Genetic influence on bone phenotypes and body composition: a Swedish twin study

Area of Science:

• Osteoporosis research
• Human genetics
• Bone biology

Background:

• Bone mineral density (BMD), bone size, and bone turnover are key determinants of fracture risk in the elderly.
• Previous twin studies indicate high heritability for BMD and bone area, and moderate heritability for bone turnover markers.
• Scandinavian countries exhibit the highest incidence of osteoporotic fractures globally, yet lack specific genetic contribution studies.

Purpose of the Study:

• To evaluate the genetic and environmental contributions to bone phenotypes in a Scandinavian population.
• To assess heritability of BMD, bone area, hip geometry, and bone turnover markers (osteocalcin and CrossLaps).

Main Methods:

• Utilized data from 102 intact like-sexed twin pairs (45 monozygotic, 57 dizygotic) from the Swedish Twin Registry.
• Measured BMD and bone area via dual-energy X-ray absorptiometry.
• Assessed serum markers for bone formation (osteocalcin) and resorption (CrossLaps).

Main Results:

• Substantial heritability observed for BMD at the lumbar spine (0.85), femoral neck (0.75), and proximal femur (0.84).
• Bone area heritability was comparable to BMD.
• Bone turnover markers showed slightly lower genetic influence: osteocalcin (0.69) and CrossLaps (0.58).

Conclusions:

• High heritability for bone phenotypes in Swedish adults suggests a significant genetic component.
• Findings encourage further research into specific genetic pathways underlying bone health and osteoporosis susceptibility.
• Understanding genetic factors is crucial for addressing high fracture incidence in Scandinavian populations.