Increased bone mineral density in postmenopausal women with type 2 diabetes mellitus

Mineral and cross-linking in collagen fibrils: The mechanical behavior of bone tissue at the nano-scale

The mineralized collagen fibril is the main building block of hard tissues and it directly affects the macroscopic mechanics of biological tissues such as bone. The mechanical behavior of the fibril itself is determined by its structure: the content of collagen molecules, minerals, and cross-links, and the mechanical interactions and properties of these components. Advanced glycation end products (AGEs) form cross-links between tropocollagen molecules within the collagen fibril and are one important factor that is believed to have a major influence on the tissue. For instance, it has been shown that brittleness in bone correlates with increased AGEs densities. However, the underlying nano-scale mechanisms within the mineralized collagen fibril remain unknown. Here, we study the effect of mineral and AGEs cross-linking on fibril deformation and fracture behavior by performing destructive tensile tests using coarse-grained molecular dynamics simulations. Our results demonstrate that after exceeding a critical content of mineral, it induces stiffening of the collagen fibril at high strain levels. We show that mineral morphology and location affect collagen fibril mechanics: The mineral content at which this stiffening occurs depends on the mineral's location and morphology. Further, both, increasing AGEs density and mineral content lead to stiffening and increased peak stresses. At low mineral contents, the mechanical response of the fibril is dominated by the AGEs, while at high mineral contents, the mineral itself determines fibril mechanics.

Mineral and cross-linking in collagen fibrils: The mechanical behavior of bone tissue at the nano-scale

The mineralized collagen fibril is the main building block of hard tissues and it directly affects the macroscopic mechanics of biological tissues such as bone. The mechanical behavior of the fibril itself is determined by its structure: the content of collagen molecules, minerals, and cross-links, and the mechanical interactions and properties of these components. Advanced-Glycation-Endproducts (AGEs) cross-linking between tropocollagen molecules within the collagen fibril is one important factor that is believed to have a major influence on the tissue. For instance, it has been shown that brittleness in bone correlates with increased AGEs densities. However, the underlying nano-scale mechanisms within the mineralized collagen fibril remain unknown. Here, we study the effect of mineral and AGEs cross-linking on fibril deformation and fracture behavior by performing destructive tensile tests using coarse-grained molecular dynamics simulations. Our results demonstrate that after exceeding a critical content of mineral, it induces stiffening of the collagen fibril at high strain levels. We show that mineral morphology and location affect collagen fibril mechanics: The mineral content at which this stiffening occurs depends on the mineral's location and morphology. Further, both, increasing AGEs density and mineral content lead to stiffening and increased peak stresses. At low mineral contents, the mechanical response of the fibril is dominated by the AGEs, while at high mineral contents, the mineral itself determines fibril mechanics.

Does obesity mediate the relationship between diabetes and osteoporosis in Chinese elderly population?

OBJECTIVES

Diabetes mellitus (DM), osteoporosis (OP), and obesity (OB) are three complex diseases. OB is associated with both DM and OP, but it is unclear whether OB mediates association between DM and OP. The study aimed to investigate the potential mediation effects of OB on association between DM and bone mineral density (BMD) by the causal inference tests (CIT).

METHODS

A total of 5682 Chinese aged over 65 years were enrolled in an ongoing cohort: Osteoporosis Preventive Project (OPP). Obesity-related indexes, including body mass index (BMI), waist circumference, and waist circumference-hip circumference-ratio (WHR), and BMD at total hip (TH) and femur neck (FN) were measured.

RESULTS

Subjects with DM had significant greater values of age, weight, BMI, waist circumference, WHR, and BMD than non-DM subjects. BMD at TH and FN was significantly associated with DM (p < 0.05) with adjustment of age both in males and females. Further CIT showed that OB-related indexes (BMI, waist circumference, and WHR) are significantly mediators in the associations between DM and BMD in females, but not in males. Furthermore, the mediation effects of waist circumference were detected on DM and TH BMD in the females of normal-weight group.

CONCLUSIONS

Obesity-related indexes, especially waist circumference, serve as significant mediator(s) between DM and OP in Chinese female elderly. Diabetes increases BMD by increasing obesity-related indexes. The findings established the intermediate role of OB underlying the association between DM and OP in human population.

