Atherosclerosis 233 (2014) 429e433

Contents lists available at ScienceDirect

Atherosclerosis journal homepage: www.elsevier.com/locate/atherosclerosis

High hexacosanoic acid levels are associated with coronary artery disease Tetsuro Miyazaki a, *, Kazunori Shimada a, Makoto Hiki a, Atsumi Kume a, Yohei Kitamura b, Kyoichi Oshida c, Naotake Yanagisawa b, Takashi Kiyanagi a, Rie Matsumori a, Hiroyuki Daida a a b c

Department of Cardiovascular Medicine, Juntendo University School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan Nutrition Research Department, Nutritional Science Institute, Morinaga Milk Industry Co., Ltd., Kanagawa, Japan Kemin Japan KK, Tokyo, Japan

a r t i c l e i n f o

a b s t r a c t

Article history: Received 20 September 2013 Received in revised form 23 December 2013 Accepted 15 January 2014 Available online 28 January 2014

Aims: Levels of saturated very long chain fatty acids (VLCFAs) are associated with coronary risk factors, including metabolic syndrome (MS), atherogenic lipoproteins, and systemic inflammation. However, the relationship between circulating levels of saturated VLCFA and coronary artery disease (CAD) remains unclear. Method: We enrolled 100 consecutive CAD patients and 40 age-, gender-, and body mass index (BMI)matched healthy control subjects. The levels of hexacosanoic acid (C26:0), a VLCFA, in whole blood were measured by gaseliquid chromatography mass spectrometry. Results: C26:0 levels were significantly higher in the CAD group than in the control group (2.42  0.32 vs. 2.27  0.24 mg/ml, P ¼ 0.01) and positively correlated with BMI (r ¼ 0.23, P ¼ 0.008), triglyceride levels (r ¼ 0.22, P ¼ 0.01), and hypertension (P ¼ 0.01). CAD patients with MS showed the highest C26:0 levels adjusted by hematocrit. Furthermore, adjusted C26:0 levels in CAD patients without MS were higher than those in controls (P ¼ 0.02), suggesting that C26:0 levels increased with the presence of CAD independent of MS. Our multivariate analysis revealed that high C26:0 levels in whole blood is an independent marker for CAD even after adjustment for age, gender, BMI, lipid profiles, fasting plasma glucose, and blood pressure. Conclusion: High C26:0 levels in whole blood may be an independent marker for identifying the risks of CAD. Ó 2014 Elsevier Ireland Ltd. All rights reserved.

Keywords: Saturated very long-chain fatty acid Coronary artery disease Hexacosanoic acid Metabolic syndrome Peroxisomal dysfunction

1. Introduction Saturated very long chain fatty acids (VLCFAs) are minor fatty acid components in human tissues and bloodstream. However, levels of C26:0, one of the saturated VLCFAs, in erythrocytes are associated with risks of age-related diseases [1]. A recent report suggested that peroxisome-related alterations and increased VLCFAs may contribute to the progression of Alzheimer’s disease [2,3]. We also reported that absolute C26:0 levels in whole blood are significantly associated with metabolic syndrome (MS) [4]. Furthermore, increased levels of another saturated VLCFA, C24:0, in erythrocytes was found to correlate with atherogenic lipoprotein profiles and inflammatory states measured by high-sensitivity C

* Corresponding author. Tel.: þ81 3 5802 1056; fax: þ81 3 5689 0627. E-mail address: [email protected] (T. Miyazaki). 0021-9150/$ e see front matter Ó 2014 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.atherosclerosis.2014.01.031

reactive protein (hs-CRP) [5]. However, few studies have investigated correlations between C26:0 levels and coronary artery disease (CAD). To our knowledge, this is the first study to demonstrate that C26:0 levels are significantly higher in CAD patients than in healthy control subjects. C26:0 levels significantly correlated with several coronary risk factors, thus representing an independent risk factor for CAD after adjustment for other coronary risk markers. 2. Materials and methods 2.1. Study subjects Our previous study showed mean and standard deviation (SD) of C26:0 levels in healthy subjects was 2.25  0.29 mg/ml whereas C26:0 levels were 2.42  0.31 mg/ml in subjects with MS [4].

