An RCT into calculating insulin start dose in type 2 diabetes

This trial compares to methods used to find the insulin dose when starting insulin in people with type 2 diabetes in whom maximal tolerated oral hypoglycaemic agents have failed to control glycaemia. One method of initiating insulin (based on height, weight, and fasting blood plasma glucose and insulin resistance) was compared with a conventional method of initiating 10 units of isophane insulin twice daily.

Sixty subjects were randomised to calculated (CALC) or conventional (C). Follow-up was at three, six and 12 months with diabetes specialist nurse (DSN) support. The outcomes that were compared were glycated haemoglobin levels (HbA1c), hypoglycaemia, weight gain, insulin dose, quality of life, treatment satisfaction, blood pressure, and frequency of DSN contact.

HbA1c levels values were reduced significantly in the CALC group during the first three months after starting insulin (p = 0.0001) and improved by one per cent overall during 12 months (p = 0.03). No difference was found in rates of hypoglycaemia, blood pressure, quality of life, and treatment satisfaction. Weight gain was seen in both groups but was significantly higher in the CALC group. People in the CALC group needed significantly less DSN time (p = 0.01).

HbA1c target values were achieved more quickly and with less DSN contact using the CALC method. The difference in weight gain with the CALC method needs further investigation.