Session Information
Date: Tuesday, October 23, 2018
Title: Osteoporosis and Metabolic Bone Disease – Basic and Clinical Science Poster
Session Type: ACR Poster Session C
Session Time: 9:00AM-11:00AM
Background/Purpose: Low body mass index (BMI)is linked to increase risk for osteoporosis , and fragility fractures and is therefore included in most fracture prediction tools. A previous work from our department (Oldroyd et al. Int J Clin Pract. 2014) demonstrated that very high BMI might also be a risk factor for osteoporosis and other authors have recently reported the ratio between lumbar spine BMD and BMI to be strongly correlated with trabecular bone score (TBS) and predictive of fragility fractures in a cohort of obese patients (Watanabe et al. Endocrine Practice. 2018The aim of our study was to assess the influence of the BMI/BMD ratio on the risk of fractures in an observational cohort of all weight categories.
Methods: All patients referred to our department for having a dual X-ray absorptiometry (DEXA) scan between June 2006 and October 2016 were queried. Results of first scans only were included in our analysis. Risk factors for osteoporosis and fragility fractures were recorded at the time of the scan and included age, gender, comorbidities, medication history, menopause age and fragility fracture history. The ratio of BMI/BMD was obtained and divided into quintiles. Logistic models were fitted unadjusted and adjusted for age and gender comparing those patients who had presented with a fragility fracture versus those who did not have a fracture. The ratios were calculated for the lumber spine and both femoral neck and total hip.
Results: 35,759 patients were included in the analysis, 30,095 (84.2%) were female. Mean age was 62.2 years (SD 12.8). 12,186 (34.1%) had sustained a fragility fracture. Mean BMI was 26.8 (SD 5.2). The results of the logistic models are shown in the table below for each site
|
site |
quintile |
Unadjusted OR |
95%CI |
Adjusted OR |
95%CI |
|
Lumbar spine |
1 |
Ref |
Ref |
Ref |
Ref |
|
N=35,759 |
2 |
1.23 |
1.15,1.33 |
1.18 |
1.09,1.27 |
|
3 |
1.49 |
1.38,1.60 |
1.36 |
1.26,1.46 |
|
|
4 |
1.80 |
1.67,1.93 |
1.58 |
1.47,1.70 |
|
|
5 |
2.29 |
2.14,2.47 |
1.97 |
1.83,2.12 |
|
|
Femoral neck |
1 |
Ref |
Ref |
Ref |
Ref |
|
N=27,956 |
2 |
1.37 |
1.27,1.48 |
1.27 |
1.17,1.37 |
|
3 |
1.59 |
1.47,1.71 |
1.39 |
1.29,1.51 |
|
|
4 |
1.91 |
1.77,2.06 |
1.60 |
1.49,1.73 |
|
|
5 |
2.55 |
2.37,2.75 |
2.07 |
1.87,2.18 |
|
|
Total hip |
1 |
Ref |
Ref |
Ref |
Ref |
|
N=27,956 |
2 |
1.51 |
1.38,1.65 |
1.39 |
1.27,1.52 |
|
3 |
1.97 |
1.80,2.15 |
1.73 |
1.591.89 |
|
|
4 |
2.31 |
2.12,2.52 |
1.94 |
1.78,2.12 |
|
|
5 |
3.33 |
3.07,3.63 |
2.61 |
2.39,2.85 |
Conclusion: BMI/BMD ratio to BMD appears to be a useful way of predicting fragility fractures in all weight categories in this large observational cohort. Further work looking at site of fracture and the utility of the ratio in a clinical setting will be presented. Particular attention will be given to the role of BMI/BMD ratio at predicting fractures in patient subsets where BMD is known to be less strongly associated with fracture risk (e.g. steroid therapy, diabetes).
To cite this abstract in AMA style:
Massarotti M, Bukhari M. Ratio of BMI to BMD at Different Sites and Association with Fragility Fractures [abstract]. Arthritis Rheumatol. 2018; 70 (suppl 9). https://acrabstracts.org/abstract/ratio-of-bmi-to-bmd-at-different-sites-and-association-with-fragility-fractures/. Accessed .« Back to 2018 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/ratio-of-bmi-to-bmd-at-different-sites-and-association-with-fragility-fractures/