title: Black race is associated with digital artery endothelial dysfunction: results from the Heart SCORE study.
abstract: OBJECTIVE
  We evaluated whether black race is independently associated with arterial endothelial dysfunction. The pathophysiological basis for race-related differences in cardiovascular disease (CVD) risk has not been established. Endothelial dysfunction, which precedes obstructive atherosclerotic disease, may contribute to CVD disparities. Accordingly, we evaluated race-related differences in digital pulse amplitude tonometry (PAT) response to an endothelium-dependent vasodilatory stimulus.
  
  
  RESULTS
  A total of 1377 subjects (41% black; mean age 58.5 ± 7.5 years; 67% female) enrolled in the Heart Strategies Concentrating on Risk Evaluation (Heart SCORE) study underwent assessment of digital pulse amplitude response to forearm occlusion-induced hyperaemia. The response was measured as a PAT ratio of hyperaemia:baseline pulse amplitude in a finger that was subject to hyperaemic stimulus divided by this same ratio in a control finger on the contralateral arm which did not undergo forearm occlusion, expressed as the natural logarithm. The average PAT ratio was significantly lower in blacks compared with whites (0.67 ± 0.44 vs. 0.80 ± 0.46, P < 0.001), signifying greater endothelial dysfunction in blacks. Black race was independently correlated with lower PAT ratio. This finding was consistent across all Framingham risk strata. Adjusted analyses showed significant gender-race interactions. With white women serving as the referent group, parameter estimates for lower PAT ratio in ascending order were as follows: black males (t = -6.93, P < 0.0001); white males (t = -3.31, P = 0.001); and black females (t = -1.12, P = 0.26).
  
  
  CONCLUSIONS
  Our findings indicate that black race is independently associated with arterial endothelial dysfunction. Racial differences in CVD risk may be related, in part, to race-related differences in endothelial dysfunction.
authors.affiliation: Cardiovascular Institute, University of Pittsburgh, 200 Lothrop Street, Pittsburgh, PA 15213, USA. mulukutlasr@upmc.edu
authors.forename: Suresh R
authors.initials: SR
authors.lastname: Mulukutla
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Venkitachalam
authors.forename: Claudia
authors.initials: C
authors.lastname: Bambs
authors.forename: Kevin E
authors.initials: KE
authors.lastname: Kip
authors.forename: Aryan
authors.initials: A
authors.lastname: Aiyer
authors.forename: Oscar C
authors.initials: OC
authors.lastname: Marroquin
authors.forename: Steven E
authors.initials: SE
authors.lastname: Reis
mesh_terms: D000368:Aged; D001158:Arteries / Q000502:physiology; D044383:Black People; D015331:Cohort Studies; D004730:Endothelium, Vascular / Q000502:physiology*; D005260:Female; D005385:Fingers / Q000098:blood supply*; D006801:Humans; D008297:Male; D008365:Manometry; D016491:Peripheral Vascular Diseases / Q000208:ethnology* / Q000503:physiopathology; D012307:Risk Factors; D014664:Vasodilation / Q000502:physiology