Association of MR-proANP with measurements of target organ damage. (A) Mean ± SE of ABI, UACR, and LV mass index (LVMI) in quartiles of plasma levels of MR-proANP in African-Americans. Cut-off values for MR-proANP quartiles were <44 pmol/L for quartile I, 44 to 62 pmol/L for II, 62 to 93 pmol/L for III, and >93 pmol/L for IV. (B) Mean ± SE of ABI and UACR in quartiles of plasma levels of MR-proANP in non-Hispanic whites. Cut-off values for MR-proANP quartiles were <44 pmol/L for quartile I, 44 to 63 pmol/L for II, 62 to 95 pmol/L for III, and >95 pmol/L for IV.