A population-based study of bone mineral density in women with longstanding type 1 (insulin dependent) diabetes

Genetically determined type 1 diabetes mellitus and risk of osteoporosis

BACKGROUND

Observational evidence suggests that type 1 diabetes mellitus (T1DM) is associated with the risk of osteoporosis (OP). Nevertheless, it is not apparent whether these correlations indicate a causal relationship. To elucidate the causal relationship, a two-sample Mendelian randomization (MR) analysis was performed.

METHODS

T1DM data was obtained from the large genome-wide association study (GWAS), in which 6683 cases and 12,173 controls from 12 European cohorts were involved. Bone mineral density (BMD) samples at four sites were extracted from the GEnetic Factors for OSteoporosis (GEFOS) consortium, including forearm (FA) (n = 8,143), femoral neck (FN) (n = 32,735), lumbar spine (LS) (n = 28,498), and heel (eBMD) (n = 426,824). The former three samples were from mixed populations and the last one was from European. Inverse variance weighting, MR-Egger, and weighted median tests were used to test the causal relationship between T1DM and OP. A series of sensitivity analyses were then conducted to verify the robustness of the results.

RESULTS

Twenty-three independent SNPs were associated with FN-BMD and LS-BMD, twenty-seven were associated with FA-BMD, and thirty-one were associated with eBMD. Inverse variance-weighted estimates indicated a causal effect of T1DM on FN-BMD (odds ratio (OR) =1.033, 95 % confidence interval (CI): 1.012-1.054, p = 0.002) and LS-BMD (OR = 1.032, 95 % CI: 1.005-1.060, p = 0.022) on OP risk. Other MR methods, including weighted median and MR-Egger, calculated consistent trends. While no significant causation was found between T1DM and the other sites (FA-BMD: OR = 1.008, 95 % CI: 0.975-1.043, p = 0.632; eBMD: OR = 0.993, 95 % CI: 0.985-1.001, p = 0.106). No significant heterogeneity (except for eBMD) or horizontal pleiotropy was found for instrumental variables, suggesting these results were reliable and robust.

CONCLUSIONS

This study shows a causal relationship between T1DM and the risk of some sites of OP (FN-BMD, LS-BMD), allowing for continued research to discover the clinical and experimental mechanisms of T1DM and OP. It also contributes to the recommendation if patients with T1DM need targeted care to promote bone health and timely prevention of osteoporosis.

Celiac Disease Screening for High-Risk Groups: Are We Doing It Right?

Celiac disease (CD) is an immune-mediated enteropathy triggered by dietary ingestion of gluten in genetically susceptible patients. CD is often diagnosed by a "case-finding" approach of symptomatic patients. In recent times, the diagnostic paradigm has shifted to investigate patients who may be asymptomatic, but are at high risk of developing CD due to shared genetic susceptibilities. These high-risk groups include first-degree relatives of CD patients and patients with Type 1 diabetes mellitus, autoimmune thyroid disease, Down's syndrome, and Turner syndrome. Moreover, CD is often diagnosed as the cause of iron deficiency anemia or unexplained chronic diarrhea. Although screening for CD with serological tests is not recommended for the general population, it should be considered in these special populations. In this review, we explore screening for CD among high-risk groups in light of recent research and development in the CD arena.

A 10-Year Prospective Study of Bone Mineral Density and Bone Turnover in Males and Females With Type 1 Diabetes

CONTEXT

In a previous community-based, cross-sectional study, males with type 1 diabetes (T1D) had lower bone mineral density (BMD) than did matched people without diabetes but females with T1D had normal BMD.

OBJECTIVE

To determine whether BMD in the males continued to decline, the neutral effect of T1D on BMD in females persisted, and whether temporal BMD changes reflected changes in bone turnover markers.

DESIGN

Longitudinal observational study.

SETTING

Urban community.

PATIENTS

Forty-eight of the original 102 original cross-sectional study participants (20 males, 28 females) of mean age 42.0 years and median diabetes duration 14.6 years at baseline who were restudied a mean of 10.3 years later.

MAIN OUTCOME MEASURES

BMD at total hip, femoral neck, lumbar spine (L1 to L4), and distal forearm. Biochemical bone turnover markers.

RESULTS

After adjustment for age, body mass index (BMI), and renal function, there was no temporal change in BMD at the hip or forearm in the males (P ≥ 0.12), but lumbar spine BMD increased (P = 0.009). Females exhibited no statistically significant change in BMD in similar multivariable models that also included postmenopausal status, except a mild increase at the forearm (P = 0.046). Age- and sex-related changes in bone turnover markers paralleled those in general population studies.

CONCLUSIONS

There is a reduction in BMD in males with T1D that occurs early in the course of the disease but then stabilizes. BMD in females with T1D remains similar to that expected for age, BMI, and postmenopausal status.

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 disease in diabetes: another manifestation of microvascular disease?

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

Bone mineral density at femoral neck and lumbar spine in adults with type 1 diabetes: a meta-analysis and review of the literature

We performed a meta-analysis to evaluate the femoral neck and lumbar spine bone mineral density (BMD) in adults with type 1 diabetes (T1D) compared with controls. Adults with T1D have modestly lower BMD at femoral neck and lumbar spine than adults without diabetes.

INTRODUCTION

Fracture risk is four to sixfold higher in adults with T1D. Since BMD is one of the major contributors for fracture risk, we performed a meta-analysis to evaluate differences in femoral neck and lumbar spine BMD between adults with T1D and controls.

METHODS

MEDLINE, Ovid, and the Cochrane library and abstracts from various scientific meetings were searched. Studies reporting the femoral neck and/or lumbar spine BMD in adults (age > 20 years) with T1D in comparison with people without diabetes were selected. General linear mixed models were used to assess differences in BMD at femoral neck and lumbar spine between subjects with T1D and controls adjusting for age, sex, and dual x-ray absorptiometry (DXA) instruments.

