Bone structure and strength are enhanced in rats programmed by early overfeeding

Area of Science:

• Endocrinology
• Bone Biology
• Nutritional Science

Background:

• Childhood obesity is a growing public health concern.
• Obesity and bone health are potentially interconnected, with implications for skeletal development.

Purpose of the Study:

• To investigate the long-term effects of early overfeeding (EO) on offspring bone health from weaning to adulthood.
• To determine if increased fat mass due to EO influences bone mineral density, structure, and biomechanical properties.

Main Methods:

• Early overfeeding induced by small litter size (SL) in rats compared to normal litter size (NL).
• Bone evaluation using dual-energy X-ray absorptiometry, computed tomography, microcomputed tomography, biomechanical testing, and serum analysis.
• Assessment of body weight, fat mass, lean mass, and visceral fat.

Main Results:

• SL offspring exhibited higher body weight, fat mass, lean mass, and visceral fat from 21 to 180 days.
• Increased total bone mineral density (BMD), bone mineral content, and bone area observed in SL offspring.
• Enhanced femur and lumbar vertebra (LV4) BMD, improved structural integrity (higher trabecular number, maximal load, stiffness, break load), and altered bone remodeling markers (higher osteocalcin, lower CTX I) in SL group at 180 days.

Conclusions:

• Excess fat mass resulting from early overfeeding contributes to increased bone mass and strength.
• Potential mediation by hormonal factors like hyperleptinemia and thyroid hormone action.
• Increased body weight and associated biomechanical loading may confer protective effects on bone health in obese individuals.