not self-reported. 5. Controlled for a variety of possible confounders or mediators
Conclusions In women, associations between depression and obesity are modified by both race/ethnicity and education. In adjusted models, only Non-Hispanic White women with moderate to high education had higher odds of depression if they were overweight or obese. Obesity may carry higher degree of stigma among this population. Educated, Non-Hispanic White women are also more likely to be treated for depression than the less educated and minorities. Some treatments cause weight gain. Although prevalence of depression increases with obesity for these groups, it never reaches the levels of Non-Hispanic Black or Hispanic women. Inverse association among Non-Hispanic Black women with <12 years of education, if true, may reflect lack of negative attitudes toward high weight in this group.