Zdrav Vestn Supl | Polymorphism AvaII of the LDL receptor I-5 Polymorphism AvaII of the LDL receptor 1 Univerza v Ljubljani, Medicinska fakulteta, Inštitut za histologijo in embriologijo 2 Kirurški oddelek, Splošna bolnišnica Murska Sobota 3 Radiološki oddelek, Splošna bolnišnica Murska Sobota 4 Interni oddelek, Splošna bolnišnica Slovenj Gradec 5 Interni oddelek, Splošna bolnišnica Murska Sobota 6 Fakulteta za vede o zdravju, Univerza na Primorskem 7 Inštitut za biostatistiko in medicinsko informatiko, Medicinska fakulteta, Univerza v Ljubljani Korespondenca/ Correspondence: prof. dr. Danijel Petrovič m: daniel.petrovic@ mf.uni-lj.si IZVIRNI ČLANEK/ORIGINAL ARTICLE Polymorphism AvaII of the LDL receptor (rs5925) is associated with carotid-intima media thickness in patients with diabetes mellitus type 2 Polimorfizem AvaII receptorja za holesterol LDL (rs5925) je povezan z debelino intime medije pri bolnikih s sladkorno boleznijo tipa 2 Jovana Nikolajević-Starčević,1 Dražen Popović,2 Marija Šantl Letonja,3 Jana Makuc,4 Maja Šeruga,5 Andreja Cokan Vujkovac,4 Zala Jenko Pražnikar,6 Janez Stare,7 Danijel Petrovič1 Izvleček Izhodišča: Povečana serumska koncentracija lipoproteinov nizke gostote (LDL) je pomem- ben dejavnik tveganja za pojav in napredovanje ateroskleroze. Genetska variabilnost v genu za receptor LDL lahko vpliva na serumsko koncen- tracijo LDL in odgovor na zdravljenje s statini ter tako na pojav in napredovanje ateroskleroze. V raziskavi smo želeli ugotoviti, ali obstaja poveza- nost med polimorfizmom AvaII gena za recep- tor LDL (rs5925) s serumskimi ravnmi lipidov in debelino intime medije pri bolnikih s sladkorno boleznijo tipa 2 (SB2). Metode: V raziskavo smo vključili 595 bolnikov s SB2 (399 zdravljenih s statini in 196 brez hipo- lipemika). Debelino intime medije smo izmerili s pomočjo B-načina ultrazvočnega prikaza. Bi- okemične analize smo opravili z uporabo stan- dardnih metod. Genotipizacija je bila izvedena z metodo PCR v realnem času. Rezultati: Razporeditev genotipov in alelne fre- kvence polimorfizma AvaII se niso statistično značilno razlikovale med bolniki s SB2, zdravlje- nimi s statini, in bolniki, ki niso jemali statinov. Pri bolnikih s SB2, zdravljenih s statini, smo najvišje serumske ravni celotnega holesterola in holesterola LDL ugotovili pri homozigotih A+A+. Po prilagoditvi na znane dejavnike tvega- nja za srčno-žilne bolezni so bili genotip A+A+ (β = 0.441 and p = 0.04), zdravljenje s statini kot tudi serumske ravni holesterola HDL, trigliceri- dov, visokoobčutljivega CRP in fibrinogena ne- odvisno povezani z debelino intime medije. Inte- rakcije genotipov A-A+ in A+A+ polimorfizma AvaII in zdravljenja s statini niso bile statistično značilne. Zaključki: Genotip A+A+ polimorfizma AvaII gena za LDL receptor je povezan z večjo debelino intime medije pri bolnikih s SB2. Abstract Introduction: Increased serum level of low- density lipoprotein (LDL) cholesterol is a well established risk factor for atherosclerosis devel- opment and progression. Genetic variation in the LDL receptor gene could modulate serum LDL level and response to statin treatment thus affecting atherosclerosis development and pro- gression. The present study was designed to in- vestigate the association between polymorphism AvaII (rs5925) of the LDL receptor gene with se- rum lipid levels and carotid intima-media thick- ness (CIMT) in patients with diabetes mellitus type 2 (DM2). Methods: 595 patients with DM2 (399 with statin therapy and 196 without) were enrolled in the study. The carotid intima-media thickness was assessed ultrasonographically. Biochemical anal- yses were performed using standard biochemical I-6 Zdrav Vestn Supl | julij 2014 | Letnik 83 IZVIRNI čLANEk/ORIGINAL ARTICLE Ključne besede: ateroskleroza; sladkorna bolezen tipa 2; debelina intime medije; LDL receptor; polimorfizem; farmakogenetika Key words: atherosclerosis; diabetes mellitus type 2; carotid intima- media thickness; LDL receptor polymorphism; pharmacogenetics Citirajte kot/Cite as: Zdrav Vestn 2014; 83 supl: I-5–12 Prispelo: 15. jul. 2013, Sprejeto: 4. mar. 2014 methods. AvaII (rs5925) genotypes were deter- mined by real-time