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

Assessment of body composition of adult Bulgarian patients with type 1 diabetes mellitus by bioelectrical impedance analysis

AIM

The aim of this study was to investigate how type 1 diabetes mellitus affects adult Bulgarians' body composition.

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.

Body Composition Characteristics of Type 1 Diabetes Children and Adolescents: A Hospital-Based Case-Control Study in Uganda

Background: Changes in body composition have been suggested as an intractable effect of Type 1 Diabetes Mellitus and its management. This study aims to compare body composition characteristics in a sample of young children and adolescents with Type 1 Diabetes Mellitus with healthy controls. Methods: In this case−control study, body composition was assessed using bioelectrical impedance among 328 participants. Anthropometric measurements included weight, height, upper arm, hip, and waist, circumferences; biceps; triceps; and subscapular and suprailiac skinfolds. From raw Bioelectrical impedance data, we calculated the impedance, phase angle, and height normalised resistance and reactance to assess body composition. Analysis of variance accounting for paired blocks was used to compare the two matched groups, while an independent Student’s t-test was used for intragroup comparisons among cases. Results: Waist Hip Ratio, biceps, triceps, subscapular and suprailiac skinfolds were higher among cases than in controls. Cases showed a higher Fat Mass Index, higher fasting blood glucose and higher glycated haemoglobin. Cases also had a higher mean value of resistance (p = 0.0133), and a lower mean value of reactance (p = 0.0329). Phase angle was lower among cases than in controls (p < 0.001). Conclusion: Our diabetic children showed higher levels of adiposity than controls. The observed differences in body composition are explained by differences in the fat-mass index. Abdominal fat accumulation was associated with poor glycaemic control and a lower phase angle.

Risk factors for fragility fractures in type 1 diabetes

OBJECTIVE

To determine clinical diabetes-related risk factors for fragility fractures in type 1 diabetes (T1D).

RESEARCH DESIGN AND METHODS

History of bone fragility fractures occurring after T1D diagnosis was assessed by questionnaire in this cross-sectional study in 600 T1D subjects. Glycated hemoglobin A1c (HbA1c) over the previous 5 years was used as an index of long-term glycemic control; complications were adjudicated by physician assessment. Multinomial logistic regression models were used to assess the associations between diabetes-related risk factors and fracture history.

RESULTS

One-hundred-eleven patients (18.5%) reported at least one fracture; of these 73.8% had only one and 26.2% had more than one fracture. Average age was 41.9 ± 12.8 years, with even gender distribution; disease duration was 19.9 ± 12.0 years; and BMI was 24.4 ± 3.7 kg/m². The 5-year average HbA1c was 7.6 ± 1.0% (60 mmol/mol). In adjusted models, reduced risk for 1 fracture was found in those with higher creatinine clearance rate (CCr) (RRR 0.22 [95% CI: 0.06-0.83] for 1 unit increase in lnCCr, p = 0.03) and increased risk in those with neuropathy (RRR 2.57 [1.21-5.46], p = 0.01). Increased risk for ≥2 fractures was found in subjects in the highest tertile of HbA1c (≥7.9%) compared with the lowest tertile (≤7.17%) (RRR 3.50 [1.04-11.7], p = 0.04) and of disease duration (≥26 years versus <14 years) (RRR 7.59 [1.60-35.98], p = 0.01).

CONCLUSIONS

Poor glycemic control and long exposure to the disease are independent diabetes-related risk factors for multiple bone fractures in T1D.

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.

The relationship between adiposity, bone density and microarchitecture is maintained in young women irrespective of diabetes status

BACKGROUND

The relationship between bone health and adiposity and how it may be affected in people with chronic metabolic conditions is complex.

METHODS

Seventeen women with type 1 diabetes mellitus (T1DM) and nine age-matched healthy women with a median age of 22.6 years (range, 17.4, 23.8) were studied by 3T MRI and MR spectroscopy to assess abdominal adiposity, tibial bone microarchitecture and vertebral bone marrow adiposity (BMA). Additional measures included DXA-based assessments of total body (TB), femoral neck (FN) and lumbar spine (LS) bone mineral density (BMD) and fat mass (FM).