Assessment of bone quality in patients with diabetes mellitus

Substantial evidence exists that diabetes mellitus is associated with an increased risk of osteoporotic fractures. Low bone strength as well as bone extrinsic factors are probably contributing to the increased bone fragility in diabetes. Bone density and quality are important determinants of bone strength. Although bone mineral density (BMD) and the fracture risk assessment tool (FRAX) are very useful clinical tools in assessing bone strength, they may underestimate the fracture risk in diabetes mellitus. Through advances in new technologies such as trabecular bone score (TBS) and peripheral quantitative computed tomography (pQCT), we can better assess the bone quality and fracture risk of patients with diabetes mellitus. Invasive assessments such as microindentation and histomorphometry have been great complement to the existing bone analysis techniques. Bone turnover markers have been found to be altered in diabetes mellitus patients and may be associated with fractures. This review will give a brief summary of the current development and clinical uses of these assessments.

Bone Mineral Density of the Radius Predicts All-Cause Mortality in Patients With Type 2 Diabetes: Diabetes Heart Study

This study aimed to determine the association between areal and volumetric bone mineral density (BMD) with all-cause mortality in patients with type 2 diabetes (T2D). Associations between BMD and all-cause mortality were examined in 576 women and 517 men with T2D in the Diabetes Heart Study. Volumetric BMD in the thoracic and lumbar spine was measured with quantitative computed tomography. Areal BMD (aBMD) in the lumbar spine, total hip, femoral neck, ultradistal radius, mid radius, and whole body was measured using dual X-ray absorptiometry. Association of BMD with all-cause mortality was determined using sequential models, stratified by sex: (1) unadjusted; (2) adjusted for age, race, smoking, alcohol, estrogen use; (3) model 2 plus history of cardiovascular disease, hypertension, and coronary artery calcification; (4) model 3 plus lean mass; and (5) model 3 plus fat mass. At baseline, mean age was 61.2 years for women and 62.7 years for men. At mean 11.0 ± 3.7 years' follow-up, 221 (36.4%) women and 238 (43.6%) men were deceased. In women, BMD at all skeletal sites (except spine aBMD and whole body aBMD) was inversely associated with all-cause mortality in the unadjusted model. These associations remained significant in the mid radius (hazard ratio per standard deviation  = 0.79; p = 0.0057) and distal radius (hazard ratio per standard deviation  = 0.76; p = 0.0056) after adjusting for all covariates, including lean mass. In men, volumetric BMD measurements but not aBMD were inversely associated with mortality and only in the unadjusted model. In this longitudinal study, lower baseline aBMD in the radius was associated with increased all-cause mortality in women with T2D, but not men, independent of other risk factors for death.

Relationship between Weight, Body Mass Index and Bone Mineral Density of Lumbar Spine in Women

Objectives

This study aims to identify a relationship between bone mineral density (BMD) of lumbar spine, and the weight and body mass index (BMI) in women.

Methods

The subjects were 1,143 females who visited the public health center. BMD (T-score), height and weight were measured and age, menopause, diabetes and hypertension, exercising status and smoking status were inquired by interview.

Results

Among the subjects, 362 (31.7%) were in the normal group and 781 (68.3%) were in the abnormal group. As the result of the logistic regression analysis with BMI (Model I), the odds ratio of getting into the abnormal BMD group as age increases by 1 year marked 1.044 (95% CI = 1.009-1.080). The odds ratio of getting into the abnormal BMD group due to menopause was 2.663 (1.516-4.679) and the odds ratio according to lack of walking exercise was 2.597 (1.878-3.591). The odds ratio with 1 kg/m² of BMI increase was 0.909 (0.862-0.959). In the logistic regression analysis with weight (Model II), the odds ratio of getting into the abnormal BMD group as age increases by 1 year marked 1.044 (1.009-1.080). The odds ratio of getting into the abnormal bone density group due to menopause was 2.575 (1.472-4.507) and the odds ratio according to lack of walking exercise was 2.598 (1.881-3.587). The odds ratio with 1 kg of weight increase was 0.963 (0.942-0.984). The Akaike's information criterion (AIC) values of Model I and Model II were 1196.18 and 1197.14 respectively, indicating Model I has the better compatibility of regression analysis model.

Conclusion

Weight, BMI and BMD had a positive correlation. However, the coefficient of correlation between weight and BMD was higher than the coefficient between BMI and BMD, which means low weight is much more likely to be related to osteoporosis with no other factor considered. On the other hand, under the condition considering age, height, menopause and walking exercise smoking status, low BMI is much more compatible as a risk factor for osteoporosis.

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm(2)) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case-control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA(1C) were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM.

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm(2)) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case-control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA(1C) were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM.

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm(2)) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case-control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA(1C) were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM.

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm(2)) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case-control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA(1C) were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM.

