African Ancestry vs. Creatine Kinase to Predict Hypertension Control: Time for a Change?

Background: African ancestry patients are considered separately in hypertension guidelines because of more severe hypertension that is presumably harder to control. However, despite the perceived benefit in reducing health disparities, racial profiling in medicine is increasingly criticized for its potential of bias and stereotyping. Therefore, we studied whether creatine kinase (CK), an ATP-regenerating enzyme that enhances vascular contractility and sodium retention, could serve as a more proximate causal parameter of therapy failure than race/ancestry. Methods: In a random multiethnic population sample, we compared the performance of African ancestry vs. resting plasma CK as predictors of treated uncontrolled hypertension. Difference in area under the receiver operating curve (AUC) was the primary outcome. Results: We analyzed 1,405 persons of African, Asian, and European ancestry (40.2% men, mean age 45.5 years, SE 0.2). Hypertension prevalence was 39% in African vs. 29% in non-African ancestry participants vs. 41% and 27% by high and low CK tertiles. Control rates of treated patients were similar by ancestry (African ancestry patients 40%, non-African ancestry 41%; P = 0.84), but 27% vs. 53% in patients with high vs. low CK (22% vs. 67% in African and 32% vs. 52% in non-African participants). AUC was 0.51 [0.41-0.60] for African ancestry vs. 0.64 [0.55-0.73] for log CK (P = 0.02). Conclusions: In contrast to African ancestry, CK might identify hypertensive patients at risk for therapy failure across different ancestry groups. Larger, prospective studies should establish whether resting plasma CK is clinically useful as an impartial method to help predict antihypertensive therapy failure.