Patients with GADA affinities in the lower first quartile ( < 4 10 ( 9 ) L/mol ) had better preserved fasting C-peptide concentrations at baseline than those with higher affinities ( mean 1.02 vs. 0.66 nmol/L ; P = 0.004 ) and retained higher concentrations over 30 months of follow-up ( mean 1.26 vs. 0.62 nmol/L ; P = 0.01 ) .