RESULTS

Although women with T1DM had similar BMI and BMA to the controls, they had higher visceral and subcutaneous adiposity on MRI (P<.05) and total body FM by DXA (P=.03). Overall, in the whole cohort, a clear inverse association was evident between BMA and BMD at all sites (P<.05). These associations remained significant after adjusting for age, BMI, FM and abdominal adiposity. In addition, visceral adiposity, but not subcutaneous adiposity, showed a positive association with BMA (r, .4, P=.03), and a negative association with total body BMD (r, .5, P=.02). Apparent trabecular separation as assessed by MRI showed an inverse association to total body BMD by DXA (r, -.4, P=.04).

CONCLUSION

Irrespective of the presence of an underlying metabolic condition, young women display a negative relationship between MRI-measured BMA and DXA-based assessment of BMD. Furthermore, an association between BMA and visceral adiposity supports the notion of a common origin of these two fat depots.

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.

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.

Body fat measurement in adolescent girls with type 1 diabetes: a comparison of skinfold equations against dual-energy X-ray absorptiometry

Aim

Skinfold measurement is an inexpensive and widely used technique for assessing the percentage of body fat (%BF). This study assessed the accuracy of prediction equations for %BF based on skinfold measurements compared to dual‐energy X‐ray absorptiometry (DXA) in girls with type 1 diabetes and healthy age‐matched controls.

Methods

We included 49 healthy girls and 44 girls with diabetes aged 12–19 years old, comparing the predicted %BF based on skinfold measurements and the %BF values obtained by a Lunar DPX‐L scanner. The agreement between the methods was assessed using an Bland–Altman plot.

Results

The skinfold measurements were significantly higher in girls with diabetes (p = 0.003) despite a nonsignificant difference in total %BF (p = 0.1). A significant association between bias and %BF was found for all tested equations in the Bland–Altman plots. Regression analysis showed that the association between skinfold measurements and %BF measured by DXA differed significantly (p = 0.039) between the girls with diabetes and the healthy controls.

Conclusion

The accuracy of skinfold thickness equations for assessment of %BF in adolescent girls with diabetes is poor in comparison with DXA measurements as criterion. Our findings highlight the need for the development of new prediction equations for girls with type 1 diabetes.

Update on Bone Health in Pediatric Chronic Disease

Children and adolescents with chronic disease are predisposed to impaired bone health. Pediatric illness, including type 1 diabetes mellitus, celiac disease, and cystic fibrosis, have significant risk of low bone mineralization and fracture due to underlying inflammation, malabsorption, lack of physical activity, and delayed puberty. Dual-energy x-ray absorptiometry is the primary imaging method to assess bone health in this population. The purpose of this review is to update readers about the assessment and management of bone health in children with common pediatric chronic illnesses and review recent advances in the prevention and treatment of impaired bone health.

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.

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.

Bone Health in Type 1 Diabetes: Where We Are Now and How We Should Proceed

Type 1 diabetes (T1D) is autoimmune disease with chronic hyperglycaemic state. Besides diabetic retinopathy, nephropathy, and neuropathy, T1D is characterized by poor bone health. The reduced bone mineralization and quality/strength, due to hyperglycemia, hypoinsulinemia, autoimmune inflammation, low levels of insulin growth factor-1 (IGF-1), and vitamin D, lead to vertebral/hip fractures. Young age of T1D manifestation, chronic poor glycemic control, high daily insulin dose, low BMI, reduced renal function, and the presence of complications can be helpful in identifying T1D patients at risk of reduced bone mineral density. Although risk factors for fracture risk are still unknown, chronic poor glycemic control and presence of diabetic complications might raise the suspicion of elevated fracture risk in T1D. In the presence of the risk factors, the assessment of bone mineral density by dual-energy X-ray absorptiometry and the search of asymptomatic vertebral fracture by lateral X-ray radiography of thorax-lumbar spine should be recommended. The improvement of glycemic control may have a beneficial effect on bone in T1D. Several experiments showed promising results on using anabolic pharmacological agents (recombinant IGF-1 and parathyroid hormone) in diabetic rodents with bone disorder. Randomized clinical trials are needed in order to test the possible use of bone anabolic therapies in humans with T1D.

