Clinical Science (2015) 128, 609–618 (Printed in Great Britain) doi: 10.1042/CS20140300 Metabolic alterations, HFE gene mutations and atherogenic lipoprotein modifications in patients with primary iron overload Tom ´ as Mero˜ no ∗ †, Fernando Brites ∗ , Carolane Dauteuille†, Marie Lhomme†, Mart´ ın Menafra ∗ , Alejandra Arteaga‡, Marcelo Castro§, Mar´ ıa Soledad Saez‖, Esteban Gonz´ alez Ballerga‡, Patricia Sorroche‖, Jorge Rey§, Philippe Lesnik†, Juan Andr´ es Sord´ a‡, M. John Chapman†, Anatol Kontush† and Jorge Daruich‡¶ ∗ Laboratory of Lipids and Lipoproteins, School of Pharmacy and Biochemistry, INFIBIOC, University of Buenos Aires, CONICET, Jun´ ın 956, 1113 Buenos Aires, Argentina †National Institute for Health and Medical Research (INSERM), UMR ICAN 1166, University of Pierre et Marie Curie – Paris 6, AP-HP , Groupe hospitalier Piti´ e-Salp´ etri` ere, ICAN, Paris F-75013, France ‡Hepatology Division, Hospital “Jos´ e de San Mart´ ın”, University of Buenos Aires, Buenos Aires, Argentina §Department of Hemotherapy and Immunohematology, Hospital “Jos´ e de San Mart´ ın”, University of Buenos Aires, Buenos Aires, Argentina ‖Central Laboratory, Italian Hospital of Buenos Aires, Buenos Aires, Argentina ¶Diagnostic and Therapeutical Gastroenterology (GEDYT), Buenos Aires, Argentina Abstract Iron overload (IO) has been associated with glucose metabolism alterations and increased risk of cardiovascular disease (CVD). Primary IO is associated with mutations in the HFE gene. To which extent HFE gene mutations and metabolic alterations contribute to the presence of atherogenic lipoprotein modifications in primary IO remains undetermined. The present study aimed to assess small, dense low-density lipoprotein (LDL) levels, chemical composition of LDL and high-density lipoprotein (HDL) particles, and HDL functionality in IO patients. Eighteen male patients with primary IO and 16 sex- and age-matched controls were recruited. HFE mutations (C282Y, H63D and S65C), measures of insulin sensitivity and secretion (calculated from the oral glucose tolerance test), chemical composition and distribution profile of LDL and HDL subfractions (isolated by gradient density ultracentrifugation) and HDL functionality (as cholesterol efflux and antioxidative activity) were studied. IO patients compared with controls exhibited insulin resistance (HOMA-IR (homoeostasis model assessment-estimated insulin resistance): +93 %, P < 0.001). Metabolic profiles differed across HFE genotypes. C282Y homozygotes (n = 7) presented a reduced β -cell function and insulin secretion compared with non-C282Y patients (n = 11) (−58 % and −73 %, respectively, P < 0.05). In addition, C282Y homozygotes featured a predominance of large, buoyant LDL particles (C282Y: 43 + − 5; non-C282Y: 25 + − 8; controls: 32 + − 7 %; P < 0.001), whereas non-C282Y patients presented higher amounts of small, dense LDL (C282Y: 23 + − 5; non-C282Y: 39 + − 10; controls: 26 + − 4 %; P < 0.01). HDL particles were altered in C282Y homozygotes. However, HDL functionality was conserved. In conclusion, metabolic alterations and HFE gene mutations are involved in the presence of atherogenic lipoprotein modifications in primary IO. To what extent such alterations could account for an increase in CVD risk remains to be determined. Key words: atherosclerosis, cardiovascular disease, hereditary haemochromatosis, high-density lipoprotein (HDL), insulin resistance, iron overload, low-density lipoprotein (LDL) INTRODUCTION Iron overload (IO) is defined as an increase in storage iron re- gardless of the presence of tissue damage [1]. Primary causes Abbreviations: AAPH, 2,2 ′ -azobis-(2-amidinopropane) hydrochloride; ALP , alkaline phosphatase; ALT, alanine aminotransferase; apo, apolipoprotein; AST, aspartate aminotransferase; BMI, body mass index; CE, cholesteryl ester; CETP , cholesteryl ester transfer protein; CVD, cardiovascular disease; FC, free cholesterol; HH, hereditary haemochromatosis; HDL, high-density lipoprotein; HDL-C, HDL-cholesterol; HFE, human haemochromatosis protein; HOMA-IR, homoeostasis model assessment-estimated insulin resistance; hsCRP , high-sensitivity C-reactive protein; IO, iron overload; LDL, low-density lipoprotein; LDL-C, LDL-cholesterol; OGTT, oral glucose tolerance test; PL, phospholipids; PMA, phorbol 12-myristate 13-acetate; TC, total cholesterol; TG, triacylglycerol; TP , total protein; VLDL, very-low-density lipoprotein; VLDL-C, VLDL-cholesterol Correspondence: Dr. Tom´ as Mero˜ no (email tomasmero@yahoo.com.ar). of IO are hereditary conditions in which the expression or the regulation of iron metabolism-related proteins or hormones is affected [2]. The most common of these conditions is hereditary haemochromatosis (HH), an affliction caused by mutations in C  The Authors Journal compilation C  2015 Biochemical Society 609 Clinical Science www.clinsci.org