Date of Award

5-2009

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Program

Nursing

Research Advisor

Patricia A. Cowan, Ph.D.

Committee

Donna Sharon Husch, Ph.D. Michelle Khoo, M.D. Muriel Curry Rice, Ph.D. Mona Newsome Wicks, Ph.D.

Abstract

Background: Obesity is a growing health care concern with cardiovascular disease (CVD) implications. African American women (AAW) have the highest prevalence rate of obesity and highest CVD morbidity and mortality rate of all ethnic groups. The traditional CVD risk factors have not been sufficient to explain this disparity in disease prevalence and outcomes. Current knowledge is limited regarding the interaction between various levels of adiposity and both traditional and emerging CVD risk factors, particularly in AAW. This study sought to explore these interactions.

Methods: The study design was a cross-sectional, descriptive, correlational analysis of 48 AAW ages 18 to 45 who had no known history of CVD. Participants completed a demographic/health history questionnaire and 7-Day Physical Activity Recall Questionnaire. Anthropometric assessment of height, weight, BMI, waist circumference, and waist-hip-ratio were determined. An average of two resting blood pressures was taken. Hypertension was defined as a systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg. Fasting blood levels were drawn of traditional (glucose, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglycerides) and emerging risk factors (fibrinogen, high density C-reactive protein [hs-CRP], plasminogen activator inhibitor-1 [PAI-1], E-selectin, quantitative insulin sensitivity check index [QUICKI], and soluble intercellular adhesion molecule-1 [sICAM-1]). Prediabetes and diabetes were determined based on the American Diabetes Association criteria. Normal values for lipids were based on Adult Treatment Panel (ATP) III guidelines. Reference lab norms were used for fibrinogen (< 350 mg/L), hs-CRP (< 2 mg/L), and PAI-1 (< 28 mg/mL). Normative values for QUICKI, sICAM-1, and E-selectin have not yet been established, thus cut-points used for these tests were from previous research studies. Analyses included descriptive statistics, t-test, chi-square, and Spearman’s correlation analysis. An alpha level of 0.05 was set a priori for statistical significance.

Results: Only 4.17% of our participants reported a history of diabetes and hypertension. The most common traditional risk factor identified was physical inactivity (72.92%), followed by a positive family history of CVD (58.3%). Obesity, defined as a measured BMI ≥ 30 kg/m2, was present in 56.25%. All of our participants had insulin resistance, and 56.25% had elevated fibrinogen levels. Our findings indicated that the obese weight group had a higher systolic blood pressure (p = 0.0002) and diastolic blood pressure (p = 0.0007), and lower HDL-c (p = 0.01) and higher triglyceride levels (p=0.02) than the normal weight group. The obese group had significantly higher levels of hs-CRP (p = 0.002) and fibrinogen (p=0.01) compared to the normal weight groups. Compared to the normal weight group, the obese group had significantly more CVD risk factors (6.9 vs. 4.1, p < 0.05).

Conclusion: Obesity is associated with a higher prevalence of both the emerging and traditional cardiovascular risk factors in AAW without a previous history of CVD. Physical inactivity is the most prevalent modifiable risk factor in this population. Focused intervention on obesity and physical inactivity could provide substantial reduction in CVD morbidity and mortality among AAW

DOI

10.21007/etd.cghs.2009.0133

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