Background

The high prevalence of severe obesity among youth necessitates a reevaluation of body mass index (BMI) metrics. There are limited data on the association of various BMI metrics with measures of cardiometabolic biomarkers in youth. Our objective was to examine the association of 6 BMI metrics with 6 cardiometabolic biomarkers in youth.

Methods

This was a cross-sectional analysis of youth aged 8 to 21 years with a wide range of BMI values (normal weight to severe obesity). BMI metrics included: BMI z-score (BMIz), BMI percentile (BMI%), BMI percent of the 95th percentile (%BMIp95), BMI percent of the median, tri-ponderal mass index (TMI), and absolute BMI. Biomarkers included: leptin, insulin, high-sensitivity C-reactive protein (hsCRP), oxidized low-density lipoprotein (oxLDL), lipoprotein A (lipoA), and high-molecular weight (HMW) adiponectin. Associations were summarized using Pearson’s coefficient of correlation.

Results

The correlation coefficients for each BMI metric are listed in descending order based on the strength of the association after the biomarker: Leptin: TMI 0.84, BMI 0.82, BMI percent of the median 0.77, %BMIp95 0.47, BMIz 0.45, BMI% 0.39;Insulin: BMI 0.69, TMI 0.65, BMI percent of the median 0.64, %BMIp95 0.40, BMIz 0.39, BMI% 0.34;hsCRP: TMI 0.49, BMI 0.48, BMI percent of the median 0.44, BMIz 0.30, %BMIp95 0.28, BMI% 0.27;oxLDL: BMI 0.69, TMI 0.26, BMIz 0.25, %BMIp95 0.25, BMI% 0.23, BMI percent of the median 0.21;LipoA: BMI 0.19, TMI 0.18, BMI percent of the median 0.14, BMI% 0.09, BMIz 0.08, %BMIp95 0.07; HMW adiponectin: BMI -0.48, BMI percent of the median -0.47, TMI -0.45, BMIz -0.28, BMI% -0.27, %BMIp95 -0.24.

Conclusions

Absolute BMI, TMI, and BMI percent of the median were more highly correlated with biomarkers of cardiometabolic risk than BMIz, BMI percentile, and %BMIp95. These data support mounting evidence that BMI, TMI, and BMI percent of the median may better reflect associated cardiometabolic risk in youth than BMIz and BMI%.