Assessment of fracture risk by the FRAX algorithm in men and women with and without type 2 diabetes mellitus: a cross-sectional study

Pancreatic fat infiltration is associated with risk of vertebral fracture in older patients with type 2 diabetes: A longitudinal multicenter study

AIMS

Patients with type 2diabetesmellitus (T2DM) have high fracture risk. This study explored the associations between pancreatic computed tomography (CT) attenuation, a marker of pancreatic fat, and risk of vertebral fracture in T2DM patients.

METHODS

A total of 1486 T2DM patients who aged 50 years and older and without preexisting vertebral fractures during 2019-2023 at our institutions were followed up untilJanuary 2024. CT attenuation of the pancreas, bone and spleen were measured. Pancreatic attenuation/spleen attenuation ratio (P/S) was calculated. Vertebral fractures were evaluated on spine CT images according to Genant's semiquantitative scoring system.

RESULTS

A total of 135 cases of vertebral fracture were identified during 26 months of follow-up and 270 patients without vertebral fracture were matched. Pancreatic CT attenuation and the P/S ratio were negatively associated with the risk of vertebral fracture (adjusted hazard ratio (aHR) = 0.97, 95 %confidence interval (CI): 0.96-0.99; aHR = 0.26, 95 %CI: 0.12-0.58). Addition of pancreatic attenuation or P/S ratio improved the performance of bone attenuation-based model (area under the curve = 0.72-0.763 vs 0.63-0.728).

CONCLUSION

Pancreatic fat infiltration is an associated factor for vertebral fracture in T2DM patients. Addition of pancreatic fat infiltration improved the predictive performance of the bone-based model.

Evaluation of Usage of a Fracture Risk Assessment by FRAX Tool in Adults With Type 2 Diabetes Mellitus

BACKGROUND

Fragility fractures are increasingly recognized as a complication of type 2 diabetes mellitus (T2DM). The FRAX-Port® is a calculation tool that assesses the 10-year risk of either major and hip fracture, integrating several clinical risk factors, including T2DM. We aimed to evaluate the fracture risk in adults with T2DM and determine the rate of patients at high risk for fracture under anti-osteoporotic therapy.

METHODS

We developed a cross-sectional study, including a convenience sample of adults with T2DM, followed in our tertiary center between 2019 and 2022. Fracture risk was evaluated according to FRAX-Port®.

RESULTS

One hundred adults were included, 54% male, with a mean age of 68.4±9.2 years. Respecting fracture risk factors, 17% had a previous fragility fracture, 12% had a history of hip fracture in their parents, 9% had active alcohol consumption, and 4% had active smoking. Additionally, 17% presented secondary osteoporosis, being the most frequent cause of systemic corticosteroid exposure (10%). Regarding diabetes-specific risk factors, 94% had a diabetes duration longer than five years; HbA1c greater than 7% in 70%; 42% had diabetic retinopathy, 33% had diabetic chronic kidney disease, 18% had peripheral neuropathy, and 7% had autonomic neuropathy; 83% were on insulin, 2% on canagliflozin and 1% on pioglitazone. According to the FRAX-Port®, the median probability of major fracture was 6.8% (IQR 6.9), and hip fracture was 2.4% (IQR 3.9). Fracture risk was high, intermediate, and low at 41%, 15%, and 44%, respectively. Lastly, 56% of participants should undergo bone densitometry and 45% had a formal recommendation to begin an anti-osteoporotic treatment. However, only 6% were under anti-osteoporotic therapy: bisphosphonates (5%) and denosumab (1%).

CONCLUSIONS

More than a third of T2DM patients evaluated had a high fracture risk. We found that FRAX-Port® is an easy-to-apply tool, which helps in the decision to perform densitometry or to institute anti-osteoporotic therapy. Given the increasing prevalence of T2DM and the associated risk of falls, this study highlights the need to recognize the fracture risk in these patients, usually a forgotten complication during the screening of risk factors for adverse events in adults with T2DM.

Performance of the Garvan Fracture Risk Calculator in Individuals with Diabetes: A Registry-Based Cohort Study

Diabetes increases fracture and falls risks. We evaluated the performance of the Garvan fracture risk calculator (FRC) in individuals with versus without diabetes. Using the population-based Manitoba bone mineral density (BMD) registry, we identified individuals aged 50-95 years undergoing baseline BMD assessment from 1 September 2012, onwards with diabetes and self-reported falls in the prior 12 months. Five-year Garvan FRC predictions were generated from clinical risk factors, with and without femoral neck BMD. We identified non-traumatic osteoporotic fractures (OF) and hip fractures (HF) from population-based data to 31 March 2018. Fracture risk stratification was assessed from area under the receiver operating characteristic curves (AUROC). Cox regression analysis was performed to examine the effect of diabetes on fractures, adjusted for Garvan FRC predictions. The study population consisted of 2618 women with and 14,064 without diabetes, and 636 and 2201 men with and without the same, respectively. The Garvan FRC provided significant OF and HF risk stratification in women with diabetes, similar to those without diabetes. Analyses of OF in men were limited by smaller numbers; no significant difference was evident by diabetes status. Cox regression showed that OF risk was 23% greater in women with diabetes adjusted for Garvan FRC including BMD (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.01-1.49), suggesting it slightly underestimated risk; a non-significant increase in diabetes-related HF risk was noted (HR 1.37, 95% CI 0.88-2.15). Garvan FRC shows similar fracture risk stratification in individuals with versus without diabetes, but may underestimate this risk.

