Retrospective comparative analysis of metabolic control and early complications in familial and sporadic type 1 diabetes patients

BackgroundGenetic susceptibility and lifestyle are associated with glycemic control and diabetic complications in type 1 diabetes (T1D).ObjectivesTo investigate metabolic control and occurrence of acute and microvascular complications among familial and sporadic T1D patients.Patients and MethodsRetrieved from our institutional registry of new T1D cases for the years 1979-2008 were 226 familial patients belonging to 121 families (58 parent-offspring, 63 sib-pairs) and 226 sporadic cases matched for age, gender, and year of diagnosis. Extracted from medical files were clinical course and therapeutic regimen.ResultsMean age at diagnosis of diabetes of the cohort was 10.8 ± 5.7 years. Throughout follow-up (11.1 ± 8.7 years) mean HbA1c values were significantly higher in familial than in sporadic cases (8.18% ± 1.15% vs. 7.85% ± 1.15%, p = 0.005). Diabetic ketoacidosis (DKA) rates were higher in familial than sporadic cases (2.8 vs. 1.9 events per 100 patient-years; incidence rate ratio (IRR) = 1.5, 95% CI [1.03, 2.22, p = 0.03]). Severe hypoglycemia events per 100 patient-years were comparable in familial and sporadic groups (3.7 vs. 4.0 events); sib-pairs had higher rates than parent-offspring (4.8 vs. 2.4 events; (IRR) = 2, 95% CI [1.03, 3.25, p = 0.03]). The percentage of patients with microvascular complications was similar in the familial (21.7%) and sporadic (26.7%) groups. In both familial and sporadic cases the most significant predictor for metabolic control and microvascular complications was diabetes duration; a higher mean HbA1c level was the predictor for DKA events.ConclusionsThe worse metabolic control and increased rate of DKA in familial T1D patients as compared to those in the sporadic T1D patients warrant intensified surveillance in this population.