430

T. Miyazaki et al. / Atherosclerosis 233 (2014) 429e433

Therefore, we estimated a difference in mean C26:0 levels of 0.3 mg/ ml between CAD patients and healthy controls, and a SD in C26:0 of 0.3 mg/ml. At least 34 subjects were needed in each group to have 80% power at the 5% significance levels to detect the anticipated difference between the two groups. Finally, we studied 100 consecutive patients with angiographic documentation of CAD at our institution and 40 age-, gender-, and body mass index (BMI)matched healthy control subjects. Coronary angiography was performed according to standard methods [6,7]. Angiograms of the CAD group showed >50% stenosis of at least one major coronary artery. Patients with acute coronary syndrome, ongoing congestive heart failure, and/or liver and/or renal dysfunction were excluded. Subjects who had anemia [male: hemoglobin (Hb) < 13 g/dL, female; Hb < 11 g/dL] were also excluded. All subjects gave informed consent, and the study was approved by the local ethical committee. Blood pressure (BP) was measured with a standard mercury sphygmomanometer after the subjects had rested for >5 min. The mean of two measurements of seated systolic and diastolic BP was used. Height and weight were measured using an automated scale, and BMI was calculated as the weight in kilograms divided by the square of height in meters. CAD patients were divided into MS and non-MS groups according to the modified International Diabetes Federation (IDF) definition of MS [8]. In brief, subjects with MS were defined as having a BMI of 25 plus two or more of the following factors: (1) elevated concentration of triglycerides (TG > 150 mg/dl) or specific treatment for this lipid abnormality; (2) reduced concentration of high density lipoprotein cholesterol (HDL-C < 40 mg/dl) or specific treatment for this lipid abnormality; (3) elevated BP (systolic BP > 130 mm Hg or diastolic BP > 85 mm Hg) or treatment for previously diagnosed hypertension; (4) elevated fasting plasma glucose (FPG concentration > 100 mg/dl) or previously diagnosed type 2 diabetes. 2.2. Blood sampling Whole blood samples were drawn after overnight fasting. Serum levels of total cholesterol (TC), TG, and HDL-C were measured by standard enzymatic methods and low-density lipoprotein cholesterol (LDL-C) values were calculated using the Friedewald formula [9]. Plasma glucose concentrations, serum insulin levels, and HbA1c, NGSP) were measured by standardized methods. 2.3. Measurement of C26:0 levels in whole blood C26:0 levels were measured as previously described [4]. C26:0 in whole blood was directly transmethylated with 14% boron trifluoride methanol solution (Sigma Aldrich Japan, Tokyo, Japan) at 90  C for 90 min. The quantification of C26:0 was performed by a fused silica capillary column (Rtx-5MS, 30 m  0.25 mm i.d.; 0.25 mm film thickness, Restek, USA) gase liquid chromatography mass spectrometry (GCeMS) system (QP2010, Shimadzu Corporation, Kyoto, Japan) using nonacosanoic acid (C29:0) methyl ester as an internal standard. The mass spectrum acquisitions of C26:0 and C29:0 methyl esters were performed in selected-ion monitoring (SIM) mode, and the target ions of these fatty acid methyl esters were 410.40 m/z and 452.40 m/z, respectively. 2.4. Statistical analysis Continuous variables were expressed as mean  SD, and categorical variables were reported as percentages. Statistical differences between the groups were analyzed by Student’s t-tests, chi-

square tests, and TukeyeKramer method. Correlations between two variables were determined by simple linear regression analysis. Stepwise multiple linear regression analysis was used to determine the factors independently related to the presence of CAD. JMP (Version 5.0 for Windows, SAS Institute, Cary, NC) was used to perform statistical analysis. P-values < 0.05 were considered statistically significant. 3. Results 3.1. Characteristics of study subjects The characteristics of the subjects in the present study are shown in Table 1. The two groups were not significantly different in terms of age, gender, BMI, and smoking status. The CAD group more often had a history of hypertension, diabetes mellitus, and dyslipidemia (P < 0.001, respectively). In the CAD group, plasma TC and TG levels were significantly increased and HDL-C levels were significantly decreased compared with the controls (P < 0.001, respectively). However, plasma LDL-C levels were not significantly different between the two groups. In the CAD group, FPG and HbA1c levels were significantly increased compared with the controls (P < 0.001, respectively). The levels of hs-CRP and serum creatinine did not differ between the two groups. Hematocrit levels were significantly higher in the control than in the CAD group (P ¼ 0.04). Patients in the CAD group received more statins, calcium channel blocker, b-blocker, and oral hypoglycemic drug therapy than those in the control group (P < 0.0001, respectively). The total number of patients treated with angiotensin-converting enzyme inhibitor (ACE-I) and/or angiotensin II receptor blocker (ARB) in the CAD group was significantly higher than that in the control group (P < 0.0001). Patients in the CAD group received more insulin therapy than those in the control group (P ¼ 0.08). Table 1 Characteristics of the study subjects.

Age (years) Male Body mass index (kg/m2) Current smoker Hypertension Hyperlipidemia Diabetes mellitus Systolic blood pressure (mmHg) Diastolic blood pressure (mmHg) Total cholesterol (mg/dL) Triglyceride (mg/dL) HDL cholesterol (mg/dL) LDL cholesterol (mg/dL) Fasting plasma glucose (mg/dL) HbA1c (%) Hs-CRP Creatinine Hematocrit Medications Statins Fibrate CCB b-blocker (%) ACE-I/ARB (%) Oral hypoglycemic drug Insulin

Control (n ¼ 40)

CAD (n ¼ 100)

P value

60  5 35 (88%) 24.0  2.6 13 (33%) 3 (8%) 19 (48%) 1 (3%) 125  10 79  8 211  36 124  80 68  19 118  31 99  12 5.7  0.5 0.162  0.489 0.9  0.2 43.8  3.6

61  6 89 (89%) 24.3  2.5 25 (25%) 76 (76%) 86 (86%) 45 (45%) 122  13 68  11 186  38 144  73 44  12 115  31 111  26 6.2  1.4 0.239  0.700 0.8  0.2 42.4  2.9

NS NS NS NS

High hexacosanoic acid levels are associated with coronary artery disease.

Levels of saturated very long chain fatty acids (VLCFAs) are associated with coronary risk factors, including metabolic syndrome (MS), atherogenic lip...
366KB Sizes 2 Downloads 2 Views