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

Effects of metformin on bone mineral density and bone turnover markers: a systematic review and meta-analysis

OBJECTIVES

Metformin is associated with osteoblastogenesis and osteoclastogenesis. This study aims to investigate the impacts of metformin therapy on bone mineral density (BMD) and bone turnover markers.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

METHODS

Searches were carried out in PubMed, EMBASE, Web of science, Cochrane library, ClinicalTrials.gov from database inception to 26 September 2022. Two review authors assessed trial eligibility in accordance with established inclusion criteria. The risk of bias was assessed using the Cochrane Risk of Bias tool (RoB V.2.0). Data analysis was conducted with Stata Statistical Software V.16.0 and Review Manager Software V.5.3.

RESULTS

A total of 15 studies with 3394 participants were identified for the present meta-analysis. Our pooled results indicated that metformin had no statistically significant effects on BMD at lumbar spine (SMD=-0.05, 95% CI=-0.19 to 0.09, p=0.47, participants=810; studies=7), at femoral (MD=-0.01 g/cm2, 95% CI=-0.04 to 0.01 g/cm2, p=0.25, participants=601; studies=3) and at hip (MD=0.01 g/cm2, 95% CI=-0.02 to 0.03 g/cm2, p=0.56, participants=634; studies=4). Metformin did not lead to significant change in osteocalcin, osteoprotegerin and bone alkaline phosphatase. Metformin induced decreases in N-terminal propeptide of type I procollagen (MD=-6.09 µg/L, 95% CI=-9.38 to -2.81 µg/L, p=0.0003, participants=2316; studies=7) and C-terminal telopeptide of type I collagen (MD=-55.80 ng/L, 95% CI=-97.33 to -14.26 ng/L, p=0.008, participants=2325; studies=7).

CONCLUSION

This meta-analysis indicated that metformin had no significant effect on BMD. Metformin decreased some bone turnover markers as N-terminal propeptide of type I procollagen and C-terminal telopeptide of type I collagen. But the outcomes should be interpreted with caution due to several limitations.

Correlation of Serum Estradiol with Bone Mineral Density and Bone Metabolism in Patients of Postmenopausal Type 2 Diabetes Mellitus Complicated with Osteoporosis

Type 2 diabetes mellitus (T2DM) complicated with osteoporosis, is a systemic metabolic disease that affects postmenopausal women. This disease is closely related to the lack of estrogen. This study aims to demonstrate the correlation between serum estradiol (E2) levels and osteoporosis, bone mineral density, and bone metabolism indicators in postmenopausal women with T2DM complicated with osteoporosis (T2DM-OP). 130 postmenopausal women with T2DM were divided into the T2DM group (n=62) and the T2DM-OP group (n=68) according to bone mineral density (BMD). In addition, 80 postmenopausal women with average blood glucose and bone density were selected as the healthy control group. We compare the serum levels of E2, bone metabolism indicators, and biochemistry indexes among the three groups of participants. Compared with the healthy control and T2DM groups, the BMD and serum level of E2 in T2DM-OP patients were significantly decreased, while the serum levels of bone alkaline phosphatase, type I procollagen amino-terminal propeptide, osteocalcin, and β-collagen C-terminal collagen cross-links were significantly increased. The serum levels of E2 in the postmenopausal T2DM-OP patients are positively correlated with BMD and negatively correlated with bone resorption indicators.

Effect of verapamil on bone mass, microstructure and mechanical properties in type 2 diabetes mellitus rats

Background

Verapamil was mainly used to treat hypertension, cardiovascular disease, inflammation and improve blood glucose in patients with diabetes, but its effects on bone mass, microstructure and mechanical properties were unclear. This study described the effects of verapamil on bone mass, microstructure, macro and nano mechanical properties in type 2 diabetic rats.

Methods

Rat models of type 2 diabetes were treated with verapamil at doses of 4, 12, 24 and 48 mg/kg/day by gavage respectively, twice a day. After 12 weeks, all rats were sacrificed under general anesthesia. Blood glucose, blood lipid, renal function and biochemical markers of bone metabolism were obtained by serum analysis, Micro-CT scanning was used to assess the microstructure parameters of cancellous bone of femoral head, three-point bending test was used to measure maximum load and elastic modulus of femoral shaft, and nano-indentation tests were used to measure indentation moduli and hardnesses of longitudinal cortical bone in femoral shaft, longitudinal and transverse cancellous bones in femoral head.

Results

Compared with T2DM group, transverse indentation moduli of cancellous bones in VER 24 group, longitudinal and transverse indentation moduli and hardnesses of cancellous bones in VER 48 group were significantly increased (p < 0.05). Furthermore, the effects of verapamil on blood glucoses, microstructures and mechanical properties in type 2 diabetic rats were dependent on drug dose. Starting from verapamil dose of 12 mg/kg/day, with dose increasing, the concentrations of P1NP, BMD, BV/TV, Tb. Th, Tb. N, maximum loads, elastic moduli, indentation moduli and hardnesses of femurs in rats in treatment group increased gradually, the concentrations of CTX-1 decreased gradually, but these parameters did not return to the level of the corresponding parameters of normal rats. Verapamil (48 mg/kg/day) had the best therapeutic effect.

Conclusion

Verapamil treatment (24, 48 mg/kg/day) significantly affected nano mechanical properties of the femurs, and tended to improve bone microstructures and macro mechanical properties of the femurs, which provided guidance for the selection of verapamil dose in the treatment of type 2 diabetic patients.