Physical activity level and body composition among adults with type 1 diabetes

AIMS

Physical activity is part of a healthy lifestyle and contributes to prevent weight gain and cardiometabolic disorders. Adults with Type 1 diabetes are at risk of weight gain attributable to various factors, including a high prevalence of sedentary lifestyle related to fear of exercise-induced hypoglycaemia. This project aims to observe the association between physical activity level and body composition in adults with Type 1 diabetes.

METHODS

Cross-sectional study; 75 adults with and 75 adults without diabetes (52% men; 41.8 ± 11.8 years old) wore a motion sensor for 1 week and performed a cardiorespiratory fitness test on an ergocycle (VO(2peak)). Body composition was assessed by dual energy X-ray absorptiometry and circumferences measures.

RESULTS

Mean body composition was not different between the two groups. VO(2peak) was lower among the group with diabetes than the control subjects (29.3 ± 9.2 vs. 33.5 ± 9.0 ml kg(-1) min(-1); P = 0.005), but their physical activity level (ratio total/resting energy expenditure) was similar (1.68 ± 0.37 vs. 1.65 ± 0.26; P = 0.572). In both groups, having an active lifestyle (physical activity level ≥ 1.7) compared with a more sedentary lifestyle (physical activity level < 1.7) was associated with lower BMI and percentage of total and truncal fat mass (P ≤ 0.030 to P ≤ 0.001). Among adults with diabetes, physical activity level was not associated with diabetes treatment (insulin doses) and control (HbA(1c) and hypoglycaemia) or cardiovascular risk factors (blood pressure and lipid profile).

CONCLUSION

As in the population without diabetes, an active lifestyle is associated with a better body composition profile in adults with Type 1 diabetes.

Sex differences in cardiovascular disease risk in adolescents with type 1 diabetes

BACKGROUND

Cardiovascular disease is seen at a younger age and at a higher prevalence in patients with type 1 diabetes than in the general population. It is well described that women with type 1 diabetes have a higher relative risk of cardiovascular disease than men with type 1 diabetes, unlike that seen in the general population. The pathophysiology behind this is unknown.

OBJECTIVE

We performed a cross-sectional study to examine sex differences in cardiovascular disease risk factors in adolescents with type 1 diabetes between ages 13 and 20 years, compared with children of a similar age without type 1 diabetes.

METHODS

All patients underwent a dual energy x-ray absorptiometry scan to measure body composition and a pulse wave test measure of arterial elasticity. Fasting serum lipid levels, apolipoprotein B, and apolipoprotein C-III levels were measured in each patient. Twenty-nine children with type 1 diabetes (10 girls, 19 boys) and 37 healthy children (18 girls, 19 boys) participated.

RESULTS

Although no sex differences for body mass index (P = 0.91) and glycosylated hemoglobin (P = 0.69) were seen, girls with type 1 diabetes had a significantly higher percent trunk fat compared with boys (P = 0.004). No sex differences were found (P > 0.05) for percent trunk fat in adolescents without diabetes. There was no sex difference among any other cardiovascular risk factors in either children with or without diabetes.

CONCLUSIONS

Female adolescents with type 1 diabetes have more centrally distributed fat, which may contribute to their relatively higher cardiovascular disease risk. Attenuation of the central distribution of fat through exercise and dietary modifications may help ameliorate their subsequent cardiovascular disease burden.

Quantitative ultrasound bone measurements in pre-pubertal children with type 1 diabetes

This case-control study aimed to assess bone status in children with type 1 diabetes mellitus (T1DM). Fifty-seven pre-pubertal patients (37 boys, aged 7.9 ± 2.5 years, T1DM duration 3.1 ± 1.6 years) and 171 age-matched healthy controls (111 boys) were studied. Quantitative ultrasound (QUS) was used to measure amplitude dependent speed of sound (Ad-SoS) at hand phalanges (expressed as standard deviation score [SDS]). Anthropometric and disease-related data (including mean HbA(1c) from whole T1DM duration [T], last year [Y], examination day [D]) were collected. Mean Ad-SoS SDS in patients -0.13 ± 1.32 (95% confidence interval [CI] -0.48, 0.22) was similar to that of controls. Subgroups discriminated according to HbA(1c) D, Y and T (cut-off 7.0%) did not differ regarding analyzed parameters. In patients, Ad-SoS SDS was comparable for both genders. Multivariable stepwise regression analysis showed significant negative influence of diabetes duration on Ad-SoS SDS. QUS findings in pre-pubertal children with T1DM do not differ from those in healthy children. Disease duration seems to affect negatively Ad-SoS SDS. However, independent prospective studies are needed to elucidate the true associations.

