Prediabetes is defined by a fasting blood glucose level of 100-125 mg/dL or a 2-hour post-oral glucose tolerance test (post-OGTT) glucose level of 140-200 mg/dL. Persons with prediabetes are at increased risk for macrovascular disease, as well as diabetes.

A German research conducted to identify subphenotypes of prediabetes revealed six prediabetes phenotypes. The investigators used oral glucose tolerance tests, MRI-measured body fat distribution, liver fat content and genetic risk in individuals who are at increased risk for type 2 diabetes. 25 years of data from 900 subjects taking part in a longitudinal family health study were analyzed for the clustering.

Three subtypes (clusters 1, 2 and 4) are the healthiest types of prediabetes. These subjects were present as generally healthy. Cluster 4 encompasses overweight subjects with broadly healthy metabolic markers. Clusters 3, 5 and 6 were linked to the highest risk of developing type 2 diabetes and secondary diseases. Cluster 5 grouped those subjects with pronounced fatty liver, while cluster 3 grouped those who produced significantly lower levels of insulin.

To further validate these six subtypes, the researchers examined data from another longitudinal study. Called Whitehall II, the UK study that tracked the metabolic health of nearly 10,000 subjects for over 20 years and the subtypes identified fitted to the large dataset affirming prediabetes can be distinguished into separate disease stratifications. The researchers shared their views that these type of researches are essential and significant towards precision medicine in the prevention of diabetes and its complications. The study was published in Nature Medicine.