PCR. Results: Genotype distribution and allele fre- quencies were not statistically significantly dif- ferent between DM2 patients with regard to statin therapy. In DM2 patients using statins the highest serum levels of total and LDL cholesterol were observed in homozygous carriers of the A+ allele. After adjustment for well established car- diovascular risk factors homozygosity for the A+ allele (β = 0.441 and p = 0.04), statin treatment as well as serum levels of HDL, triglycerides, hsCRP and fibrinogen were independently as- sociated with CIMT. Interactions of AvaII gen- otypes A-A+ and A+A+ with statin treatment were not statistically significant. Conclusion: Homozigosity for the A+ allele of the AvaII polymorphism is associated with greater CIMT in DM2 patients. Introduction Atherosclerotic cardiovascular disease (CVD) is now considered the major cause of chronic illness and early death in individu- als with diabetes mellitus type 2 (DM2). The increased cardiovascular disease burden in patients with DM2 could, at least partially, be attributed to abnormalities in lipid and lipoprotein metabolism. Increased serum levels of cholesterol, especially low density lipoprotein (LDL), is one of the most im- portant risk factors for atherosclerosis de- velopment and progression and its lowering remains the primary target in management of dislypidemia.1 LDL receptor (LDLR) plays an important role in cholesterol homeostasis as it regula- tes the uptake of LDL particles by the liver and delivers cholesterol to the adrenal glan- ds and gonads for steroid hormone synthe- sis and to the liver for bile acid synthesis.2 The human LDL receptor gene is located on chromosome 19 and contains 18 exons separated by 17 introns.3 Until now, more than 770 mutations in the LDLR gene were reported.4 Despite those causing familial hypercholesterolemia and consequently inc- reased CVD risk, the impact of mutations of the LDL receptor gene on serum choleste- rol levels and susceptibility to CVD is not well known. Previous studies reported an association between AvaII polymorphism and serum cholesterol level in both normo- lipidemic and hypercholesterolemic indivi- duals5-8, whereas Nakazone et al. reported no such association.9 AvaII polymorphi- sm has been also reported to be associated with variations in lipid lowering response to statin treatment in hypercholesterolemic patients.10,11 Furthermore, previous studi- es reported an association between AvaII polymorphism with CAD.7,12 Until now, there was no study investigating the associ- ation between AvaII polymorphism of the LDL receptor with carotid atherosclerosis. High-resolution B-mode ultrasono- graphy is a noninvasive method to assess vessel wall characteristics of the carotid ar- teries. It allows quantification of different surrogate markers of atherosclerosis such as carotid intima-media thickness (CIMT), presence of plaque and its structure as well as stenosis degree. CIMT is a good marker of early atherosclerosis and its progression.13 It correlates well with cardiovascular risk fac- tors and future cardiovascular events.14,15 The present study was designed to in- vestigate the association between the polymorphism AvaII (rs5925) of the LDL receptor gene with serum lipid levels and carotid intima-media thickness in subjects with diabetes mellitus type 2. Materials and Methods Patients In this cross-sectional study, 599 su- bjects with type 2 diabetes were enrolled. Among them 399 were on statin therapy: 234 (58.6 %) received atorvastatin 20 mg per day, 90 (22.5 %) received rosuvastatin 10 mg per day and 75 (18.9 %) received simvasta- tin 40 mg per day); 196 out of 599 subjects (33.4 %) with type 2 diabetes were without hypolipemic therapy. They were selected among patients admitted to the diabetes Polymorphism AvaII of the LDL receptor Zdrav Vestn Supl | Polymorphism AvaII of the LDL receptor I-7 IZVIRNI čLANEk/ORIGINAL ARTICLE outpatient clinics of the General Hospitals Murska Sobota and Slovenj Gradec, Slove- nia. Patients were excluded if they had ho- mozygous familial hypercholesterolaemia or a previous cardiovascular event such as myocardial infarction or a cerebral