Clinical predictors and time course of the improvement in β–cell function with short‐term intensive insulin therapy in patients with Type 2 diabetes

AIMS: In patients with Type 2 diabetes, a short course of intensive insulin therapy can improve β-cell function and even induce transient remission of diabetes. However, not all patients respond to this therapy. Although the achievement of fasting glucose < 7.0 mmol/l one day after stopping intensive insulin therapy can identify patients in whom β-cell function has improved, we sought to determine clinical predictors for the early identification of such responders and the time course of response. METHODS: We pooled data from two studies in which 97 patients with Type 2 diabetes mellitus (median 3 years duration) and HbA1c 51 ± 8.7 mmol/mol (6.8 ± 0.8%) underwent 4-8 weeks of intensive insulin therapy, consisting of basal detemir and pre-meal insulin aspart. They were classified as responders (n = 74) or non-responders (n = 23), defined by the achievement of fasting glucose < 7.0 mmol/l after stopping intensive insulin therapy. RESULTS: On logistic regression analyses, duration of diabetes (odds ratio OR = 0.72, 95% confidence interval CI 0.56-0.92, P = 0.009) and baseline fasting glucose (OR = 0.40, 95% CI 0.24-0.68, P = 0.001) emerged as predictors of the likelihood of responding. Ninety per cent of patients with duration ≤ 4 years and fasting glucose ≤ 8.0 mmol/l responded to intensive insulin therapy. Despite having lower glucose levels during intensive insulin therapy, responders had less hypoglycaemia than non-responders (median 0.3 vs. 1.6 episodes/week, P < 0.0001), with rates of hypoglycaemia diverging sharply from the third week onwards. CONCLUSION: At baseline, shorter duration of diabetes and lower fasting glucose can identify patients most likely to benefit from short-term intensive insulin therapy. Most importantly, during therapy, responders had less hypoglycaemia from the third week onwards, despite lower glycaemia, suggesting that 2 weeks of intensive insulin therapy may be needed to improve endogenous islet function.