Low physical activity levels and high serum C-reactive protein (CRP) levels are risk
factors for coronary artery disease (CAD) in both men and women. However,
postmenopausal women who take hormone replacement therapy (HRT) may have
increased risk of CAD because of HRT-related increases in serum CRP. There are two
manuscripts in this dissertation. The purpose of the first manuscript was to determine
whether higher physical activity energy expenditure was associated with lower serum
CRP, independent of oral HRT status and body fatness, in 133 postmenopausal women.
Higher physical activity energy expenditures were significantly associated with lower
serum CRP levels (r=-0.21, p=0.0l9), independent of oral HRT use, age, smoking
behavior, alcohol consumption, aspirin use, and statin use. However, in the complete
multivariate model, which included body fat, the association between higher physical
activity and lower serum CRP levels was abolished. The purpose of the second study
was to quantify the biological variability of insulin resistant CAD risk factors in a sample
of 8 postmenopausal women. Risk factor outcomes, including serum total cholesterol,
serum triglycerides (TG), serum high-density lipoprotein cholesterol (HDL-C), serum
glucose, plasma insulin, serum CRP, waist and hip circumferences, abdominal sagittal diameter, body fat, systolic (SBP) and diastolic blood pressure, and self-reported physical
activity energy expenditure, were measured on two occasions, 7-12 days apart. High
absolute biological variability values (by standard error of measurement) were observed
for serum TG (32.0 mg/dl), serum CRP (5.6 mg/l), SBP (4.0 mmHg), and physical
activity (9.4 kcal/kg/week). High relative biological variability (by within-subjects
coefficient of variation ���27.3%) was also observed for serum TG, serum CRP, and
physical activity. Bland-Altman plots identified individual outliers for serum TG, serum
CRP, plasma insulin, and SBP. Together, the results suggest that the correlations
between lower levels of serum CRP and higher levels of physical activity, though
significant, may have been attenuated by the high biological variability of both serum
CRP and physical activity. Thus, the importance of higher levels of physical activity, in
decreasing serum CRP and the concomitant risk of heart disease, may be underestimated
in the absence of serial measurement of serum CRP and physical activity. / Graduation date: 2002
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/32409 |
| Date | 12 October 2001 |
| Creators | Manns, Patricia J. |
| Contributors | Williams, Daniel P. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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