Fracture risk in women with type II diabetes. Results from a historical cohort with fracture follow-up

Discrepancies in type of first major osteoporotic fracture and anti-osteoporotic therapy in elderly people with type 2 diabetes mellitus: A retrospective Danish cohort study

OBJECTIVE

Subjects with diabetes mellitus have an increased risk of fractures. We aimed to identify discrepancies in the first type of major osteoporotic fracture (MOF) and anti-osteoporotic therapy between subjects with type 2 diabetes (T2D) and subjects without diabetes. Methods and research design. We conducted a retrospective national cohort study by access to all discharge diagnoses (ICD-10 system) and redeemed drug prescriptions (ATC classification system). We included all subjects alive and Danish citizens in 2010 and identified subjects with T2D diagnosed after the age of 50 between 1998 and 2018. Only subjects with a MOF after the index date were included in the main analysis. The type of MOF was identified by diagnosis codes and categorized into Humerus, Forearm, Spine, and Hip. Multinomial logistic regression modeling was used to assess the predicted probability changes in MOF type between T2D and control subjects. Data on first anti-osteoporotic therapy after the MOF was assessed by redeemed drug prescriptions. Mortality and time to therapy after the MOF were evaluated by cox proportional hazards.

RESULT

We included 26,588 subjects with T2D and 97,982 subjects without diabetes. The mean age was age 69.33 (±10.34) for T2D and 69.85 (±10.19) for control subjects. The cohort was primarily females (67 %). Subjects with T2D had a higher probability of hip (3.98 % [95 % CI 3.29; 4.67]) and humerus (2.82 % [95 % CI 2.17; 3.46]) fractures as the first MOF compared to control subjects. However, the probability of forearm fractures as the first MOF was 6.77 % (95 % CI 6.08; 7.46) lower among subjects with T2D. The multiple adjusted hazard ratio for anti-osteoporotic treatment after the first MOF was 0.80 (95 % CI 0.77; 0.88) for T2D compared to controls among treatment-naïve subjects.

CONCLUSION

Forearm fractures were the most frequent type of MOF and were more prevalent in control subjects. Subjects with T2D had a significantly higher probability of hip and humerus fractures as the first MOF but had a 20 % lower chance of anti-osteoporotic treatment afterwards.

Differences in the roles of types 1 and 2 diabetes in the susceptibility to the risk of fracture: a systematic review and meta-analysis

BACKGROUND

Diabetes mellitus (DM) causes excess risk of fracture at varied sites. Whereas, the difference between the roles of types 1 DM (T1DM) and 2 DM (T2DM) diabetes in the risk of fractures remains limited and inconclusive. We, therefore, conducted a meta-analysis to assess the differences for the associations of T1DM and T2DM with the risk of fractures.

METHODS

We systematically searched PubMed, Embase, and the Cochrane library for eligible studies until May 2021. The odds ratios (ORs) with 95% confidence intervals (CIs) were used to calculate the pooled effect estimates for the associations of T1DM and T2DM with the risk of fractures using the random-effects model. An indirect comparison results for the ratio of OR (ROR) with 95% CI were also applied to assess the difference between T1DM and T2DM with the risk of fractures.

RESULTS

Twenty-two cohort studies involving a total of 6,484,851 individuals were selected for meta-analysis. We noted that T1DM was associated with an increased risk of all fractures (OR: 1.72; 95% CI 1.36-2.19; P < 0.001), and fractures at the hip (OR: 4.01; 95% CI 2.90-5.54; P < 0.001), upper arm (OR: 2.20; 95% CI 1.61-3.00; P < 0.001), ankle (OR: 1.97; 95% CI 1.24-3.14; P = 0.004), and vertebrae (OR: 2.18; 95% CI 1.85-2.57; P < 0.001). Moreover, T2DM induced excess risk to all fractures (OR: 1.19; 95% CI 1.09-1.31; P < 0.001), including fractures at the hip (OR: 1.25; 95% CI 1.15-1.35; P < 0.001), upper arm (OR: 1.42; 95% CI 1.20-1.67; P < 0.001), and ankle (OR: 1.15; 95% CI 1.01-1.31; P = 0.029). Furthermore, we noted that T1DM versus T2DM was associated with greater risk to all fractures (ROR: 1.45; 95% CI 1.12-1.87; P = 0.005), including fractures at the hip (ROR: 3.21; 95% CI 2.30-4.48; P < 0.001), upper arm (ROR: 1.55; 95% CI 1.09-2.20; P = 0.015), and ankle (ROR: 1.71; 95% CI 1.06-2.78; P = 0.029).

