Asymmetric dimethylarginine and L-homoarginine prospectively relate to carotid wall thickness in a South African cohort

BACKGROUND AND AIMS: The L-arginine derivatives asymmetric (ADMA) and symmetric dimethylarginine (SDMA), as well as L-homoarginine may have opposing effects in the pathogenesis of atherosclerosis. We aimed to investigate (i) 5-year changes in arginine derivatives, and (ii) the association between baseline arginine derivatives and follow-up measures of carotid wall thickness in South Africans.

METHODS AND RESULTS: This study included men (n = 187) and women (n = 396) who took part in the 2010 and 2015 data collections of the South African arm of the Prospective Urban and Rural Epidemiology (PURE) study. Arginine derivatives were determined in plasma with liquid chromatography-tandem mass spectrometry. Carotid intima-media thickness (cIMT) and cross-sectional wall area (CSWA) were determined with B-mode ultrasonography.

RESULTS: Mean values of arginine derivatives did not change over time. In the study group, follow-up cIMT (β = - 0.10 p = 0.018) and CSWA (β = - 0.12; p = 0.004) inversely associated with baseline L-homoarginine, and cIMT inversely associated with ADMA (β = - 0.09; p = 0.033). In women, CSWA inversely associated with both ADMA (β = - 0.11; p = 0.034) and L-homoarginine (β = - 0.11; p = 0.024). No such associations were found in men.

CONCLUSION: These results suggest that higher levels of L-homoarginine may play a protective role against vascular injury and delay progression of carotid wall thickening in this cohort. The role of ADMA in atherosclerosis deserves further investigation in this population.