Hip fracture risk assessment using composite indices of femoral neck strength: the Rancho Bernardo study

Abstract Introduction Bone mineral density (BMD) measurement, a tool used to diagnose osteoporosis (OP) and to predict fracture risk, has not been found very useful in type 2 diabetic (T2DM) patients. They have a 69% higher fracture risk despite having higher hip and lumbar spine BMD than the non-diabetic population. The aim of this study was to examine the impact of 3 different fracture risk assessment (FRAX) models using surrogate adjustments for T2DM in predicting osteoporotic fracture risk over 10 years. Material and Methods Observational retrospective study included 98 patients with OP or osteopenia: 94 women and 4 men admitted in the National Institute of Endocrinology between 2011-2019. 50 % (n= 49) of the patients had T2DM, while the other half were non-diabetic patients. BMI, BMD, lipid profile, serum creatinine, calcium, phosphorus, 25(OH)vitamin D, HbA1c were assessed. BMD was measured on a GE Lunar osteodensitometer. The risk of major osteoporotic fracture in 10 years was assessed with FRAX adjusted for Romania. For diabetic patients, FRAX was adjusted by adding 10 years to patients’ age (model 1), by using rheumatoid polyarthritis as a substitute for T2DM (model 2) or by lowering T score with 0.5 DS (model 3). Results Non-diabetic patients had a lower BMI (p=0.001) and a lower BMD (p=0.03) than diabetic patients. A higher BMI correlated with a higher hip BMD (p=0.004). For diabetic patients, FRAX risk without adjustment was statistically significant lower than FRAX risk calculated with model 1 and 2 (p< 0.001) for both major and hip fracture risk. Unadjusted FRAX risk was lower than the one calculated with model 3 only for hip fracture risk (p<0.001). Model 1 FRAX adjustment led to a statistically significant risk of both major osteoporotic fracture (p= 0.004) and hip fracture (p=0.04) over 10 years in diabetic patients than non-diabetic patients, though diabetic patients had higher BMD. The same observation was made when FRAX was adjusted by model 2 (p=0.001) or by model 3 (p=0.001). HbA1c correlated inversely with FRAX adjusted with all three models. Discussion FRAX calculator does not include T2DM among secondary causes of OP and this precludes a proper risk assessment independent of BMD. Trabecular bone assessment (TBS) captures a larger portion of the diabetes-associated fracture risk than BMD, however TBS it is not fully independent of the BMD. We examined 3 models of adjusted FRAX in T2DM patients that showed an important increase in fracture risk prediction when adding BMD - independent risk factors into FRAX calculator. Conclusion T2DM patients have a greater risk of major osteoporotic fracture in 10 years at the same BMD compared with non-diabetic population. New models of FRAX adjusted for T2DM are needed in assessing the intervention threshold for OP/osteopenia of patients with T2DM.

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Moving Beyond Hip Fracture Risk Assessment for Patients on Dialysis

Kidney International Reports ◽

10.1016/j.ekir.2018.09.004 ◽

2018 ◽

Vol 3 (6) ◽

pp. 1253-1254 ◽

Cited By ~ 1

Author(s):

Lucas E. Nikkel

Keyword(s):

Risk Assessment ◽

Hip Fracture ◽

Fracture Risk ◽

Fracture Risk Assessment ◽

Hip Fracture Risk

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Diabetes and Femoral Neck Strength: Findings from The Hip Strength Across the Menopausal Transition Study

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/jc.2011-1883 ◽

2012 ◽

Vol 97 (1) ◽

pp. 190-197 ◽

Cited By ~ 54

Author(s):

Shinya Ishii ◽

Jane A. Cauley ◽

Carolyn J. Crandall ◽

Preethi Srikanthan ◽

Gail A. Greendale ◽

...

Keyword(s):

Bone Mineral Density ◽

Insulin Resistance ◽

Femoral Neck ◽

Fracture Risk ◽

Bone Mineral ◽

Areal Bone Mineral Density ◽

Mineral Density ◽

Femoral Neck Strength ◽

Composite Indices ◽

Neck Strength

Context: Diabetes mellitus is associated with increased hip fracture risk, despite being associated with higher bone mineral density in the femoral neck. Objective: The objective of the study was to test the hypothesis that composite indices of femoral neck strength, which integrate dual-energy x-ray absorptiometry derived femoral neck size, femoral neck areal bone mineral density, and body size and are inversely associated with hip fracture risk, would be lower in diabetics than in nondiabetics and be inversely related to insulin resistance, the primary pathology in type 2 diabetes. Design: This was a cross-sectional analysis. Setting and Participants: The study consisted of a multisite, multiethnic, community-dwelling sample of 1887 women in pre- or early perimenopause. Outcome Measurements: Composite indices for femoral neck strength in different failure modes (axial compression, bending, and impact) were measured. Results: Adjusted for age, race/ethnicity, menopausal stage, body mass index, smoking, physical activity, calcium and vitamin D supplementation, and study site, diabetic women had higher femoral neck areal bone mineral density [+0.25 sd, 95% confidence interval (CI) (+0.06, +0.44) sd] but lower composite strength indices [−0.20 sd, 95% CI (−0.38, −0.03) sd for compression, −0.19 sd, 95% CI (−0.38, −0.003) sd for bending, −0.19 sd, 95% CI (−0.37, −0.02) sd for impact] than nondiabetic women. There were graded inverse relationships between homeostasis model-assessed insulin resistance and all three strength indices, adjusted for the same covariates. Conclusions: Despite having higher bone density, diabetic women have lower indices of femoral neck strength relative to load, consistent with their documented higher fracture risk. Insulin resistance appears to play an important role in bone strength reduction in diabetes.

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