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, log[Lp(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, log[Lp(a)] was correlated positively with total and LDL cholesterol and negatively with triglycerides and BMI (P < 0.1). ABI was significantly correlated with log[Lp(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.