Comparison of waist circumference percentiles versus body mass index percentiles for diagnosis of obesity in a large cohort of children.
BACKGROUND
Waist circumference may offer improved diagnosis of obesity in youth compared with body mass index (BMI), but empirical evidence is limited.


OBJECTIVE
To compare the ability of BMI percentile using UK reference data and waist circumference percentile using UK reference data to diagnose high fat mass in English children.


METHODS
In 7,722 9-10-year-olds (3,809 boys, 3,913 girls) sensitivity and specificity were calculated and receiver operator characteristic (ROC) analyses undertaken to determine the diagnostic accuracy of BMI and waist circumference z-scores to define high fat mass measured by dual energy x-ray absorptiometry (DXA). High fat mass was defined as being in the top decile of fatness for each sex (359 boys and 367 girls).


RESULTS
The area under the ROC curve was slightly higher for BMI percentile (0.92 in boys, 95% CI: 0.91 -0.93; 0.94 in girls, 95% CI: 0.93-0.95) than waist circumference percentile (0.89 in boys, 95% CI: 0.86-0.91; 0.81 in girls, 95% CI: 0.73-0.90). Specificity of BMI percentile was slightly but significantly higher than that of waist circumference percentile for both sexes (p<0.05 in each case).


CONCLUSIONS
The present study suggests that waist circumference percentile has no advantage over BMI percentile for the diagnosis of high fat mass in children.
Reilly
John J
JJ
University of Glasgow Medical Faculty, Division of Developmental Medicine, Yorkhill Hospitals, Glasgow, Scotland. jjr2y@clinmed.gla.ac.uk
Dorosty
Ahmad R
AR
Ghomizadeh
Narges Miri
NM
Sherriff
Andrea
A
Wells
Jonathan C
JC
Ness
Andrew R
AR
D015502:Absorptiometry, Photon; D050154:Adiposity; D015992:Body Mass Index; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000175:diagnosis* / Q000453:epidemiology; D050177:Overweight / Q000453:epidemiology; D012372:ROC Curve; D012680:Sensitivity and Specificity; D006113:United Kingdom / Q000453:epidemiology; D055105:Waist Circumference