Femoral Artery Atherosclerosis Is Associated With Physical Function Across the Spectrum of the Ankle-Brachial Index: The San Diego Population Study

Women's Reproductive History and Pre-Clinical Peripheral Arterial Disease in Late Life: The San Diego Population Study

Objective: Reproductive events have been linked with increased cardiovascular risk in women, but whether they are associated with pre-clinical peripheral arterial disease (PAD) has been understudied. We evaluated associations between reproductive factors and later-life ankle-brachial index (ABI), femoral artery intima-media thickness (fIMT), and femoral plaques. Methods: Cross-sectional analysis of 707 multiethnic women who participated in a follow-up exam of the San Diego Population Study in 2007-2011. To assess associations between reproductive factors (age at menarche, parity, age at menopause, surgical menopause, hormone therapy) with ABI, and Doppler ultrasound measurements of common and superficial fIMT, linear regression was used; for femoral plaque presence, logistic regression was used. Models were adjusted for age, race/ethnicity, and cardiometabolic factors. We tested interactions of reproductive factors with menopause type (natural vs. surgical). Results: Women were on average 71 years old, and 56% were non-Hispanic White. Reproductive factors were not associated with fIMT, femoral plaque presence, or ABI. There were significant interactions between menopause type (surgical vs. natural) and oral contraceptive use (-β: 0.04, p = 0.03) for ABI, as well as between menopause type and parity (β: 0.11, p = 0.05) and age at menopause (β: 0.001, p = 0.05) for fIMT. Among women with natural menopause, oral contraceptive use was associated with higher ABI (β: 0.03, p = 0.007) and older age at natural menopause was related to greater fIMT (β: 0.009, p = 0.06). Among women with surgical menopause, nulliparity was marginally associated with greater fIMT (β: 0.33, p = 0.07). Conclusions: Reproductive history may not be independently associated with later-life lower extremity atherosclerosis in women. Studies are necessary to confirm findings and examine pregnancy-related exposures in relation to pre-clinical PAD.

An exploratory factor analysis of inflammatory and coagulation markers associated with femoral artery atherosclerosis in the San Diego Population Study

BACKGROUND AND AIMS

Several biomarkers of inflammation and coagulation have been implicated in lower extremity atherosclerosis. We utilized an exploratory factor analysis (EFA) to identify distinct factors derived from circulating inflammatory and coagulation biomarkers then examined the associations of these factors with measures of lower extremity subclinical atherosclerosis, including the ankle-brachial index (ABI), common and superficial femoral intima-media thickness (IMT), and atherosclerotic plaque presence, burden, and characteristics.

METHODS

The San Diego Population Study (SDPS) is a prospective, community-living, multi-ethnic cohort of 1103 men and women averaged age 70. Regression analysis was used to assess cross-sectional associations between the identified groupings of biomarkers (factors) and the ABI and femoral artery atherosclerosis measurements.

RESULTS

Two biomarker factors emerged from the factor analysis. Factor 1 consisting of C-reactive protein (CRP), interleukin (IL)-6, and fibrinogen was significantly associated with higher odds (OR = 1.99, p < 0.01) of a borderline ABI value (0.91-0.99), while Factor 2 containing D-dimer and pentraxin (PTX)-3 was significantly associated with higher common femoral artery (CFA) IMT (β = 0.23, p < 0.01) and lower ABI (β = -0.03, p < 0.01).

CONCLUSIONS

Two groupings of biomarkers were identified via EFA of seven circulating biomarkers of inflammation and coagulation. These distinct groups are differentially associated with markers of lower extremity subclinical atherosclerosis. Our findings suggest that high inflammatory and coagulation burden were better markers of more severe lower-extremity disease as indicated by low ABI rather than early atherosclerotic lesion development in the femoral artery.