RESULTS

Sixteen studies met the inclusion criteria. The femoral neck BMD was modestly lower in adults with T1D compared to controls (-0.055 g/cm²; 95% CI: -0.065, -0.045). There were no differences in lumbar spine BMD between adults with T1D and controls (0.0062 g/cm²; 95% CI -0.04, 0.016). However, in a sensitivity analysis, lumbar spine BMD was modestly lower in adults with T1D compared to controls (-0.035 g/cm²; -0.049, -0.02). Studies using Lunar DXA instruments have reported higher lumbar spine and femoral neck BMD compared to studies using Hologic DXA instruments.

CONCLUSION

Femoral neck and lumbar spine BMD were modestly lower in adults with T1D compared to controls. However, this modest reduction in femoral neck and lumbar spine BMD cannot explain much higher observed fracture risk in adults with T1D.

Bone health in subjects with type 1 diabetes for more than 50 years

AIMS

Few data regarding prevalence of and risk factors for poor bone health in aging individuals with long-standing T1D are available. In this study, we aim to describe the prevalence of bone fragility and to identify factors associated with low bone density in individuals with long-term T1D.

METHODS

We examined the prevalence of non-vertebral fractures in 985 subjects enrolled in the Joslin 50-Year Medalist Study and measured bone mineral density (BMD) by dual-energy X-ray absorptiometry at the femoral neck, lumbar spine and radius in a subset (65 subjects, mean age 62.6 years, duration 52.5 years, HbA1c 7.1%) with no significant clinical or demographic differences from the rest of the cohort.

RESULTS

Medalists have low prevalence of fractures (0.20% hip and 0.91% wrist) and normal Z-score values (spine +1.15, total hip +0.23, femoral neck -0.01, radius +0.26; p > 0.05 for differences vs. 0 at all sites). A significant relationship was found between lower BMD and higher total cholesterol, triglycerides and LDL levels, but not HbA1c. Low BMD at the femoral neck was associated with cardiovascular disease after adjustment for confounding factors: prevalence risk ratio of CVD [95% CI] 4.6 [1.2-18.1], p = 0.03. No other diabetic vascular complication was found to be associated with low BMD.

CONCLUSIONS

These are the first data regarding bone health in aging individuals who have had diabetes for 50 or more years. The low rates of non-vertebral fractures and the normal Z-score suggest the long T1D diabetes duration did not increase the risk of bone fractures in Medalists compared to non-diabetic peers. Additionally, the association with cardiovascular disease demonstrates the BMD differences in groups are likely not due to glycemic control alone.

Severity and pattern of bone mineral loss in endocrine causes of osteoporosis as compared to age-related bone mineral loss

Background:

Data are scant on bone health in endocrinopathies from India. This study evaluated bone mineral density (BMD) loss in endocrinopathies [Graves’ disease (GD), type 1 diabetes mellitus (T1DM), hypogonadotrophic hypogonadism (HypoH), hypergonadotropic hypogonadism (HyperH), hypopituitarism, primary hyperparathyroidism (PHPT)] as compared to age-related BMD loss [postmenopausal osteoporosis (PMO), andropause].

Materials and Methods:

Retrospective audit of records of patients >30 years age attending a bone clinic from August 2014 to January 2016 was done.

Results:

Five-hundred and seven records were screened, out of which 420 (females:male = 294:126) were analyzed. A significantly higher occurrence of vitamin D deficiency and insufficiency was noted in T1DM (89.09%), HyperH (85%), and HypoH (79.59%) compared to age-related BMD loss (60.02%; P < 0.001). The occurrence of osteoporosis among females and males was 55.41% and 53.97%, respectively, and of osteopenia among females and males was 28.91% and 32.54%, respectively. In females, osteoporosis was significantly higher in T1DM (92%), HyperH (85%), and HypoH (59.26%) compared to PMO (49.34%; P < 0.001). Z score at LS, TF, NOF, and greater trochanter (GT) was consistently lowest in T1DM women. Among men, osteoporosis was significantly higher in T1DM (76.67%) and HypoH (54.55%) compared to andropause (45.45%; P = 0.001). Z score at LS, TF, NOF, GT, and TR was consistently lowest in T1DM men. In GD, the burden of osteoporosis was similar to PMO and andropause. BMD difference among the study groups was not significantly different after adjusting for body mass index (BMI) and vitamin D.

Conclusion:

Low bone mass is extremely common in endocrinopathies, warranting routine screening and intervention. Concomitant vitamin D deficiency compounds the problem. Calcium and vitamin D supplementations may improve bone health in this setting.

Epidemiology of Skeletal Health in Type 1 Diabetes

The skeleton is adversely affected by type 1 diabetes (T1D). Patients with T1D of both sexes have an increased risk of fracture that begins in childhood and extends across the entire lifespan. T1D is characterized by mild to modest deficits in bone density, structure, and microarchitecture. Current evidence suggests that the observed bone deficits in T1D are the result of impaired bone formation rather than increased bone resorption. There is emerging data that bone quality is impaired in T1D, which may explain the findings that fracture risk is elevated out of proportion to the degree of bone mineral deficit. In this review, we summarize the current knowledge regarding the epidemiology of skeletal health in T1D. Given the high individual and societal burden of osteoporotic fracture, there is an urgent need to better understand the etiology of T1D-related bone disease so that clinical strategies to prevent fracture can be developed.

Assessment risk of osteoporosis in Chinese people: relationship among body mass index, serum lipid profiles, blood glucose, and bone mineral density

OBJECTIVE

The aim of our study was to investigate the relationship among age, sex, body mass index (BMI), serum lipid profiles, blood glucose (BG), and bone mineral density (BMD), making an assessment of the risk of osteoporosis.

MATERIALS AND METHODS

A total of 1,035 male and 3,953 female healthy volunteers (aged 41-95 years) were recruited by an open invitation. The basic information, including age, sex, height, weight, waistline, hipline, menstrual cycle, and medical history, were collected by a questionnaire survey and physical examination. Serum lipid profiles, BG, postprandial blood glucose, and glycosylated hemoglobin were obtained after 12 hours fasting. BMD in lumbar spine was measured by dual-energy X-ray absorptiometry scanning.

