Abnormal blood lipids (dyslipidemia) may begin damaging arteries early in life. That’s why current guidelines recommend that children and teens with type 1 diabetes and high cholesterol qualify for medication if lifestyle changes are not effective.
This concern was the trigger for a new study led by Michelle Katz, M.D., M.P.H., a Pediatric Endocrinologist at Joslin Diabetes Center. Published in the American Diabetes Association journal Diabetes Care (October, 2016), it stemmed from the concern that more children with type 1 diabetes are at risk for dyslipidemia, putting them at greater risk for cardiovascular disease in adulthood.
After collecting medical records from children and teens with type 1 diabetes Dr. Katz and her team examined the relationship between A1c and lipid levels as well as between body mass index (BMI, a measure of weight status) and lipids (LDL cholesterol, the so-called bad cholesterol; HDL cholesterol, the so-called good cholesterol; and non-HDL cholesterol).
The investigation involved 572 youth with type 1 diabetes who had their A1c, BMI and lipid levels measured between the ages of six and 18 and rechecked again over a 10-year period on average.
“What we saw was that changes in A1c do have a significant impact on changes in LDL and non-HDL cholesterol,” says Dr. Katz. “And those changes are more substantial as youth age into their young adult years.”
The study showed that every 1 percent increase in A1c was associated with approximately a 2 to 6 mg/dl point increase in harmful LDLs, with a greater increase in LDLs as study participants progressed from pre-adolescence to young adulthood.
Additionally, one standard deviation in BMI was associated with an LDL increase of about 2 mg/dl when study participants were 10 years old, and increased to about 8 mg/dl when study participants were 19 years old. The association between changes in A1c and BMI with changes in non-HDL as children and teens entered adulthood were similar to the associations found with LDL.
“Addressing elevations in A1c and BMI as children enter into adolescence and beyond may lead to improvements in lipid levels,” says Dr. Katz. “For BMI, it takes really large changes in weight status to impact LDL and non-HDL levels.”
Along with demonstrating that it’s harder to impact LDL levels with changes in A1c when children are young, the researchers also found that the influence of A1c and BMI on “good” HDL was small and not dependent on age.
“It’s important because if kids have a very high A1c, they may have a substantial change in their cholesterol level – a decrease in LDL or non-HDL — with a big change in their A1c, but if their A1c is already close to optimal, then small changes in their A1c aren’t going to be sufficient to get their LDL or non-HDL cholesterol to a goal level,” says Dr. Katz. Similarly, with BMI it seems to take really large changes in weight status to have a substantial impact on LDL cholesterol.
“Lifestyle changes continue to be important and we always hesitate to start medication in youth without first trying to improve their diet and levels of physical activity,” says Dr. Katz. “But the healthcare community needs to recognize that some patients may be working really hard to implement the changes we recommend, yet may not see large improvements in their cholesterol levels, especially for those in the school age population. It may change it a little, but it’s important to be realistic about the improvement that some children and teens might achieve.”