Abstract P250: Comparison of Clinical Variables Independently Associated With Large Artery Stiffness and Microvascular Dysfunction in African-American Diabetic Patients

Abstract

Rationale: Diabetes mellitus is a risk factor for large and small vessel disease and portends a disproportionate morbidity and mortality burden in African Americans. Diabetes is often accompanied by cardiovascular risk factors that predispose to arteriopathy, it’s been shown to impair large and small vessel function prior to onset of target organ damage. Factors contributing to subclinical vascular dysfunction have not been well studied in this population. The objective of this study was to compare clinical variables associated with large artery stiffness and microvascular dysfunction. Methods: A total of 141 patients with diabetes were recruited from medical clinics over a 6 month period. Medical information was obtained via interview and medical record review including laboratory results. Pooled Cohort Score was calculated for each subject. Microvascular function was assessed by vascular reactivity index (VRI), which assesses changes in digital temperature before and after release of arterial cuff occlusion (VENDYS 5000BC DTM system (Endothelix, Inc.). Large artery stiffness was assessed by carotid-femoral pulse wave velocity (PWV) using applanation tonometry (Sphygmocor, Atcor Inc.). Results: Mean age was 60+8 years, 64% were female. 80% had hypertension, 90% had dyslipidemia and 15% had chronic kidney disease. Mean HbA1C levels were 8.1+2.2%. On univariate analysis, Pooled-cohort-score was significantly correlated with PWV (r=.25, p=.003) but not with VRI (r=.02, p=.78). Neither PWV nor VRI was significantly correlated with HbA1c. On multivariate analysis, PWV was independently associated with age, gender, creatinine level and waist circumference but not with traditional risk factors (R2=.26, p<.001 for model). VRI was not significantly correlated with any of the clinical or laboratory measures. Conclusions: Large artery stiffness is independently associated with age, female gender, renal function and waist circumference but not with poorer glycemic control. In contrast, microvascular dysfunction was not associated with any of the clinical or laboratory measures. The role of metabolic risk factors in the differential progression of subclinical large and small artery vessel dysfunction and outcomes merit further study.