RESULTS

The age-adjusted BMD in females was significantly lower than in males. With aging, greater differences of BMD distribution exist in elderly females than in males (P<0.001), and the fastigium of bone mass loss was in the age range from 51 to 55 in females and from 61 to 65 years in males. After adjustment for sex, there were significant differences in BMD among BMI-stratified groups in both males and females. The subjects with a BMI of <18.5 had a higher incidence of osteoporosis than BMI ≥18.5 in both sexes. BMD in type 2 diabetes mellitus with a BG of >7.0 mmol/L was lower than in people with BG of ≤7.0 mmol/L (P<0.001). People with serum high-density lipoprotein cholesterol levels of ≥1.56 mmol/L had a greater prevalence of osteoporosis compared with high-density lipoprotein cholesterol ≤1.55 mmol/L. Logistic regression with odds ratios showed that no association was found among total cholesterol, triglyceride, low-density lipoprotein cholesterol, glycosylated hemoglobin, postprandial blood glucose and BMD.

CONCLUSION

The present study further confirmed that factors such as age, sex, weight, BMI, high-density lipoprotein cholesterol, and diabetes are significant predictors of osteoporosis in the Chinese people.

MECHANISMS IN ENDOCRINOLOGY: Mechanisms and evaluation of bone fragility in type 1 diabetes mellitus

Subjects with type 1 diabetes mellitus (T1DM) have decreased bone mineral density and an up to sixfold increase in fracture risk. Yet bone fragility is not commonly regarded as another unique complication of diabetes. Both animals with experimentally induced insulin deficiency syndromes and patients with T1DM have impaired osteoblastic bone formation, with or without increased bone resorption. Insulin/IGF1 deficiency appears to be a major pathogenetic mechanism involved, along with glucose toxicity, marrow adiposity, inflammation, adipokine and other metabolic alterations that may all play a role on altering bone turnover. In turn, increasing physical activity in children with diabetes as well as good glycaemic control appears to provide some improvement of bone parameters, although robust clinical studies are still lacking. In this context, the role of osteoporosis drugs remains unknown.

Bone Geometry, Volumetric Density, Microarchitecture, and Estimated Bone Strength Assessed by HR-pQCT in Adult Patients With Type 1 Diabetes Mellitus

The primary goal of this cross-sectional in vivo study was to assess peripheral bone microarchitecture, bone strength, and bone remodeling in adult type 1 diabetes (T1D) patients with and without diabetic microvascular disease (MVD+ and MVD-, respectively) and to compare them with age-, gender-, and height-matched healthy control subjects (CoMVD+ and CoMVD-, respectively). The secondary goal was to assess differences in MVD- and MVD+ patients. Fifty-five patients with T1DM (MVD+ group: n = 29) were recruited from the Funen Diabetes Database. Dual-energy X-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT) of the ultradistal radius and tibia, and biochemical markers of bone turnover were performed in all participants. There were no significant differences in HR-pQCT parameters between MVD- and CoMVD- subjects. In contrast, MVD+ patients had larger total and trabecular bone areas (p = 0.04 and p = 0.02, respectively), lower total, trabecular, and cortical volumetric bone mineral density (vBMD) (p < 0.01, p < 0.04, and p < 0.02, respectively), and thinner cortex (p = 0.03) at the radius, and lower total and trabecular vBMD (p = 0.01 and p = 0.02, respectively) at the tibia in comparison to CoMVD+. MVD+ patients also exhibited lower total and trabecular vBMD (radius p = 0.01, tibia p < 0.01), trabecular thickness (radius p = 0.01), estimated bone strength, and greater trabecular separation (radius p = 0.01, tibia p < 0.01) and network inhomogeneity (radius p = 0.01, tibia p < 0.01) in comparison to MVD- patients. These differences remained significant after adjustment for age, body mass index, gender, disease duration, and glycemic control (average glycated hemoglobin over the previous 3 years). Although biochemical markers of bone turnover were significantly lower in MVD+ and MVD- groups in comparison to controls, they were similar between the MVD+ and MVD- groups. The results of our study suggest that the presence of MVD was associated with deficits in cortical and trabecular bone vBMD and microarchitecture that could partly explain the excess skeletal fragility observed in these patients.

The relationships between blood pressure, blood glucose, and bone mineral density in postmenopausal Turkish women

BACKGROUND

Hypertension, diabetes mellitus, and osteoporosis are important comorbidities commonly seen in postmenopausal women. The aim of the present study was to investigate the relationships between blood pressure, blood glucose, and bone mineral density (BMD) in postmenopausal Turkish women.

METHODS

In this cross-sectional study, 270 consecutive patients who were admitted to an outpatient clinic with vasomotor symptoms and/or at least 1 year of amenorrhea were included. The patients were categorized into three groups according to their blood pressure and metabolic status as follows: normotensive, hypertensive nondiabetics, and hypertensive diabetics. The T- and z-scores of the proximal femur and lumbar vertebrae were measured with the dual-energy X-ray absorptiometry method to assess the BMD of the study groups.

RESULTS

Lumbar vertebral T-scores (P<0.001), lumbar vertebral z-scores (P<0.003), and proximal femoral T-scores (P<0.001) were demonstrated to be significantly lower in the hypertensive diabetic group compared to the hypertensive nondiabetic and normotensive groups. Systolic blood pressure was significantly inversely correlated with lumbar vertebral T-scores (r=-0.382; P=0.001), lumbar vertebral z-scores (r=-0.290; P=0.001), and proximal femoral T-scores (r=-0.340; P=0.001). Moreover, diastolic blood pressure was significantly inversely correlated with lumbar vertebral T-scores (r=-0.318; P=0.001), lumbar vertebral z-scores (r=-0.340; P=0.001), and proximal femoral T-scores (r=-0.304; P=0.001). Hypertension (odds ratio [OR]: 2.541, 95% confidence interval [CI]: 1.46-3.48, P=0.003), diabetes mellitus (OR: 2.136, 95% CI: 1.254-3.678, P=0.006), and age (OR: 1.069, 95% CI: 1.007-1.163, P=0.022) were found to be significant independent predictors of osteopenia in a multivariate analysis, after adjusting for other risk parameters.

