Endocrine Abstracts

Objective: To compare clinical characteristics in individuals with established Type 1 diabetes mellitus with and without altered hypoglycaemia unawareness (AHA) / severe hypoglycaemia (SH).

Methods: Individuals with AHA and/or SH and controls matched for age, sex and duration of diabetes but with no history of AHA or SH were identified from databases of those attending the Newcastle Diabetes centre with Type 1 diabetes. Characteristics were confirmed from clinical records and the laboratory results database.

Results: 39 individuals with AHA/SH (26(67%) female; mean age 53; mean duration of diabetes 26 years) and 27 controls (17(63%) female ; mean age 46; mean duration of diabetes 27 years) were identified. In the AHA/SH group, 21(54%) had experienced episodes of severe hypoglycaemia. Hba1c was 8.7% AHA/SH vs 9.2% controls. The mean insulin dose in the AHA/SH was 0.65 U/kg vs 0.79 U/kg in the controls. 34(87%) AHA/SH vs 25(93%) controls were employing human insulin (Monotard: 12(31%) AHA/SH vs 2(7%) controls; free-mixing in syringes 12(31%) vs 0 controls). Number of daily insulin injections was 4 or more in 16(41%) AHA/SH vs 19(70%) controls. Lipohypertrophy was documented in 13(33%) AHA/SH vs 1(3.7%) controls. Autoimmune thyroid disease was recorded in 8(21%) AHA/SH vs 2(7%) controls; Addison's disease 2(5%) AHA/SH vs 0 controls; coeliac disease 1(2.6%) AHA/SH vs 0 controls. Diabetic retinopathy was described in 20(51%) AHA/SH vs 12(44%) controls; microalbuminuria 13/20 tested (55%) AHA/SH vs 4(14.8%) controls; peripheral neuropathy 8(21%) AHA/SH vs 3(11%) controls; macrovascular disease 5(12%) AHA/SH vs 4(14.8%) controls.

Conclusions: There were a higher percentage of individuals with AHA/SH on a twice daily insulin regime, Monotard insulin, free-mixing insulin in syringes or with documented lipohypertrophy in comparison to controls. Thyroid or other concomitant autoimmune disease and microvascular complications were more common.