Early decrease in resting energy expenditure with bedtime insulin therapy

Abstract Aims In type 2 diabetes (T2D), insulin-induced weight gain may stem from a reduction in resting energy expenditure (REE). We sought to determine the early effects of insulin introduction on REE in 20 poorly controlled T2D patients. Methods After improving the glycaemia, REE was measured on Day 0 and Day 4 during two treatment regimens: bedtime insulin ( n = 10, group 1); and one off (3-day) intravenous insulin infusion ( n = 10, group 2). Results Both groups were similar in age, gender, BMI, C-peptide, HbA1c and initial REE. By Day 4, fasting glycaemia had similarly improved in both groups: group 1: −5.3 ± 2.7 mmol/L vs group 2: −5.8 ± 4.2 mmol/L. In group 2, the second REE was measured 12 h after stopping the intravenous insulin infusion, whereas subcutaneous insulin was maintained in group 1. REE did not change in group 2 (−1.3 ± 6.5%), whereas it decreased significantly in group 1 (−8.0 ± 7.0%; P < 0.05). Conclusion Bedtime insulin led to an early and specific reduction in REE.