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.
MON-389 Fracture Risk Assessment Models for Patients With T2DM