The association between physical activity, cardiorespiratory fitness, and lipoprotein(a) concentrations in a tri-ethnic sample of women: The Cross-Cultural Activity Participation Study

The purpose of this cross-sectional study was threefold: (1) to examine ethnic differences in plasma lipoprotein(a) [Lp(a)] concentrations; (2) to examine the relationship between physical activity levels (moderate, moderate-vigorous, and total MET-min/day) and Lp(a) concentrations; and (3) to determine the relationship between maximal treadmill time and Lp(a) concentrations among African-American, Native American, and Caucasian women (n=140, ages 40-70 years: 54.5+/-10.7). Physical activity records were kept for two 4-day periods, scheduled 1 month apart, a total of 8 days, and each activity was assigned a code from the 'Compendium of physical activity'. Subjects completed a graded exercise test to determine maximal treadmill time, and a fasted blood sample was collected to quantify Lp(a) concentration. Lp(a) concentrations were negatively skewed with a geometric mean of 28.3 mg/dl (25-75%: 10.4-43.1 mg/dl) in African-Americans (n=47), 2.9 mg/dl (25-75%: 1.2-7.4 mg/dl) in Native Americans (n=45), and 9.4 mg/dl (25-75%: 2.6-22.4 mg/dl) in Caucasians (n=48). African-American women had significantly higher (p<0.05) Lp(a) concentrations than either Native Americans or Caucasians. No relationships were observed among moderate, moderate-vigorous, and total MET-min/day of physical activity, maximal treadmill time, and Lp(a) concentrations. Significant ethnic differences in Lp(a) concentrations were found, with African-American women having higher Lp(a) concentrations than Native American and Caucasian women. Lp(a) concentrations were not associated with any physical activity variables. Therefore, physical activity and maximal treadmill time did not influence Lp(a) concentrations in this tri-ethnic population of women.