Distributions of Microdamage Are Altered Between Trabecular Rods and Plates in Cancellous Bone From Men With Type 2 Diabetes Mellitus

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of fragility fracture despite exhibiting normal to high bone mineral density (BMD). Conditions arising from T2DM, such as reduced bone turnover and alterations in microarchitecture, may contribute to skeletal fragility by influencing bone morphology and microdamage accumulation. The objectives of this study were (i) to characterize the effect of T2DM on microdamage quantity and morphology in cancellous bone, and (ii) relate the accumulation of microdamage to the cancellous microarchitecture. Cancellous specimens from the femoral neck were collected during total hip arthroplasty (T2DM: n = 22, age = 65 ± 9 years, glycated hemoglobin [HbA1c] = 7.00% ± 0.98%; non-diabetic [non-DM]: n = 25, age = 61 ± 8 years, HbA1c = 5.50% ± 0.4%), compressed to 3% strain, stained with lead uranyl acetate to isolate microdamage, and scanned with micro-computed tomography (μCT). Individual trabeculae segmentation was used to isolate rod-like and plate-like trabeculae and their orientations with respect to the loading axis. The T2DM group trended toward a greater BV/TV (+27%, p = 0.07) and had a more plate-like trabecular architecture (+8% BV_plates , p = 0.046) versus non-DM specimens. Rods were more damaged relative to their volume compared to plates in the non-DM group (DV_rods /BV_rods versus DV_plates /BV_plates : +49%, p < 0.0001), but this difference was absent in T2DM specimens. Longitudinal rods were more damaged in the non-DM group (DV_{longitudinal rods} /BV_{longitudinal rods} : +73% non-DM versus T2DM, p = 0.027). Total damage accumulation (DV/BV) and morphology (DS/DV) did not differ in T2DM versus non-DM specimens. These results provide evidence that cancellous microarchitecture does not explain fracture risk in T2DM, pointing to alterations in material matrix properties. In particular, cancellous bone from men with T2DM may have an attenuated ability to mitigate microdamage accumulation through sacrificial rods. © 2022 American Society for Bone and Mineral Research (ASBMR).

Management of bone fragility in type 2 diabetes: Perspective from an interdisciplinary expert panel

AIM

Bone fragility is increasingly recognized as a relevant complication of type 2 diabetes (T2D) and diabetic patients with fragility fractures have higher mortality rates than non diabetic individuals or diabetic patients without fractures. However, current diagnostic approaches for fracture risk stratification, such as bone mineral density measurement or the use of risk assessment algorithms, largely underestimate fracture risk in T2D patients. A multidisciplinary expert panel was established in order to in order to formulate clinical consensus recommendations on bone health assessment and management of fracture risk in patients with T2D.

DATA SYNTHESIS

The following key questions were addressed: a) which are the risk factors for bone fragility in T2D?, b) which diagnostic procedures can be currently used to stratify fracture risk in T2D patients?, c) which are the effects of antidiabetic treatments on bone?, and d) how to prevent and treat bone fragility in T2D patients? Based on the available data members of this panel suggest that the stratification of fracture risk in patients with diabetes should firstly rely on the presence of a previous fragility fracture and on the individual risk profile, with the inclusion of T2D-specific risk factors (namely T2D duration above 10 yrs, presence of chronic T2D complications, use of insulin or thiazolidinediones and persistent HbA1c levels above 8% for at least 1 year). Two independent diagnostic approaches were then suggested in the presence or the absence of a prevalent fragility fracture, respectively.

CONCLUSIONS

Clinical trials in T2D patients at risk for fragility fractures are needed to determine the efficacy and safety of available antiresorptive and anabolic agents in this specific setting.

Follicle-stimulating hormone and estradiol are associated with bone mineral density and risk of fractures in men with type 2 diabetes mellitus

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with a higher fracture risk. Sex hormones are important for maintaining skeletal health. It is not clear which sex hormone(s) contribute(s) to bone mineral density (BMD) and fracture risk in males with T2DM. This study investigated the relationships of these parameters in males with T2DM.

METHODS

This study involved 482 men with T2DM. BMDs at the lumbar spine (L2-4), femoral neck (FN), and total hip (TH) were measured by dual-energy X-ray absorptiometry (DXA). The 10-year probability of fractures was assessed using the modified Fracture Risk Algorithm (FRAX) tool. Serum levels of sex hormones were measured.

RESULTS

Follicle-stimulating hormone (FSH) and estradiol (E2) were associated with BMDs at L2-4 (FSH, β = -.162, P < .05; E2, β = .176, P < .001), and E2 was associated with BMD at FN (β = .137, P < .05) and TH (β = .140, P < .05). FSH was associated with major osteoporotic fractures (β = .288, P < .001) and hip fractures (β = .235, P < .001). Higher FSH was a risk factor for osteoporosis/osteopenia (odds ratios [OR] = 2.92, 95% CI = 1.66-5.14, P < .001), whereas higher E2 was a protective factor (OR = 0.37, 95% CI = 0.22-0.60, P < .001). Patients in the higher tertile of FSH and lower tertile of E2 had an increased risk of osteoporosis/osteopenia (OR = 5.05, 95% CI = 1.37-18.65, P < .05).