Evaluation of Quality and Bone Microstructure Alterations in Patients with Type 2 Diabetes: A Narrative Review

Bone fragility is a common complication in subjects with type 2 diabetes mellitus (T2DM). However, traditional techniques for the evaluation of bone fragility, such as dual-energy X-ray absorptiometry (DXA), do not perform well in this population. Moreover, the Fracture Risk Assessment Tool (FRAX) usually underestimates fracture risk in T2DM. Importantly, novel technologies for the assessment of one microarchitecture in patients with T2DM, such as the trabecular bone score (TBS), high-resolution peripheral quantitative computed tomography (HR-pQCT), and microindentation, are emerging. Furthermore, different serum and urine bone biomarkers may also be useful for the evaluation of bone quality in T2DM. Hence, in this article, we summarize the limitations of conventional tools for the evaluation of bone fragility and review the current evidence on novel approaches for the assessment of quality and bone microstructure alterations in patients with T2DM.

Impact of diabetes mellitus on risk of major complications after hip fracture: a systematic review and meta-analysis

BACKGROUND

The impact of diabetes mellitus (DM) on adverse outcomes in hip fracture patients is unclear. Furthermore, no review has synthesized evidence on this subject. Therefore, the current study was designed to answer the following research question: Does DM increase the risk of mortality and major systemic complications in patients with hip fractures?

METHODS

PubMed, Embase, and Google Scholar were searched from 1st January 2000 to 1st August 2021 for studies comparing DM and non-DM patients with hip fractures. Outcomes of interest were pooled using risk ratios (RR). The study was registered on PROSPERO (CRD42021268525).

RESULTS

Sixteen studies were included. Meta-analysis revealed a statistically significant increased risk of mortality in diabetics as compared to non-diabetics after 1 year (RR: 1.24 95% CI 1.08, 1.43 I2 = 62% p = 0.003). Pooled analysis of eight studies reporting adjusted mortality outcomes also demonstrated similar results (RR: 1.17 95% CI 1.09, 1.25 I2 = 74% p < 0.0001). We noted a statistically significant increase in the risk of cardiac complications (RR: 1.44 95% CI 1.17, 1.78 I2 = 19% p = 0.0005) and risk of renal failure in diabetics as compared to non-diabetics (RR: 1.32 95% CI 1.04, 1.68 I2 = 0% p = 0.02); but no difference in the risk of cerebrovascular (RR: 1.45 95% CI 0.74, 2.85 I2 = 47% p = 0.28), pulmonary (RR: 0.94 95% CI 0.73, 1.23 I2 = 8% p = 0.67) and thromboembolic complications (RR: 0.81 95% CI 0.56, 1.17 I2 = 28% p = 0.26).

CONCLUSION

Our results indicate that diabetics have an increased risk of mortality as compared to non-diabetics. Scarce data indicates that the risk of cardiac complications and renal failure are increased in patients with DM but there is no difference in the risk of cerebrovascular, pulmonary, or thromboembolic complications. Further studies are needed to strengthen the current conclusions.

Fracture Patterns in Type 1 and Type 2 Diabetes Mellitus: A Narrative Review of Recent Literature

PURPOSE OF REVIEW

In this narrative review, we have summarized the literature on fracture risk in T1DM and T2DM with a special focus on fracture site, time patterns, glucose-lowering drugs, and micro- and macrovascular complications.

RECENT FINDINGS

T1DM and T2DM were associated with an overall increased fracture risk, with preferent locations at the hip, vertebrae, humerus, and ankle in T1DM and at the hip, vertebrae, and likely humerus, distal forearm, and foot in T2DM. Fracture risk was higher with longer diabetes duration and the presence of micro- and macrovascular complications. In T2DM, fracture risk was higher with use of insulin, sulfonylurea, and thiazolidinediones and lower with metformin use. The increased fracture risk in T1DM and T2DM concerns specific fracture sites, and is higher in subjects with longer diabetes duration, vascular complications, and in T2DM with the use of specific glucose-lowering medication.

Assessment of risk factors for bone fractures in patients with type 2 diabetes mellitus: A study in Saudi Arabia

BACKGROUND AND AIMS

This study aimed to estimate the prevalence of bone fractures and analyze their associated risk factors in people with and without type 2 diabetes (T2D) in Saudi Arabia.

METHODS

This study was conducted among 1188 people (581 type 2 diabetes) in Prince Sultan Military Medical City, Riyadh, Saudi Arabia. In addition to the demographic variables, glycated hemoglobin (HbA1c), creatinine, estimated glomerular filtration rate (eGFR), use of teriparatide, presence of rheumatoid arthritis, presence of chronic obstructive pulmonary disease (COPD), Bone mineral density (BMD), Trabecular Bone Score (TBS) and Fracture Risk using the Fracture Risk Assessment Tool (FRAX) were also collected.

RESULTS

There were 1188 people (mean age 66.5 ± 8.7yrs) included in this study, of which 1068 (89.9%) were female, and 120 (10.1%) were male. A total of 112 (9.4%) individuals had a fracture history. Female, use of teriparatide, TBS (partially degraded and degraded), FRAX with TBS (MOF), and FRAX with TBS (Hip fx) were identified as independent risk factors for fracture in the whole study population. Teriparatide use and FRAX with TBS (MOF) were observed as independent risk factors for fracture in the non-diabetic population, whereas age, creatinine, eGFR, teriparatide, osteopenia, osteoporosis, TBS (partially degraded, degraded), FRAX with TBS (MOF), FRAX with TBS (Hip fx) were determined as independent risk factors for fracture among patients with diabetes.

CONCLUSION

Patients with T2D were observed to have a higher risk for fractures. The findings of the study highlight the requirement for fracture prevention strategies in patients with diabetes.

Risk of non-vertebral fractures in men with type 2 diabetes: A systematic review and meta-analysis of cohort studies

PURPOSE

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disorder. Research regarding the risk of non-vertebral fractures in men, especially in elderly men with T2DM, has not been a priority. T2DM is not a known independent risk factor for low-energy fractures in patients. We aimed to explore the relationship between men (especially older men) with T2DM and the risk of non-vertebral fractures and the reasons for the sex differences.