CONCLUSION

The present study is the first to evaluate the relationships between blood pressure, blood glucose, and BMD in postmenopausal Turkish women. Moreover, both hypertension and diabetes were demonstrated as significant independent predictors of osteopenia in postmenopausal Turkish women. Clinicians should be aware of the high risk of developing osteopenia in diabetic hypertensive postmenopausal women.

An update on diabetes related skeletal fragility

There are several mechanisms by which diabetes could affect bone mass and strength. These mechanisms include insulin deficiency; hyperglycemia; the accumulation of advanced glycation end products that may influence collagen characteristics; marrow adiposity and bone inflammation. Furthermore, associated diabetic complications and treatment with thaizolidinediones may also increase risk of fracturing. The following article provides its readers with an update on the latest information pertaining to diabetes related bone skeletal fragility. In the authors' opinion, future studies are needed in order to clarify the impact of different aspects of diabetes metabolism, glycemic control, and specific treatments for diabetes on bone. Given that dual energy x-ray absorptiometry is a poor predictor of bone morbidity in this group of patients, there is a need to explore novel approaches for assessing bone quality. It is important that we develop a better understanding of how diabetes affects bone in order to improve our ability to protect bone health and prevent fractures in the growing population of adults with diabetes.

Association between bone mineral density and type 1 diabetes mellitus: a meta-analysis of cross-sectional studies

A few studies have investigated the relationship between type 1 diabetes mellitus (T1DM) and bone mineral density (BMD) values. This meta-analysis was performed to explore differences between T1DM and healthy individuals in BMD values measured at five bone sites.We searched the database of PubMed for cross-sectional studies about the association of T1DM and BMD, and a meta-analysis was conducted.The results suggested significant association between T1DM and decreased BMD values of total body. The pooled mean differences (MDs) were -0.06 [95% confidence interval (CI): -0.11, -0.01] for all people. As for the association between T1DM and spine BMD values, the pooled MDs were -0.04 (95% CI: -0.07, -0.01) for males and -0.03 (95% CI: -0.06, 0.00) for females <20 years old. As for femur BMD values, the pooled MDs were -0.06 (95% CI: -0.13, 0.00) for all people, -0.03 (95% CI: -0.06, -0.01) for females and -0.04(95% CI: -0.05, -0.02) for males. As for hip BMD values, the pooled MDs were -0.06 (95% CI: -0.08, -0.04) for females. As for forearm BMD values, the pooled MDs were -0.01 (95% CI: -0.02, 0.00) for females.The results of this meta-analysis suggest the overall association between T1DM and reduced BMD values. Notably, the influence of T1DM on BMD seems to depend on gender or patient's age. Reduced BMD values may occur early after T1DM diagnosis. Future clinical and basic research studies are needed to further understand the mechanisms of decreased BMD values in T1DM patients.

Prevalence and determinants of osteoporosis in patients with type 1 and type 2 diabetes mellitus

BACKGROUND

Increased risk of osteoporosis and its clinical significance in patients with diabetes is controversial. We analyze osteoporosis prevalence and determinants of bone mineral density (BMD) in patients with type 1 and 2 diabetes.

METHODS

Three hundred and ninety-eight consecutive diabetic patients from a single outpatient clinic received a standardized questionnaire on osteoporosis risk factors, and were evaluated for diabetes-related complications, HbA1c levels, and lumbar spine (LS) and femoral neck (FN) BMD. Of these, 139 (71 men, 68 women) type 1 and 243 (115 men, 128 women) type 2 diabetes patients were included in the study. BMD (T-scores and values adjusted for age, BMI and duration of disease) was compared between patient groups and between patients with type 2 diabetes and population-based controls (255 men, 249 women).

RESULTS

For both genders, adjusted BMD was not different between the type 1 and type 2 diabetes groups but was higher in the type 2 group compared with controls (p < 0.0001). Osteoporosis prevalence (BMD T-score < -2.5 SD) at FN and LS was equivalent in the type 1 and type 2 diabetes groups, but lower in type 2 patients compared with controls (FN: 13.0% vs 21.2%, LS: 6.1% vs 14.9% men; FN: 21.9% vs 32.1%, LS: 9.4% vs 26.9% women). Osteoporosis prevalence was higher at FN-BMD than at LS-BMD. BMD was positively correlated with BMI and negatively correlated with age, but not correlated with diabetes-specific parameters (therapy, HbBA1c, micro- and macrovascular complications) in all subgroups. Fragility fracture prevalence was low (5.2%) and not different between diabetes groups. Fracture patients had lower BMDs compared with those without fractures; however, BMD T-score was above -2.5 SD in most patients.

CONCLUSIONS

Diabetes-specific parameters did not predict BMD. Fracture occurrence was similar in both diabetes groups and related to lower BMD, but seems unrelated to the threshold T-score, <-2.5 SD. These results suggest that osteoporosis, and related fractures, is a clinically significant and commonly underestimated problem in diabetes patients.

Type 1 diabetes and osteoporosis: A review of literature

With better care and intensive insulin therapy, microvascular complications have reduced and longevity has increased in patients with type 1 diabetes (T1DM). Therefore, there is a need to change the focus from microvascular complications to cardiovascular disease and osteoporosis. Though number of studies from other parts of the world show that patients with T1DM are at increased risk of osteoporosis and fractures, there is a paucity of data from India. A number of factors and mechanisms affecting bone health in patients with T1DM have been proposed. The main defect in genesis of osteoporosis is osteoblastic function, rather than osteoclastic overfunction. Assessment of bone mineral density by dual X-ray absorptiometry and other risk factors for osteoporosis, as a part of diagnostic procedure can help to design tailored treatment plans. A physically active healthy lifestyle, prevention of diabetic complications and adequate calcium and vitamin D supplementation are the mainstay for prevention of osteoporosis. Treatment of osteoporosis is not evidence based but it is proposed to be similar to osteoporosis associated with other conditions. Bisphosphonates are the mainstay for treatment of osteoporosis in patients with T1DM. However, more studies are needed to make definitive guidelines on prevention and treatment of osteoporosis in patients with T1DM.

