Minireview: The link between fat and bone: does mass beget mass?

Area of Science:

• Endocrinology
• Bone Biology
• Metabolic Research

Background:

• Osteoporosis is less prevalent in individuals with higher fat mass, suggesting a protective role for adipose tissue.
• Hormones and signaling molecules like adipokines (e.g., leptin) and osteocalcin mediate complex interactions between fat and bone metabolism.
• Peroxisome proliferator-activated receptor γ (PPARγ) influences mesenchymal stem cell differentiation, impacting both fat and bone lineages.

Purpose of the Study:

• To explore the intricate physiological relationship between fat mass and bone health.
• To investigate the molecular mechanisms linking adipose tissue and skeletal integrity.
• To determine the extent to which body fat influences bone mass and to identify potential therapeutic targets for osteoporosis and obesity.

Main Methods:

• Review of recent scientific literature on the interplay between adipose tissue and bone.
• Analysis of studies investigating hormonal and molecular signaling pathways (adipokines, osteocalcin, PPARγ).
• Examination of findings from animal models (e.g., fat-depleted mice) and human epidemiological data.

Main Results:

• While high fat mass correlates with lower osteoporosis risk, studies question its primary role in determining bone mass.
• Mice lacking fat do not exhibit a distinct skeletal phenotype, and human bone mass is not solely dependent on adipose tissue.
• Molecular links exist, including adipokine modulation of bone cells and osteocalcin's effect on insulin sensitivity and fat mass.

Conclusions:

• The relationship between fat mass and bone mass is complex and not fully explained by adipose tissue alone.
• Emerging evidence highlights the importance of the integrated physiology at the fat-bone interface.
• Further understanding of these interactions could lead to novel therapeutic strategies for managing both osteoporosis and obesity.