METHODS

The PubMed, MEDLINE, and Cochrane Library databases were searched for articles on T2DM and fracture risk. A meta-analysis, including heterogeneity testing, publication bias analysis, and subgroup analysis of the included studies, was performed using STATA software.

RESULTS

Sixteen studies involving 1,758,225 participants, 59,909 non-vertebral fracture events, and 6430 vertebral fracture events were included in this research. The adjusted relative risk of T2DM and non-vertebral fracture in men was 1.20 (95% confidence interval [CI] 1.09-1.31), implying that men with T2DM have a slightly increased risk of non-vertebral fracture.

CONCLUSION

Male patients with T2DM have a slightly increased risk of non-vertebral fractures. Due to the differences in bone strength, sex steroid hormone levels, bone quality and muscle strength and balance, men with type 2 diabetes have a lower risk of non-vertebral fractures than women.

The effect of luseogliflozin on bone microarchitecture in older patients with type 2 diabetes: study protocol for a randomized controlled pilot trial using second-generation, high-resolution, peripheral quantitative computed tomography (HR-pQCT)

BACKGROUND

Older patients with type 2 diabetes mellitus (T2DM) have an increased risk of bone fracture independent of their bone mineral density (BMD), which is explained mainly by the deteriorated bone quality in T2DM compared to that in non-diabetic adults. Sodium-glucose co-transporter (SGLT) 2 inhibitors have been studied in several trials in T2DM, and the Canagliflozin Cardiovascular Assessment Study showed an increased fracture risk related to treatment with the SGLT2 inhibitor canagliflozin, although no evidence of increased fracture risk with treatment with other SGLT2 inhibitors has been reported. The mechanism of the difference in the fracture risk between the SGLT2 inhibitors is unknown, but the differences among the SGLT2 inhibitors in the selectivity of SGLT2 against SGLT1 may affect bone metabolism, since among the SGLT2 inhibitors the selectivity of canagliflozin is lowest. We will investigate whether the SGLT2 inhibitor luseogliflozin, which has the higher SGLT2 selectivity, affects bone metabolism by using high-resolution, peripheral quantitative computed tomography (HR-pQCT) which provides direct in vivo morphometric information about the bone microarchitecture.

METHODS/DESIGN

This is a single-center, randomized, open-label, active-controlled, parallel pilot trial. Eligible participants are older (age ≥ 60 years) individuals with T2DM with HbA1c levels at 7.0-8.9%. A total of 24 participants will be allocated to either the luseogliflozin group (taking luseogliflozin) or the control group (taking metformin) in a 1:1 ratio to compare the groups' changes in bone microarchitecture of the radius and tibia which are analyzed by HR-pQCT before and at 48 weeks after the administration of each medication. The laboratory data associated with glycemic control and bone metabolism will be collected every 12 weeks during the study. Recruitment began in June 2019.

DISCUSSION

The reason that we use metformin as an active control is to avoid yielding differences in glycemic control between the luseogliflozin and control groups. Besides, metformin is considered to have a neutral effect on bone. This trial should reveal the effect of luseogliflozin on bone metabolism in older patients with T2DM.

TRIAL REGISTRATION

The study was registered with the University Hospital Medical Information Network (UMIN000036202) on 1 April 2019 and with the Japan Registry of Clinicla Trials (jRCTs071180061) on 14 March 2019.

Canagliflozin and fracture risk in individuals with type 2 diabetes: results from the CANVAS Program

AIMS/HYPOTHESIS

An increased risk of fracture with canagliflozin vs placebo was reported from the CANagliflozin cardioVascular Assessment Study (CANVAS) Program, with heterogeneity of findings identified between the two trials that comprise the CANVAS Program, CANVAS and CANVAS-R. The objective of these analyses was to identify reasons for the possibly different effects on fracture observed between CANVAS and CANVAS-R.

METHODS

This study was an analysis of two highly similar trials, CANVAS and CANVAS-R, conducted in 10,142 individuals with type 2 diabetes and history or high risk of cardiovascular disease who received canagliflozin (pooled 100/300 mg once daily) or placebo. Outcomes assessed in this analysis were effects on adjudicated fractures overall and by type, location, association with a fall, dose and follow-up time.

RESULTS

A total of 496 participants recorded ≥1 fracture event during follow-up (15.40 vs 11.93 per 1000 patient-years with canagliflozin vs placebo; HR 1.26 [95% CI 1.04, 1.52]). There was significant heterogeneity in the effects on fracture (p = 0.005) between CANVAS (n = 4330: HR 1.55 [95% CI 1.21, 1.97]) and CANVAS-R (n = 5812: HR 0.86 [95% CI 0.62, 1.19]). The between-study heterogeneity in fracture risk was not clearly explained by differences in baseline characteristics, interactions of randomised treatment with participant characteristics, dose effects, duration of follow-up, metabolic effects, adverse events related to falls or adverse events possibly causing falls.

CONCLUSIONS/INTERPRETATION

There was no evidence to explain clearly the fracture risk observed in the CANVAS Program or the heterogeneity in fracture risk between the two studies. The recently reported null result for fracture in the Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) trial suggests that the observed association in CANVAS is likely to be a chance finding, although an unidentified fall-related mechanism remains a possibility.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01032629, NCT01989754.

Falls and Fractures in Diabetes-More than Bone Fragility

PURPOSE OF REVIEW

Based on a systematic literature search, we performed a comprehensive review of risk factors for falls and fractures in patients with diabetes.

