Lipoprotein(a) and peripheral atherosclerosis in older adults

As part of an ancillary study to the Systolic Hypertension in the Elderly Program, carotid and lower extremity arterial disease (LEAD) were evaluated in 369 subjects, 186 with a systolic blood pressure (SBP) greater than or equal to 160 mmHg, and 183 with SBP < 160 mmHg. Both groups had a diastolic blood pressure (DBP) < 90 mmHg. Internal carotid stenosis was identified by Doppler and LEAD was assessed using the ankle to arm systolic blood pressure ratio, commonly called the ankle/arm index (AAI). Lp(a) values were obtained from frozen sera and values greater than or equal to 20 mg/dl were considered elevated. Rates of carotid stenosis were 24% among those with an Lp(a) greater than or equal to 20 mg/dl and 14% among those with an Lp(a) level < 20 mg/dl (P = 0.020). The relationship between Lp(a) and LEAD was even stronger. Those with an Lp(a) greater than or equal to 20 mg/dl had a 36% prevalence of a low AAI vs 14% among those with a Lp(a) level < 20 mg/dl (P < 0.001). Lp(a) values were also associated with the severity of LEAD. Controlling for other risk factors did not reduce the association between either LEAD or carotid stenosis and an Lp(a) greater than or equal to 20 mg/dl. Thus, Lp(a) appears to be independently associated with peripheral atherosclerosis in older adults, both men and women. The relationship is particularly strong for atherosclerotic disease of the lower extremities.