The number of European children under the age of five with Type 1 diabetes could double by 2020, a rapid increase that points to environmental factors, researchers say.

The study in Saturday's issue of The Lancet was based on an analysis of 29,311 cases of Type 1 diabetes in 20 European countries between 1989 and 2003.

'These findings suggest that the incidence of Type 1 diabetes is increasing even faster than before, pointing towards harmful changes in the environment in which contemporary children live.'— Dr. Dana Dabelea

Type 1 diabetes is caused by insulin deficiency and is treated with insulin injections. It occurs when insulin-producing cells in the pancreas that are needed to control blood sugar are destroyed.

"By 2020, the predicted number of new cases is 24,400, but this change is not shared evenly between the age groups, with incidence of Type 1 diabetes in the youngest age group expected to double in both sexes," Dr. Chris Patterson of Queen's University in Belfast, Gyula Soltesz of Pecs University in Hungary and colleagues wrote in the study.

Diagnoses were rising at a rate of 3.9 per cent per year overall, and increasing by 5.4 per cent per year among those under five.

Based on those trends, the number of cases among children under five is predicted to double, to 20,113 in 2020 from 9,955 in 2005, the researchers said.

Cases among European children under the age of 15 are predicted to rise even more, to 159,767 in 2020 from 93,584 in 2005.

Environmental changes implicated

The increase has been so rapid that genetics alone can't be driving the change, the researchers said. The highest increases were in Eastern Europe, where lifestyle habits are changing faster than in Western Europe.

Modern lifestyle habits such as increased weight and height in infancy, women having children later and greater numbers of caesarean births may be possible factors, but are too weak to explain more than part of the rise in incidence rates, Patterson said.

"These findings suggest that the incidence of Type 1 diabetes is increasing even faster than before, pointing towards harmful changes in the environment in which contemporary children live," Dr. Dana Dabelea of the University of Colorado in Denver wrote in a commentary.

A higher proportion of cases diagnosed at younger ages could result in more patients with potentially life-threatening ketoacidosis — raised acidity of the blood caused by the unregulated breakdown of fats and proteins by the liver.

"In the absence of any effective means to prevent Type 1 diabetes, European countries need to ensure appropriate planning of services and that resources are in place to provide high-quality care for the increased numbers of children who will be diagnosed with diabetes in future years," the team wrote.

"Many people live full and healthy lives. However, the longer the person has diabetes the higher the risk of complications such as heart disease, kidney failure and blindness," Dr. Iain Frame, director of research at Diabetes UK, said in a statement.

"However, a lot more research is needed before we can come to any concrete conclusions about the causes of this rise in Type 1 diabetes in younger children."