Age-based reference ranges for annual height velocity in US children

Area of Science:

• Pediatric endocrinology
• Growth and development
• Biostatistics

Background:

• Linear growth, assessed by height velocity (HV), is a key health biomarker in children.
• Existing US reference ranges for HV lack percentiles and Z-scores for early or late maturing children outside peak velocity.
• This limits accurate growth assessment in diverse pediatric populations.

Purpose of the Study:

• To establish contemporary, age-specific reference ranges for height velocity (HV) in a US youth cohort.
• To provide HV percentiles and Z-scores that account for variations in pubertal timing.
• To improve the clinical assessment of child development and overall health.

Main Methods:

• Utilized data from the Bone Mineral Density in Childhood Study, a multi-center, multi-ethnic cohort of 1500 children (aged 5-19).
• Analyzed over 4000 annual HV measurements collected over 7 years.
• Determined age-specific reference ranges using the LMS method, categorizing pubertal status by clinical assessment.

Main Results:

• Generated reference ranges (3rd-97th percentiles) for HV across the cohort and for early, average, and late pubertal timing subgroups.
• Observed earlier pubertal onset and distinct HV patterns in African American girls compared to non-African American girls, which normalized after adjusting for pubertal timing.
• No significant sex-based differences in HV patterns were noted for males after pubertal timing adjustment.

Conclusions:

• The new HV reference ranges allow for growth assessment relative to peers, considering individual pubertal timing.
• These data facilitate the calculation of Z-scores and exact percentiles for HV, valuable for clinical and population studies.
• Improved HV assessment supports better monitoring of child development and health outcomes.