Change in overall PA was significantly associated with postprandial log-transformed plasma insulin ( = -0.002 ; 95 % confidence interval ( CI ) , -0.003 to 0.000 ; P = 0.008 ) , C-peptide ( = -2.7 ; 95 % CI , -4.9 to -0.5 ; P = 0.01 ) , and glucose concentration ( = -0.006 ; 95 % CI , -0.01 to -0.002 ; P = 0.002 ) .