Diabetes starts 20 years before diagnosis

The first signs of type 2 diabetes can be identified perhaps 20 years before diagnosis, according to a survey presented at the EASD’s annual annual conference in Berlin (1-5 October).

A Japanese study has seen more than 27,000 non-diabetic adults (mean age 49) between 2005 and 2016, and found that fasting glucose, higher body mass index (BMI) and decreased insulin sensitivity were detectable up to 10 years ago from the diagnosis of diabetes as well as prediabetes.

“As the vast majority of people with type 2 diabetes pass the prebiotic stage, our findings suggest that elevated metabolic indices for diabetes are detectable for more than 20 years prior to diagnosis,” said lead investigator Hiroyuki Sagesaka from the Aizawa Hospital in Matsumoto, Japan.

Previous studies have shown that risk factors such as obesity and increased fasting glucose may occur up to 10 years before someone diagnosed with diabetes. Sagesaka and colleagues evaluated the fasting glucose curves, BMI and insulin sensitivity in individuals who developed diabetes and pre-diabetes.

At the start of the study, 27,392 non-diabetic subjects were examined for fasting glucose and mean blood glucose (HbA1c), and were monitored until diagnosis of type 2 diabetes or pre-diabetes by the end of 2016.

During the study, 1,067 new cases of type 2 diabetes were identified. The findings showed that several risk factors were more common among people who continued to develop type 2 diabetes than those who did not. In particular, BMI, fasting glucose and insulin resistance were at a higher level up to 10 years prior to diagnosis, and the differences widened over time.

For example, mean fasting glucose at 10 years prior to diagnosis was 101.5 mg / dL in people who developed diabetes versus 94.5 mg / dL in those who did not develop. At 5 years prior to diagnosis, it was 105 mg / dL versus 94 mg / dL and at one year before diagnosis was 110 mg / dL versus 94 mg / dL.

Of the 15,778 normal blood glucose subjects in the initial screening study, 4,781 developed prediabetes during the study period, while the disorders were present at least 10 years prior to the diagnosis of diabetes.

“Because prevention trials in people with pre-diabetes appear to be less successful, it may take much longer than pre-diabetes to intervene to prevent diabetes,” said Sagesaka.

Worldwide, it is estimated that 425 million adults (aged 20-79 years) lived with diabetes in 2017 and are projected to increase to 629 million by 2045.