Fibroblast growth factor-21, body composition, and insulin resistance in pre-pubertal and early pubertal males and females.

Abstract

OBJECTIVE:

Accumulating evidence derived primarily from animal models suggests that fibroblast growth factor-21 (FGF-21) may affect the musculoskeletal system via effects on the capacity of tissues to respond to insulin. A proportion of musculoskeletal properties and underpinnings of promoting/preventing insulin resistance are established early in the pubertal transition. Thus, the objective of this study was to test the hypothesis that insulin resistance and/or obesity will promote greater FGF-21 concentration which will be inversely associated with musculoskeletal parameters [lean mass and bone mineral content (BMC)] in pre-/early pubertal children. Given the sexual dimorphic nature of musculoskeletal development of fat mass accrual, differences by obesity status and sex were also investigated.

DESIGN:

Cross-sectional.

PATIENTS:

Children ages 7-12 years (n = 69, 38% male, 48% non-Hispanic black, 45% obese).

MEASUREMENTS:

Fasting FGF-21, glucose and insulin measures were obtained. An estimate of insulin resistance was derived using the homoeostatic model assessment of insulin resistance (HOMA-IR). Body composition (BMC, lean mass and fat mass) was assessed by DXA. Multivariate regression analysis was used to evaluate the influence of FGF-21 on BMC, lean mass and HOMA-IR as dependent variables. Obesity status was established based on BMI z-score.

RESULTS:

FGF-21 concentrations did not differ by obesity status or by sex. There was an inverse association between FGF-21 and BMC among nonobese individuals (P = 0·01) and an inverse association between FGF-21 and lean mass among females (P = 0·02), which were both independent of fat mass. FGF-21 was inversely associated with HOMA-IR in males, but not females (P = 0·04).

CONCLUSIONS:

The existence of relationships of FGF-21 with musculoskeletal parameters and insulin resistance raises the possibility of crosstalk between these systems. These findings suggest that circulating FGF-21 may differ in its association with bone, lean mass and insulin resistance depending on sex and weight status.

• Authors: Lynae J Hanks, Krista Casazza, Ambika P Ashraf, Stephenie Wallace, Orlando M Gutiérrez
• Journal: Clinical endocrinology (Clin Endocrinol (Oxf)) Vol. 82 Issue 4 Pg. 550-6 (Apr 2015) ISSN: 1365-2265 [Electronic] England
• PMID: 25039824 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: © 2014 John Wiley & Sons Ltd.

Chemical References

• Blood Glucose
• Insulin
• fibroblast growth factor 21
• Fibroblast Growth Factors

Topics

• Blood Glucose (metabolism)
• Body Composition
• Body Mass Index
• Body Weight
• Bone Density
• Child
• Female
• Fibroblast Growth Factors (metabolism)
• Humans
• Insulin (metabolism)
• Insulin Resistance
• Male
• Obesity (physiopathology)
• Puberty
• Regression Analysis
• Sex Factors
• Sexual Maturation