stroke. The research protocol was approved by the National Medical Ethics Committee. Clini- cal data, including smoking habits, duration and treatment of diabetes, arterial hyper- tension, hyperlipidemia and consuming any other drugs were obtained from medical records and questionnaires. Patients were asked if they were smokers at the time of recruitment (current smoker). Ultrasonographic analysis A high resolution B mode ultrasound analysis was performed using a portable ultrasound system, Toshiba Aplio SSA-700 (Toshiba Medical. System Corp., Tokyo, Ja- pan) connected to a multi-frequency (7.5–10 MHz) linear array transducer. All examina- tions were performed by two radiologists, blinded to the participant’s diabetes status. Patients were examined in the supine po- sition with the head tilted backwards. The carotid arteries were examined from the supraclavicular fossa to the submandibular angle, including the common carotid artery (CCA), carotid bifurcations and the origins of the internal carotid arteries (ICA). Polymorphism AvaII of the LDL receptor Table 1: Baseline characteristics of patients with DM2 with regard to statin therapy. Statin + n = 399 Statin - n = 196 p Age (years) 62.1 ± 8.5 61.7 ± 10.5 0.74 Male gender (%) 222 (55.6) 117 (59.7) 0.35 Duration of DM2 (years) 12.5 ± 11.3 11.9 ± 6.5 0.48 Smoking (%) 43 (10.8) 10 (5.1) 0.02 Waist circumference (cm) 110 (102–118) 106 (98–113) 0.03 BMI (kg/m2) 31.12 ± 4.62 30.34 ± 4.34 0.12 SBP (mm Hg) 148.7 ± 19.7 147.9 ± 21.6 0.74 DBP (mm Hg) 84.5 ± 11.3 86.9 ± 11.9 0.08 Fasting glucose (mmol/L) 8.24 ± 2.40 7.88 ± 2.78 0.44 HbA1c (%) 8.03 ± 4.51 7.54 ± 1.31 0.12 Total cholesterol (mmol/L) 4.55 ± 1.13 4.87 ± 1.31 0.03 HDL cholesterol (mmol/L) 1.1 (0.9–1.3) 1.2 (1.0–1.5) 0.51 LDL holesterol (mmol/L) 2.49 ± 0.92 2.90 ± 0.94 <0.001 Triglycerides (mmol/L) 2.2 (1.5–3.3) 2.2 (1.3–2.9) 0.64 hs-CRP (mg/L) 2.83 ± 2.65 2.74 ± 2.54 0.76 Fibrinogen (g/L) 3.97 ± 1.05 3.96 ± 1.18 0.93 ApoA1 (g/L) 1.68 ± 0.34 1.73 ± 0.34 0.42 ApoB (g/L) 0.87 ± 0.20 0.92 ± 0.21 0.19 Continuous variables were expressed as means ± standard deviations when normally distributed and as median (interquartile range) when asymmetrically distributed. Categorical variables were expressed as frequency (percentage). BMI-body mass index; SBP-systolic blood pressure; DBP-diastolic blood pressure; HbA1c – glycated haemoglobin; hs-CRP-high sensitivity C-reactive protein. I-8 Zdrav Vestn Supl | julij 2014 | Letnik 83 IZVIRNI čLANEk/ORIGINAL ARTICLE The CIMT, defined as the distance from the leading edge of the lumen-intima inter- face to the leading edge of the media-adven- titia interface, was measured at 3 sites along the 10mm-long segment of the far wall of the CCA free of plaques, in agreement with the carotid intima-media thickness con- sensus.16 The CIMT on the left and on the right were calculated as the mean of three readings, and the mean of the left and right CCA-CIMT measurements was used in the analysis. The interobserver reliability for CIMT measurements was found to be sub- stantial (κ = 0.74, p < 0.001). Biochemical analyses Blood samples for biochemical analyses: total cholesterol, triglyceride levels, high- -density lipoprotein (HDL), low-density lipoprotein (LDL) cholesterol level, fasting blood glucose and glycated haemoglobin (HbA1c), hsCRP and fibrinogen were col- lected after a 12-hour fasting period. All the blood biochemical analyses were determi- ned by using standard biochemical methods in the hospital’s accredited lab. Serum con- centrations of apolipoprotein B (ApoB) and apoliporpotein A1 (ApoA1) were measured by a turbidimetric immunoassay on an AU 680 Chemistry System analyzer (Beckman Coulter, Nyon, Switzerland). Genotyping The genomic DNA was extracted from 100µL of whole blood using a FlexiGene DNA isolation kit, in accordance with the recommended protocol (Qiagene GmbH, Hilden, Germany). The AvaII (rs5925) polymorphism was determined with real-ti- me PCR using StepOne™ (48-well) Real-Ti- me PCR Systems (Applied Biosystems, Fo- ster City, CA, USA). We used commercially available genotyping kit TagMan SNP Ge- notyping assay (C__2804279_10) (Applied Biosystem, Foster