Hyperinsulinemia, which encompasses the range of metabolic abnormalities from high blood sugar (hyperglycemia) to type 2 diabetes to cardiovascular disease, is shown to have adverse impacts on bone health. The condition lowers levels of osteocalcin thereby inhibiting bone remodeling.
Bone cells, called osteocytes, are responsible for the mineralization and resorption of bone. Hyperinsulinemia blunts antioxidant activity, increasing reactive oxygen species (free radicals) and inhibits mitochondrial function. Optimal mitochondrial function is necessary for the production of osteoblasts—cells that are responsible for the formation of mineral deposition and bone tissue—and properly functioning osteocytes.
Moreover, hyperinsulinemia decreases the availability of vitamin D due to sequestration by fat cells, compromising the health of bone cells by reducing osteocalcin synthesis and favoring bone cell death. Hyperglycemia increases AGEs (Advanced Glycation End products) in bone collagen formation. Other downstream effects include magnesium deficiency, which is adversely impacted by high blood sugar levels.
What is astonishing is that fragility fractures occur in the setting of normal or even increased bone mineral density—which is supposed to be desirable. This begs the question, is the DEXA bone mineral density test reliable, or even valid given bone density doesn’t equate to bone strength in this context? Inquiring minds want to know!
Given these emerging observations about fragility fractures, it’s important that everyone be screened for hyperinsulinemia in assessing risk factors for bone fracture—even those with normal bone mineral density.
But here’s the good news: the remedy is glucose restriction. A low-carbohydrate ketogenic diet lowers blood sugar, decreasing excess insulin exposure and increasing antioxidant activity and mitochondrial function which benefits bone cell viability. In this setting, osteocalcin production is increased, normalizing bone remodeling which confers structural integrity and reduces risk of fracture.
To your health!
Leyla Muedin, MS, RD, CDN