RECENT FINDINGS

Patients with diabetes have an increased risk of fractures partly explained by increased bone fragility. Several risk factors as altered body composition including sarcopenia and obesity, impaired postural control, gait deficits, neuropathy, cardiovascular disease, and other co-morbidities are considered to increase the risk of falling. Diabetes and bone fragility is well studied, but new thresholds for fracture assessment should be considered. In general, the risk factors for falls in patients with diabetes are well documented in several studies. However, the fall mechanisms among diabetic patients have only been assessed in few studies. Thus, a gab of knowledge exits and may influence the current understanding and treatment, in order to reduce the risk of falling and thereby prevent fractures.

The effects of natural nano-sized clinoptilolite and Nigella sativa supplementation on serum bone markers in diabetic rats

Introduction: Many studies confirm that diabetes mellitus is associated with higher risks of bone fracture. The beneficial effects of Nigella sativa (NS) and clinoptilolite in preventing/reducing some diabetes-related disorders have been shown. This study was conducted to examine the effects of separate and concurrent supplementation of natural nano-sized clinoptilolite (NCLN) and NS on serum bone markers in rats with type 2 diabetes.

Methods: A total of 42 (case=36 and control=6) adult male Wistar rats were divided into 2 groups: diabetic and non-diabetic. An oral glucose tolerance test and a homeostatic model assessment of insulin resistance (HOMA-IR) test were conducted to confirm diabetes. Then, the diabetic group was divided into 4 subgroups: [1] control (n=9), [2] NS 1%/food (n=9), [3] NCLN 2%/food (n=9), [4] NS 1%/food + NCLN 2%/food (n=9). After 7 weeks, serum levels of bone markers were determined using ELISA kits.

Results: Analysis showed that serum levels of alkaline phosphatase (ALP) in the NCLN group (1318.6 ± 217.5 U/L) was significantly (P<0.05) higher than other intervented groups. On the other hand, serum levels of calcium in NCLN+NS group (10.8 ± 2.6 mg/dL) were higher (P=0.027) compared to all other study groups. However, rats in the NS group had higher (535.8 ± 49.3 pg/mL) PTH (P<0.0001) compared to other supplementation groups. There were no significant differences in vitamin D and osteoprotegerin.

Conclusion: The results of the current study suggest that bone mineralization may be affected by concurrent use of NS and NCLN through influencing calcium circulation. Moreover, dietary NS administration is strongly related to an augmented level of PTH.

Efficacy of anti-osteoporotic medications in patients with type 1 and 2 diabetes mellitus: a systematic review

PURPOSE

Both type 1 (T1DM) and type 2 diabetes mellitus (T2DM) have been associated with bone fragility and increased fracture risk. However, little is known regarding the effect of anti-osteoporotic treatment on bone mineral density (BMD) and/or fracture risk in these patients. We aimed to systematically investigate the efficacy of anti-osteoporotic medications in patients with diabetes in comparison with non-diabetic subjects.

METHODS

MEDLINE and Scopus databases were searched (up to 31st October 2017).

RESULTS

Nine studies fulfilled the pre-defined inclusion criteria [patients with T2DM (n = 8) or either T1DM or T2DM (n = 1)]. Regarding fracture risk, five studies were identified. Alendronate demonstrated comparable vertebral anti-fracture efficacy in patients with and without diabetes (n = 2), whereas non-vertebral fracture risk was either the same (n = 1) or higher in diabetic patients (n = 1). Raloxifene also demonstrated comparable vertebral anti-fracture efficacy in both groups (n = 2), without any effect on non-vertebral fractures in either group. In one study, diabetic patients exposed to raloxifene demonstrated the same vertebral and non-vertebral fracture risk with non-diabetic patients. Teriparatide (n = 1) demonstrated the same non-vertebral fracture rates in both patients with and without T2DM. Regarding BMD, equal increases in spine BMD were observed with alendronate (n = 4), risedronate (n = 1), and teriparatide (n = 1). With respect to hip BMD, similar increases were observed with teriparatide (n = 1), whereas data regarding alendronate were controversial (n = 3). No eligible study was found for zoledronic acid, ibandronate, strontium ranelate, denosumab, or bazedoxifene.

CONCLUSIONS

The presence of diabetes does not alter anti-osteoporotic treatment response, regarding BMD increase and vertebral fracture risk reduction.

Soy and the risk of type 2 diabetes mellitus: A systematic review and meta-analysis of observational studies

BACKGROUND

Increasing studies have focused on the relationship between soy intake and type 2 diabetes mellitus risk, but the results are inconsistent. We conduct a meta-analysis to evaluate the relationship.

METHODS

The databases of PubMed, Web of Science and Embase were searched up to Dec 2016. A random-effect model was used to pool the results of included studies.

RESULTS

Eight studies with 19 reports met the inclusion criteria. A significant inverse association was shown between soy intake and type 2 diabetes mellitus risk with an overall RR of 0.77 (95% CI = 0.66-0.91) with high heterogeneity. Besides, there was an obvious relationship between soy protein and isoflavones intake and risk of T2DM with the summary RR was 0.88 (95% CI = 0.80-0.97) with no heterogeneity. In the subgroup analysis, a statistically significant protective effect of soy consumption was observed in women (RR = 0.65; 95% CI = 0.49-0.87), cross-sectional studies (RR = 0.45; 95% CI = 0.30-0.67), and Asian populations (RR = 0.73; 95% CI = 0.61-0.88).

CONCLUSIONS

Soy products and soy constituents (soy protein and soy isoflavones) may be associated with a lower risk of type 2 diabetes mellitus. Future studies should focus on the dose-response effect and the mechanism.

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.

Hyperglycemia is associated with increased bone mineral density and decreased trabecular bone score in elderly Japanese men: The Fujiwara-kyo osteoporosis risk in men (FORMEN) study

PURPOSE

Patients with type 2 diabetes mellitus (T2DM) have an increased fracture risk despite having higher areal bone mineral density (aBMD). This study aimed to clarify the association between glycemic and insulin resistance status and bone microarchitecture, and whether pentosidine and bone turnover markers play any roles in the association.

