Familiality of triglyceride and LPL response to exercise training: the HERITAGE study

The main purpose of the present investigation was to test whether and to what extent familial/genetic factors are involved in the changes of postheparin lipoprotein lipase (deltaPH-LPL) activity and triglyceride (deltaTG) levels in response to exercise training. Additional hypotheses were also tested as to whether there were familial/genetic factors shared by baseline and the corresponding response to exercise training (i.e., by baseline triglyceride (TG(B)) and deltaTG and by baseline postheparin lipoprotein lipase (PH-LPL(B)) and deltaPH-LPL activity).

Serum TG and PH-LPL were measured in 459 subjects from 99 sedentary Caucasian families of the HERITAGE Family study before (baseline) and after completing a 20 wk (3 times per week) exercise training protocol. The training protocol had a target intensity of 75% of the heart rate associated with baseline VO2max during the last 6 wk. PH-LPL activity was measured in the study subjects. Both univariate and bivariate familial correlation analyses were applied to the baseline and response data.

The maximal heritabilities for deltaTG and deltaPH-LPL activity were 22% and 15%, respectively. There were no common familial factors for TG(B) and deltaTG, nor were there any for PH-LPL(B) and deltaPH-LPL. However, we found that there were common familial factors underlying deltaTG and deltaPH-LPL; these familial factors seemed to differ across sex and generation groups.

Although there were no common familial factors underlying the covariation between the baseline triglyceride and PH-LPL activity and the corresponding responses to exercise training (i.e., TG(B) with deltaTG or PH-LPL(B) with deltaPH-LPL), the deltaTG and deltaPH-LPL covariation apparently share some common familial determinants.