CONCLUSIONS

For males with T2DM, FSH and E2 are significantly associated with BMD, osteoporosis/osteopenia, and fracture risk.

Fracture Risk Assessment Tool May Not Indicate Bone Fragility in Women With Type 2 Diabetes

BACKGROUND

Diabetes carries a known risk of bone fracture despite high bone mineral density (BMD). The fracture risk assessment tool (FRAX) predicts the 10-year major osteoporotic fracture risk and hip fracture risk. We investigated the effects of clinical parameters on the FRAX score and evaluated the validity of FRAX for evaluating current bone fragility in diabetes subjects.

MATERIALS AND METHODS

Forty-seven thousand, three hundred eighty-nine Japanese women participated in the Chiba bone survey, a population-based, multicenter, cross-sectional study of postmenopausal osteoporosis; we estimated FRAX scores without BMD and compared scores between subjects with and without type 2 diabetes.

RESULTS

Mean FRAX major osteoporotic fracture risk was significantly higher in the diabetes group. A multiple regression model demonstrated some clinical parameters that affected the FRAX score and, after adjusting for such parameters, the FRAX score was not significantly different between the diabetes and nondiabetes groups, although the type 2 diabetes rate was significantly higher in subjects with a fracture in the past 5 years, which reflected current bone fragility. After adjusting for clinical parameters, the diabetes rate remained significantly higher in subjects with a fracture in the past 5 years, confirming that type 2 diabetes influences current bone fragility. Our study demonstrated that type 2 diabetes truly carries a risk of bone fracture, but adjusted FRAX major osteoporotic fracture risk is not significantly different between subjects with and without type 2 diabetes.

CONCLUSIONS

The FRAX major osteoporotic fracture risk without BMD does not correctly indicate current bone fragility in Japanese middle-aged women with type 2 diabetes.

DPP4 Activities Are Associated with Osteopenia/Osteoporosis and Fracture Risk in Newly Diagnosed Type 2 Diabetes

BACKGROUND

Recent studies have shown the beneficial effect of dipeptidyl peptidase-4 (DPP4) inhibitor on bone turnover in diabetes mellitus. However, little clinical evidence for DPP4 activity in newly diagnosed type 2 diabetes is available. This study was designed to investigate the relationship between plasma DPP4 activity and osteoporosis/osteopenia and fracture risk in newly diagnosed type 2 diabetes.

METHODS

A total of 147 subjects with newly diagnosed type 2 diabetes were enrolled for this cross-sectional study. The bone mineral density (BMD) at the lumbar spine (L1-4) and femoral neck (FN) was measured by dual-energy X-ray absorptiometry (DXA). The 10-year probability of major osteoporotic fracture (MOF) and hip fracture (HF) was assessed by a modified fracture risk algorithm (FRAX) tool. The plasma DPP4 activity and clinical variables were measured. Correlation analyses between DPP4 activity and osteoporosis/osteopenia and fracture risk were performed.

RESULTS

Elevated plasma DPP activities were significantly associated with a higher proportion of osteoporosis/osteopenia (50% for quartile-1, 56.4% for quartile-2, 65.8% for quartile-3 and 72.2% for quartile-4). With increasing plasma DPP activities, the incidence rate of osteoporosis/osteopenia is gradually increasing (P for the trend between quartiles = 0.04). Of note, a statistically significant linear correlation was found between plasma DPP4 activities and modified FRAX MOF (r = 0.20, P=0.02). Moreover, plasma DPP4 activities were also positively related to modified FRAX HF in newly diagnosed type 2 diabetic patients (r = 0.21, P=0.01).

CONCLUSIONS

Elevated plasma DPP4 activity tended to be associated with a higher proportion of osteoporosis/osteopenia and increased the fracture risk in newly diagnosed type 2 diabetes.

Pathophysiology and Management of Type 2 Diabetes Mellitus Bone Fragility

Individuals with type 2 diabetes mellitus (T2DM) have an increased risk of bone fragility fractures compared to nondiabetic subjects. This increased fracture risk may occur despite normal or even increased values of bone mineral density (BMD), and poor bone quality is suggested to contribute to skeletal fragility in this population. These concepts explain why the only evaluation of BMD could not be considered an adequate tool for evaluating the risk of fracture in the individual T2DM patient. Unfortunately, nowadays, the bone quality could not be reliably evaluated in the routine clinical practice. On the other hand, getting further insight on the pathogenesis of T2DM-related bone fragility could consent to ameliorate both the detection of the patients at risk for fracture and their appropriate treatment. The pathophysiological mechanisms underlying the increased risk of fragility fractures in a T2DM population are complex. Indeed, in T2DM, bone health is negatively affected by several factors, such as inflammatory cytokines, muscle-derived hormones, incretins, hydrogen sulfide (H2S) production and cortisol secretion, peripheral activation, and sensitivity. All these factors may alter bone formation and resorption, collagen formation, and bone marrow adiposity, ultimately leading to reduced bone strength. Additional factors such as hypoglycemia and the consequent increased propensity for falls and the direct effects on bone and mineral metabolism of certain antidiabetic medications may contribute to the increased fracture risk in this population. The purpose of this review is to summarize the literature evidence that faces the pathophysiological mechanisms underlying bone fragility in T2DM patients.