METHODS

A total of 2012 community-dwelling men aged ≥65years completed baseline measurements of spine aBMD, fasting plasma glucose (FPG) and serum insulin, hemoglobin A1c (HbA1c), osteocalcin, type I procollagen N-terminal propeptide, type I collagen C-terminal crosslinking telopeptide, tartrate-resistant acid phosphatase isoenzyme 5b, pentosidine, height and weight and an interview regarding past disease history. Homeostasis model assessment-insulin resistance (HOMA-IR) was also calculated. T2DM was defined as physician-diagnosed middle age or elderly-onset diabetes mellitus, or according to biochemical test results. To evaluate bone microarchitecture, trabecular bone score (TBS) was calculated at the same vertebrae as those used for aBMD measurement.

RESULTS

After excluding participants who had a disease history and/or were taking medications affecting bone metabolism, 1683 men (age, 72.9±5.2years) were analyzed. Men with T2DM had significantly higher aBMD compared to those without T2DM. There was no significant difference in TBS. However, FPG, HbA1c and HOMA-IR levels were significantly inversely correlated with TBS after adjusting for age, BMI and aBMD. Multivariate linear regression analyses revealed that glycemic indices (FPG and HbA1c) were significantly associated with increased aBMD and decreased TBS, and that HOMA-IR was associated only with TBS. These associations did not change after further adjusting for bone turnover makers and pentosidine levels.

CONCLUSIONS

Hyperglycemia and elevated insulin-resistance were associated with low TBS independently of bone turnover and pentosidine levels.

The association between insulin use and volumetric bone mineral density, bone micro-architecture and bone strength of the distal radius in patients with type 2 diabetes - The Maastricht study

Type 2 diabetes mellitus (T2DM) has been associated with an increased risk of fractures, despite normal to increased bone mineral density (BMD). Insulin use is one of the factors linked to this increased fracture risk. However, direct negative effects of insulin on bone quality are not expected since insulin is thought to be anabolic to bone. In this cross-sectional study the association between insulin use and volumetric BMD (vBMD), bone micro-architecture and bone strength of the distal radius, as measured with HR-pQCT, was examined. Data from 50 participants with T2DM of The Maastricht Study (mean age 62±7.5years, 44% women) was used. Participants were classified as insulin user (n=13) or non-insulin user (n=37) based on prescription data. Linear regression analysis was used to estimate the association between current insulin use and HR-pQCT derived parameters. After adjustment for age, sex, body mass index, glycated hemoglobin A1c and T2DM duration, insulin use was associated with lower total vBMD (standardized beta (β):-0.56 (95% CI:-0.89 to -0.24)), trabecular vBMD (β:-0.58 (95% CI:-0.87 to -0.30)), trabecular thickness (β:-0.55 (95% CI:-0.87 to -0.23)), cortical thickness (β:-0.41 (95% CI:-0.74 to -0.08)), log cortical pore volume (β:-0.43 (95% CI:-0.73 to -0.13)), bone stiffness (β:-0.39 (95% CI:-0.62 to -0.17)) and failure load (β:-0.39 (95% CI:-0.60 to -0.17)) when compared to the non-insulin users. Insulin use was not associated with cortical vBMD, trabecular number, trabecular separation, cortical porosity and cortical pore diameter. This study indicates that insulin use is negatively associated with bone density, bone micro-architectural and bone strength parameters. These findings may partly explain the previously observed increased fracture risk in insulin users, although there may be residual confounding by other factors related to disease severity in insulin users.

Fracture risk in patients with type 2 diabetes mellitus and possible risk factors: a systematic review and meta-analysis

Aim

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of bone fractures. A variable increase in fracture risk has been reported depending on skeletal site, diabetes duration, study design, insulin use, and so on. The present meta-analysis aimed to investigate the association between T2DM with fracture risk and possible risk factors.

Methods

Different databases including PubMed, Institute for Scientific Information, and Scopus were searched up to May 2016. All epidemiologic studies on the association between T2DM and fracture risk were included. The relevant data obtained from these papers were analyzed by a random effects model and publication bias was assessed by funnel plot. All analyses were done by R software (version 3.2.1) and STATA (version 11.1).

Results

Thirty eligible studies were selected for the meta-analysis. We found a statistically significant positive association between T2DM and hip, vertebral, or foot fractures and no association between T2DM and wrist, proximal humerus, or ankle fractures. Overall, T2DM was associated with an increased risk of any fracture (summary relative risk =1.05, 95% confidence interval: 1.04, 1.06) and increased with age, duration of diabetes, and insulin therapy.

Conclusion

Our findings strongly support an association between T2DM and increased risk of overall fracture. These findings emphasize the need for fracture prevention strategies in patients with diabetes.

Long-term use of dipeptidyl peptidase-4 inhibitors and risk of fracture: A retrospective population-based cohort study

AIMS

To investigate the association between long-term dipeptidyl peptidase-4 (DPP-4) inhibitor use and risk of fracture among people with type 2 diabetes mellitus (T2DM).

METHODS

A retrospective population-based cohort study, using data from the Clinical Practice Research Datalink database (2007-2015), was conducted. All those (N = 328 254) with at least one prescription for a non-insulin antidiabetic drug (NIAD), aged ≥18 years at the time of data collection, were included. Cox proportional hazards models were used to estimate the hazard ratios of any fracture, osteoporotic fracture and hip fracture in DPP-4 inhibitor users compared with those using other NIADs. Analyses were stratified by continuous duration of DPP-4 inhibitor use. Time-dependent adjustments were made for age, sex, lifestyle, comorbidity and concomitant drug use.

