Blood Pressure and Arterial Stiffness in Kenyan Adolescents With α+Thalassemia

Abstract

Background-—Recent studies have discovered that a-globin is expressed in blood vessel walls where it plays a role in regulating vascular tone. We tested the hypothesis that blood pressure (BP) might differ between normal individuals and those with a+ thalassemia, in whom the production of a-globin is reduced. Methods and Results-—The study was conducted in Nairobi, Kenya, among 938 adolescents aged 11 to 17 years. Twenty-four- hour ambulatory BP monitoring and arterial stiffness measurements were performed using an arteriograph device. We genotyped for a+ thalassemia by polymerase chain reaction. Complete data for analysis were available for 623 subjects; 223 (36%) were heterozygous ( a/aa) and 47 (8%) were homozygous ( a/ a) for a+ thalassemia whereas the remaining 353 (55%) were normal (aa/aa). Mean 24-hour systolic BP SD was 118 12 mm Hg in aa/aa, 117 11 mm Hg in a/aa, and 118 11 mm Hg in a/ a subjects, respectively. Mean 24-hour diastolic BP SD in these groups was 64 8, 63 7, and 65 8 mm Hg, respectively. Mean pulse wave velocity (PWV) SD was 7 0.8, 7 0.8, and 7 0.7 ms 1 , respectively. No differences were observed in PWV and any of the 24-hour ambulatory BP monitoring-derived measures between those with and without a+ thalassemia. Conclusions-—These data suggest that the presence of a+ thalassemia does not affect BP and/or arterial stiffness in Kenyan adolescents.