REPRODUCIBILITY OF PLASMA SUBSTRATE LEVELS DURING EXERCISE: THE HERITAGE FAMILY STUDY

1885 We determined the reproducibility of plasma substrates in the HERITAGE Family Study protocol assayed in 60 subjects (25F, 35M, aged 19 - 55 yrs) at rest, 50W, 60% ˙VO2max, 80% ˙VO2max, and at˙VO2max. Blood samples were collected in a non-fasting state on 3 separate days within a 3-wk period to assess within subject day-to-day variation (DD). Technical error (TE) was determined by generating split samples which were assayed in a blind fashion and compared to original samples. Means ([horizontal bar over]x), DD and intraclass correlation coefficients (ICC) for the repeated tests are shown below for glucose, FFA and total proteins: TableTableTE ranged from 0.07 to 0.11 mM, 10 to 13 μM and 0.9 to 1.2 g/L for glucose, FFA and total proteins, respectively. We conclude that the TE is low, DD is high and the ICC is moderate for these substrates during the exercise protocol.