Ethnic Differences in Aortic Pulse Wave Velocity Occur in the Descending Aorta and May Be Related to Vitamin D

We studied aortic pulse wave velocity (aPWV), a predictor of cardiovascular events independent of blood pressure, in a multiethnic sample of British men, to investigate the roles for blood levels of vitamin D and aldosterone in total and regional aortic stiffness. Total aPWV was estimated noninvasively by the Arteriograph device (aPWV(AG)) in 198 men, with its length measure calibrated by magnetic resonance. PWVs over the aortic arch and descending aorta were measured by magnetic resonance in a subsample (n = 47). Mean (SE) aPWV(AG) in South Asians (n = 68; age 55 +/- 10 years), at known higher coronary disease risk than other groups, was 0.5 m/s (0.2 m/s) higher than in African Caribbeans (n = 67; 55 +/- 10 years), at lowest coronary disease risk here, and Europeans (n = 63; 57 +/- 8 years), adjusted for age, systolic blood pressure, and diabetes mellitus (P = 0.01). By magnetic resonance, PWV over the descending aorta in South Asians was 0.7 m/s (0.3 m/s) and 0.8 m/s (0.3 m/s) higher than in African Caribbeans and Europeans, respectively; PWV over the aortic arch was not different. South Asians and African Caribbeans had 21 nmol/L (3 nmol/L) and 14 nmol/L (3 nmol/L) lower mean (SE) 25(OH)D than Europeans (P<0.001). Unlike aldosterone, 25(OH)D was negatively correlated with aPWV(AG) adjusted for age and systolic blood pressure, as well as weakened or removed ethnic differences in aPWV(AG) in regression models. These data suggest that aortic stiffness as aPWV parallels coronary disease risk in ethnic groups, descending aortic but not arch PWV has this feature, and serum 25(OH) D is an independent negative correlate of aPWV and may partly account for ethnicity-related differences in aPWV and coronary disease risk