Vertebral Fractures in Type 2 Diabetes Patients: Utility of Trabecular Bone Score and Relationship With Serum Bone Turnover Biomarkers

BACKGROUND

Patients with type 2 diabetes (T2D) have an increased risk for vertebral fracture (VF). The aim of this study is to determine the utility of trabecular bone score (TBS) in T2D patients with VF and the relationship of TBS with serum bone turnover biomarkers (SBTBs).

METHODOLOGY

Postmenopausal T2D female patients were prospectively enrolled. All patients received: (1) dual-energy X-ray absorptiometry exam for bone mineral density (BMD), T-score, and TBS values; (2) lateral lumbar spine radiographs for VF assessment; and (3) SBTBs: bone specific alkaline phosphatase and Beta-C-Terminal telopeptides. BMD, T-score, TBS, and SBTBs were tested for association with VF.

RESULTS

The study included 285 T2D patients (mean age = 61.1 years) and 32 patients had VF (11.2%). TBS had the strongest association with VF in T2D patients (area under curve 0.775). The TBS cutoff values for VF are 1.279 in T-score ≥1 and 1.236 in T-score <-1. In patients without VF, all sites of BMD and TBS are significantly associated with SBTBs, but in patients with VF, no associations are found between SBTBs and all sites of BMD and TBS.

CONCLUSIONS

TBS can assess bone quality in the spine. The low TBS cutoff values for T2D patients with VF imply T2D does impair bone quality. Thus, TBS should be incorporated in VF risk assessment in T2D patients. In addition, a dissociated relationship between BMD and TBS with SBTBs represents imbalanced bone turnover rate and results in bone fragility and VF.

Comparison of FRAX in postmenopausal Asian women with and without type 2 diabetes mellitus: a retrospective observational study

Objective

To compare the fracture risk in postmenopausal Asian women with or without type 2 diabetes mellitus (T2DM).

Methods

The study cohort comprised data from consecutive postmenopausal women with T2DM that were retrieved from a prospectively maintained institutional database from 2001 to 2009. Postmenopausal women without DM from the Medical Examination Center from 2001 to 2009 formed the control cohort. The primary endpoint was the World Health Organization Fracture Risk Algorithm (FRAX, revised 2013) score. The secondary endpoint was bone mineral density (BMD).

Results

There were 1014 individuals included for the assessment (T2DM, n=500 and non-DM, n=514). Based on the FRAX model, the risk of major osteoporotic fractures and hip fractures over the next 10 years was higher in the T2DM group compared with the non-DM group. Compared with the T2DM group, the non-DM group had a lower BMD. After adjusting for age, gender, history of alcohol consumption, smoking status, body mass index, and low-density lipoprotein, the differences were statistically significant.

Conclusions

Compared with postmenopausal women without DM, postmenopausal women with T2DM had a significantly higher fracture risk calculated using the FRAX model. Early intervention for postmenopausal women with T2DM may be necessary, although T2DM is associated with a high BMD.

Associations of serum sex hormone binding globulin with bone mineral densities and higher 10-year probability of fractures in postmenopausal women with type 2 diabetes mellitus

Background

Postmenopause and type 2 diabetes mellitus (T2DM) are associated with higher fracture risk. Sex hormones are important in maintaining woman skeleton health. The relationships of sex hormone(s) with bone mineral density (BMD) and fracture risk are still unclear in diabetic-postmenopausal women. This study aimed to investigate the relationships of sex hormones with BMDs and fracture risk in postmenopausal women with T2DM.

Methods

Two hundred and fourteen postmenopausal women with T2DM were included. BMDs at lumbar spine (L2-4), femoral neck (FN) and total hip (TH) were measured by dual-energy X-ray absorptiometry (DXA). The 10-year probability of fractures was accessed by modified fracture risk algorithm (FRAX) tool. Serum concentrations of sex hormones were measured.

Results

Sex hormone binding globulin (SHBG) was a determinant of BMDs at L2-4 (β=-0.199, P<0.05), TH (β=-0.233, P<0.05), major osteoporotic fracture (MOF) (β=0.253, P<0.001) and hip fracture (HF) (β=0.262, P<0.001). Per SD increase in SHBG caused a 2% increase in the risk of osteoporosis/osteopenia. SHBG in quartile-4 was associated with 4.21 higher risk of osteoporosis/osteopenia compared with SHBG in quartile-1.

Conclusions

In postmenopausal women with T2DM, higher serum SHBG tended to be associated with lower BMDs, and increased the risk of osteoporosis/osteopenia and the fracture risk.

