Children with Type 1 diabetes should be screened for lipid abnormalities at annual review
S Howard & J Allgrove
Background: Hypercholesterolaemia has been identified as a major risk factor for cardiovascular disease in adults with Diabetes Mellitus (DM), and studies have shown evidence of raised lipid levels in children with Diabetes. However, current NICE guidelines state that Routine screening for elevated blood lipid levels is not recommended for children and young people with type 1 diabetes; although ISPAD and APEG recommendations are for lipid screening in those over 12 yrs of age. While, increasingly, practice is to screen the Paediatric Diabetic population for lipid abnormalities, it is important to consider that worsening glycaemic control may correlate with hypercholesterolaemia.
Objectives: To establish the relationship between diabetes control and hypercholesterolaemia in our Paediatric population.
Method: Data collected at annual screening between 1994 and 2008 of children <18 yrs with Type 1 (T1DM) and Type 2 (T2DM) diabetes were studied. Hypercholesterolaemia was defined as serum cholesterol >5 mmol/l. HbA1c values were adjusted to allow for variation in measurement methods.
Results: One thousand three hundred and eighty results for children with T1DM showed elevated serum cholesterol in 17.6% of children <12 yrs (n=626) and 25% in children of 1218 yrs (n=756). In T2DM hypercholesterolaemia was present in 75% of those <12 yrs (n=12) and 29.4% in those of 1218 yrs (n=85).
In T1DM there was a clear association between increasing cholesterol and HbA1c values. In those <12 yrs, the percentage of patients with raised cholesterol increased from 0% in those with HbA1c of 6 or less (n=6), to 17% in those with HbA1c of 910 (n=117) and 35% in those with HbA1c of >14 (n=14). This trend was even more striking in the 1218 yr olds, with again 0% elevated cholesterol in the group with HbA1c of 6 or less (n=16) rising to 18 and 43% for HbA1c of 910 (n=131) and over 14 (n=47) respectively. The type 2 population showed an increase in percentage with hypercholesterolaemia with rising HbA1c, but the trend was less striking.
Conclusions: Annual screening in our Paediatric Diabetic population has identified elevated cholesterol levels in 25% of T1DM children between 12 and 18 yrs, and in a smaller but notable proportion of those with T1DM <12 yrs of age. Prevalence in the T2DM population was also high. Importantly, rising HbA1c levels are associated with increasingly severe hypercholesterolaemia, and this trend was clear in both children of 1218 yrs and children <12 yrs of age with T1DM. Our findings support the practice of annual screening for lipid disorders in children with type 1 DM, and highlight the association between poor glycaemic control and hypercholesterolaemia, not only in children of 1218 yrs but also in the younger Diabetic population.