By Linda Carroll

(Reuters Health) – The earlier a child is diagnosed with type 1 diabetes, the greater the risk of heart disease and a life shortened by as much as 18 years, a large study suggests.

Experts had assumed those heightened risks were explained by kids living longer with the disease, but the new analysis indicates that some other factor associated with onset in early childhood may also be involved, according to the report published in The Lancet.

While having to live longer with high glucose levels probably has an effect, “there is also some evidence that developing diabetes younger is associated with a more aggressive form of type 1 diabetes,” said Naveed Sattar, a professor of metabolic medicine at the University of Glasgow in the UK, who co-led the study. “We need more research to really investigate why younger diabetes is more damaging.”

The type 1 version of the disease has a different cause from the type 2 diabetes mostly seen in adults, which is often related to obesity and sedentary behavior. Type 1 diabetes is an autoimmune disorder in which the body attacks cells in the pancreas that make insulin.

“Insulin is the hormone needed by everyone to help the body use or store blood glucose properly,” Sattar said in an email. Without insulin, the glucose “stays in the blood and so blood levels climb.”

Nobody knows what sends the body’s own immune system attacking pancreatic cells, said Dr. Erin Kershaw, chief of endocrinology at the University of Pittsburgh Medical Center in Pennsylvania, who wasn’t involved in the study.

“The risk for this is heritable, but why and when it starts is not really understood,” she said. “There’s most likely an environmental component, and probably bad luck.”

Sattar and his colleagues studied 27,195 individuals aged 18 years and older in the Swedish National Diabetes Register who had been diagnosed with type 1 diabetes and compared them with 135,178 age-matched people in the general population who did not have diabetes.

The researchers followed the group through medical records, with half of the subjects followed for at least 10 years, during which time 959 of those with diabetes and 1,501 people without diabetes died.

People who developed type 1 diabetes before the age of 10 were more than four times as likely as their counterparts in the general population without diabetes to die of any cause during the follow-up period, and four times as likely to die of cardiovascular disease.

Those with diabetes diagnosed before age 10 were also about 30 times as likely as counterparts without diabetes to develop heart disease and 31 times as likely to experience a heart attack, overall. Among just the women with early-onset diabetes, those rates were 60 times and 90 times, respectively.

In contrast, people who developed type 1 diabetes between the ages of 26 and 30, were about three times as likely as the general population to die during the follow-up, and about six times as likely to develop heart disease or experience a heart attack.

The drop in risk with later-onset diabetes relative to nondiabetics also means that people with the youngest-onset disease were six times as likely overall as those who developed type 1 diabetes at an older age to have a heart attack, for example.

For those with diabetes onset before age 10, these increased risks translated to an average shortening of life by nearly 18 years for women and 14 years for men, the authors calculate.

The new findings “should remind doctors that patients with type 1 diabetes are at especially high risk of heart disease when they become adults and therefore other ways to lower heart attack risks should be considered more often than is currently the case – these include more help to stop smoking, checking and treating high blood pressure and cholesterol more aggressively, Sattar said.

“Currently patients with type 1 diabetes appear to less often receive statins at most adults ages than those with type 2 diabetes. In truth, these patients deserve greater consideration of statins as their heart disease risks tend to be higher at most given ages.”

While the new findings seem dire, “they present an opportunity to improve the treatment of these individuals,” Kershaw said. “Now that we know that early onset is an independent risk factor, maybe we need targeted programs to raise physician awareness.”

The findings also suggest that doctors might try sooner to get blood pressure and cholesterol under control in patients with early onset type 1 diabetes, even the younger ones, Kershaw noted. “We don’t usually start people on statins and blood pressure medications until they are 40. Maybe we need to reconsider how we target patients. Maybe we do need to put them on these medications at an earlier age.”

SOURCE: The Lancet, online August 11, 2018.