The effect of diabetic neuropathy on foot bones: a systematic review and meta-analysis

AIMS

It is proposed that diabetic neuropathy may affect peripheral bone. Direct innervation of bone as well as neural control over its vascular supply and muscular influences may be affected by diabetes-induced peripheral neuropathies. Associated changes to bone may contribute to the occurrence of foot bone pathology in this population. This systematic review aims to examine the literature related to the effect of diabetic neuropathy on foot bones.

METHODS

Studies examining relationships between neuropathy and indicators of bone health (e.g. bone mineral density) in populations with diabetes were sought. Relevant publications were obtained from searches in MEDLINE, CINAHL and Embase in the period up to March 2013. Meta-analysis was performed using a random effects model in the statistical package Stata version 12.1.

RESULTS

Ten studies met the inclusion criteria and were included in the narrative synthesis. All studies were cross-sectional or case-control in design. Four of the 10 included studies found results indicating poorer bone health in those with diabetes and neuropathy compared with those with diabetes without neuropathy. Seven of the 10 studies were able to be included in a meta-analysis. The mean pooled effect was -0.36 (95% CI -0.76 to 0.04; P = 0.08), indicating a non-significant trend towards poorer bone health in those with diabetic neuropathy.

CONCLUSIONS

We did not find a significant relationship between presence of neuropathy in those with diabetes and poorer peripheral bone health. However, methodological limitations of the included studies mean further research is required to investigate this theoretical relationship.

A five-year prospective study of bone mineral density in men and women with diabetes: the Fremantle Diabetes Study

To examine longitudinally the effect of diabetes on bone structure and metabolism, we measured bone mineral density (BMD) and turnover markers in 26 type 1 (mean age 49 years) and 27 type 2 (mean age 65 years) diabetic patients without known osteoporosis from a community-based sample at baseline and 5 years later. In the 17 type 1 men, BMD fell at the femoral neck (0.804 ± 0.145 vs. 0.769 ± 0.129 g/cm(2); P = 0.003) with no change at lumbar spine or forearm. In the 11 type 2 women, BMD decreased at all sites except spine (femoral neck 0.779 ± 0.119 vs. 0.742 ± 0.090 g/cm(2); P = 0.019). BMD did not fall at any site in type 1 women or type 2 men. There was an increase in serum alkaline phosphatase and trend to higher serum beta carboxyl-terminal type I collagen telopeptide concentrations in the type 1 patients, and a decrease in free testosterone in the type 1 men. These data show that the rate of demineralization at the femoral neck in type 1 men is similar to that in older post-menopausal type 2 women. Changes in biochemical markers suggest that, in type 1 men, there is ineffective bone formation associated with accelerated bone resorption and lower sex steroid bioavailability. These findings may have implications for the clinical management of young male adults with diabetes.

Vitamin D receptor gene BsmI, FokI, ApaI, TaqI polymorphisms and bone mineral density in a group of Turkish type 1 diabetic patients

Previous studies have suggested an influence of vitamin D receptor alleles on bone metabolism and on susceptibility to type 1 diabetes mellitus in different ethnic populations. We aimed to investigate the distribution of vitamin D receptor (VDR) alleles in relation to biochemical bone turnover parameters and bone densitometry measurements in a group of Turkish type 1 diabetic patients. One hundred and seventeen patients (M/F 57/60, 27.6 ± 7.3 y duration of diabetes 8.1 ± 6.3 y) and 134 healthy controls (M/F 61/73, 26.2 ± 5.3 y) were included in the study. Bone mineral density (BMD) was evaluated by dual-energy X-ray absorptiometry (DEXA). The vitamin D receptor gene (VDR) polymorphisms FokI, Bsm1, Apa1, and Taq1 were examined using a PCR-based restriction analysis. Serum levels of calcium, phosphor osteocalcin, intact parathyroid hormone, and C telopeptide were measured. Vitamin D receptor Bsm1 Fok1, Apa1, and Taq1 genotype distributions were not different between patient with diabetes and control groups. BMD was 0.77 ± 0.2 g/cm(2) vs. 0.97 ± 0.2 g/cm(2) (P = 0.0001) for the femur, 1.0 ± 0.1 g/cm(2) vs. 1.13 ± 0.1 g/cm(2) (P = 0.001) for type 1 diabetic patients and controls. Bone turnover markers were significantly lower in type 1 diabetic group. BMD measurements and bone metabolic markers were not different between the genotypes in either the patient with diabetes or the controls. The VDR gene polymorphisms, Bsm1, Fok 1, Apa1, and Taq1 showed no influence on bone metabolism in our group of type 1 diabetic patients.

The bone marrow microenvironment contributes to type I diabetes induced osteoblast death

Type I diabetes increases an individual's risk for bone loss and fracture, predominantly through suppression of osteoblast activity (bone formation). During diabetes onset, levels of blood glucose and pro-inflammatory cytokines (including tumor necrosis factor α (TNFα)) increased. At the same time, levels of osteoblast markers are rapidly decreased and stay decreased chronically (i.e., 40 days later) at which point bone loss is clearly evident. We hypothesized that early bone marrow inflammation can promote osteoblast death and hence reduced osteoblast markers. Indeed, examination of type I diabetic mouse bones demonstrates a greater than twofold increase in osteoblast TUNEL staining and increased expression of pro-apoptotic factors. Osteoblast death was amplified in both pharmacologic and spontaneous diabetic mouse models. Given the known signaling and inter-relationships between marrow cells and osteoblasts, we examined the role of diabetic marrow in causing the osteoblast death. Co-culture studies demonstrate that compared to control marrow cells, diabetic bone marrow cells increase osteoblast (MC3T3 and bone marrow derived) caspase 3 activity and the ratio of Bax/Bcl-2 expression. Mouse blood glucose levels positively correlated with bone marrow induced osteoblast death and negatively correlated with osteocalcin expression in bone, suggesting a relationship between type I diabetes, bone marrow and osteoblast death. TNF expression was elevated in diabetic marrow (but not co-cultured osteoblasts); therefore, we treated co-cultures with TNFα neutralizing antibodies. The antibody protected osteoblasts from bone marrow induced death. Taken together, our findings implicate the bone marrow microenvironment and TNFα in mediating osteoblast death and contributing to type I diabetic bone loss.

