Antonio J Amor1, Emilio Ortega2, Verónica Perea2, Montserrat Cofán2, Aleix Sala-Vila2, Isabel Nuñez2, Rosa Gilabert2, Emilio Ros2. 1. From the Endocrinology and Nutrition Service, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain (A.J.A., E.O., M.C., A.S.-V., E.R.); Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Spain (A.J.A., E.O., M.C., A.S.-V., E.R.); Service of Endocrinology, Hospital Universitari Mútua de Terrassa, Spain (V.P.); and Vascular Unit, Centre de Diagnòstic per l'Imatge, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain (I.N., R.G.). ajamor@clinic.ub.es. 2. From the Endocrinology and Nutrition Service, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain (A.J.A., E.O., M.C., A.S.-V., E.R.); Centro de Investigación Biomédica en Red Fisiopatología de la Obesidad y Nutrición, Instituto de Salud Carlos III, Spain (A.J.A., E.O., M.C., A.S.-V., E.R.); Service of Endocrinology, Hospital Universitari Mútua de Terrassa, Spain (V.P.); and Vascular Unit, Centre de Diagnòstic per l'Imatge, Institut d'Investigacions Biomèdiques August Pi Sunyer, Hospital Clínic, Barcelona, Spain (I.N., R.G.).
Abstract
OBJECTIVE: Bilirubin is a potent antioxidant that has been inversely related to cardiovascular disease. There is little information on serum total bilirubin (TB) in relation to atherosclerosis in familial dyslipidemia. We assessed the association between TB and carotid and femoral atherosclerosis in this high-risk group. APPROACH AND RESULTS: We evaluated 464 individuals with familial dyslipidemia (56% men; median age, 48 years), 322 with familial hypercholesterolemia, and 142 with familial combined hyperlipidemia. Carotid and femoral arteries were imaged bilaterally with a standardized ultrasonographic protocol. Mean and maximum intima-media thickness and plaque presence (≥1.2 mm) and height were recorded. Cross-sectional associations between TB and atherosclerosis variables were investigated in multivariable-adjusted models, including lipid values and hypolipidemic drug use. Inflammatory markers (C-reactive protein, total leukocyte count, and lipoprotein[a]) were also determined. Increasing TB levels were associated with decreasing intima-media thickness of all carotid segments (P<0.05, all). TB also related to carotid plaque, present in 78% of individuals, and to plaque burden (≥3 plaques), with odds ratios (95% confidence interval) 0.59 (0.36-0.98) and 0.57 (0.34-0.96) for each increase of 0.5 mg in TB, respectively. Findings were confirmed in a validation cohort of 177 subjects with nonfamilial dyslipidemia. Only the familial combined hyperlipidemia group, with higher inflammation-related markers, showed an inverse association between TB and femoral plaque height (β=-0.183; P=0.030). CONCLUSIONS: TB was inversely and independently associated with carotid plaque burden in familial and nonfamilial dyslipidemia. These findings support the use of TB as a biomarker of atherosclerosis in this high-risk group.
OBJECTIVE:Bilirubin is a potent antioxidant that has been inversely related to cardiovascular disease. There is little information on serum total bilirubin (TB) in relation to atherosclerosis in familial dyslipidemia. We assessed the association between TB and carotid and femoral atherosclerosis in this high-risk group. APPROACH AND RESULTS: We evaluated 464 individuals with familial dyslipidemia (56% men; median age, 48 years), 322 with familial hypercholesterolemia, and 142 with familial combined hyperlipidemia. Carotid and femoral arteries were imaged bilaterally with a standardized ultrasonographic protocol. Mean and maximum intima-media thickness and plaque presence (≥1.2 mm) and height were recorded. Cross-sectional associations between TB and atherosclerosis variables were investigated in multivariable-adjusted models, including lipid values and hypolipidemic drug use. Inflammatory markers (C-reactive protein, total leukocyte count, and lipoprotein[a]) were also determined. Increasing TB levels were associated with decreasing intima-media thickness of all carotid segments (P<0.05, all). TB also related to carotid plaque, present in 78% of individuals, and to plaque burden (≥3 plaques), with odds ratios (95% confidence interval) 0.59 (0.36-0.98) and 0.57 (0.34-0.96) for each increase of 0.5 mg in TB, respectively. Findings were confirmed in a validation cohort of 177 subjects with nonfamilial dyslipidemia. Only the familial combined hyperlipidemia group, with higher inflammation-related markers, showed an inverse association between TB and femoral plaque height (β=-0.183; P=0.030). CONCLUSIONS:TB was inversely and independently associated with carotid plaque burden in familial and nonfamilial dyslipidemia. These findings support the use of TB as a biomarker of atherosclerosis in this high-risk group.