DIAGNOSIS OF ENDOCRINE DISEASE: Evaluation of bone fragility in endocrine disorders

An underlying disease affecting bone health is present in up to 40% and 60% of osteoporotic post-menopausal women and men respectively. Among the disorders leading to a secondary form of osteoporosis, the endocrine diseases are highly represented. A frequent finding in patients affected with an endocrine-related forms of bone disease is that the skeletal fragility is partially independent of the bone density, since the fracture risk in these patients is related more to a reduction of bone quality than to a decrease of bone mass. As a consequence, bone mineral density evaluation by dual-X-ray Absorptiometry may be inadequate for establishing the risk of fracture in the setting of the endocrine-related forms of osteoporosis. In the recent years several attempts to non-invasively estimating bone quality have been done. Nowadys, some new tools are available in the clinical practice for optimizing the fracture risk estimation in patients with endocrine disorders. The aim of this review is to summarise the evidences regarding the role of the different imaging tools for evaluating bone density and bone quality in the most frequent forms of endocrine-related osteoporosis, such as obesity, diabetes, acromegaly, thyrotoxicosis, primary hyperparathyroidism, hypercortisolism and hypogonadism. For each of these disorders, data regarding both the current available tools and the future possible new techniques for assessing bone fragility in patients with endocrine diseases are reported.

High serum osteopontin levels are associated with prevalent fractures and worse lipid profile in post-menopausal women with type 2 diabetes

PURPOSE

Patients with type 2 diabetes (T2DM) have increased fracture risk. Osteopontin (OPN) is a protein involved in bone remodeling and inflammation. The aim of this study was to evaluate the association of OPN with fracture prevalence and with metabolic parameters in post-menopausal women with T2DM.

METHODS

Sixty-four post-menopausal women with T2DM (age 67.0 ± 7.8 years, diabetes duration 8.9 ± 6.7 years), enrolled in a previous study, were followed up (3.6 ± 0.9 years). Previous fragility fractures were recorded. The FRAX score (without BMD) was calculated and biochemical parameters (plasma glucose, HbA1c, lipid profile and renal function) were assessed. Serum 25OH-vitamin D, calcium, PTH and OPN were evaluated at baseline. The association between OPN and fracture prevalence at baseline was evaluated by a logistic model.

RESULTS

OPN levels were higher in patients with previous fractures (n.25) than in patients without previous fractures at baseline (n.39) (p = 0.006). The odds of having fractures at baseline increased by 6.7 (1.9-31.4, 95% CI, p = 0.007) for each increase of 1 ng/ml in OPN levels, after adjustment for vitamin D and HbA1c levels. Fracture incidence was 4.7%. Higher OPN associated with a decrease in HDL-cholesterol (p = 0.048), after adjustment for age, basal HDL-cholesterol, basal and follow-up HbA1c and follow-up duration. 25OH-vitamin D associated with an increase in FRAX-estimated probability of hip fracture at follow-up (p = 0.029), after adjustment for age, 25OH-vitamin D and time.

CONCLUSIONS

In post-menopausal women with T2DM, OPN might be a useful marker of fracture and worse lipid profile.

Development and Validation of a Simple Hip Fracture Risk Prediction Tool for Type 2 Diabetes: The Fremantle Diabetes Study Phase I

OBJECTIVE

To develop a type 2 diabetes hip fracture risk tool in community-based patients, to validate it in an independent cohort, and to compare its performance against the only published prediction equation to include type 2 diabetes as a risk factor (QFracture).

RESEARCH DESIGN AND METHODS

Hip fracture hospitalizations in 1,251 participants with type 2 diabetes aged 40-89 years from the longitudinal Fremantle Diabetes Study Phase I (FDS1) were ascertained between entry (1993-1996) and end-2012. Competing risk regression modeling determined independent predictors of time to first fracture over 10 years and the coefficients incorporated in a risk model. The model was validated in 286 participants with type 2 diabetes from the Busselton Health Study (BHS).

RESULTS

Fifty FDS1 participants (4.0%) experienced a first hip fracture during 10,306 person-years of follow-up. Independent predictors of fracture were older age, female sex, lower BMI, peripheral sensory neuropathy, and estimated glomerular filtration rate <45 mL/min/1.73 m². The model-predicted mean 10-year incident fracture risk was 3.3% with good discrimination, calibration, and accuracy. For a 3% cutoff, sensitivity was 76.0%, specificity 71.9%, positive predictive value (PPV) 10.1%, and negative predictive value (NPV) 98.6%. Model performance in the small BHS sample was also good (sensitivity 66.7%, specificity 79.8%, PPV 6.2%, and NPV 99.2%). QFracture performed well in FDS1 but required availability of 25 variables.

CONCLUSIONS

The FDS1 hip fracture risk equation is a simple validated adjunct to type 2 diabetes management that uses variables that are readily available in routine care.

FRAX tool in type 2 diabetic subjects: the use of HbA1c in estimating fracture risk

AIMS

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of fractures, despite having greater bone mineral density (BMD) than non-diabetic subjects. This has led to the hypothesis that the presence of impaired bone quality among diabetics reduces bone strength. The Fracture Risk Assessment Score (FRAX) algorithm, introduced to facilitate the evaluation of fracture risk, underestimates the risk of fracture in diabetic patients. The purpose of this study is to confirm the relationship between the degree of metabolic compensation and the 10-year probability of a major fracture or a hip osteoporotic fracture observed in our previous study and to ascertain whether glycosylated hemoglobin (HbA_1c) can improve the predictive value of FRAX in patients with T2DM.