Prevalence and predictors of osteopenia and osteoporosis in adults with Type 1 diabetes

AIMS

To determine the prevalence and biochemical/hormonal determinants of osteopenia and osteoporosis in adults with Type 1 diabetes.

METHODS

One hundred and two patients (52 female, 50 male) with Type 1 diabetes aged 20-71 years underwent cross-sectional assessment of biochemical/hormonal markers of bone metabolism, and bone mineral density (BMD) measurement at forearm, hip and spine using dual energy x-ray absorptiometry. BMD data were available for 102 age- and gender-matched population-based control subjects.

RESULTS

After adjusting for age and body mass index (BMI), osteopenia and osteoporosis were more common at the spine in males with Type 1 diabetes than in control subjects (P = 0.030). In Type 1 males, after adjustment for age and BMI, BMD, T- and Z-scores at the hip, femoral neck and spine were lower compared with age-matched control subjects (P < or = 0.048). Female Type 1 patients and control subjects had similar BMDs and T- and Z-scores at all sites. On multiple linear regression analysis, which adjusted for the natural logarithm of the sex hormone binding globulin concentration, smoking status and alcohol consumption, and (for women) menopausal status, each of BMI, serum ionized calcium and serum alkaline phosphatase (negatively) were independently associated with BMD at the hip and femoral neck in Type 1 diabetic subjects.

CONCLUSIONS

Adult males with Type 1 diabetes have reduced bone density at the hip, femoral neck and spine when compared with age-matched control subjects. Impaired bone formation may occur in Type 1 diabetes.

Young women with type 1 diabetes have lower bone mineral density that persists over time

OBJECTIVE

Individuals with type 1 diabetes have decreased bone mineral density (BMD), yet the natural history and pathogenesis of osteopenia are unclear. We have previously shown that women with type 1 diabetes (aged 13-35 years) have lower BMD than community age-matched nondiabetic control subjects. We here report 2-year follow-up BMD data in this cohort to determine the natural history of BMD in young women with and without diabetes.

RESEARCH DESIGN AND METHODS

BMD was measured by dual-energy X-ray absorptiometry at baseline and 2 years later in 63 women with type 1 diabetes and in 85 age-matched community control subjects. A1C, IGF-1, IGF binding protein-3, serum osteocalcin, and urine N-teleopeptide were measured at follow-up.

RESULTS

After adjusting for age, BMI, and oral contraceptive use, BMD at year 2 continued to be lower in women >or=20 years of age with type 1 diabetes compared with control subjects at the total hip, femoral neck, and whole body. Lower BMD values were observed in cases <20 years of age compared with control subjects; however, the differences were not statistically significant. Lower BMD did not correlate with diabetes control, growth factors, or metabolic bone markers.

CONCLUSIONS

This study confirms our previous findings that young women with type 1 diabetes have lower BMD than control subjects and that these differences persist over time, particularly in women >or=20 years of age. Persistence of low BMD as well as failure to accrue bone density after age 20 years may contribute to the increased incidence of osteoporotic hip fractures seen in postmenopausal women with type 1 diabetes.

Bone mineralization in young patients with type 1 diabetes mellitus and screening-identified evidence of celiac disease

The aims of this study were to evaluate bone mineral density (BMD) and bone turnover markers in patients with type 1 diabetes and screening-identified evidence of celiac disease, i.e., celiac autoimmunity. We screened 50 consecutive type 1 diabetic patients for IgA antitissue transglutaminase to identify those with celiac autoimmunity. Eight seropositive patients were identified on this screening, and 12 patients matched for gender and age range were selected as a control group from among the type 1 diabetic patients without celiac autoimmunity. Patients and controls underwent dual-energy X-ray absorptiometry (DEXA) for measurement of bone mineral status and had their blood levels of osteocalcin, carboxy-terminal telopeptide of type I collagen (CTX), calcium, and phosphorus determined. BMD was further adjusted for height, weight, and pubertal stage. Radiographic and blood markers of bone mineralization were compared between patients and controls. BMD (Z-score) at the lumbar spine was -1.44 +/- 0.5 SD for patients and 0.04 +/- 0.2 SD for controls (P = 0.02). Bone mineral content was 37.9 +/- 4.5 g for patients and 49.4 +/- 2.6 g for controls (P = 0.049). Adjusted BMD was -0.62 +/- 0.5 SD for patients and 0.81 +/- 0.09 SD for controls (P = 0.04). After adjustment, four patients and none of the controls presented BMD < -1 SD (P = 0.01). Osteocalcin, CTX, calcium, and phosphorus blood levels were not significantly different between patients and controls. Celiac autoimmunity is associated with reduced bone mineralization in type 1 diabetic patients. The pathophysiological mechanisms and clinical relevance of this finding remain to be further investigated.

Understanding the pathology and mechanisms of type I diabetic bone loss

Type I (T1) diabetes, also called insulin dependent diabetes mellitus (IDDM), is characterized by little or no insulin production and hyperglycemia. One of the less well known complications of T1-diabetes is bone loss which occurs in humans and animal models. This complication is receiving increased attention because T1-diabetics are living longer due to better therapeutics, and are faced with their existing health concerns being compounded by complications associated with aging, such as osteoporosis. Both male and female, endochondrial and intra-membranous, and axial and appendicular bones are susceptible to T1-diabetic bone loss. Exact mechanisms accounting for T1-diabetic bone loss are not known. Existing data indicate that the bone defect in T1-diabetes is anabolic rather than catabolic, suggesting that anabolic therapeutics may be more effective in preventing bone loss. Potential contributors to T1-diabetic suppression of bone formation are discussed in this review and include: increased marrow adiposity, hyperlipidemia, reduced insulin signaling, hyperglycemia, inflammation, altered adipokine and endocrine factors, increased cell death, and altered metabolism. Differences between T1-diabetic- and age-associated bone loss underlie the importance of condition specific, individualized treatments for osteoporosis. Optimizing therapies that prevent bone loss or restore bone density will allow T1-diabetic patients to live longer with strong healthy bones.