RESULTS

Current use of DPP-4 inhibitors was not associated with risk of any fracture (adjusted hazard ratio [HR] 0.99 [95% confidence interval {CI} 0.93-1.06]) as compared with current other NIAD use. Current use of DPP-4 inhibitors was also not associated with risk of osteoporotic or hip fracture. After stratification by continuous duration of DPP-4 inhibitor use the highest category was not associated with any (>4.0-8.5 years of use, adjusted HR 0.99 [95% CI 0.70-1.41]), osteoporotic (>3.0-8.5 years of use, adjusted HR 0.75 [95% CI 0.52-1.09]) or hip (>2.0-8.5 years of use; adjusted HR 1.24 [95% CI 0.85-1.79]) fracture.

CONCLUSION

Continuous long-term DPP-4 inhibitor use (defined as >4.0-8.5 years of DPP-4 inhibitor use for any fracture, >3.0-8.5 years for osteoporotic fracture and >2.0-8.5 years for hip fracture was not associated with risk of any, osteoporotic or hip fracture. These findings may be of value for clinical decisions regarding treatment of patients with T2DM, especially those at high risk of fracture.

Relationship between the FRAX® score and falls in community-dwelling middle-aged and elderly people

OBJECTIVES

Falls is a risk factor for fracture. The FRAX^® predicts fractures. Whether the FRAX^® is associated with fall in both gender is inconclusive. The aim of our study is to evaluate the association between FRAX scores and falls.

METHODS

The cross-sectional study set from 2009 to 2010 included 1200 community-dwelling people who were systematically sampled in central Taiwan. The 1200 participants (men: 524; women: 676; ≥40 years old) completed questionnaires about socioeconomic status; lifestyle; medical and fall history were completed. FRAX scores with and without bone mineral density (BMD) were calculated by using the Taiwan calculator.

RESULTS

A total of 19.8% participants fell down. Binary regression models showed that diabetes mellitus history (OR: 1.61; 95% CI: 1.03-2.52), the FRAX without BMD in a continuous major score (OR: 1.06; 95% CI: 1.03-1.09), continuous hip score (OR: 1.11; 95% CI: 1.05-1.16), categorical major score ≥ 10% (OR: 1.81; 95% CI: 1.25-2.61), and categorical hip score ≥ 3% (OR: 1.80; 95% CI: 1.30-2.50) were independent risk factors for falls. FRAX with BMD in a continuous major score (OR: 1.04; 95% CI: 1.02-1.06), continuous hip score (OR: 1.06; 95% CI: 1.02-1.09), categorical major score ≥ 10% (OR: 1.52; 95% CI: 1.09-2.12), and categorical hip score ≥ 3% (OR: 1.53; 95% CI: 1.13-2.09) were also independent risk factors.

CONCLUSIONS

We concluded that FRAX^® scores with and without BMD were unanimously correlated with falls in community-dwelling middle-aged and elderly males and females.

Visit-to-visit variation of fasting plasma glucose is a predictor of hip fracture in older persons with type 2 diabetes: the Taiwan Diabetes Study

We investigated the association between fasting plasma glucose variability (FPG-CV) and the risk of hip fracture in elderly diabetic patients. Our finding showed a temporal association between FPG-CV and hip fracture as patients categorized as FPG-CV greater than 25.4 % showed an increased risk in hip fractures.

INTRODUCTION

Hip fracture is a major health burden in the population and is associated with high rates of mortality and morbidity especially in elderly. It is evident that diabetes mellitus is a risk factor of osteoporosis which is a significant risk factor of hip fracture. However, epidemiological studies exploring the risks of hip fracture among type 2 diabetic patients are limited.

METHODS

A retrospective study of 26,501 ethnic Chinese older persons enrolled in the National Diabetes Care Management program in Taiwan was conducted; related factors were analyzed with extended Cox proportional hazards regression models to competing risk data on hip fracture incidence.

RESULTS

The results show a temporal association between FPG-CV and hip fracture as patients categorized as FPG-CV greater than 25.4 % showed an increased risk in hip fractures, confirming a linear relationship between the two. After multivariate adjustment, the risk of hip fracture increased among patients with FPG-CV of 25.4-42.3 % and >42.3 % compared with patients with FPG-CV of ≦ 14.3 % (hazard ratio, 1.35; 95 % confidence interval 1.14-1.60 and 1.27; 1.07-1.52, respectively). Significant linear trends among various FPG-CV were observed.

CONCLUSIONS

Thus, the present study demonstrated the importance of glucose stability for fracture prevention in older persons with type 2 diabetes. Future studies should be conducted to explore whether reduction in glucose oscillation in older adults with diabetes mellitus can reduce the risk of hip fracture.

Metformin Prevents Nonunion after Three-Cannulated-Screw Fixation in Displaced Femoral Neck Fractures: A Retrospective Study

Patients aged from 40 to 60 with displaced fractures of the femoral neck (Garden III or IV) who received fixation with three cannulated screws from January 2005 to December 2012 were evaluated retrospectively for the development of nonunion. Plasma HbA1C, a marker for long-term plasma glucose level, anti-T2DM medication, and other potential risk factors were recorded for the purpose of this study. There were no differences between the union and nonunion groups with respect to age, gender, Garden classification, Pauwel's angle, reduction quality, and T2DM presence. There were significant differences in reduction quality and preoperative plasma HbA1C level between patients with and those without union. The odds ratio (OR) for fracture nonunion was 2.659 (95% confidence interval [CI], 1.530–4.620) in subjects with anatomical reduction compared with those without anatomical reduction, 4.797 (95% CI, 1.371–16.778), in subjects with poor blood glucose control (HbA1C > 10%). The metformin usage showed a preventive effect on nonunion development (OR: 0.193 and CI: 0.060–0.616). The nonunion rate of metformin group (6.7%, 6/89) was even much lower than that of patients without T2DM (17.4%, 80/460).

