ESPE Abstracts

Background: Although differences in pubertal timing alters frequency of indicators of attained stature at the extremes, its magnitude is unknown across ethnic groups of US youths.

Methods: We performed analyses of anthropometry and Tanner staging data of 3206 cross-sectional national sample of youths ages 8–18y (53% male (n=1606), 72% Non-Hispanic White (NHW), 9% Mexican American (MA) and 19% Non-Hispanic Black (NHB). Specialized Tanner-stage-age growth models were used to derive Tanner-age adjusted Z-scores. The prevalence of short (<−1S.D.) and tall (>=+1S.D.) status was quantified after adjustment for Tanner stage-age height Z-scores (TSA_HAZ). We then examined average growth patterns with age splines across estimated Z-scores by sex and race/ethnicity.

Results: Highly variable patterns of prevalence of shortness and tallness via chronologic-age height Z-score (CA_HAZ) was observed in results stratified by Tanner stages, race-ethnicity and sex. Tallness CA_HAZ prevalence was high among NHW and NHB males relative to MA (40.0 – 43.3, vs 20.5%) and in females, the ranking was (39.2% NHB > NHW 29.6 > MA 20.3, each P=0.0167). In both sexes, this pattern was eliminated with TSA_HAZ, with MA youth becoming statistically not different from their NHW and NHB peers on both stature indicators.

Conclusions: Differences in timing of puberty between race-ethnic groups affects estimated prevalence of shortness and tallness of attained height. Considerable pubertal maturation effects remain uncaptured with age-conditioned height Z-scores. Adjustment for pubertal development might help isolate crucial determinants of attained stature and other aspects of body composition which may be most responsive to intervention programs in populations of youths.