Osteoporosis among patients with type 1 and type 2 diabetes

Both diabetes and fractures are prevalent in adults. The relationship between diabetes and osteoporosis is complex and, although it has been investigated extensively, the subject remains controversial. While low bone mineral density (BMD) is consistently observed in type 1 diabetes, the relationship is less clear in type 2 diabetes, with some studies reporting modestly increased or unchanged BMD. Both type 1 and type 2 diabetes have been associated with a higher risk of fractures. Despite discrepancies between BMD and fracture rates, clinical trials uniformly support the fact that new bone formation and bone microarchitecture and, thus, bone quality, are altered in both types of diabetes. Although a causal association between diabetes and osteoporosis cannot be established on the basis of existing data, it is possible to conclude from many studies and from a better understanding of the physiopathology of diabetes that it can increase the risk of fractures through skeletal (decreased BMD and bone quality) and extraskeletal (increased risk of falls) factors. Even though osteoporosis screening or prophylactic treatment in all patients with type 1 and type 2 diabetes is not being recommended at present, such patient populations should be given general guidelines regarding calcium and vitamin D intakes, exercise and the avoidance of potential risk factors for osteoporosis. The extent of diagnostic and therapeutic interventions should be based on the individual's risk profile for fractures.

Osteoporosis in patients with diabetes mellitus

Demographic trends with longer life expectancy and a lifestyle characterized by low physical activity and high-energy food intake contribute to an increasing incidence of diabetes mellitus and osteoporosis. Diabetes mellitus is a risk factor for osteoporotic fractures. Patients with recent onset of type 1 diabetes mellitus may have impaired bone formation because of the absence of the anabolic effects of insulin and amylin, whereas in long-standing type 1 diabetes mellitus, vascular complications may account for low bone mass and increased fracture risk. Patients with type 2 diabetes mellitus display an increased fracture risk despite a higher BMD, which is mainly attributable to the increased risk of falling. Strategies to improve BMD and to prevent osteoporotic fractures in patients with type 1 diabetes mellitus may include optimal glycemic control and aggressive prevention and treatment of vascular complications. Patients with type 2 diabetes mellitus may additionally benefit from early visual assessment, regular exercise to improve muscle strength and balance, and specific measures for preventing falls.

Bone mineral density and hip structural analysis in type 1 diabetic men

OBJECTIVE

The risk of non-vertebral fractures is increased in men with type 1 diabetes (DM1) but studies have shown only moderately decreased or normal bone mineral density (BMD) in these patients. No previous studies have evaluated hip strength and geometry indices in DM1 patients. This study was therefore designed to characterize associations between BMD, dual X-ray absorptiometry (DXA)-based hip strength indices, metabolic control, and DM1chronic complications.

DESIGN AND METHODS

The study was performed on 36 males aged 43.6 +/- 5.1 years with long-lasting DM1 and 36 healthy males matched for age, weight, and height. BMD in lumbar spine, total hip, upper and lower part of the femoral neck, hip axis length, cross-sectional area and moment of inertia (CSMI), and glycated hemoglobin (HbA1c) were measured.

RESULTS

DM1 men had decreased spine BMD (P < 0.05) and normal total hip BMD in comparison with controls. Hip geometry and strength indices were comparable in both groups. However, M1 men had decreased CSMI and upper femur BMD but these differences did not reach statistical significance (P = 0.06). BMD changes and hip strength parameters did not correlate with HbA1c.

CONCLUSIONS

Middle-aged DM1 men have decreased lumbar spine BMD, normal hip BMD and normal hip strength indices. These changes are not influenced by metabolic control and presence of chronic microvascular complications.

Reduced peripheral nerve function is related to lower hip BMD and calcaneal QUS in older white and black adults: the Health, Aging, and Body Composition Study

Bone tissue is innervated, and peripheral nerve function may impact BMD. Older black and white men and women (N = 2200) in the Health, Aging, and Body Composition Study with worse sensory and motor peripheral nerve function had lower hip BMD and calcaneal BUA independent of lean mass, strength, physical ability, and diabetes. Poor peripheral nerve function may directly affect bone.

INTRODUCTION

Bone tissue is innervated, yet little is known about the impact of nerve function on BMD. Poor peripheral nerve function may contribute to lower BMD and higher fracture risk, particularly in those with diabetic neuropathy.

MATERIALS AND METHODS

The Health, Aging, and Body Composition (Health ABC) Study included annual exams in white and black men and women 70-79 years of age recruited from Pittsburgh and Memphis. Nerve function in legs/feet was assessed by 1.4- and 10-g monofilament detection, vibration threshold, and peroneal motor nerve conduction velocity (NCV) and amplitude (CMAP). Total hip BMD, heel broadband ultrasound attenuation (BUA), and total fat and lean mass were measured 1 year later (QDR 4500A, Sahara QUS; Hologic).

RESULTS

Participants (N = 2200) were 48% men and 37% black. Poor nerve function (lower monofilament detection, higher vibration threshold, lower CMAP, lower NCV) was associated with 1.4-5.7% lower BUA and significant for all but NCV, adjusted for demographics, diabetes, body composition, and physical ability. Results were similar for adjusted hip BMD, with 1.0-2.9% lower BMD, significant for monofilament and CMAP testing. When considering the components of BMD, total hip area was 1.8-4.9% higher in those with the worst nerve function, although BMC showed little difference. Lower monofilament detection and CMAP were independently associated with lower heel BUA (p < 0.01), and monofilament detection was associated with lower hip BMD (p < 0.05) in regression additionally adjusted for lifestyle factors, bone-active medications, and diabetes-related complications.

