Ethnicity, social class and hostility: effects on in vivo β-adrenergic receptor responsiveness

Abstract

Little is known about the potential influences of social and psychosocial variables in accounting for ethnic differences in the β-adrenergic receptor. We examined the effects of ethnicity, social class, and other variables on an in vivo marker of β-adrenergic receptor responsiveness (Chronotropic 25 Dose, CD 25) for 224 African-Americans and Caucasian-Americans. Social class was determined using the clinician-rated Hollingshead two-factor index. The Cook–Medley hostility and Buss–Durkee assaultiveness subscales were administered to a subset of subjects. Results indicated that African-Americans had decreased β-receptor responsiveness compared to Caucasian-Americans after controlling for social class, age, and smoking ( P=0.001). Secondary analysis for a subset of subjects revealed significant hostility×ethnicity interactions, such that hostility predicted decreased β-receptor responsiveness for Caucasian-Americans ( P=0.004), but not for African-Americans. Thus, decreased β-adrenergic receptor responsiveness in African-Americans does not appear to be due to differences in current social class, age, or smoking status, nor to higher reports of hostility.