Characteristics of bone turnover, bone mass and bone strength in Spontaneously Diabetic Torii-Lepr fa rats

The Spontaneously Diabetic Torii-Lepr (fa) (SDT-fa/fa) rat is a new model of obese type 2 diabetes. The SDT-fa/fa rat shows obesity and hyperglycemia at a young age compared to the Spontaneously Diabetic Torii (SDT-+/+) rat; however, bone abnormalities in the SDT-fa/fa rat have not been investigated. The objective of the present study was to investigate the effects of obese type 2 diabetes on bone turnover, bone mass, and bone strength in the SDT-fa/fa rat. Sprague-Dawley rats were used as control animals, and SDT-+/+ rats were used as non-obese type 2 diabetic rats. Serum osteocalcin and urine deoxypyridinoline levels were decreased in SDT-fa/fa rats compared to control rats at a young age. SDT-fa/fa rats showed decreases in bone mineral density and bone mineral content of the whole tibia, and shortening of the tibia and femur compared to control and SDT-+/+ rats. Deterioration in bone geometrical properties of the femur midshaft such as cortical thickness and minimum moment of inertia, was observed in SDT-fa/fa rats compared to control and SDT-+/+ rats. Furthermore, trabecular bone volume of the distal femur was decreased in SDT-fa/fa rats compared to control rats. These negative effects on bone in SDT-fa/fa rats caused severe decreases in maximum load, stiffness, and energy absorption of the femur. In addition, serum levels of homocysteine, a candidate for bone fragility markers, were elevated in SDT-fa/fa rats compared to control and SDT-+/+ rats. In conclusion, the SDT-fa/fa rat may be a useful model to investigate bone abnormalities in obese type 2 diabetes.

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm(2)) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case-control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA(1C) were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM.

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm²) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case–control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA_1C were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM.

Evaluation of bone mineral density in type 2 diabetes mellitus patients before and after treatment

BACKGROUND

The relationship between bone mineral density (BMD) and type 2 diabetes mellitus (T2DM) has been controversial. Recent studies have revealed adverse impact of antidiabetic drugs on BMD in type 2 diabetic patients. However, the influence of various antihyperglycaemic agents on BMD has not been well studied.

METHOD

A total of 200 patients with T2DM were screened initially for the study. Finally 67 patients (M:34, F:33) who satisfied the requirement of having been on one year of prescribed therapy were included for analysis.

RESULTS

Bone mineral density was lower in diabetic patients as compared to controls (hip 0.962 ± 0.167 g/cm(2) vs 1.013 ± 0.184 g/cm(2), P = 0.05; spine 0.929 ± 0.214 g/cm(2) vs 1.113 ± 0.186 g/cm(2), P < 0.00001). In males BMD was significantly lower at spine (P < 0.00001) and in females BMD was significantly lower in both at the spine (P < 0.00001) and hip (P < 0.032). On multivariate analysis significant positive correlation was found between spine BMD and body mass index (BMI) (r = 0.372, P = 0.002), total cholesterol (r = 0.272, P = 0.026), low-density lipoprotein (r = 0.242, P = 0.047), and triglycerides (r = 0.282, P = 0.021). There was no correlation between BMD and glycosylated haemoglobin (r = 0.158, P = 0.265). A significant decrease in BMD at spine and hip was seen with the use of glitazones and metformin while increase was noted with sulphonylurea and its combination.

CONCLUSION

Men and women with T2DM have lower BMD. Bone mineral density did not have correlation to glycaemic control. Glitazones, metformin, and insulin are associated with decrease in BMD at spine, and hip, while sulphonylureas are associated with increase in BMD.

Osteoporosis and type 2 diabetes mellitus: what do we know, and what we can do?

Diabetes mellitus (DM) is a pandemic and chronic metabolic disorder with substantial morbidity and mortality. In addition, osteoporosis (OP) is a silent disease with a harmful impact on morbidity and mortality. Therefore, this systematic review focuses on the relationship between OP and type 2 diabetes mellitus (T2DM). Systematic reviews of full-length articles published in English from January 1950 to October 2010 were identified in PubMed and other available electronic databases on the Universiti Sains Malaysia Library Database. The following keywords were used for the search: T2DM, OP, bone mass, skeletal. Studies of more than 50 patients with T2DM were included. Forty-seven studies were identified. The majority of articles (26) showed increased bone mineral density (BMD), while 13 articles revealed decreased BMD; moreover, eight articles revealed normal or no difference in bone mass. There were conflicting results concerning the influence of T2DM on BMD in association with gender, glycemic control, and body mass index. However, patients with T2DM display an increased fracture risk despite a higher BMD, which is mainly attributable to the increased risk of falling. As a conclusion, screening, identification, and prevention of potential risk factors for OP in T2DM patients are crucial and important in terms of preserving a good quality of life in diabetic patients and decreasing the risk of fracture. Patients with T2DM may additionally benefit from early visual assessment, regular exercise to improve muscle strength and balance, and specific measures for preventing falls. Patient education about an adequate calcium and vitamin D intake and regular exercise is important for improving muscle strength and balance. Furthermore, adequate glycemic control and the prevention of diabetic complications are the starting point of therapy in diabetic patients.