METHODS

Our data derive from a retrospective clinical study conducted at the "Tor Vergata" Polyclinic in Rome on 6355 subjects over 50 years of age evaluated for osteoporosis. All available clinical records were examined. HbA_1c was available for 242 of these subjects and all had had a Dual-energy X-ray Absorption (DXA) scan of the lumbar spine and femoral neck. The risk of fracture was estimated using the Italian version of the FRAX algorithm.

RESULT

Patients with T2DM had BMD and T-scores higher than those of non-diabetic subjects, while FRAX average values were higher in the non-diabetic group. HbA_1c and FRAX are inversely correlated with each other: for each incremental percentage point of HbA_1c growth, the FRAX major osteoporotic fracture probability is reduced by 0.915 points and the FRAX hip osteoporotic fracture probability by 1.438 points. The introduction of a correction factor derived from HbA_1c, resulted in mean FRAX values of diabetic patients equivalent to those of non-diabetic subjects.

CONCLUSIONS

We propose a correction factor derived from HbA_1c that could enhance the predictive ability of fracture risk estimated by the FRAX algorithm in subjects with T2DM.

Fracture risk in type 2 diabetic patients: A clinical prediction tool based on a large population-based cohort

BACKGROUND

An increased fracture risk has been described as a complication of Type 2 diabetes mellitus (T2DM). Clinical prediction models for general population have a limited predictive accuracy for fractures in T2DM patients. The aim was to develop and validate a clinical prediction tool for the estimation of 5-year hip and major fracture risk in T2DM patients.

METHODS AND RESULTS

A cohort of newly diagnosed T2DM patients (n = 51,143, aged 50-85, 57% men) was extracted from the Information System for the Development of Research in Primary Care (SIDIAP) database, containing computerized primary care records for >80% of the population of Catalonia, Spain (>6 million people). Patients were followed up from T2DM diagnosis until the earliest of death, transfer out, fracture, or end of study. Cox proportional hazards regression was used to model the 5-year risk of hip and major fracture. Calibration and discrimination were assessed. Hip and major fracture incidence rates were 1.84 [95%CI 1.64 to 2.05] and 7.12 [95%CI 6.72 to 7.53] per 1,000 person-years, respectively. Both hip and major fracture prediction models included age, sex, previous major fracture, statins use, and calcium/vitamin D supplements; previous ischemic heart disease was also included for hip fracture and stroke for major fracture. Discrimination (0.81 for hip and 0.72 for major fracture) and calibration plots support excellent internal validity.

CONCLUSIONS

The proposed prediction models have good discrimination and calibration for the estimation of both hip and major fracture risk in incident T2DM patients. These tools incorporate key T2DM macrovascular complications generally available in primary care electronic medical records, as well as more generic fracture risk predictors. Future work will focus on validation of these models in external cohorts.

The risks of sarcopenia, falls and fractures in patients with type 2 diabetes mellitus

Fracture risk in patients with type 2 diabetes mellitus (T2DM) is increased, and the mechanism is multifactorial. Recent research on T2DM-induced bone fragility shows that bone mineral density (BMD) is often normal or even slightly elevated. However, bone turnover may be decreased and bone material and microstructural properties are altered, especially when microvascular complications are present. Besides bone fragility, extra-skeletal factors leading to an increased propensity to experience falls may also contribute to the increased fracture risk in T2DM, such as peripheral neuropathy, retinopathy and diabetes medication (e.g. insulin use). One of the probable additional contributing factors to the increased fall and fracture risks in T2DM is sarcopenia, the age-related decline in skeletal muscle mass, quality and function. Although the association between sarcopenia, fall risk, and fracture risk has been studied in the general population, few studies have examined the association between T2DM and muscle tissue and the risks of falls and fractures. This narrative review provides an overview of the literature regarding the multifactorial mechanisms leading to increased fracture risk in patients with T2DM, with a focus on sarcopenia and falls.

Bone disease in diabetes: another manifestation of microvascular disease?

Type 1 and type 2 diabetes are generally accepted to be associated with increased bone fracture risk. However, the pathophysiological mechanisms of diabetic bone disease are poorly understood, and whether the associated increased skeletal fragility is a comorbidity or a complication of diabetes remains under debate. Although there is some indication of a direct deleterious effect of microangiopathy on bone, the evidence is open to question, and whether diabetic osteopathy can be classified as a chronic, microvascular complication of diabetes remains uncertain. Here, we review the current knowledge of potential contributory factors to diabetic bone disease, particularly the association between diabetic microangiopathy and bone mineral density, bone structure, and bone turnover. Additionally, we discuss and propose a pathophysiological model of the effects of diabetic microvascular disease on bone, and examine the progression of bone disease alongside the evolution of diabetes.

