Lipoprotein(a) Is an Independent Risk Factor for Peripheral Arterial Disease in Chinese Type 2 Diabetic Patients in Taiwan

OBJECTIVE: To examine the association between lipoprotein(a) Lp(a) and peripheral arterial disease (PAD) and determine the optimal cutoff in Chinese type 2 diabetic patients in Taiwan. RESEARCH DESIGN AND METHODS: Serum Lp(a) was determined in 557 type 2 diabetic patients (243 men and 314 women) recruited consecutively from a diabetes clinic at the National Taiwan University Hospital. Ankle-brachial index (ABI) <0.9 was diagnosed as PAD (n = 45) and <0.8 as severe PAD (n = 20). Potential confounders included age, sex, BMI, waist-to-hip ratio (WHR), diabetes duration, insulin usage, smoking, hypertension, systolic and diastolic blood pressure, fasting plasma glucose (FPG), total cholesterol, triglycerides, and HDL and LDL cholesterol. RESULTS: The distribution of Lp(a) was right skewed and no significant differences for sex, WHR, insulin usage, smoking, hypertension, and systolic and diastolic blood pressure were observed. In men, logLp(a) was correlated positively with age, duration, and total and LDL cholesterol (borderline significant, P < 0.1) and negatively with BMI, triglycerides, and FPG (P < 0.1). In women, logLp(a) was correlated positively with total and LDL cholesterol and negatively with triglycerides and BMI (P < 0.1). ABI was significantly correlated with logLp(a), especially in men or in patients with PAD. The optimal cutoff determined by discriminant analysis was 13.3 mg/dl. Patients with Lp(a) above this value had a 2.7-fold higher risk of PAD after multivariate adjustment. Lp(a) also significantly increased from no PAD to mild and severe PAD (17.1 +/- 14.4, 23.7 +/- 20.3, and 36.9 +/- 22.8 mg/dl, respectively, P < 0.001). CONCLUSIONS: Lp(a) is an independent risk factor for PAD in type 2 diabetic patients in Taiwan. The optimal cutoff is 13.3 mg/dl.