Correlation between the middle phalanx of the third finger skeletal maturation staging system and insulin-like growth factor-1 levels among Indian children - A 3-year longitudinal study.

Introduction: Tracking insulin-like growth factor-1 (IGF-1) level alongside the middle phalanx of the third finger (MP3) staging modification could provide valuable insights into the relationship between hormonal factors and skeletal maturation during different stages of growth. Longitudinal studies indeed play a crucial role in understanding these complex relationships over time, allowing for a more comprehensive assessment of how IGF-1 might serve as a marker for pubertal growth stages.

Methodology: The present longitudinal prospective cohort study was done among 26 boys and 26 girls. For each child, once in every 6 months for 3 years, blood samples (to estimate IGF-1 level) and X-rays of the left hand middle finger were taken. DRG IGF-1 600 Human Enzyme-Linked Immunosorbent Assay kit was used for the quantitative measurement of IGF1 from serum. The MP3 stages of the middle phalanx of the middle finger were evaluated using a modified MP3 system. The collected data were subjected to suitable descriptive and inferential statistics.

Results: The mean IGF1 levels were significantly higher in girls compared to boys across all the stages of MP3 skeletal maturity indicators. However, in both boys and girls, IGF-1 levels showed increasing trends from Stage F to H where it peaked and showed deceleration to Stage I (P < 0.05).

Conclusion: The observed increase in serum IGF-1 levels during pubertal stages, followed by a decline in late puberty, aligning with the stages of skeletal maturation, suggests a close relationship between hormonal changes and bone development.