Search

The aim of this retrospective study was to verify whether the daily number of insulin injections could have affected metabolic control in 181 unselected diabetic patients (age 0.66-14.75 yr at onset of diabetes) followed in our clinic from the 1970s to the 1990s. They were evaluated regularly since onset of disease for a mean follow-up period of 6.8 years. The factor with the greatest effect on HbA1c levels was the year of disease onset, which was negatively correlated with HbA1c independently of the daily number of injections and disease duration. Disease duration showed an effect on metabolic control only in the first 5 years of disease. Daily insulin injections affected metabolic control above all as regards 1 vs 2 or more injections. Regarding the change in insulin regimen from 2 to 3-4 injections, there was an improvement in metabolic control in patients with HbA1c > 9% and a worsening in those with HbA1c < 7%/ After the first 5 years of the disease HbA1c levels were higher in adolescent patients than in both younger and older patients. In conclusion, increasing the daily number of injections does not seem in itself capable of eliciting marked improvement in metabolic control, as in our young diabetic patients in the last decade. Multiple insulin injection therapy seems to be mostly indicated for patients with poor control and for adolescents.

In 105 children and adolescents with IDDM, insulin antibodies were detected as a percentage of radiolabelled insulin both at onset of disease and during the first 8 years of treatment. At diagnosis, 29 patients (27%) were insulin autoantibody positive (IAA+). An inverse relationship was found between IAA levels and age at diagnosis. No significant correlation was seen between IAA positivity and HLA antigens, while there was a negative correlation between IAA and C-peptide levels in the second year of the disease. The percentage of insulin antibody (IA) positive patients increased after insulin administration, with a maximum peak between the first and second year of the disease. The IA response to insulin therapy was similar in IAA+ and IAA- patients, while it was greater in younger children. No relationship was found between IA levels and haemoglobin A1c values, daily insulin requirement, HLA and early complications. No difference in either percentage of positivity or IA levels was seen in patients treated continually for the first 5 years of the disease with monocomponent porcine insulin or human insulin. A negative correlation was found between IA and C-peptide levels in the first and second years of the disease. In conclusion, we have shown that, even after many years of disease, neither IAA nor IA, induced in equal measures by current human insulin preparations, have significant effects on the clinical course of the disease.