SEARCH: Youth with type 1 diabetes, short disease duration had abnormal lipid, lipoprotein profiles
Glycemic control may be an important mediator of these abnormalities.
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Youth with type 1 diabetes and suboptimal glycemic control had elevated lipid levels and atherogenic changes in lipoprotein composition compared with healthy peers, according to findings from the SEARCH for Diabetes in Youth Case-Control study.
Regardless of glycemic control, presence of diabetes was associated with elevated apolipoprotein B levels and more small, dense LDL particles. The goal of the SEARCH study was to compare lipid profiles and abnormalities of 512 youth aged 10 to 22 years and 188 healthy controls. Youth with diabetes had a mean disease duration of 4.22 years.
“The majority of studies on this topic are done in adults with childhood-onset type 1 diabetes and, therefore, patients have a longer duration of disease by the time lipids are measured. We were interested in whether these lipid abnormalities were apparent at younger ages and shorter diabetes duration,” Dana Dabelea, MD, PhD, associate professor in the department of epidemiology at the Colorado School of Public Health, told Endocrine Today.
Recently published findings from the SEARCH study demonstrated lipid levels outside recommended targets in a substantial proportion of youth with type 1 diabetes, especially if they had suboptimal glycemic control. These new data were in line with previous findings in adults, according to the researchers.
Abnormal lipid concentrations, atherogenic changes
“Youth with type 1 diabetes had a more atherogenic lipid and lipoprotein profile, specifically those youth with less than optimally controlled diabetes,” said Dabelea, who is also the principal investigator for the Colorado site of SEARCH.
Those with type 1 diabetes and good glycemic control (n=164) had similar lipid concentrations (total cholesterol, LDL and LDL particle size) to healthy youth. Particularly, some lipid levels (HDL, non-HDL, triglycerides and triglyceride:HDL ratio) were less atherogenic than levels observed in healthy youth. However, youth who exhibited suboptimal glycemic control (n=348) had elevated total cholesterol, LDL and non-HDL.
In addition, elevated ApoB levels and more small, dense LDL particles were more common among patients with type 1 diabetes.
“These findings may also signal a need for early screening for lipid abnormalities in youth with diabetes, even at a relatively young age and after relatively short disease duration,” she said. “Measuring ApoB and LDL particle size — two of the less commonly tested lipids — may be important in youth with type 1 diabetes, as these are strongly associated with cardiovascular risk in adults."
The researchers concluded that optimal glycemic control may be an important mediator of these abnormalities.
“Glycemic control is important in lowering the prevalence of lipid abnormalities because youth with good glycemic control don’t seem to be at risk,” Dabelea said. – by Katie Kalvaitis
Guy J. Diabetes Care. 2009;32:416-420.
This was an eye-opening cross-sectional study regarding the effects of glycemic control on lipids in youth with type 1 diabetes. Youth with well-controlled type 1 diabetes had good lipid profiles that were even better than the control population, but those with uncontrolled diabetes had worse lipid profiles. Medication choices for hyperlipidemia are limited for this group. Clinically, this means that we need to be more aware of lipid abnormalities in youth with diabetes. We may now have one more reason to shoot for aggressive control in youth with type 1 diabetes. Further prospective randomized studies are needed to show that improving glycemic control in fact improves lipid profiles in this population.
– Anuj Bhargava, MD, MBA, CDE
President, Iowa Diabetes
and Endocrinology Research Center