Reversal of Type 2 diabetes after bariatric surgery is determined by the degree of achieved weight loss in both short- and long-duration diabetes.

AIM

To define the impact of duration of diabetes and extent of weight loss on the reversibility of Type 2 diabetes after bariatric surgery.

METHODS

Complete data were collated from 89 individuals with Type 2 diabetes mellitus undergoing any bariatric surgical procedure in a specialist bariatric centre. People with a preoperative HbA1c < 43 mmol/mol (6.1%) were excluded. Diabetes duration was defined as: short, < 4 years; medium, 4-8 years; and long, > 8 years.

RESULTS

An HbA1c of <43 mmol/mol (6.1%) was achieved by 62% of patients in the short-duration group and 26% of patients in the long-duration group. Normoglycaemia was rarely achieved in the long-duration group if weight loss was < 25 kg. In the whole cohort there was a clear relationship of greater weight loss with lower HbA1c levels (Rs = -0.53; P < 0.0001).

CONCLUSIONS

The study shows that the degree of achieved weight loss is the major determinant of return to normal blood glucose levels after bariatric surgery. Normoglycaemia can be achieved in long-duration Type 2 diabetes, but a greater degree of weight loss is required than for short-duration diabetes.