Congenital heart disease and the prevalence of underweight and obesity from age 1 to 15 years: data on a nationwide sample of children

OBJECTIVE: We examined the prevalence of underweight and obesity in children with congenital heart disease (CHD) compared with the general population. METHODS: Using the Danish National Patient Registry, we identified individuals born and diagnosed with CHD in Denmark during 1996–2012 who were alive at 1 year of age. A unique personal identifier enabled identification of CHD subjects, as well as birth year and sex-matched (1:10) general population controls. The Children’s Database has recorded height and weight measured by clinical providers at preventive health checks offered to all children in Denmark. Data recording were made mandatory in 2011. Obesity was defined as body mass index (BMI) above the 95thpercentile and underweight as BMI below the fifth percentile for age and sex. We determined the prevalence of underweight and obesity at study subjects’ first height and weight recording. For those underweight at age 1 year, prevalence of underweight and obesity at later recordings was assessed. RESULTS: We identified 9194 children with CHD of which 2679 (29%) had at least one recording of height and weight. The control cohort demonstrated a similar portion of anthropometric data: 30 047 (31%) of 96 585 controls. The prevalence of underweight and obesity at CHD study subjects’ first height and weight recording was 9.7% (95% CI 8.7 to 11) and 4.1% (95% CI 3.4 to 4.9), respectively. Among individuals with CHD who were underweight at age 1 year (n=78), 51 (65%) had additional BMI recordings between ages 2 and 5 years with a subsequently diminished prevalence of underweight of 27% (95% CI 20 to 35) and none were obese. CONCLUSION: The CHD population had an increased prevalence of underweight compared with the general population. Data indicated potential for BMI normalisation among those initially underweight at age 1 year. The prevalence of obesity in children with CHD was comparable with that of the general population.