Researchers Scrutinize Genes, Lifestyles as Incidence of Type 1 Doubles Among Finnish Children Over a 25-Year Period

Since the 1950s, Finland has recorded the world’s highest incidence of type 1 diabetes as a percentage of its population.

That distinction—although India is now suffering a major type 2 diabetes epidemic—is one that Finland will likely maintain in the wake of disturbing statistics recently published by Finnish scientists: From 1980 through 2005, the number of Finnish children 15 or younger who developed type 1 diabetes increased by 102 percent.

Researcher Dr. Valma Harjutsalo at the National Public Health Institute in Helsinki and a team of colleagues studied three national databases, looking for the incidence of type 1 diagnoses among children over the 25-year period. Their study excluded children with type 2 diabetes or diabetes brought on as a consequence of other conditions, such as Down’s syndrome, congenital pancreatic defects or steroid use.

The database showed that 10,737 children (5,816 boys and 4,921 girls) had been diagnosed with type 1 before age 15 over the quarter-century period. What troubled them was the dramatic increase in the incidence of type 1 over 25 years: Diagnoses of type 1 increased from 31.4 per 100,000 in 1980 to 64.2 per 100,000 in 2005—a 102 percent increase.

They found that the greatest annual percentage increase in diagnoses, 4.7 percent, occurred in children 0-4. (That figure compares to a worldwide average of 2.5 percent to 3 percent for that age group.)

The Finns theorize that genetic risk factors and environmental triggers team up to create the onset of type 1. For example, scientists worldwide believe that a high birth weight and early weight gain in infancy are risk factors for the disease—a belief seemingly borne out by the dramatic increase in the percentage of Finnish children between ages 5 and 15 who are now labeled as overweight or obese: from 9.5 percent in the mid-1980s to 20 percent now.

They also believe that other environmental factors have contributed to the onset of type 1 in younger and younger children, but are not sure what they are. The research team says that unhealthy, but as yet unknown, changes in Finland’s everyday environment may be causing an earlier triggering of the genes that make children susceptible to type 1.

Source: The Lancet