The transient effect of strict glycaemic control on B cell function in newly diagnosed type 1 (insulin-dependent)...

Within 24h of diagnosis, 15 consecutive Type 1 (insulin-dependent) diabetic patients were allocated at random to one of two treatment groups: group A (n = 9, mean age: 28 years, range: 17-35 years) was treated conventionally with one or two daily doses of insulin; group B (n = 6, mean age: 27 years, range: 21-37 years) was treated with nine daily injections of fast-acting insulin for ten days and there-after conventionally as for group A. The mean diurnal blood glucose concentration during the initial ten days of insulin treatment was 11.7 +/- 0.5 mmol/l (mean +/- SEM) in group A and 6.4 +/- 0.3 mmol/l in group B (p less than 0.01). Pancreatic B cell function was evaluated 1, 7, 14, 90, and 180 days after the start of insulin treatment from the C-peptide response to a standard meal. At one and seven days after diagnosis, no difference was found in B cell function between the two groups. After 14 days, the amount of C-peptide secreted during the test meal was 18.0 +/- 2.6 nmol (mean +/- SEM) in group A compared with 29.0 +/- 3.6 nmol in group B (p less than 0.05). After 90 and 180 days, no difference was demonstrated in B cell function. The maximal B cell function observed was similar in the two groups, but occurred earlier in group B (at 14 days) than in group A (at 90 days) (p less than 0.05). This study indicates that strict initial glycaemic control may lead to an earlier improvement in B cell function, but that this improvement is of short duration.