Low-trauma fractures without osteoporosis

In clinical practice, areal bone mineral density (aBMD) is usually measured using dual-energy X-ray absorptiometry (DXA) to assess bone status in patients with or without osteoporotic fracture. As BMD has a Gaussian distribution, it is difficult to define a cutoff for osteoporosis diagnosis. Based on epidemiological considerations, WHO defined a DXA-based osteoporosis diagnosis with a T-score <-2.5. However, the majority of individuals who have low-trauma fractures do not have osteoporosis with DXA (i.e., T-score <-2.5), and some of them have no decreased BMD at all. Some medical conditions (spondyloarthropathies, chronic kidney disease and mineral bone disorder, diabetes, obesity) or drugs (glucocorticoids, aromatase inhibitors) are more prone to cause fractures with subnormal BMD. In the situation of fragility fractures with subnormal or normal BMD, clinicians face a difficulty as almost all the pharmacologic treatments have proved their efficacy in patients with low BMD. However, some data are available in post hoc analyses in patients with T score >-2. Overall, in patients with a previous fragility fracture (especially vertebra or hip), treatments appear to be effective. Thus, the authors recommend treating some patients with a major fragility fracture even if areal BMD T score is above -2.5.

The association between glucose metabolism status, diabetes severity and a history of fractures and recent falls in participants of 50 years and older-the Maastricht Study

In this cohort of relatively young and well-treated participants with type 2 diabetes, we found no association between diabetes status and a history of previous fractures and recent falls. Furthermore, no association between diabetes severity and previous fractures or recent falls was found.

INTRODUCTION

In this study, we examined the association between glucose metabolism status and historical fractures or recent falls and the effect of diabetes severity (glucose control, insulin use, and diabetes duration) on falls and fractures in the participants with type 2 diabetes.

METHODS

Cross-sectional data from 2005 participants of the Maastricht Study. Falls in the past 6 months and fractures ≥age 50 were assessed by questionnaire. Glucose metabolism status (normal glucose metabolism, impaired glucose metabolism, or type 2 diabetes) was based on the oral glucose tolerance test and medication use.

RESULTS

In the completely adjusted model, the odds for a fall were not significantly higher in those with impaired glucose metabolism status (OR (95%CI) 1.28 (0.93-1.77)) or with type 2 diabetes (OR (95%CI) 1.21 (0.80-1.81)) compared with the group with normal glucose metabolism. Within the group with type 2 diabetes, there were no significant differences with regard to reported falls between participants with HbA1c >7 % (53 mmol/mol) versus HbA1c ≤7 % (OR (95%CI) 1.05 (0.58-1.90)), insulin users versus non-insulin users (OR (95%CI) 1.51 (0.79-2.89)), and with a diabetes duration >5 versus ≤5 years (OR (95%CI) 0.52 (0.46-1.47)). Similarly, neither glucose metabolism status nor diabetes severity was associated with prior fractures.

CONCLUSIONS

Glucose metabolism status was not significantly associated with previous fractures and recent falls. In addition, in this cohort of relatively young and well-treated participants with type 2 diabetes, diabetes severity was not associated with previous fractures and recent falls.

The utility of dual-energy X-ray absorptiometry, calcaneal quantitative ultrasound, and fracture risk indices (FRAX® and Osteoporosis Risk Assessment Instrument) for the identification of women with distal forearm or hip fractures: A pilot study

PURPOSE

Dual-energy X-ray absorptiometry (DXA) is considered the "gold standard" in predicting osteoporotic fractures. Calcaneal quantitative ultrasound (QUS) variables are also known to predict fractures. Fracture risk assessment tools may also guide us for the detection of individuals at high risk for fractures. The aim of this case-control study was to evaluate the utility of DXA bone mineral density (BMD), calcaneal QUS parameters, FRAX® (Fracture Risk Assessment Tool), and Osteoporosis Risk Assessment Instrument (ORAI) for the discrimination of women with distal forearm or hip fractures.

MATERIALS AND METHODS

This case-control study included 20 women with a distal forearm fracture and 18 women with a hip fracture as cases and 76 age-matched women served as controls. BMD at the spine, proximal femur, and radius was measured using DXA and acoustic parameters of bone were obtained using a calcaneal QUS device. FRAX® 10-year probability of fracture and ORAI scores were also calculated in all participants. Receiver operating characteristic (ROC) analysis was used to assess fracture discriminatory power of all the tools.

RESULTS

While all DXA BMD, and QUS variables and FRAX® fracture probabilities demonstrated significant areas under the ROC curves for the discrimination of hip-fractured women and those without, only 33% radius BMD, broadband ultrasound attenuation (BUA), and FRAX® major osteoporotic fracture probability calculated without BMD showed significant discriminatory power for distal forearm fractures.

CONCLUSIONS

It can be concluded that QUS variables, particularly BUA, and FRAX® major osteoporotic fracture probability without BMD are good candidates for the identification of both hip and distal forearm fractures.

The utility of lumbar spine trabecular bone score and femoral neck bone mineral density for identifying asymptomatic vertebral fractures in well-compensated type 2 diabetic patients

The objective of the study was to evaluate the usefulness of trabecular bone score (TBS) and bone mineral density (BMD) for identifying vertebral fractures (VFx) in well-compensated type 2 diabetic (T2D) patients. TBS and femoral neck BMD below certain cutoffs may be useful for identifying VFx in well-compensated T2D patients.

INTRODUCTION

In T2D, the prevalence of VFx is increased, especially in poorly compensated and complicated diabetic patients. The possibility of predicting the fracture risk in T2D patients by measuring BMD and TBS, an indirect parameter of bone quality, is under debate. Therefore, the objective was to evaluate the usefulness of TBS and BMD for identifying VFx in well-compensated T2D patients.