City, CA, USA) following the manufacturer’s instructions. Statistical analysis Continuous variables were expressed as means ± standard deviations, when normal- ly distributed, and as median (interquartile range) when asymmetrically distributed. Normality of the continuous variables was examined by the Kolmogorov–Smirnov test. Continuous clinical data were compared using an unpaired Student’s t test or analysis of variance (ANOVA) when normally dis- tributed and the Mann-Whitney U-test or the Kruskal-Wallis H-test when asymme- trically distributed. The Pearson X2 test was used to compare discrete variables and to test whether the genotypes distribution is in Hardy-Weinberg equilibrium. Pearson’s correlation was performed to examine the association between independent variables. Due to the high correlation of LDL choleste- rol with total cholesterol (r = 0.86, p < 0.001) and ApoB (r = 0.82, p < 0.001) they were not included together in the same statistical model. For the same reason, the body mass index (BMI) was not included in the mo- del together with the waist circumference (r = 0.45, p < 0.001) while the systolic blo- od pressure was not included in the model together with the diastolic blood pressure (r = 0.57, p < 0.001). To determine the association of the AvaII polymorphism with CIMT, a multiple linear regression analysis was performed. Linear regression model was adjusted for the pre- sence of well established cardiovascular risk factors: age, gender, BMI, smoking, hyper- tension and systolic blood pressure. The results were presented as standardized β coefficients and P-values. Model fitness was evaluated by r-squared (coefficient of deter- Polymorphism AvaII of the LDL receptor Table 2: Genotype distribution and allele frequencies of the AvaII polymorphism in subgroups of patients with diabetes with regard to statin therapy. AvaII Statin + n = 399 Statin – n = 196 p A-A- 67 (16.8) 26 (13.3) 0.41A-A+ 189 (47.4) 91 (46.4) A+A+ 143 (35.8) 79 (40.3) Allele frequencies A- 323 (40.5) 143 (36.5) 0.18 A+ 475 (59.5) 249 (63.5) Results were presented as frequency (percentage). Zdrav Vestn Supl | Polymorphism AvaII of the LDL receptor I-9 IZVIRNI čLANEk/ORIGINAL ARTICLE mination). A two-tailed P value less than 0.05 was considered statistically significant. A statistical analysis was performed using the SPSS program for Windows version 20 (SPSS Inc., Chicago, IL). Results Baseline characteristics of study participants The baseline clinical and biochemical characteristics of the study participants with regard to statin therapy are shown in Table 1. There was no statistically significant difference regarding age, gender distributi- on and duration of DM2 between the two subgroups. Patients with DM2 using statins had higher smoking prevalence (p = 0.02) and greater waist circumference (p = 0.03) than those without statin therapy. As expec- ted, serum levels of total and LDL choleste- rol were statistically significantly lower in patients with DM2 using statins (p = 0.03 and < 0.001, respectively). No statistically significant difference in BMI, systolic and diastolic blood pressure, fasting glucose and HbA1c levels was observed between the two subgroups of patients with DM2. Further- more, serum levels of ApoA1, ApoB and inflammatory markers (hsCRP and fibrino- gen) were not statistically significantly diffe- rent between the two subgroups. The AvaII genotype distribution and al- lele frequencies in patients with DM2 with regard to statin therapy are shown in Table 2. The genotype distribution in both subgro- ups of patients with DM2 was compatible Polymorphism AvaII of the LDL receptor Table 3: Plasma levels of lipid parameters and inflammatory markers and CIMT in patients with DM2 with regard to AvaII genotypes and statin treatment. Statin AvaII A-A- A-A+ A+A+ p Total chol. (mmol/L) + 4.14 ± 0.81 4.53 ± 1.21 4.76 ± 1.13 0.03 - 4.64 ± 1.39 4.67 ± 1.11 5.04 ± 1.51 0.27 LDL (mmol/L) + 2.14 ± 0.74 2.46 ± 0.93 2.68 ± 0.95 0.02 - 2.70 ± 0.68 2.78 ± 0.93 3.02 ± 1.01 0.28 HDL (mmol/L) + 1.1 (1.0–1.35) 1.1 (1.0–1.35) 1.1 (1.0–1.5) 0.73 - 1.1 (0.95–1.28) 1.2 (0.9–1.3) 1.1 (1.0–1.5) 0.75 Triglycerides (mmol/L) + 1.9 (1.25–2.75) 1.84 (1.28–2.8) 1.9 (1.3–2.7) 0.99 - 2.1 (1.0–2.7) 2.0 (1.4–3.1) 1.8 (1.2–2.3) 0.17 ApoA1 (g/L) + 1.54 ± 0.21 1.65 ± 0.39 1.64 ± 0.33 0.54 - 1.72 ± 0.30 1.68 ± 0.28 1.66 ± 0.33 0.92 ApoB (g/L) + 0.82 ± 0.24 0.85 ± 0.20 0.92 ± 0.18 0.18 - 0.97 ± 0.12 0.97 ± 0.17 0.89 ± 0.25 0.51 hs-CRP (mg/L) + 2.98 ± 2.56 2.64 ± 2.86 2.78 ± 2.65 0.77 - 2.19 ± 1.67 3.46 ± 3.81 2.99 ± 2.77 0.32 Fibrinogen (g/L) + 4.98 ± 1.48 4.34 ± 1.10 4.17 ± 1.14 0.13 - 4.72 ± 1.33 4.48 ± 1.12 4.16 ± 1.34 0.50 CIMT (µm) + 870 ± 276 924 ± 212 979 ± 194 0.26 - 967 ± 231 972 ± 267 999 ± 231 0.71 Continuous variables were expressed as means ± standard deviations when normally distributed and as median (interquartile range) when asymmetrically distributed. I-10 Zdrav Vestn Supl | julij 2014 | Letnik 83 IZVIRNI čLANEk/ORIGINAL ARTICLE with Hardy-Weinberg expectations. No sta- tistically significant difference in either ge- notype distribution or allele frequencies was observed in patients with DM2 with regard to statin therapy (p = 0.41 and 0.18, respec- tively). Biochemical parameters and CIMT with regard to AvaII genotypes Table 3 outlines the serum levels of lipid parameters, ApoA1, ApoB and inflammato- ry markers (hsCRP and fibrinogen) in pati- ents with DM2 with regard to AvaII geno- types and statin treatment. Serum levels of total and LDL cholesterol were statistically significantly different with regard to the AvaII genotypes in patients with DM2 using statins. Homozygous carriers of the A+ alle- le had the highest serum levels of total and LDL cholesterol (p = 0.03 and 0.02, respec- tively). In DM2 patients without statin the- rapy no statistically significant difference in biochemical parameters with regard to the AvaII genotypes was observed. In both subgroups of DM2 patients the greatest CIMT values were observed in ho- mozygous carriers of the A+ allele, but the differences were not statistically significant (p = 0.26 and 0.71) (Table 3). Association of AvaII polymorphism and statin treatment with CIMT The results of the multiple linear regres- sion analysis for variables independently as- sociated with CIMT are presented in Table 4. Interactions of AvaII genotypes A-A+ and A+A+ with statin treatment were not stati- stically significant (data not shown) so they have been excluded from the model. After adjustment for age, gender, BMI, smoking, hypertension and systolic blood pressure, variables independently associated with CIMT were: serum levels of HDL, triglyce- rides, hsCRP and fibrinogen as well as ho- mozygosity for the A+ allele and statin tre- atment. Homozygosity for the A+ allele was associated with greater CIMT (β = 0.441; p = 0.04). Interestingly, serum triglyceride level was inversely associated with CIMT (β = 0.327, p = 0.007). Serum ApoB level was not independently associated with CIMT (p = 0.37). The model explained 44 % of va- riation of CIMT. Replacing serum levels of ApoB in the model with LDL did not change the results of multivariate linear regression analysis to any meaningful extent. Discussion In the present study we observed an as- sociation between homozygosity for the A+ allele of the AvaII polymorphism and CIMT in patients with diabetes mellitus type 2. To the best of our knowledge, this is the first study investigating the association be- tween LDL receptor polymorphism and CIMT in patients with diabetes mellitus type 2. In the present study the distribution of AvaII genotypes and allele frequencies were not statistically significantly different between DM2 patients with regard to statin treatment. Frequency of the A+ allele and A+A+ polymorphism observed in our study were higher than those previously reported in healthy European populations.17,18 Simi- lar pattern of the AvaII genotypes distributi- on have been previously reported in patients with high risk CVD7,10. Common DNA polymorphisms in ge- nes involved in lipid metabolism could be Polymorphism AvaII of the LDL receptor Table 4: Linear regression analysis for variables independently associated with CIMT. CIMT β p HDL (mmol/L) -0.351 0.006 ApoB (g/L) 0.009 0.37 Triglycerides (mmol/L) -0.327 0.007 hsCRP (mg/L) 0.271 0.04 Fibrinogen (g/L) 0.362 