CONCLUSIONS

This study found that T1DM caused an excess risk to all fractures, including fractures at the hip, upper arm, and ankle than T2DM. Further studies should therefore be conducted to directly compare the differences between T1DM and T2DM with the risk of fractures at various sites.

Gut Microbiota in Bone Health and Diabetes

PURPOSE OF REVIEW

Patients with diabetes mellitus (DM) are at increased risk of developing osteopathogenesis and skeletal fragility. The role of the gut microbiota in both DM and osteopathy is not fully explored and may be involved in the pathology of both diseases.

RECENT FINDINGS

Gut microbiota alterations have been observed in DM and osteopathogenic disorders as compared with healthy controls, such as significantly lower abundance of Prevotella and higher abundance of Lactobacillus, with a diminished bacterial diversity. Other overlapping gastro-intestinal features include the loss of intestinal barrier function with translocation of bacterial metabolites to the blood stream, induction of immunological deficits and changes in hormonal and endocrinal signalling, which may lead to the development of diabetic osteopathy. Signalling pathways involved in both DM and osteopathy are affected by gut bacteria and their metabolites. Future studies should focus on gut microbiota involvement in both diseases.

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.

Antidiabetic Treatment, Level of Glycemic Control, and Risk of Fracture in Type 2 Diabetes: a Nested, Case-Control Study

CONTEXT

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of low-trauma fractures. However, the effect of antidiabetic medication in relation to glycemic control on the risk of fracture is poorly understood.

OBJECTIVE

This work aimed to evaluate the association between the level of glycemic control, use of antidiabetic medication, and risk of low-trauma fractures in patients with newly diagnosed T2DM.

METHODS

We conducted a nested case-control analysis among individuals registered in the Clinical Practice Research Datalink. The base population consisted of patients with newly diagnosed T2DM from 1995 to 2017. Cases were patients with a low-trauma fracture after T2DM diagnosis. We matched 4 controls to each case. Exposures of interest were glycemic control (last glycated hemoglobin [HbA1c] level before fracture) and type of diabetes treatment. We conducted conditional logistic regression analyses adjusted for several confounders.

RESULTS

We identified 8809 cases and 35 219 controls. Patients with current metformin use and HbA1c levels of less than 7.0% and between 7.0-8.0% had a reduced risk of fractures (adjusted odds ratio 0.89; 95% CI, 0.83-0.96 and 0.81; 95% CI, 0.73-0.90, respectively) compared with untreated patients. However, in patients receiving metformin plus 1 or 2 other antidiabetic drugs, or insulin (alone or in addition to other antidiabetic medication), the level of glycemic control was not associated with the risk of fracture compared with untreated patients.

CONCLUSIONS

While patients with good or medium glycemic control receiving current metformin monotherapy had a lower risk of fracture compared with untreated patients, glycemic control in patients receiving treatment other than metformin was not associated with risk of fracture.

Diabetes mellitus and risk of low-energy fracture: a meta-analysis

BACKGROUND

Low-energy fracture risk is significantly increased in diabetes mellitus, the purpose of this article is to systematically evaluate the association between diabetes mellitus and risk for low-energy fracture.

METHODS

We conducted a systematic literature search of Medline, Embase, Science Citation Index, Wiley Online Library database through January 2019. Pooled relative risks (RR) with corresponding 95% confidence intervals (95% CI) were calculated with random-effects model to assess the strength of association.

