A retrospective study on the incidence and risk factors of severe hypoglycemia in primary care

To investigate the incidence and risk factors of severe hypoglycemia (SH) in primary care. SH was defined as hypoglycemia with coma, or the need of glucose or glucagon injection. We performed a cross-sectional retrospective study in patients with diabetes treated in primary care in Germany. We analyzed an unselected sample of participants with type 1 (n = 373) and type 2 diabetes (n = 4481) who participated in an insurance plan from the health care insurer Deutsche BKK. Data of participants with type 1 diabetes are as follows: women, n = 155 (42%); age, 49±16 years; diabetes duration, 20+13 years; BMI, 28±6 kg/m2; GHb, 7.1+1.5%; GHb≤7%, n = 263 (71%); GHb≥8.5%, n = 48 (13%). Data of participants with type 2 diabetes: women, n = 1979 (44%); age, 66±10 years; diabetes duration, 8±7 years; BMI, 30±5 kg/m2; GHb, 6.6±1.3%; GHb≤7%, n = 3747 (84%); GHb≥8.5%, n = 360 (8%); insulin therapy, n = 1175 (26%). The incidence of SH in type 1 diabetes: 1.3% (CI: 0.4%, 3.1%) per year; type 2 diabetes with insulin therapy: 0.9% (CI: 0.5%, 1.7%); without insulin therapy: 0.3% (CI: 0.1%, 0.6%). The event rate was 0.02 SH per patient/year in type 1 diabetes and 0.01 in type 2 diabetes, respectively. Low BMI, GHb, insulin therapy and female gender were associated with an increased risk of SH. In primary care, patients with diabetes can achieve good glycemic control with very rare events of SH. Due to low incidence, SH would have been an inappropriate parameter to evaluate the outcome quality of diabetes therapy in primary care.