Association made between small cortical bone size and insulin resistance in prediabetes

Insulin resistance is linked with smaller cortical bone size in young men without diabetes, new research suggests.
Belgium scientists believe that insulin resistance, which can cause type 2 diabetes, could affect cortical bone size and partially explain why people with type 2 diabetes have an elevated fracture risk. Cortical bone is the hard, outer part of the bone.
This new study from Ghent University Hospital revealed that insulin resistance has an inverse and independent association with bone size: people who were more insulin resistant had less of the hard bone casing.
Bone size was reduced in individuals with insulin resistance, even after accounting for body composition and muscle size, with bone fragility thought to be an early indicator of the pathophysiology of type 2 diabetes.
Lead study author Charlotte Verroke, MD, told Medscape Medical News: “The relationship between insulin resistance and bone geometry most likely results from a combination of factors, including direct effects of insulin resistance on bone as well as nondirect factors such as fat mass and physical activity.”
In the analysis, Verroken’s team examined 996 men aged between 25-45 years, all of whom had completed questionnaires on their lifestyle and medication history. None of the participants had diabetes at the beginning of the analysis.
Participants with insulin resistance had much smaller bones than those without insulin resistance, and due to the number of possible explanations Verroken’s team stressed the importance of identifying and monitoring insulin resistance earlier in patients.
Verroken added a benefit of this study is that it investigated the relationship between insulin resistance and bone geometry in young, healthy – albeit all male – individuals, avoiding any “potentially confounding effects of chronic diseases”.
“When investigating this relationship in a diabetic population, for example, it would be difficult to ascertain whether any observed association represents an effect of insulin resistance itself or rather an effect of diabetes-associated comorbidities or complications,” she said.
“Furthermore, the presence of an association between insulin resistance and bone geometry in this non-diabetic population confirms our hypothesis that diabetes-associated bone fragility might develop early as a consequence of insulin resistance, rather than being a late complication of type 2 diabetes.”
The findings appear online in the Journal of Clinical Endocrinology and Metabolism.