Weak genetic relationship between trabecular bone morphology and obesity in mice

Area of Science:

• Bone biology and genetics
• Obesity research
• Skeletal structure analysis

Background:

• Obesity is linked to metabolic diseases but may reduce osteoporotic fracture risk.
• The interplay between obesity and bone trabecular structure involves mechanical loading and hormonal signaling.
• Understanding these complex interactions is crucial for bone health research.

Purpose of the Study:

• To investigate the influence of sex, high-fat diet, and genetics on bone trabecular structure in a murine obesity model.
• To analyze body weight, fat pad weight, and serum leptin levels in relation to bone density.
• To identify genetic factors influencing trabecular bone morphology and its relationship with obesity.

Main Methods:

• Utilized 481 mice from 16 LGXSM recombinant inbred (RI) strains, a murine obesity model.
• Assessed trabecular density and structure in lumbar, caudal vertebrae, and proximal tibia.
• Measured body weight, fat pad weight, and serum leptin levels.

Main Results:

• Males exhibited higher vertebral trabecular density; females showed higher tibial trabecular density.
• High-fat diet minimally increased trabecular density despite significant obesity and leptin level changes.
• Moderate to strong heritabilities and high genetic correlations were observed for trabecular traits.
• Obesity-related traits showed low and non-significant genetic correlations with trabecular properties.

Conclusions:

• Genetic variation significantly impacts trabecular bone structure, contrasting plate-like with rod-like morphologies.
• Obesity has a minor effect on trabecular bone morphology in this murine model.
• Identified 20 genomic locations for trabecular properties, with only a quarter overlapping with obesity-related genes.