RESULTS

Thirty-seven studies met the inclusion criteria, which included 3,123,382 participants. The pooled RR of any fracture in people with diabetes mellitus was 1.5 (95% CI 1.3-1.8; P < 0.05). The significant association not found in subgroup analysis of prospective design, follow-up period ≥ 10 year (all P > 0.05). The pooled RR of hip fracture in people with diabetes mellitus was 2.0 (95% CI 1.8-2.3; P < 0.05). In addition, subgroup analysis shown higher risk of hip fracture in type 1 diabetes (RR: 5.3). The pooled RR of vertebral fracture with diabetes mellitus was 1.4 (95% CI 0.9-2.2; P = 0.196). Subgroup analysis by type of diabetes showed that the RR of vertebral fracture for patients with unknown-type diabetes was 2.4 (95% CI 1.4-4.0; P < 0.05). Diabetes mellitus was associated with fractures at other sites, and effect estimates was statically significant.

CONCLUSIONS

Diabetes mellitus is an independent risk factor for low-energy fracture, and this relationship is more pronounced in hip fracture.

Sodium-glucose cotransporter 2 inhibitors and fracture risk in patients with type 2 diabetes mellitus: a meta-analysis of randomized controlled trials

Background:

Patients with type 2 diabetes mellitus (T2DM) have an increased risk of fracture compared with those without T2DM. Some oral glucose-lowering agents may increase the incidence of fracture. Whether sodium-glucose co-transporter 2 inhibitors (SGLT2is) are associated with increased risk of fracture remains unclear.

Methods:

We retrieved articles from PubMed, Embase, Cochrane Library database, and other sources up to 24 October 2019. We included randomized controlled trials (RCTs) that reported fractures and analyzed the fracture incidence of SGLT2i, canagliflozin, dapagliflozin, and empagliflozin. Subgroup analysis was also performed based on baseline characteristics.

Results:

A total of 78 RCTs with 85,122 patients were included in our analysis. The overall SGLT2i fracture incidence was 2.56% versus 2.77% in the control group [odds ratio (OR), 1.03; 95% confidence interval (CI) (0.95, 1.12); p = 0.49]. Compared with the control treatment, treatment with canagliflozin led to a higher rate of fractures [OR, 1.17; 95% CI (1.00, 1.37); p = 0.05], but no significant difference was observed when compared with dapagliflozin [OR, 1.02; 95% CI (0.90, 1.15); p = 0.79] or empagliflozin [OR, 0.89; 95% CI (0.73, 1.10); p = 0.30]. Subgroup analysis showed that, in a follow-up of less than 52 weeks, SGLT2i decreased the incidence of fracture by 29% [OR, 0.71; 95% CI (0.55, 0.93); p = 0.01], but this benefit was lost when the follow-up extended to more than 52 weeks [OR, 1.08; 95% CI (0.98, 1.18); p = 0.12].

Conclusion:

Canagliflozin seems to increase the risk of fracture, while other SGLT2is do not result in a higher incidence of fracture.

The risk of hip and non-vertebral fractures in type 1 and type 2 diabetes: A systematic review and meta-analysis update

BACKGROUND

Diabetes is associated with increased fracture risk but we do not know what affects this risk. We investigated the risk of hip and non-vertebral fractures in diabetes and whether this risk was affected by age, gender, body mass index, diabetes type and duration, insulin use and diabetic complications.

METHODS

We selected a previously published review to be updated. MEDLINE, Embase and Cochrane databases were searched up to March 2020. We included observational studies with age and gender-adjusted risk of fractures in adults with diabetes compared to adults without diabetes. We extracted data from published reports that we summarised using random effects model.

FINDINGS

From the 3140 records identified, 49 were included, 42 in the hip fracture analysis, reporting data from 17,571,738 participants with 319,652 fractures and 17 in the non-vertebral fracture review, reporting data from 2,978,487 participants with 181,228 fractures. We found an increase in the risk of fracture in diabetes both for hip (RR 4.93, 3.06-7.95, in type 1 diabetes and RR1.33, 1.19-1.49, in type 2 diabetes) and for non-vertebral fractures (RR 1.92, 0.92-3.99, in type 1 and RR 1.19, 1,11-1.28 in type 2). At the hip, the risk was higher in the younger population in both type 1 and type 2 diabetes. In those with type 2 diabetes, longer diabetes duration and insulin use was associated with an increased risk. We did not investigate the effect of bone density, falls, anti-diabetic drugs and hypoglycemia.

