SAN FRANCISCO — Doubling of insulin resistance was associated with a 10% to 14% decrease in bone strength among participants in the Biomarker Project of the Midlife in the United States Study.
To determine whether insulin resistance has negative effects on bone remodeling and results in reduced bone strength relative to load, Preethi Srikanthan, MD, MS, of the University of California Los Angeles, and colleagues analyzed data for 634 nondiabetic participants in the MIDUS II study. Insulin resistance was calculated using HOMA-IR, and projected 2D bone mineral density in the lumbar spine and left hip were measured using DXA. Additionally, researchers used the hip DXA scans to measure length and width at the femoral neck axis (FNAL and FNW, respectively).
Srikanthan and colleagues created indices of femoral neck strength relative to load in different failure modes using body weight and height measurements. Indices were: BMDxFNW/weight for compression strength; BMDx(FNW)2/(FNALxweight) for bending strength; and BMDxFNWxFNAL/(heightxweight) for impact strength. The researchers examined the relationship between HOMA-IR and the strength indices and adjusted for age, gender, menopausal transition stage, race, BMI and study site.
Srikanthan reported that every doubling of HOMA-IR was associated with a 0.10 to 0.14 standard deviation decrease in strength indices (P<.001). Additionally, higher levels of fasting insulin, but not glucose, were independently associated with lower bone strength, such that each doubling of fasting insulin was linked with a 0.08 to 0.16 SD decrease in the three composite femoral neck strength indices.
“The study is a cross-sectional analysis, and hence while we cannot say that insulin resistance causes bone strength indices to decline, insulin resistance can be noted as a marker for lower bone strength,” Srikanthan told Endocrine Today. “This finding could have significant public health implications for the bone health of a large number of obese individuals, as it emphasizes that being obese not only increases your risk of being diabetic, but it also increases your risk for fragile bones.” – by Stacey L. Adams
For more information:
Srikanthan P. #FP24-6. Presented at: The Endocrine Society Annual Meeting and Expo; June 15-18, 2013; San Francisco.
Disclosure: The researchers report no relevant financial disclosures.