Relation of the renin–angiotensin–aldosterone system with potential cardiac injury and remodelling: the SABPA study

Abstract

Abstract Purpose: The renin-angiotensin-aldosterone system (RAAS) plays an important role in maintaining hemodynamic homeostasis. Ethnic disparities exist regarding RAAS activity due to sympathetic activity and sodium-water retention, however the implications thereof on cardiac damage is unknown. This study investigated the associations of cardiac troponin T (cTnT), N-terminal pro-brain natriuretic peptide (NTproBNP) and subclinical LVH with components of the RAAS (renin, aldosterone and aldosterone-to-renin ratio (ARR)) and copeptin in a black and white South African cohort. Materials and methods: The study population consisted of 305 participants (black\u2009=\u2009139, white\u2009=\u2009166) aged 20–62 years. Serum cTnT, NTproBNP, Cornell product, components of the RAAS (active renin, aldosterone and ARR) and copeptin were determined. Results: The black group had lower renin (p\u2009<\u20090.001) and higher ARR (p\u2009<\u20090.001), cTnT (p\u2009=\u20090.015) and Cornell product compared to whites (all p\u2009<\u20090.001). NTproBNP and copeptin were similar between the groups. After forward stepwise adjustments for multiple confounders, inverse associations of cTnT with renin (β\u2009=\u2009−0.17, p\u2009=\u20090.018) and aldosterone (β\u2009=\u2009−0.14, p\u2009=\u20090.048) as well as an inverse association between NTproBNP and aldosterone (β\u2009=\u2009−0.25, p\u2009<\u20090.001) were observed in the white population only. In the black group cTnT associated positively with renin (β\u2009=\u20090.16, p\u2009=\u20090.040) and copeptin (β\u2009=\u20090.21, p\u2009=\u20090.020) and inversely with ARR (β\u2009=\u2009−0.15, p\u2009=\u20090.047). Additionally, NTproBNP associated positively with copeptin (β\u2009=\u20090.18, p\u2009=\u20090.045). No correlations were observed between the RAAS and Cornell product in any of the groups. Conclusions: Our findings suggest that RAAS, together with cardiac stress may function differently in cardiac damage and remodelling in the two ethnic groups; which may influence treatment in clinical practice.