CONCLUSION

Diabetes is associated with an increase in both hip and non-vertebral fracture risk.

Incident Fracture Risk in Type 2 Diabetic Postmenopausal Women in Mainland China: Peking Vertebral Fracture Study

Using data from the Peking Vertebral Fracture Study, we conducted a longitudinal cohort study to investigate the association between type 2 diabetes mellitus (T2DM) and the risk of incident fractures, especially of vertebral fractures (VFs), and we also examined the modifying effect of body mass index (BMI) on this association and the effect of bone mineral density (BMD) T-score as a risk factor for incident fractures in T2DM. Chinese postmenopausal women were enrolled (n = 982), among whom 186 had T2DM. Incident VFs were confirmed by lateral radiographs of the thoracolumbar spine (T4-L5), while incident clinical non-VFs were self-reported. BMDs at the lumbar spine (LS) and femoral neck (FN) were measured by dual-energy X-ray absorptiometry. T2DM and non-DM women were at similar risk for VFs (OR 0.74, 95% CI 0.32-1.74), even adjusting for age, BMI, BMD, and previous fractures. Meanwhile, T2DM women had nearly twice the risk for non-VFs (HR 1.95, 95% CI 1.11-3.35) compared with non-DM women. After stratifying by BMI, the risk of VFs remained similar between diabetics and non-diabetics despite their BMI status (p for interaction = 0.470), and the risk of non-VFs was positively associated with T2DM only in women with BMI ≥ 25 kg/m² (HR 3.59, 95% CI 1.68-7.65) (p for interaction = 0.065). Although LS BMD T-score was similarly and negatively associated with incident VFs both in T2DM (OR 0.34, 95% CI 0.12-0.88) and non-DM women (OR 0.60, 95% CI 0.44-0.82) (p for interaction = 0.430), the FN BMD T-score was not found to be significantly associated with either non-VFs or VFs among T2DM women. Comparing T2DM and non-DM women with similar fracture risks, the mean difference in LS T-score was - 0.36 (95% CI - 1.77 to 1.04) for VF, and difference in FN T-score was 1.61 (95% CI - 0.11 to 3.34) for non-VF. In conclusion, Chinese postmenopausal women with T2DM had a similar risk of incident VFs, but a significantly higher risk of incident non-VF, compared to women without DM. Higher BMI did not modify the effect of T2DM on risk of VFs, but it increased the association between T2DM and risk of non-VFs. LS BMD T-score was similarly and negatively associated with VF risk in T2DM and non-DM women and appear to be useful for clinical evaluation of VF risk.

Skeletal Fragility in Type 2 Diabetes Mellitus

Type 2 diabetes (T2D) is associated with an increased risk of fracture, which has been reported in several epidemiological studies. However, bone mineral density in T2D is increased and underestimates the fracture risk. Common risk factors for fracture do not fully explain the increased fracture risk observed in patients with T2D. We propose that the pathogenesis of increased fracture risk in T2D is due to low bone turnover caused by osteocyte dysfunction resulting in bone microcracks and fractures. Increased levels of sclerostin may mediate the low bone turnover and may be a novel marker of increased fracture risk, although further research is needed. An impaired incretin response in T2D may also affect bone turnover. Accumulation of advanced glycosylation endproducts may also impair bone strength. Concerning antidiabetic medication, the glitazones are detrimental to bone health and associated with increased fracture risk, and the sulphonylureas may increase fracture risk by causing hypoglycemia. So far, the results on the effect of other antidiabetics are ambiguous. No specific guideline for the management of bone disease in T2D is available and current evidence on the effects of antiosteoporotic medication in T2D is sparse. The aim of this review is to collate current evidence of the pathogenesis, detection and treatment of diabetic bone disease.