September saw the 10th anniversary of the publication of the landmark United Kingdom Prospective Diabetes Study (UKPDS), which comprised a series of studies that have greatly improved our understanding and practice of controlling blood glucose in people with type 2 diabetes.1 Nevertheless, intensive control in the group treated with sulfonylurea or insulin had an equivocal effect on preventing cardiovascular disease compared with conventional treatment (percentage risk reduction for myocardial infarction 16%, 95% confidence interval 0% to 19%), with the P value of 0.052 on the boundary of conventional statistical significance.2 A study of intensive control with metformin in overweight people seemed to give clearer results (39%, 11% to 59%),3 but the study was underpowered, and a subgroup analysis in people taking metformin plus sulfonylurea raised the potential of harm.

However, October saw the publication of the results of the UKPDS 10 year follow-up study, which found that patients in the sulfonylurea or insulin group had a significant 15% reduction in myocardial infarction even though they achieved the same glucose control as patients in the less tightly controlled group over the five year extension.4 The results reflect those of the Diabetes Control and Complications Trial in type 1 diabetes. This also found no effect of glucose control on cardiovascular outcomes (with …