Longitudinal screening of serum lipids in children and adolescents with Type 1 diabetes in a UK clinic population.

Aims: To determine the prevalence of abnormal lipid levels in a large group of children and adolescents with Type 1 diabetes and to examine the changes longitudinally. In addition, to study the relationships of any lipid abnormalities to glycaemic control, age and duration of diabetes.

Methods: Non-fasting blood samples were taken annually from all the patients in the Oxford Children's diabetes clinic and total cholesterol (TC), high-density lipoprotein (HDL) cholesterol, triglycerides (TG) and glycated haemoglobin (HbA(1c)) measured over a period of 8 years. Low-density lipoprotein (LDL) cholesterol and non-HDL were calculated from these values and compared. Tests performed less than 4 months after diagnosis were excluded.

Results: A total of 229 children had complete data from more than 1 year and 798 sets of data were examined. TC was lower in males and increased with duration of diabetes and with increasing HbA(1c). HDL cholesterol fell with increasing age, but independently increased with duration, and was not related to HbA(1c). LDL cholesterol and non-HDL cholesterol were highly correlated (r = 0.9). Both were lower in males and increased with duration of diabetes. Non-HDL cholesterol increased with HbA(1c). A total of 23.7% had HDL cholesterol < 1.1 mmol/l and 22.5% had TC > 5.2 mmol/l. Thirty-eight per cent had LDL cholesterol > 2.6 mmol/l and 10.8% > 3.4 mmol/l, the thresholds for lifestyle and drug intervention respectively.

Conclusions: Abnormalities in plasma lipid levels are common in this age group and the prevalence increases with poor glycaemic control and with duration of diabetes. Around 10% of adolescents would fit criteria for lipid-lowering medication in adults, but further study is needed to examine the risks and benefits in this age group.