• We are sorry, but NCBI web applications do not support your browser and may not function properly. More information
Logo of nihpaAbout Author manuscriptsSubmit a manuscriptNIH Public Access; Author Manuscript; Accepted for publication in peer reviewed journal;
J Adolesc Health. Author manuscript; available in PMC May 1, 2010.
Published in final edited form as:
PMCID: PMC2744155
NIHMSID: NIHMS112278

Early Markers of Pubertal Onset: Height and Foot Size

Kanti R. Ford, M.D.,1 Jane C. Khoury, Ph.D.,2 and Frank M. Biro, M.D.1

Abstract

This longitudinal study compared the timing of foot and height velocities with pubertal onset in girls. There was no difference between ages of increased foot and height growth velocities; both occurred before onset of secondary sexual characteristics. Change in foot size may represent an early marker for transition to puberty.

Keywords: Puberty, pubertal onset, growth velocity

Introduction

The biologic and physiologic changes during the teen years are more strongly correlated with pubertal maturation than chronologic age. Common markers of pubertal onset include self or parental report of menarche, height velocity, and breast development. Difficulties in determining breast stage development in the obese child[1] and teen inaccuracies in self-report[2] limit the use of such methods.

The availability of an easy, cost-effective, reliable, non-invasive method to assess the onset of puberty may be useful in both clinical and research settings. The primary purpose of this project was to determine if change in foot size may be used as a marker for the onset of puberty. We compared the age at which the foot size increased, with the age when secondary sexual characteristics were observed and the age at which height velocity increased.

Methods

The subjects in this study were girls currently enrolled in the Cincinnati site of the Breast Cancer and Environmental Research Centers. Girls in the Cincinnati project, “Growing Up Female,” were 6 to 7 years old at the time of recruitment. They were recruited from public and parochial schools in the greater Cincinnati area and through the Breast Cancer Registry of Greater Cincinnati. Parental consent and participant assent were obtained on all participants. Girls were seen every six months and were included in this analysis if there had been at least one visit with secondary sexual characteristics. Girls were excluded from inclusion if they had secondary sexual characteristics at first visit, if they did not enter puberty in the first 24 months of the study, or if they had visits without foot measurements. The final analysis was completed on 86 eligible girls. The study was approved by the Internal Review Board of our institution.

Height, weight, foot size, and maturation ratings were obtained every six months. We used the Brannock foot device™ Junior European model to determine foot length. Each girl’s bare, right foot was measured one time while standing. A subset of 48 participants had repeated foot length measures; 38/48 had identical foot lengths, an additional 7/48 had repeated measures within 0.33 cm, and 3/48 had repeated measures within 0.66 cm. The intraclass correlation for foot length in these 48 participants was 0.992. Height measurements were made three times; a third measurement was obtained if the first two measures differed by a pre-set amount (0.5cm). We used mean values for analysis. Trained healthcare providers performed sexual maturity ratings for breast development and pubic hair. Breast and pubic hair staging were done by inspection and palpation based on the Tanner Stages of sexual maturity. Onset of puberty was defined as either Tanner Breast Stage 2 or Pubic Hair 2. Height velocity and foot size velocity were calculated by taking the difference in value between consecutive visits divided by the number of days between these visits, to provide annualized data. A mixed model approach was used to examine the relationship between age of increase of height velocity, increase in foot size velocity, and appearance of secondary sexual characteristics. This method was also used to test for the interaction of race, and subsequent overall race effect. SASR 9.1 was used to manage and analyze the data.

Results

There were 86 eligible girls for this study. The sample was 73% white, and 27% African American. The mean age of onset of secondary sexual characteristics was 8.79 years in this sample (SD = 0.92) (Table). The mean age for foot velocity increase was 8.40 years (SD = 0.95) and the mean age for height velocity increase was 8.27 years (SD = 0.89).

Table 1
Results comparing age (in years) of onset of secondary sexual characteristics with increase in height velocity and increase in foot size velocity.

There was a statistically significant difference between age at onset of secondary sexual characteristics and age of foot velocity increase (p = 0.007), as well as age at onset of secondary sexual characteristics and age of increase in height velocity (p = 0.0005). There was no significant difference in age of foot velocity increase and height velocity increase (p = 0.39). (Figure 1) The relationships between age at onset of secondary sexual characteristics with height velocity and foot velocity were similar when using age at onset of breast development (data not shown). There was no significant race interaction (p = 0.92) but there was an overall race effect (p = 0.0006). African American girls in this study started all markers an average 0.42 years (SD = 1.30) before their White American peers. (Figure 2)

Figure 1
Relationship between foot growth, height velocity, and onset of puberty.
Figure 2
Race has an effect on the timing/initiation of events, not the sequence. Race effect = 0.006, race by sequence interaction = 0.92.

Conclusions

Recognizing the exact onset of puberty provides researchers and clinicians with a method to categorize patients for teaching or therapy. For example, the age at onset of puberty is associated with adult body mass index[3] as well as social and psychological issues in adulthood.[4, 5] In this study sample, the age at which there was increase in both foot size and height was younger than the age of pubertal onset (defined as the onset of secondary sexual characteristics). There was no statistically significant difference between the age when height velocity increased and age when foot size velocity increased. This project demonstrated no statistical difference in sequence of events among races, although African American girls reached each marker earlier than White American girls. Parents and children may easily recall a change in footwear, necessitating new shoes versus remembering when the onset of breast development or appearance of pubic hair began. Therefore, using the change in a pre-pubertal child’s foot size could be an early, viable, non-invasive marker to document the onset of puberty.

Acknowledgements

We would like to thank the study participants, families, study helpers, and the staff of Growing Up Female for all their hard work and dedication.

Source(s) of support: Grant ES 012770 and USPHS Grant Number MO1 RR 08084, General Clinical Research Centers Program, National Center for Research Resources, NIH.

Footnotes

Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

References

1. Herman-Giddens ME, Kaplowitz PB, Wasserman R. Navigating the recent articles on girls’ puberty in Pediatrics: What do we know and where do we go from here? Pediatrics. 2004;113:911–917. [PubMed]
2. Dorn LD. Measuring puberty. J Adolesc Health. 2006;39:625–626. [PubMed]
3. Kindblom JM, Lorentzon M, Norjavaara E, et al. Pubertal timing is an independent predictor of central adiposity in young adult males: The Gothenburg Osteoporosis and Obesity Determinants Study. Diabetes. 2006;55:3047–3052. [PubMed]
4. Freedman DS, Khan LK, Serdula MK, Dietz WH, Srinivasan SR, Berenson GS. The relation of menarchal age to obesity in childhood and adulthood: The Bogalusa Heart Study. BioMed Central Pediatrics. 2003;3:3. [PMC free article] [PubMed]
5. Graber JA, Seeley JR, Brooks-Gunn J, Lewinsohn PM. Is pubertal timing associated with psychopathology in young adulthood? J Am Acad Child Adolesc Psychiatry. 2004;43:718–726. [PubMed]
PubReader format: click here to try

Formats:

Related citations in PubMed

See reviews...See all...

Cited by other articles in PMC

See all...

Links

  • MedGen
    MedGen
    Related information in MedGen
  • PubMed
    PubMed
    PubMed citations for these articles

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...