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.

Teriparatide in patients with osteoporosis and type 2 diabetes

Despite evidence for higher fracture risk, clinical effects of osteoporosis treatments in type 2 diabetes (T2D) are largely unknown. Post hoc analyses of the DANCE observational study compared T2D patients and patients without diabetes to assess the effect of teriparatide, an osteoanabolic therapy on skeletal outcomes and safety. Patients included ambulatory men and women with osteoporosis receiving teriparatide 20μg/day SQ up to 24months followed by observation up to 24months. Main outcome measures included nonvertebral fracture incidence comparing 0-6months with 6+ months of teriparatide, change from baseline in BMD and back pain severity, and serious adverse events. Analyses included 4042 patients; 291 with T2D, 3751 without diabetes. Treatment exposure did not differ by group. For T2D patients, fracture incidence was 3.5 per 100 patient-years during 0-6months treatment, and 1.6 during 6months to treatment end (47% of baseline, 95% CI 12-187%); during similar periods, for patients without diabetes, fracture incidence was 3.2 and 1.8 (57% of baseline, 95% CI 39-83%). As determinants of fracture outcome during teriparatide treatment, diabetes was not a significant factor (P=0.858), treatment duration was significant (P=0.003), and the effect of duration was not significantly different between the groups (interaction P=0.792). Increases in spine and total hip BMD did not differ between groups; increase in femoral neck BMD was greater in T2D patients than in patients without diabetes (+0.34 and +0.004g/cm(2), respectively; P=0.014). Back pain severity decreased in both groups. Teriparatide was well tolerated without new safety findings. In conclusion, during teriparatide treatment, reduction in nonvertebral fracture incidence, increase in BMD, and decrease in back pain were similar in T2D and non-diabetic patients.

Association of bone mineral density and diabetic retinopathy in diabetic subjects: the 2008-2011 Korea National Health and Nutrition Examination Survey

Because diabetic retinopathy increases fracture risk, we studied the association between bone mineral density (BMD) and diabetic retinopathy in a nationally representative sample. A significant association between the presence of diabetic retinopathy and low BMD was observed. Therefore, diabetic retinopathy might be considered as a marker of low BMD.

INTRODUCTION

Several diabetic complications, including nephropathy, retinopathy, and peripheral neuropathy, are associated with a higher fracture risk in diabetic subjects. However, in contrast to diabetic nephropathy and peripheral neuropathy, which are associated with low bone mineral density (BMD), little is known about the association between BMD and diabetic retinopathy. The aim of the present study was to determine whether the prevalence of diabetic retinopathy is associated with BMD.

METHODS

This cross-sectional study included a nationally representative sample consisting of 4357 men aged 50 years and older and 4392 postmenopausal women who participated in the Korea National Health and Nutritional Examination Survey (KNHANES) from 2008 to 2011 and underwent BMD measurement by dual-energy X-ray absorptiometry (DXA) and diabetic retinopathy assessments using seven standard gradable photographs.

RESULTS

The diabetic women with retinopathy had lower mean BMD at all measured sites than those without retinopathy, although the BMD difference between the two groups was small (3-5 %). In addition, the diabetic women with retinopathy were 2.27 times more likely to have osteoporosis following adjustments for all clinically relevant covariates. However, the prevalence of diabetes mellitus (DM) or diabetic retinopathy was not associated with the prevalence of osteoporosis in men.

CONCLUSIONS

This study has shown that the presence of diabetic retinopathy is significantly associated with a reduced BMD and increased prevalence of osteoporosis in diabetic women.

Femoral bone structure in Otsuka Long-Evans Tokushima Fatty rats

Objectives

Type 2 diabetes mellitus (T2DM) increases fracture risk despite normal to high levels of bone mineral density. Bone quality is known to affect bone fragility in T2DM. The aim of this study was to clarify the trabecular bone microstructure and cortical bone geometry of the femur in T2DM model rats.

Methods

Five-week-old Otsuka Long-Evans Tokushima Fatty (OLETF; n = 5) and Long-Evans Tokushima Otsuka (LETO; n = 5) rats were used. At the age of 18 months, femurs were scanned with micro-computed tomography, and trabecular bone microstructure and cortical bone geometry were analyzed.

Results

Trabecular bone microstructure and cortical bone geometry deteriorated in the femur in OLETF rats. Compared with in LETO rats, in OLETF rats, bone volume fraction, trabecular number and connectivity density decreased, and trabecular space significantly increased. Moreover, in OLETF rats, cortical bone volume and section area decreased, and medullary volume significantly increased.

Conclusions

Long-term T2DM leaded to deterioration in trabecular and cortical bone structure. Therefore, OLETF rats may serve as a useful animal model for investigating the relationship between T2DM and bone quality.

Technologies for assessment of bone reflecting bone strength and bone mineral density in elderly women: an update

Reduced bone mineral density is a strong risk factor for fracture. The WHO's definition of osteoporosis is based on bone mineral density measurements assessed by dual x-ray absorptiometry. Several on other techniques than dual x-ray absorptiometry have been developed for quantitative assessment of bone, for example, quantitative ultrasound and digital x-ray radiogrammetry. Some of these techniques may also capture other bone properties than bone mass that contribute to bone strength, for example, bone porosity and microarchitecture. In this article we give an update on technologies which are available for evaluation primarily of bone mass and bone density, but also describe methods which currently are validated or are under development for quantitative assessment of other bone properties.

Diabetes mellitus and risk of hip fractures: a meta-analysis

This meta-analysis revealed that diabetic adults had a twofold greater risk of hip fractures compared with non-diabetic populations, and this association was more pronounced in type 1 diabetes.