METHODS

Ninety-nine T2D postmenopausal women in good metabolic control (glycosylated haemoglobin 6.8 ± 0.7 %) and 107 control subjects without T2D were evaluated. In all subjects, we evaluated the following: the BMD at the lumbar spine (LS) and the femoral neck (FN); the TBS by dual X-ray absorptiometry; and VFx by radiography. In T2D subjects, the presence of diabetic retinopathy, neuropathy, and nephropathy was evaluated.

RESULTS

T2D subjects had increased VFx prevalence (34.3 %) as compared to controls (18.7 %) (p = 0.01). T2D subjects presented higher BMD (LS -0.8 ± 1.44, FN -1.06 ± 1.08), as compared to controls (LS -1.39 ± 1.28, p = 0.002; FN -1.45 ± 0.91, p = 0.006, respectively). TBS was not different between diabetics and controls. In fractured T2D patients, LS-BMD, FN-BMD, and TBS were reduced (-1.2 ± 1.44; -1.44 ± 1.04; 1.072 ± 0.15) and the prevalence of retinopathy (15.4 %) was increased than in nonfractured T2D subjects (-0.59 ± 1.4, p = 0.035; -0.87 ± 1.05, p = 0.005; 1.159 ± 0.15, p = 0.006; 1.8 %, p = 0.04, respectively). The combination of TBS ≤1.130 and FN-BMD less than -1.0 had the best diagnostic accuracy for detecting T2D fractured patients (SP 73.8 %, SN 63.6 %, NPV 78.9 %, PPV 56.8 %).

CONCLUSIONS

TBS and FN-BMD below certain cutoffs may be useful for identifying VFx in well-compensated T2D patients.

Clinical evidence of diabetes mellitus end-organ damage as risk factor for falls complicated by hip fracture: A multi-center study of 1225 patients

AIMS

To identify the differential characteristics of patients with type 2 diabetes mellitus (T2DM) complicated by end-organ damage who experience a fall-related hip fracture.

METHODS

We analyzed the socio-demographic data and index fall clinical characteristics of a group of patients with nephropathy, neuropathy or retinopathy related to T2DM consecutively admitted to six hospitals in Barcelona, Spain because of a fall-related hip fracture.

RESULTS

Out of 1225 patients admitted because of a fall-related hip fracture, 107 (8.7%) had clinical evidence of end-organ damage related to T2DM. Among this cohort the mean number of falls during the year prior to the index admission was 2.6±3.2; and 29 of them (27.1%) had already experienced three or more falls. Most falls leading to the index admission took place at the patients' home, from a standing position, and during daylight time. An intrinsic cause of falling was identified in all but one of these patients. Multiple stepwise logistic regression analysis showed that, compared to patients without this diagnosis, patients with complicated T2DM were younger (odds ratio 0.762), had less prevalence of dementia (odds ratio 0.078), but had experienced a higher number of falls in the previous year (odds 1.183).

CONCLUSIONS

A significant amount of patients with clinical evidence of end-organ damage due to T2DM who experience a fall-related hip fracture have a history of recurrent falling in the previous year. These patients should be identified and offered preventive actions aimed at reducing their risk of falling.

Bone damage in type 2 diabetes mellitus

This review focuses on the mechanisms determining bone fragility in patients with type 2 diabetes mellitus (T2DM). Despite bone mineral density (BMD) is usually normal or more often increased in these patients, fracture incidence is high, probably because of altered bone "quality". The latter seems to depend on several, only partly elucidated, mechanisms, such as the increased skeletal content of advanced glycation end-products causing collagen deterioration, the altered differentiation of bone osteogenic cells, the altered bone turnover and micro-architecture. Disease duration, its severity and metabolic control, the type of therapy, the presence or absence of complications, as like as the other known predictors for falls, are all relevant contributing factors affecting fracture risk in T2DM. In these patients the estimate of fracture risk in the everyday clinical practice may be challenging, due to the lower predictive capacity of both BMD and risk factors-based algorithms (e.g. FRAX).

Increased fracture risk in patients with type 2 diabetes mellitus: an overview of the underlying mechanisms and the usefulness of imaging modalities and fracture risk assessment tools

Type 2 diabetes mellitus has recently been linked to an increased fracture risk. Since bone mass seems to be normal to elevated in patient with type 2 diabetes, the increased fracture risk is thought to be due to both an increased falling frequency and decreased bone quality. The increased falling frequency is mainly a result of complications of the disease such as a retinopathy and polyneuropathy. Bone quality is affected through changes in bone shape, bone micro-architecture, and in material properties such as bone mineralization and the quality of collagen. Commonly used methods for predicting fracture risk such as dual energy X-ray absorptiometry and fracture risk assessment tools are helpful in patients with type 2 diabetes mellitus, but underestimate the absolute fracture risk for a given score. New imaging modalities such as high resolution peripheral quantitative computed tomography are promising for giving insight in the complex etiology underlying the fragility of the diabetic bone, as they can give more insight into the microarchitecture and geometry of the bone. We present an overview of the contributing mechanisms to the increased fracture risk and the usefulness of imaging modalities and risk assessment tools in predicting fracture risk in patients with type 2 diabetes.