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm(2)) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case-control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA(1C) were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM.

Association between bone mineral density and type 2 diabetes mellitus: a meta-analysis of observational studies

Type 2 diabetes mellitus (T2DM) influences bone metabolism, but the relation of T2DM with bone mineral density (BMD) remains inconsistent across studies. The objective of this study was to perform a meta-analysis and meta-regression of the literature to estimate the difference in BMD (g/cm(2)) between diabetic and non-diabetic populations, and to investigate potential underlying mechanisms. A literature search was performed in PubMed and Ovid extracting data from articles prior to May 2010. Eligible studies were those where the association between T2DM and BMD measured by dual energy X-ray absorptiometry was evaluated using a cross-sectional, cohort or case-control design, including both healthy controls and subjects with T2DM. The analysis was done on 15 observational studies (3,437 diabetics and 19,139 controls). Meta-analysis showed that BMD in diabetics was significantly higher, with pooled mean differences of 0.04 (95% CI: 0.02, 0.05) at the femoral neck, 0.06 (95% CI: 0.04, 0.08) at the hip and 0.06 (95% CI: 0.04, 0.07) at the spine. The differences for forearm BMD were not significantly different between diabetics and non-diabetics. Sex-stratified analyses showed similar results in both genders. Substantial heterogeneity was found to originate from differences in study design and possibly diabetes definition. Also, by applying meta-regression we could establish that younger age, male gender, higher body mass index and higher HbA(1C) were positively associated with higher BMD levels in diabetic individuals. We conclude that individuals with T2DM from both genders have higher BMD levels, but that multiple factors influence BMD in individuals with T2DM.

Effects of ovariectomy on bone metabolism and bone mineral density in spontaneously diabetic Torii-Lepr(fa) rats

The Spontaneously Diabetic Torii-Lepr(fa) (SDT- fa/fa) rat is a new model of obese type 2 diabetes. The female SDT-fa/fa rat shows obesity, hyperglycemia and hyperlipidemia from a young age. However, it is not known whether diabetes and estrogen deficiency can lead to bone abnormalities in the female SDT-fa/fa rat. The objective of the present study was to investigate the effects of ovariectomy (OVX) on bone metabolism and bone mineral density (BMD) in the female SDT-fa/fa rat. Female Sprague-Dawley rats were used as control animals. The BMDs of the whole tibia and fifth lumbar (L5) vertebral body were analyzed at 30 weeks after OVX. Serum osteocalcin, a bone formation marker, and urine deoxypyridinoline (DPD), a bone resorption marker, were sequentially analyzed before and at 5, 15 and 30 weeks after OVX. Serum osteocalcin and urine DPD levels were lower in SDT-fa/fa rats than in control rats before OVX. Both serum osteocalcin and urine DPD levels were elevated in control rats 5-30 weeks after OVX, but only the urine DPD levels were elevated in SDT-fa/fa rats 5-30 weeks after OVX. SDT-fa/fa rats showed a decrease in the BMDs of the whole tibia and L5 vertebral body compared with control rats. OVX decreased the BMDs of the whole tibia and L5 vertebral body in control rats, but not in SDT-fa/fa rats. These data suggest that estrogen deficiency is not a risk factor for bone loss in type 2 diabetes mellitus.

Bone health and type 2 diabetes mellitus: a systematic review

PURPOSE

To systematically review the literature related to bone health in older adults with type 2 diabetes mellitus (T2DM).

METHODS

We conducted a systematic review of the literature from January 2005 until February 2010, using keywords related to T2DM and bone-health imaging technology in older adults (aged ≥60 years) to search PubMed, OVID MEDLINE, Ageline, CINAHL, Embase, and PsycINFO.

RESULTS

We found a total of 13 studies that met the inclusion criteria for this review. The majority of the studies used dual X-ray absorptiometry (DXA) and showed either higher or similar areal bone mineral density (aBMD) for older adults with T2DM relative to healthy controls. Studies using more advanced imaging suggested that there may be differences in bone geometry between older adults with and without T2DM.

CONCLUSIONS

Older adults with T2DM have similar or higher aBMD at the hip relative to older adults without T2DM, despite previous literature reporting an increased risk of low-trauma fractures. Recent studies with advanced imaging have suggested that there may be differences in bone geometry between older adults with T2DM and those without. Health professionals, especially physiotherapists, should be aware of the increased risk and include assessment of fall risk factors and exercise prescription for fall prevention for older adults with T2DM.