The findings are from a sub-study of the Diabetes Control and Complications trial. Type-1 diabetes patients were assigned to either intensive or conventional therapy.
The latest analysis used International Diabetes Federation criteria to determine MetS in 1,337 patients over nine years.
This showed that the rate of MetS increased from 13.7 to 45.4 per cent in the intensive therapy group.
A rise in MetS prevalence was also seen in the conventional therapy group, although smaller.
This increased risk is largely due to weight gain as blood glucose comes under control, said the researchers from Hull York Medical School.
But the higher risk of MetS associated with intensive therapy is offset by health improvements through better glycaemic control, they added.
MetS was also a poor predictor of future risk of micro- and macrovascular complications, with high insulin resistance at baseline being the best indicator.