[Clinical practice guidelines for evaluation and treatment of osteoporosis associated to endocrine and nutritional conditions. Bone Metabolism Working Group of the Spanish Society of Endocrinology]

OBJECTIVE

To provide practical recommendations for evaluation and treatment of osteoporosis associated to endocrine diseases and nutritional conditions.

PARTICIPANTS

Members of the Bone Metabolism Working Group of the Spanish Society of Endocrinology, a methodologist, and a documentalist.

METHODS

Recommendations were formulated according to the GRADE system (Grading of Recommendations, Assessment, Development, and Evaluation) to describe both the strength of recommendations and the quality of evidence. A systematic search was made in MEDLINE (Pubmed), using the following terms associated to the name of each condition: AND "osteoporosis", "fractures", "bone mineral density", and "treatment". Papers in English with publication date before 18 October 2011 were included. Current evidence for each disease was reviewed by two group members, and doubts related to the review process or development of recommendations were resolved by the methodologist. Finally, recommendations were discussed in a meeting of the Working Group.

CONCLUSIONS

The document provides evidence-based practical recommendations for evaluation and management of endocrine and nutritional diseases associated to low bone mass or an increased risk of fracture. For each disease, the associated risk of low bone mass and fragility fractures is given, recommendations for bone mass assessment are provided, and treatment options that have shown to be effective for increasing bone mass and/or to decreasing fragility fractures are listed.

Hip strength in adults with type 1 diabetes is associated with age at onset of diabetes

We investigated the association of age at onset of type 1 diabetes with areal bone mineral density (aBMD), estimates of bone strength, and outer diameter. Using dual-energy X-ray absorptiometry (DXA), aBMD, axial strength (cross-sectional area [CSA]), bending strength (section modulus [SM]), and outer diameter at the narrow neck, intertrochanter, and shaft of the proximal femur were determined for 60 adults. Analysis of covariance (ANCOVA) was used to determine if the DXA-based measures of bone were related to age at onset and if this relationship differed by gender. Age at onset, gender, and the interaction of age at onset by gender were included in the ANCOVA models along with current age, duration, height, lean soft tissue mass, and hemoglobin A1c as covariates. In the adjusted models with CSA, SM, or outer diameter as the dependent variable, age at onset (p<0.01) and gender (p<0.0001) were significant with no interaction. For shaft aBMD, there was a significant age at onset by gender interaction (p=0.0285), where an earlier onset was associated with lower aBMD in the femoral shaft of females but not males. The findings suggest that an earlier onset of type 1 diabetes is associated with lower measures of bone strength and outer diameter.

Glycaemic control is positively associated with prevalent fractures but not with bone mineral density in patients with Type 1 diabetes

AIM

There are conflicting data regarding the risk of osteoporosis in patients with Type 1 diabetes. We investigated an association between diabetes, bone mineral density and prevalent fractures.

METHODS

A single-centre, cross-sectional study of men and pre-menopausal women with Type 1 diabetes (n = 128) and a matched control group (n = 77) was conducted. The primary outcome measure was bone mineral density and secondary measures were markers of bone metabolism and prevalent fractures.

RESULTS

Hip and total body bone mineral densities were significantly lower in women with diabetes compared with control subjects. In men, no difference in bone mineral density was found. A multivariate regression analysis in women with diabetes revealed higher BMI as the strongest predictor of higher total hip, femoral neck and total body bone mineral density, whereas previous fractures were inversely associated with total hip bone mineral density and C-terminal telopeptide of type I collagen with total body bone mineral density. Poor long-term glycaemic control was not associated with low bone mineral density. Fracture frequency was higher in patients with diabetes compared with control subjects (1.64 vs. 0.62 per 100 patient-years; P < 0.05). In a multivariable model, long-term HbA(1c) control was associated with increased clinical fracture prevalence (OR 1.92; 95% CI 1.09-2.75) in those with diabetes.