0.01 Statin treatment -0.237 0.04 A-A+ 0.242 0.26 A+A+ 0.441 0.04 Model adjusted for age, gender, BMI, smoking, hypertension and systolic blood pressure. Zdrav Vestn Supl | Polymorphism AvaII of the LDL receptor I-11 IZVIRNI čLANEk/ORIGINAL ARTICLE responsible for normal variation in serum lipid profile and consequently to susceptibi- lity to CVD. The evidence of an association between AvaII polymorphism and serum lipid levels is consistent, showing higher serum levels of total and LDL cholesterol in individuals carrying the A+ allele.5-8 As some previous studies reported that AvaII polymorphism could affect lipid lowering response to treatment with fluvastatin and pravastatin10,11 we analyzed lipid parame- ters in DM2 patients on statin therapy and those without statin separately. In both su- bgroups of DM2 patients serum levels of total and LDL cholesterol increased from A-A- to the A+A+ genotype. However, dif- ferences in serum total and LDL cholesterol levels were statistically significantly different only in those on statin therapy. Limited number of studies investiga- ting the association between the AvaII polymorphism and response to statin tre- atment yielded contradictory results.10,11 However, in the present study interactions of both A-A+ and A+A+ genotype with sta- tin treatment were not statistically signifi- cant. Further prospective studies are needed to elucidate whether the AvaII polymorphi- sm of the LDL receptor gene affects response to statin treatment. After adjustment for well established risk factors for atherosclerosis, homozygosity for the A+ allele was independently associated with increased CIMT. Due to the LDL par- ticles’ heterogeneity, a high concentration of small particles can occur despite a normal LDL cholesterol level, as often seen in pati- ents with diabetes. As the total serum ApoB level may give a better estimate of the con- centration of atherogenic particles than the LDL level,19 we adjusted linear regression analysis for ApoB level instead for LDL. Our results further support the evidence of association between A+A genotype with CVD.7,12 This association is, at least partial- ly, mediated by higher serum levels of total and LDL cholesterol observed in A+A+ ho- mozygtes in both subgroups of DM2 pati- ents. However, the mechanism underlying such association is still unknown. AvaII polymorphism represents a silent mutation which does not affect amino acid sequen- ce, so the observed association probably results from a linkage disequilibrium with other functional variant.5,17 Moreover, it has been suggested that the second domain of the LDL receptor (coded by exon 13) is 33 % homologous with a portion of the extracel- lular domain of the epidermal growth fac- tor precursor, a peptide hormone involved in growth stimulation.3,20 However, the im- portance of this finding needs to be further investigated. Our study has possible limitations due to its cross-sectional design and relatively small sample size, providing limited power to study moderate genetic effects and to de- tect interactions with other, potentially rele- vant variables. Further studies are needed to definitely elucidate the impact of the gene- tic variability of the LDLR gene in modula- ting lipid and apolipoprotein levels as well as CVD risk. Further prospective studies are needed to elucidate whether the AvaII polymorphism of the LDL receptor gene af- fects response to statin treatment. Conclusion This is the first study investigating the association of the AvaII polymorphism with CIMT in patients with DM2. We observed an association between homozigosity for the A+ allele with greater CIMT in patients with diabetes. References 1. Catapano AL, Reiner Z, De Backer G, Graham I, Taskinen MR, Wiklund O et al. ESC/EAS Guide- lines for the management of dyslipidaemias The Task Force for the management of dyslipidaemi- as of the European Society of Cardiology (ESC) and the European Atherosclerosis Society (EAS). Atherosclerosis 2011; 217: 3-46. 2. Brown MS, Goldstein JL. A receptor-mediated pathway for cholesterol homeostasis. Science 1986; 232: 34-47. 3. 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