Plasma Kallistatin is Associated with Leukocyte Telomere Length in Young African Americans

Abstract

ObjectiveLarge population studies demonstrate that African Americans versus their Caucasian counterparts have a steeper decline in leukocyte telomere lengths (LTL) with age. Telomere shortening plays an important role in cellular aging. Kallistatin, a novel tissue kallikrein inhibitor, has anti‐inflammatory and anti‐oxidant properties. Recently we have shown that kallistatin inhibited vascular injury and cell apoptosis in animal models and cultured cells. Thus we aimed to test our hypothesis that plasma kallistatin levels are positively associated with LTL in African Americans.MethodsLeukocyte telomere lengths (the relative ratio of telomere repeat copy number (T) to single‐copy gene copy number (S)) were determined by a quantitative polymerase chain reaction method in 188 (60 males and 128 females) apparently healthy young African American subjects aged 13 to 49 years. Plasma kallistatin levels were measured by enzyme‐linked immunosorbent assay.ResultsCompared to males, females were older (24.0 ± 9.19 vs 17.9 ± 4.5 years, p<0.001), and had slightly shorter LTL (T/S ratio 1.00 ± 0.23 vs 1.09 ± 0.27, p= 0.03). In the whole sample, plasma kallistatin levels are positively and significantly associated with LTL (r=0.31, p<0.001). The significance persisted after adjusting for age, sex, and body mass index (r= 0.16, p=0.04).ConclusionThis is the first study to examine the relationship between kallistatin and telomeres in humans. Kallistatin may have anti‐cellular aging effect, which may be attributed to its anti‐inflammatory and anti‐oxidant properties. These finding indicate that plasma kallistatin might serve as a biomarker for cellular aging in humans.Support or Funding InformationHZ and YD are supported by NHLBI PO1 HL69999 and AHA 14GRANT20480211.