IGT increases mortality risk, mostly attributable to type 2 diabetes

Patients with impaired glucose tolerance (IGT) have an increased mortality risk, according to a new Chinese study.
China-Japan Friendship Hospital researchers added that much of this increased risk was driven by the progression to type 2 diabetes.
In this new retrospective study, the Beijing-based study team analysed the Da Qing Diabetes Prevention study, a six-year lifestyle intervention study that was initiated in 1986 and involved 542 participants with IGT.
At 23 years after the study finished, the researchers evaluated incidences of type 2 diabetes, diabetes-related complications, mortality and causes of death.
Overall, 32.1 per cent of the study population died and 79 per cent had developed type 2 diabetes. Significantly, 74.7 per cent of participants died after progression to type 2 diabetes.
Participants who developed type 2 diabetes during the first 10 years of follow-up had the highest cumulative mortality rate (37.8 per cent). This compared with 28.6 per cent of those which progressed to type 2 diabetes in 10 to 20 years, and 13.9 per cent for participants who didn’t develop type 2 diabetes within 20 years.
Those who progressed to type 2 diabetes had a significantly elevated risk of death compared with participants who did not develop the condition.
“IGT was associated with increased risk of death, but much of the increase was the result of the subsequent development of type 2 diabetes in many of those with IGT,” said the researchers.
“The results provide a strong rationale for type 2 diabetes prevention in people with IGT because they indicate that the risk of death in people with IGT is much lower before than after the development of type 2 diabetes.”
The study was published in Diabetes Care.