RESUMO
BACKGROUND: Arterial stiffness of patients with coronary artery disease (CAD), which is expected to be increased due to a generalized atherosclerotic process of human body, may be more evident after the acute increase of blood pressure (BP) or peripheral vascular resistance. Isometric handgrip exercise is a simple and easily applicable method to achieve this goal. We investigated the changes of hemodynamic parameters and arterial stiffness indexes after handgrip exercise in patients with CAD. METHODS: Forty-two subjects, who underwent coronary angiography (CAG), were enrolled. After CAG, baseline arterial waveforms were traced at the aortic root and external iliac artery using right coronary catheters. Arterial waveforms were recorded at 1, 2, and 3 min in the aortic root and at 3 min in the external iliac artery after isometric handgrip exercise at 30% ~ 40% of the maximal handgrip power. Augmentation pressure (AP) and augmentation index (AIx) were measured at aortic pressure waveforms. Pulse wave velocity (PWV) was calculated using the ECG-gated time difference of the upstroke of arterial waveforms and the distance between the aortic root and the external iliac artery. RESULTS: Thirty patients had CAD (CAD group), and others showed no significant coronary stenosis (non-CAD group). Baseline hemodynamic parameters including AIx and PWV were not different between both groups. After isometric handgrip exercise, central systolic blood pressure (BP), central diastolic BP, central pulse pressure, peripheral systolic BP, and peripheral pulse pressure were increased in all patients. AIx inclined significantly from 1 min after exercise only in patients with CAD (before 17.7% ± 9.7% vs. 3 min after exercise 22.3% ± 10.7%, p < 0.001). PWV also increased significantly after exercise only in patients with CAD (before 10.03 ± 1.99 m/s vs. 3 min after 11.09 ± 2.45 m/s, p < 0.001). CONCLUSIONS: Arterial stiffness indexes at rest were not different between patients with and without CAD. After isometric handgrip exercise, increased arterial stiffness became evident only in patients with CAD.
RESUMO
BACKGROUND: Increased low density lipoprotein cholesterol (LDL-C) level and the presence of metabolic syndrome (MetS) are important risk factors for cardiovascular disease (CVD) in type 2 diabetes mellitus (T2DM). Recent studies demonstrated apolipoprotein B (apoB), a protein mainly located in LDL-C, was an independent predictor of the development of CVD especially in patients with T2DM. The aim of this study was to investigate the relationship between apoB and MetS in T2DM patients. METHODS: We analyzed 912 patients with T2DM. Fasting blood samples were taken for glycated hemoglobin, high-sensitivity C-reactive protein, total cholesterol, triglyceride (TG), high density lipoprotein cholesterol, LDL-C, and apoB. MetS was defined by the modified National Cholesterol Education Program Adult Treatment Panel III criteria. We performed a hierarchical regression analysis with apoB as the dependent variable. Age, sex, the number of components of MetS and LDL-C were entered at model 1, the use of lipid-lowering medications at model 2, and the individual components of MetS were added at model 3. RESULTS: Seventy percent of total subjects had MetS. ApoB level was higher in subjects with than those without MetS (104.5±53.3 mg/dL vs. 87.7±33.7 mg/dL, P<0.01) even after adjusting for LDL-C. ApoB and LDL-C were positively correlated to the number of MetS components. The hierarchical regression analysis showed that the increasing number of MetS components was associated with higher level of apoB at step 1 and step 2 (ß=0.120, P<0.001 and ß=0.110, P<0.001, respectively). At step 3, TG (ß=0.116, P<0.001) and systolic blood pressure (ß=0.099, P<0.05) were found to significantly contribute to apoB. CONCLUSION: In patients with T2DM, apoB is significantly related to MetS independently of LDL-C level. Of the components of MetS, TG, and systolic blood pressure appeared to be determinants of apoB.