Vasopressin, urine concentration, and hypertension: a new perspective on an old story.

Bankir et al. (1) report that young, healthy black individuals concentrate urine significantly more than matched white individuals and excrete lower urine volumes. In addition, they found that, among men, pulse pressure was significantly higher in normotensive black individuals than in white individuals, although there was no significant difference in systolic and diastolic BP. These findings refocus attention on vasopressin as a hypertensive hormone, however with a new mechanistic twist and a novel interpretation of an ethnic difference. Bankir et al. also report a direct association between urine concentration and pulse pressure in men but not in women. Again, the correlation coefficient was stronger in black men than in white men. This early difference may be important because elevated pulse pressure is associated with an increased risk for cardiovascular events. The authors suggest that vasopressin could contribute to hypertension via its antidiuretic effects and that vasopressin V2 receptor antagonists might lower BP. Possibly, vasopressin plays a greater role in individuals with blunted renin-angiotensin system, as is the case in black individuals. Acutely, this notion has experimental support (2). In their analysis, Bankir et al. (1) relied on a data set that was generated at Indiana University Medical Center 35 yr ago. Neither urine osmolarity nor vasopressin was measured in the Indiana University protocol. Nevertheless, …