CONCLUSIONS

Type 1 diabetes contributes to low bone mineral density in women. Previous fractures and low BMI were strong predictors of impaired bone mineral density and should therefore be considered in risk estimation. Fractures are more frequent in Type 1 diabetes. Long-term hyperglycaemia may account for impaired bone strength, independently from bone mineral density.

Comparison of some of the physicochemical characteristics of type 2 diabetic and normal human bones: a sample study

AIM

The aim of this study was to compare some of the physicochemical characteristics of type 2 diabetic bones (DBs) and normal bones (NBs).

MATERIALS AND METHODS

The organic and inorganic parts of human NBs and DBs were separated using conventional methods, and their physicochemical characteristics were compared using infrared (IR) spectroscopy, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, thermogravimetric analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM).

RESULTS

The IR spectrum of the collagen part of DBs has showed the presence of carbonyl groups, indicating cross-linking in the α-chain. This was also confirmed by the increased thermal stability (22°C) in DB collagen. The XRD data of the inorganic part of DBs have revealed decreased crystallinity. SEM images of the inorganic part of DBs have shown a porous (weak) nature compared to those of NBs, which exhibited a compact (healthy) nature.

CONCLUSION

The cross-linking in DB collagen molecules and the decreased and defective crystallinity in the inorganic portion of DBs might be the reasons for the increased risk of fracture among diabetic patients.

Bone metabolic abnormalities associated with well-controlled type 1 diabetes (IDDM) in young adult women: a disease complication often ignored or neglected

OBJECTIVES

This investigation on a homogenous cohort of young adult Caucasian type 1 diabetic (IDDM) patients (1) aimed at studying the occurrence of low bone mineral density (BMD) at an early stage prior to menopause (i.e., during the first decade after peak bone mass) and (2) elucidating the possible mechanisms underlying IDDM-induced bone complication.

METHODS

Twenty-seven female patients with insulin-treated and well-controlled diabetes, without renal complications, and 32 well-matched healthy controls, aged between 30 and 40 years and fulfilling rigorous inclusion criteria to minimize bone-confounding factors, were enrolled. Areal BMD was evaluated by dual energy X-ray absorptiometry at axial (lumbar spine) and appendicular (femur) sites, using diagnostic WHO reference (T-scores). Osteoblast functions, bone metabolism, related key minerals, and 2 osteoclast-stimulating calciotropic hormones regulating their serum levels were assessed biochemically.

RESULTS

The number of cases with low BMD (T-score below -1.1 SD) was almost 2-fold greater (p < 0.01) in the IDDM group. BMD was significantly lower in this group for 3 lumbar sites (p < 0.01) and femur Ward's triangle (p < 0.05). Bone formation was reduced, as evidenced by the suppressions of osteocalcin (OC; p < 0.01) and IGF-I (p < 0.001). However, bone alkaline phosphatase (bALP) was induced (p < 0.01), in contrast to what is usually observed in cases of reduced bone formation. Correlated total ALP activity was also significantly increased. There was no change in the specific marker of bone resorption (urinary deoxypyridinoline). Serum calcium was significantly elevated, particularly after adjustment for albumin (p < 0.001), despite lower 1,25(OH)(2)D(3) (p < 0.001) and no elevation of PTH. All significant bone-related biochemical changes were significantly correlated with glycosylated hemoglobin, a clinical indicator of long-term glycemic control, indicating a direct effect of the disease.

CONCLUSIONS

Bone loss in the IDDM group results from a decrease in bone formation rather than an increase of bone resorption. The induction of bALP is indicative of impaired osteoblast differentiation and maturation, which delayed (down-regulated) later stages of matrix mineralization, as evidenced by lower OC and BMD.

Bone status in adolescents with type 1 diabetes

AIMS

The aim of the study was to investigate the potential negative impact of type 1 diabetes on bone status of adolescents. Bone status in adolescents with type 1 diabetes was assessed by means of quantitative ultrasound (QUS) and the influence of metabolic control and other disease-related and growth variables was analysed.

