Ultrasonographically assessed carotid atherosclerosis in Japanese type 2 diabetic patients: Role of nonesterified fatty acids.
The aim of the present study was to evaluate the association of carotid atherosclerosis (intimal-medial thickness [IMT] in plaque-free segments and carotid stenosis in plaque segments) with serum nonesterified fatty acids (NEFA) in diabetic and nondiabetic patients. Fifty-one nonobese nonhypertensive Japanese type 2 diabetic patients aged 38 to 83 years (60.0 +/- 1.5 years, mean +/- SEM) and 23 age-matched (60.4 +/- 2.2 years, P =.439; range, 36 to 74 years) and sex-matched nondiabetic subjects were examined. The duration of diabetes was 9.6 +/- 1.0 years. Body mass index (BMI), blood pressure (systolic pressure, diastolic pressure), glycosylated hemoglobin (HbA(1c)), and fasting concentrations of plasma glucose, serum lipids (triglycerides, total, and high-density lipoprotein [HDL] cholesterol, low-density lipoprotein [LDL] cholesterol) and serum NEFA were measured. Using high-resolution B-mode ultrasound scan, we measured IMT in plaque-free segments of bilateral common carotid arteries, and the mean of IMT in 2 vessels was used for the analysis. Furthermore, we calculated the degree of stenosis in plaque segments of bilateral common carotid arteries. The degree of carotid stenosis was expressed as a percentage ratio between the area of plaque and that of the lumen using the formula (Lumen Area - Residual Lumen) x 100. Both the areas were automatically measured by the system on a frozen transverse scanning plane at the site of maximal narrowing. When 2 or more plaques were present in the vessel, only that causing the greatest degree of stenosis was considered for analysis. Univariate regression analyses showed that mean IMT in plaque-free segments was positively correlated with age (r =.498, P =.0004) and NEFA (r =.354, P =.0188) in type 2 diabetic patients. The degree of stenosis was positively correlated to age (r =.422, P =.0028), duration of diabetes (r =.313, P =.0268) and NEFA (r =.540, P =.0003) in diabetic patients. Other variables, including BMI and lipid profile, were not associated both with mean IMT in plaque-free segments and the degree of stenosis in plaque segments in our diabetic patients. Multiple regression analyses showed that mean IMT in plaque-free segments was independently associated with age (P =.0003, F = 15.2), which explained 26.1% of the variability of IMT in our diabetic patients. The degree of stenosis was independently predicted by NEFA (P =.0047, F = 8.9), which explained 17.2% of the variability of the carotid stenosis in our diabetic patients. In contrast, mean IMT in plaque-free segments was positively correlated to age in nondiabetic subjects (r =.450, P =.0347). There was, however, no relationship between the degree of stenosis and the variables, including age and NEFA, in nondiabetic subjects. These results indicate that the factors contributing to IMT in plaque-free segments and the degree of carotid stenosis in plaque segments are different in nonobese nonhypertensive Japanese type 2 diabetic patients. IMT in plaque-free segments was independently associated with age both in nondiabetic and diabetic subjects, whereas the serum NEFA level independently predicted the degree of stenosis in plaque segments in our diabetic patients, while not in nondiabetic subjects. Thus, NEFA is considered to be one of the new risk factors responsible for the progression of carotid atherosclerosis in nonobese nonhypertensive Japanese type 2 diabetic patients.
Taniguchi A
,Nakai Y
,Fukushima M
,Teramura S
,Hayashi R
,Hama K
,Marumoto K
,Watanabe T
,Yoshioka I
,Sakaguchi K
,Kishimoto H
,Matsushita K
,Okumura T
,Tokuyama K
,Nagasaka S
,Sakai M
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Maximum carotid intima-media thickness improves the prediction ability of coronary artery stenosis in type 2 diabetic patients without history of coronary artery disease.
Carotid intima-media thickness (CIMT), a marker of early atherosclerosis and vascular remodelling, is one of the independent predictors of coronary artery disease (CAD). However, it is unknown whether ultrasonic assessment of carotid atherosclerosis, including CIMT, improves the prediction ability for CAD over and above conventional coronary risk factors in the diabetic patients.
Ultrasonic scanning of the common carotid artery (CCA), the carotid bulb (Bul), and the internal carotid artery (ICA) was performed. The site with the greatest IMT, including plaque lesions, was sought along the arterial walls and max-IMT (the greatest IMT in the observation-possible areas of the CCA, Bul and ICA) was measured. The association of max-IMT with coronary artery stenosis assessed by coronary computed tomography angiography and the incremental effect of adding max-IMT to the conventional risk factors for predicting coronary artery stenosis were evaluated in 241 asymptomatic type 2 diabetic patients.
Multiple logistic regression analyses showed that max-IMT was significantly associated with coronary artery stenosis even after adjustment for conventional risk factors. ROC curve analysis revealed that the AUC significantly increased after addition of max-IMT to conventional coronary risk factors [from 0.64 (95% CI; 0.57-0.71) to 0.74 (95% CI; 0.67-0.80), p = 0.020]. The addition of max-IMT to conventional coronary risk factors increased the AUC in obese patients (from 0.58 to 0.76, p = 0.012) but not in non-obese patients (from 0.68 to 0.72, NS).
In type 2 diabetic patients without apparent cardiovascular disease, the addition of max-IMT to conventional risk factors substantially improves the risk stratification for CAD.
Irie Y
,Katakami N
,Kaneto H
,Kasami R
,Sumitsuji S
,Yamasaki K
,Tachibana K
,Kuroda T
,Sakamoto K
,Umayahara Y
,Ueda Y
,Kosugi K
,Shimomura I
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