Osteocalcin: a new link between bone and energy metabolism. Some evolutionary clues

Area of Science:

• Endocrinology
• Metabolic Research
• Bone Biology

Background:

• Emerging evidence indicates bone actively participates in regulating systemic energy and glucose metabolism.
• Osteoblasts, the bone-forming cells, are increasingly recognized for their endocrine functions.

Purpose of the Study:

• To review and synthesize current human evidence on the role of bone, specifically osteocalcin, in energy and glucose metabolism.
• To explore the interplay between bone, insulin signaling, and metabolic health.

Main Methods:

• Review of cross-sectional and longitudinal studies in humans.
• Analysis of existing literature on osteocalcin's effects on carbohydrate metabolism and related conditions.

Main Results:

• Osteocalcin is identified as a key regulator of carbohydrate metabolism in humans.
• Physical activity's muscular load may link osteoblasts to the insulin axis.
• The osteoblast-insulin axis might influence nonalcoholic steatohepatitis and exhibits paradoxical effects in acromegaly and bone repair.

Conclusions:

• Osteocalcin likely plays a significant role in systemic energy metabolism due to shared cellular origins with adipocytes and muscle cells.
• Further research is needed to fully characterize osteocalcin's bioactivity, especially in conditions like renal failure.
• Osteocalcin is crucial for understanding calcium-glucose metabolism interactions, with receptor discovery being a key future direction.