CONCLUSIONS

Poor peripheral nerve function may directly related to lower BMD, likely through an increase in bone area in older adults, independent of lean mass, strength, physical ability, and diabetes. Whether those with impaired nerve function are at higher risk for fracture independent of falls needs to be studied.

Middle-aged premenopausal women with type 1 diabetes have lower bone mineral density and calcaneal quantitative ultrasound than nondiabetic women

OBJECTIVE

To determine whether middle-aged premenopausal women with type 1 diabetes had more self-reported fractures and lower bone mineral density (BMD) compared with nondiabetic women.

RESEARCH DESIGN AND METHODS

Participants were premenopausal women aged 35-55 years with type 1 diabetes (n = 67; 32.2 +/- 5.3 years duration) and without diabetes (n = 237). Total hip, femoral neck, whole-body, and spine BMD were measured by dual X-ray absorptiometry. Calcaneal broadband ultrasound attenuation (BUA) was assessed with quantitative ultrasound.

RESULTS

Women with type 1 diabetes were more likely to report a fracture after age 20 years compared with nondiabetic women (33.3 vs. 22.6%; age-adjusted odds ratio 1.89 [95% CI 1.02-3.49]). Type 1 diabetes was associated with lower total hip BMD (0.890 vs. 0.961 g/cm2; P < 0.001), femoral neck BMD (0.797 vs. 0.847 g/cm2; P = 0.001), whole-body BMD (1.132 vs. 1.165 g/cm2; P < 0.01), and lower calcaneal BUA (71.6 vs. 84.9 dB/MHz; P < 0.001) after multivariate adjustment. BMD was 3-8% lower in type 1 diabetic compared with control women and calcaneal BUA was 15% lower. Spine BMD and biomarkers of bone remodeling were not significantly different between groups. In the type 1 diabetic women, reduced monofilament detection and blindness were both associated with lower BMD.

CONCLUSIONS

Lower BMD in premenopausal women with type 1 diabetes may substantially increase their risk of developing osteoporosis after menopause. Type 1 diabetic women should be targeted for osteoporosis screening and possible fracture prevention as they transition through menopause.

Is insulin an anabolic agent in bone? Dissecting the diabetic bone for clues

Diabetic osteoporosis is increasingly recognized as a significant comorbidity of type 1 diabetes mellitus. In contrast, type 2 diabetes mellitus is more commonly associated with modest increases in bone mineral density for age. Despite this dichotomy, clinical, in vivo, and in vitro data uniformly support the concept that new bone formation as well as bone microarchitectural integrity are altered in the diabetic state, leading to an increased risk for fragility fracture and inadequate bone regeneration following injury. In this review, we examine the contribution that insulin, as a potential anabolic agent in bone, may make to the pathophysiology of diabetic bone disease. Specifically, we have assimilated human and animal data examining the effects of endogenous insulin production, exogenous insulin administration, insulin sensitivity, and insulin signaling on bone. In so doing, we present evidence that insulin, acting as an anabolic agent in bone, can preserve and increase bone density and bone strength, presumably through direct and/or indirect effects on bone formation.

Bone mineral density in diabetic children and adolescents: a follow-up study

OBJECTIVE

To establish whether T1DM can affect bone mineral density (BMD) in children and adolescents.

RESEARCH DESIGN AND METHODS

We performed a cross-sectional and longitudinal study of 57 diabetic children and adolescents and 57 normal controls. Total body and lumbar BMD and bone mineral content (BMC) were assessed by DXA (Lunar DPX) and volumetric transformation was calculated using the Katzman formula for total body BMD (BMAD) and using the Kroger formula for Lumbar BMD (L2L4BMDvol). BMC, BMAD, BMDspine, and L2L4BMDvol were adjusted for confounding factors such as age, gender, BMI, height, weight, and pubertal stage.

RESULTS

BMDspine in the control group increased by 0.006 (g/cm(2))/year; while in the 39 diabetic patients longitudinally studied, it dropped by 0.006 (g/cm(2))/year during a follow-up period of 51 +/- 27 months. The average time spent weekly doing physical activity resulted in T1DM group directly correlated to BCM (P < 0.001) and inversely correlated with BMDspine (P < 0.05) and L2L4BMDvol (P < 0.01). L2L4BMDvol resulted significantly correlated with previous BMD spine (R = 0.63; P < 0.0001) and BMC evaluation (R = 0.42; P < 0.01) but not with BMAD. A second lumbar DXA evaluation performed in 38 patients after 1.00 +/- 0.16 years confirmed a small but significant decrease of 1.6% per year in L2L4BMDvol. The percentage of variation of L2L4BMDvol between the two evaluations was not correlated with the level of metabolic control, insulin requirement, and duration of the disease. Patients with complications showed similar L2L4BMDvol to patients without complications.

CONCLUSIONS

Diabetic children and adolescents show a slight negative pattern of spine mineralization, which does not depend on metabolic control and microvascular complications.

Body composition and bone mineral density in long-standing type 1 diabetes

OBJECTIVES

To study body composition and bone mineral density (BMD) in adult patients with long-standing type 1 diabetes mellitus.

RESEARCH DESIGN AND METHODS

In a population-based study, body composition and BMD were evaluated by dual energy X-ray absorptiometry in 38 patients with type 1 diabetes since childhood, compared with 38 age- and sex-matched controls. The mean age was 43 years (range 33-55 years) and the mean duration of diabetes was 33 years (range 28-37 years).

RESULTS

Besides a tendency to a reduced abdominal fat mass in diabetic males, no difference was observed in fat mass, muscle mass, or BMD between the groups. Significant correlations were found between insulin dosage and whole body fat mass in diabetic females and between serum cholesterol levels and abdominal fat mass in diabetic males.

CONCLUSION

Patients with long-standing type 1 diabetes with onset in childhood and adolescence seem to show only minor differences in body composition and no difference in BMD compared with closely matched healthy controls.