Insulin Resistance May Cause Weak Bones

Insulin resistance -- even if it hasn't yet developed into overt diabetes -- may cause bones to weaken, suggests a study completed by University of California/Los Angeles (UCLA; California, USA) researchers.  Preethi Srikanthan and team examined data collected on 634 men and women, ages 40 to 65 years, enrolled in the Midlife in the United States Study (MIDUS) and who did not have diabetes. The participants underwent dual-energy x-ray absorptiometry (DXA), which was used to calculate bone mineral density in the lumbar spine and left hip and femoral neck axis length and width.  The median Homeostasis Model of Assessment-Insulin Resistance (HOMA-IR) was 2.47 and the median glycated hemoglobin (HbA1c) was 5.86%.  The researchers examined the relationship between insulin resistance and three composite indices of femoral neck strength relative to load -- compression strength index, bending strength index, and impact strength index. The association observed between a doubling of HOMA-IR and reductions in all three measures of bone strength remained statistically significant after adjustment for age, sex, race/ethnicity, menopause transition stage in women, study site, and body mass index.  Further, each doubling of the HOMA-IR was associated with a 9% to 14% decrease in the bone strength markers.  The study authors submit that: “This suggests that perhaps we should be looking at more the quality and strength of bone with something like a bone strength marker rather than just bone mineral density.”