Objectives: To determine the significance of Lipoprotein (a) (Lp(a)) as a risk factor for atherosclerotic lower limb peripheral vascular disease (PVD), and its relationship to other demographic and biochemical variables and disease pattern and severity.
Design: Prospective case-control study.
Material and methods: Demographic and biochemical risk factors, lipoprotein fractions and Lp(a) were measured in 200 patients with PVD and 200 age- and sex-matched control subjects. Lp(a) levels were correlated with traditional risk factors and clinical and vascular laboratory disease parameters.
Results: Patients with PVD have a higher incidence of smoking, hypertension, and diabetes mellitus; and had significantly higher levels of serum cholesterol, triglycerides, LDL, VLDL, apolipoprotein B, fasting glucose, fibrinogen, plasminogen, haematocrit, white cell and platelet counts; but lower levels of HDL and apolipoprotein A1. Fasting Lp (a) concentration is an independent risk factor for PVD and is significantly higher in the patients (median = 26.1 mg/dl [4.8-195], mean = 36.5 +/- 32.6 mg/dl) than in controls (median = 18.2 mg/dl [5.4-216], mean = 27.2 +/- 28.1 mg/dl; p < 0.0001). In patients with PVD, Lp(a) correlated positively with plasma LDL, cholesterol, fibrinogen, renal disease, and apolipoprotein B. Fasting levels of > 24 mg/dl incurred a two-fold increase in risk of PVD. Patients with a higher Lp(a) have a significantly higher incidence of resting pain and ulcerations, and regression analysis confirmed smoking and Lp(a) level to be associated with the SVS category of disease severity.
Conclusions: Lipoprotein (a) is a significant independent risk factor for PVD. Lp(a) levels correlated with LDL, cholesterol, fibrinogen, apolipoprotein B and disease severity. An elevated Lp(a) level may be associated with more severe forms of PVD.