Severe hypoglycemia and ketoacidosis over one year in Italian pediatric population with type 1 diabetes mellitus: A multicenter retrospective observational study

Background and aims: Evaluation of incidence and correlates of severe hypoglycemia (SH) and diabetes ketoacidosis (DKA) in children and adolescents with T1DM. Methods and results: Retrospective study conducted in 29 diabetes centers from November 2011 to April 2012. The incidence of SH and DKA episodes and their correlates were assessed through a questionnaire administered to parents of patients aged 0-18 years. Incidence rates and incident rate ratios (IRRs) were estimated through multivariate Poisson regression analysis and multilevel analysis. Overall, 2025 patients were included (age 12.4±3.8 years; 53% males; diabetes duration 5.6±3.5 years; HbA1c 7.9±1.1%). The incidence of SH and DKA were of 7.7 and 2.4events/100py, respectively. The risk of SH was higher in females (IRR=1.44; 95%CI 1.04-1.99), in patients using rapid acting analogues as compared to regular insulin (IRR=1.48; 95%CI 0.97-2.26) and lower for patients using long acting analogues as compared to NPH insulin (IRR=0.40; 95%CI 0.19-0.85). No correlations were found between SH and HbA1c levels. The risk of DKA was higher in patients using rapid acting analogues (IRR=4.25; 95%CI 1.01-17.86) and increased with insulin units needed (IRR=7.66; 95%CI 2.83-20.74) and HbA1c levels (IRR=1.63; 95%CI 1.36-1.95). Mother's age was inversely associated with the risk of both SH (IRR=0.95; 95%CI 0.92-0.98) and DKA (IRR=0.94; 95%CI 0.88-0.99). When accounting for center effect, the risk of SH associated with the use of rapid acting insulin analogues was attenuated (IRR=1.48; 95%CI 0.97-2.26); 33% and 16% of the residual variance in SH and DKA risk was explained by center effect. Conclusion: The risk of SH and DKA is mainly associated with treatment modalities and strongly depends on the practice of specialist centers.