Division of Anti-aging, Department of Internal Medicine, National Defense Medical College, Tokorozawa, Japan.
J Atheroscler Thromb. 2012;19(7):664-72. doi: 10.5551/jat.12666. Epub 2012 May 10.
Cigarette smoking is a strong risk factor for atherosclerotic disease; however, it remains unclear whether the impact of other risk factors differs by smoking status. The aim of this study was to investigate this issue, especially with regard to low-density and high-density lipoprotein (LDL/HDL) levels.
In total, 448 healthy, middle-aged men (aged 37 to 61) participated in this study. Smoking habits were recorded, carotid intima-media thickness (IMT) was measured by B-mode ultrasound, and serum lipids and other biochemical parameters were determined from fasted blood samples.
Among the overall subjects, multivariate regression analyses showed that IMT was significantly associated with age (p < 0.0001 for mean IMT, p= 0.002 for max IMT), body mass index (BMI, mean IMT, p= 0.028), LDL-C levels (mean/max IMT, p= 0.001), HDL-C levels (max IMT, p= 0.022) and current smoking habit (mean IMT, p=0.012). Subgroup analyses according to smoking status revealed that LDL-C levels were significantly associated with mean/max IMT in current smokers (p=0.001) but not in ex- or nonsmokers (never smoked subjects). After adjusting for age, BMI, systolic blood pressure, hemoglobin A1c and serum lipids, mean IMT respectively increased and decreased progressively across LDL-C and HDL-C quartiles (p= 0.004 and 0.045) in the overall subjects. These associations were observed in current smokers (p= 0.01) but not in ex- or nonsmokers for LDL-C, and were observed in ex- and nonsmokers (p= 0.025, 0.017, respectively) but not in current smokers for HDL-C.
The impact of LDL-C/HDL-C levels on carotid IMT differs by smoking status. These observations imply that distinct mechanisms are involved in the (anti) atherogenesis of LDL/HDL according to smoking status.
吸烟是动脉粥样硬化疾病的一个重要危险因素；然而，目前尚不清楚其他危险因素的影响是否因吸烟状况而异。本研究旨在探讨这一问题，特别是在低密度脂蛋白（LDL）/高密度脂蛋白（HDL）水平方面。
共有 448 名健康的中年男性（年龄 37 至 61 岁）参与了这项研究。记录吸烟习惯，通过 B 型超声测量颈动脉内膜-中层厚度（IMT），并从空腹血样中测定血清脂质和其他生化参数。
在所有受试者中，多变量回归分析显示，IMT 与年龄显著相关（平均 IMT 的 p<0.0001，最大 IMT 的 p=0.002）、体重指数（BMI，平均 IMT，p=0.028）、LDL-C 水平（平均/最大 IMT，p=0.001）、HDL-C 水平（最大 IMT，p=0.022）和当前吸烟习惯（平均 IMT，p=0.012）。根据吸烟状况进行的亚组分析显示，LDL-C 水平与当前吸烟者的平均/最大 IMT 显著相关（p=0.001），但与前吸烟者或不吸烟者无关（从未吸烟的受试者）。在调整年龄、BMI、收缩压、糖化血红蛋白和血清脂质后，在所有受试者中，LDL-C 和 HDL-C 四分位数的平均 IMT 分别呈递增和递减趋势（p=0.004 和 0.045）。这些关联在前吸烟者中观察到（p=0.01），但在非吸烟者或从不吸烟者中未观察到 LDL-C 的关联，在后吸烟者和非吸烟者中观察到（p=0.025，0.017），但在当前吸烟者中未观察到 HDL-C 的关联。
LDL-C/HDL-C 水平对颈动脉 IMT 的影响因吸烟状况而异。这些观察结果表明，根据吸烟状况，LDL/HDL 的抗动脉粥样硬化机制不同。