INTRODUCTION

The relationship between diabetes mellitus and risk of hip fracture yielded conflicting results. We conducted a meta-analysis to investigate the association between diabetes mellitus and the risk of hip fractures based on observational studies.

METHODS

We conducted a systematic literature search of PubMed and Embase databases through May 2015. We selected cohort and case-control studies providing at least age-adjusted risk ratio (RR) and corresponding 95 % confidence intervals (CI) of hip fractures among diabetic and non-diabetic subjects. Moreover, we pooled the female-to-male RR of hip fractures from studies that reported gender-specific risk estimate in a single study.

RESULTS

Twenty-one studies involving 82,293 hip fracture events among 6,995,272 participants were identified. Diabetes mellitus was associated with an increased risk of hip fractures (RR 2.07; 95 % CI 1.83-2.33) in a random effects model. Subgroup analysis indicated that excess risk of hip fracture was more pronounced in type 1 diabetes (RR 5.76; 95 % CI 3.66-9.07) than that in type 2 diabetes (RR 1.34; 95 % CI 1.19-1.51). The pooled female-to-male RR of hip fractures was 1.09 (95 % CI 0.93-1.28).

CONCLUSIONS

Individuals with diabetes mellitus have an excessive risk of hip fractures, and this relationship is more pronounced in type 1 diabetes. The association between diabetes and hip fracture risk is similar in men and women.

Finite element models predict the location of microdamage in cancellous bone following uniaxial loading

High-resolution finite element models derived from micro-computed tomography images are often used to study the effects of trabecular microarchitecture and loading mode on tissue stress, but the degree to which existing finite element methods correctly predict the location of tissue failure is not well characterized. In the current study, we determined the relationship between the location of highly strained tissue, as determined from high-resolution finite element models, and the location of tissue microdamage, as determined from three-dimensional fluoroscopy imaging, which was performed after the microdamage was generated in-vitro by mechanical testing. Fourteen specimens of human vertebral cancellous bone were assessed (8 male donors, 2 female donors, 47-78 years of age). Regions of stained microdamage, were 50-75% more likely to form in highly strained tissue (principal strains exceeding 0.4%) than elsewhere, and generally the locations of the regions of microdamage were significantly correlated (p<0.05) with the locations of highly strained tissue. This spatial correlation was stronger for the largest regions of microdamage (≥1,000,000μm(3) in volume); 87% of large regions of microdamage were located near highly strained tissue. Together, these findings demonstrate that there is a strong correlation between regions of microdamage and regions of high strain in human cancellous bone, particularly for the biomechanically more important large instances of microdamage.

Fatigue-induced microdamage in cancellous bone occurs distant from resorption cavities and trabecular surfaces

Impaired bone toughness is increasingly recognized as a contributor to fragility fractures. At the tissue level, toughness is related to the ability of bone tissue to resist the development of microscopic cracks or other tissue damage. While most of our understanding of microdamage is derived from studies of cortical bone, the majority of fragility fractures occur in regions of the skeleton dominated by cancellous bone. The development of tissue microdamage in cancellous bone may differ from that in cortical bone due to differences in microstructure and tissue ultrastructure. To gain insight into how microdamage accumulates in cancellous bone we determined the changes in number, size and location of microdamage sites following different amounts of cyclic compressive loading. Human vertebral cancellous bone specimens (n=32, 10 male donors, 6 female donors, age 76 ± 8.8, mean ± SD) were subjected to sub-failure cyclic compressive loading and microdamage was evaluated in three-dimensions. Only a few large microdamage sites (the largest 10%) accounted for 70% of all microdamage caused by cyclic loading. The number of large microdamage sites was a better predictor of reductions in Young's modulus caused by cyclic loading than overall damage volume fraction (DV/BV). The majority of microdamage volume (69.12 ± 7.04%) was located more than 30 μm (the average erosion depth) from trabecular surfaces, suggesting that microdamage occurs primarily within interstitial regions of cancellous bone. Additionally, microdamage was less likely to be near resorption cavities than other bone surfaces (p<0.05), challenging the idea that stress risers caused by resorption cavities influence fatigue failure of cancellous bone. Together, these findings suggest that reductions in apparent level mechanical performance during fatigue loading are the result of only a few large microdamage sites and that microdamage accumulation in fatigue is likely dominated by heterogeneity in tissue material properties rather than stress concentrations caused by micro-scale geometry.

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.

Androgen deprivation therapy, diabetes and poor physical performance status increase fracture risk in Chinese men treated for prostate cancer

We investigated the fracture risk after androgen deprivation therapy (ADT) for prostate cancer in the Chinese population. All Chinese prostate cancer patients who were treated primarily by radical prostatectomy or radiotherapy, with or without further ADT, from year 2000 to 2009 were reviewed. We compared the fracture risk in patients who were given ADT (ADT group) with those who were not given any ADT (non-ADT group). Potential risk factors including age, diabetes mellitus, hypertension, hyperlipidemia, ischemic heart disease and performance status were reviewed. The fracture risk was analyzed with Kaplan-Meier and multivariate Cox regression analyses. Our cohort consisted of 200 patients in the non-ADT group and 252 patients in the ADT group. The ADT group was shown to have higher fracture risk (p = 0.036) upon Kaplan-Meier analysis. Upon multivariate Cox regression analyses, diabetes mellitus (HR 4.39, 95% CI 1.08-17.83, p = 0.039), poor performance status (HR 3.14, 95% CI 1.24-8.00, p = 0.016) and the use of ADT (HR 4.89, 95% CI 1.03-23.17, p = 0.045) were associated with increased fracture risk. In conclusion, the fracture risk should be considered while deciding on ADT in Chinese men, especially in diabetic patients with poor performance status.