Prevalence of injection–meal interval usage and its association with variables of metabolic control in patients with Type 1 and Type 2 diabetes

Abstract

Regular human insulin is usually recommended with an injection-meal interval. It is not known how many patients follow these recommendations and, of those who do, the injection-meal interval remains incompletely studied. We investigated the injection-meal interval in patients with Type 1 and Type 2 diabetes and the association with metabolic control in routine care. Four hundred and seventy-one consecutive patients with Type 1 or Type 2 diabetes were interviewed to determine their injection-meal interval in a university outpatient clinic setting in Germany in 2006. Four hundred and thirty-three interviews were suitable for analysis (143 Type 1 diabetes, 290 Type 2 diabetes). HbA(1c) was Diabetes Control and Complications Trial adjusted. Among those with Type 1 diabetes, 27% 'always', 27% 'sometimes' and 46% 'never' used an injection-meal interval. Forty-three per cent of patients with Type 2 diabetes always used an injection-meal interval, 12% sometimes and 45% never. Among patients with Type 1 diabetes, there was no difference in HbA(1c) between those who always used an injection-meal interval (n=39, age 58 years, duration of diabetes 21.1 years, BMI 28.7 kg/m², HbA(1c) 7.50%/58 mmol/mol) compared with those who never used an injection-meal interval (n=66, age 47.3 years, duration of diabetes 17.4 years, BMI 27.3 kg/m², HbA(1c) 7.55%/59 mmol/mol). Among patients with Type 2 diabetes, HbA(1c) in those who always used an injection-meal interval (n = 124, age 65 years, duration of diabetes 13.8 years, BMI 32.6 kg/m², HbA(1c) 7.31%/56 mmol/mol) is 0.27% lower compared with those who never used an injection-meal interval (n=130, age 64.3 years, duration of diabetes 16 years, BMI 32.8 kg/m², HbA(1c) 7.58%/59 mmol/mol). Nearly half of insulin-treated patients do not use an injection-meal interval. We found no significant association between adherence to injection-meal interval and HbA(1c) in patients with Type 1 diabetes, but a slightly lower HbA(1c) in patients with Type 2 diabetes who always use an injection-meal interval.