Home blood glucose monitoring, glycosylated hemoglobin and fructosamine: their relationships in diabetic patients with and without residual C-peptide secretion.

HbA1c and fructosamine (F) were determined at monthly intervals in insulin-treated diabetic outpatients with (n = 25; C-peptide [+]) and without (n = 30; C-peptide [-]) residual B-cell function (post-prandial C-peptide: 0.76 +/- 0.33 and less than or equal to 0.09 pmol/ml, respectively; mean +/- SD), performing home blood glucose monitoring (HBGM) (40 determinations/month; memory containing reflectometer) during 4 months. Mean monthly blood glucose did not change with time and was equivalent in both groups (9.3 +/- 3.3 and 9.4 +/- 2.0 mmol/l). The magnitude of glycemic excursions was lower in C-peptide [+] than C-peptide [-] patients (mean intra-individual coefficients of variation: 31% and 47%, respectively; P less than 0.001). Overall mean HbA1c was of 7.12 +/- 1.32 and 7.30 +/- 1.06% and F levels were of 44 +/- 6 and 48 +/- 7 mumol/g protein (P less than 0.001) in the C-peptide [+] and [-] groups, respectively. In C-peptide [+] patients, HbA1c strongly correlated with prior mean monthly blood glucose at all visits (range of r valeurs = 0.71-0.84; P less than 0.001); the relation between F and mean monthly blood glucose was always significant but weaker (r = 0.48-0.62; P less than 0.05-0.001). In C-peptide [-] patients, HbA1c correlated weakly with mean blood glucose, only when averaged over 8 weeks (r = 0.40-0.59; P less than 0.05-0.001) but F did not correlate with blood glucose, whether averaged over 1-8 week periods.(ABSTRACT TRUNCATED AT 250 WORDS