P115 LEUKOCYTE TELOMERE LENGTH AND ITS RELATION TO NITRIC OXIDE METABOLITES IN A BI-ETHNIC SAMPLE: THE SABPA STUDY

Abstract

Objectives: Shorter leukocyte telomere length is associated with cardiovascular risk and decreased nitric oxide bioavailability. Aforementioned are also linked with increased oxidative stress and inflammation. 1,2 Telomere length, NO metabolites (NOx), blood pressure, oxidative stress and inflammation markers in a bi-ethnic population were compared. The associations of telomere length with NOx and markers of oxidative stress and inflammation were investigated. Methods: Included were 152 black and 186 white teachers, aged 23 to 68 years. Ambulatory blood pressure was measured. Leukocyte telomere length, NOx and glutathione peroxidase (GPx), marker of oxidative stress, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), inflammatory markers and L-citrulline, marker of NO synthesis, were analysed. Results: Black men and women had higher blood pressure (p < 0.001), higher IL-6 (p ≤ 0.016), shorter telomeres (p < 0.001) but similar NOx levels when compared to their white counterparts. GPx activity was higher and L-citrulline lower in black compared to white groups (p ≤ 0.002). Independent positive associations of telomere length with NOx (adj R2=0.21;β=0.249;p=0.03) and GPx activity (adj R2=0.21;β=0.229;p=0.03) were indicated in white men and TNF-α (adj R2=0.33;−β=0.274;p=0.01) in white women. These associations were absent in the black groups. Conclusion: Telomere length of black men and women was shorter but not associated with NOx and age or markers of oxidative stress and inflammation, as observed in the white groups. Therefor it seems that the less favourable cardiovascular and inflammatory profiles of blacks were unrelated to shorter telomere lengths. The lower L-citrulline levels indicate decreased NO synthesis that may affect the association between telomere length and NOx.