METHODS

Group I consisted of 99 pubertal (Tanner > or = 2) adolescents (49 female), aged 14.3 +/- 2.5 years, diabetes duration 4.6 +/- 2.3 years. Controls (group II) were 297 children, matched by sex and age, from a healthy population. The influence of glycated haemoglobin (current: HbA(1c)D; last year's mean: HbA(1c)Y; whole duration mean: HbA(1c)T), diabetes duration, percentage of life with disease and daily insulin requirement (DIR) on amplitude dependent speed of sound (Ad-SoS) at distal phalanges was studied.

RESULTS

In comparison to the control group, adolescents with type 1 diabetes presented significantly higher BMI SDS (0.82 [95% CI 0.54, 1.10] vs -0.06 [95% CI -0.16, 0.04] p < 0.001) and lower Ad-SoS SDS (-0.34 [95% CI -0.57, -0.11] vs -0.03 [95% CI -0.15, 0.08], p < 0.05). No correlation between Ad-SoS SDS and sex, DIR or diabetes duration was observed. The lower Ad-SoS SDS reflects reduced bone status, and the reduction was significantly more marked in those patients whose HbA(1c)T was higher than 7.0% when compared with those whose HbA(1c)T was lower.

CONCLUSIONS

Bone status of adolescents with type 1 diabetes mellitus assessed with QUS differs from that of healthy peers and is dependent on long-term metabolic control.

Diabetes and osteoporosis

Care of patients with diabetes should include assessment of bone health. The extension of the average life expectancy of people with diabetes, which has accompanied improvements in medical care, has also increased the significance of osteoporosis. In addition to the usual causes of osteoporosis associated with aging, bone health is also compromised by diabetes. Studies on bone involvement in patients with diabetes mellitus have generated conflicting results, largely because of the pathogenetic complexity of the condition. It is now clear that patients with type 1 diabetes have lower bone mineral density (BMD) and a higher risk of fractures. Evidence is emerging that patients with type 2 diabetes who have complications are also at increased risk of certain types of osteoporotic fractures, despite having a higher BMD when compared to patients with type 1 diabetes. Although many factors, including number and type of falls, visual impairment, neuropathy, and reduced muscle strength, influence the probability of fractures, the most significant factor seems to be the strength of the bone itself. Thus, sarcopenia, a reduction in muscle mass and muscle strength, is considered one of the main determinants of bone fragility. The aim of this review is to examine the occurrence of osteoporosis in type 1 and type 2 diabetes.

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.

Discrepancies in bone mineral density and fracture risk in patients with type 1 and type 2 diabetes--a meta-analysis

INTRODUCTION AND HYPOTHESIS

Diabetes affects bone metabolism. The hypothesis was that type 1 (T1D) and type 2 (T2D) affects BMD and fracture risk differently.

MATERIAL AND METHODS

Pubmed, Embase, and Web of Science were searched using the terms "diabetes", "fracture", and "bone mineral".

RESULTS

Hip fracture risk was increased in T1D (RR = 6.94, 95% CI: 3.25-14.78, five studies) and T2D (1.38, 95% CI: 1.25-1.53, eight studies) compared to subjects without diabetes. The increase in relative hip fracture risk was significantly higher in T1D than in T2D. BMD Z-score was decreased in the spine (mean +/- SEM -0.22 +/- 0.01) and hip (-0.37 +/- 0.16) in T1D and increased in the spine (0.41 +/- 0.01) and hip (0.27 +/- 0.01) in T2D. A meta-regression showed that body mass index (BMI) was a major determinant for BMD in both the spine and hip. Glycated haemoglobin (HbA1C) was not linked to BMD. The increase in fracture risk was higher and BMD lower in patients with complications to diabetes.

CONCLUSIONS

Hip fracture risk is increased in both T1D and T2D, whereas BMD is increased in T2D and decreased in T1D. A common factor such as complications may explain the increase in fracture risk, whereas BMI may ameliorate the increase in fracture risk in T2D.

Bone density and markers of bone remodeling in type 1 male diabetic patients

AIMS

To assess the prevalence and severity of bone disease in type 1 diabetic patients and to determine serum markers of bone remodeling as well as their relationship with bone mineral density (BMD).

METHODS

BMD [by dual energy x-ray absorptiometry (DXA)] and serum markers of bone remodeling [osteocalcin, c-terminal telopeptide of type I collagen (CTX)], leptin and osteoprotegerin (OPG) were measured in 42 adult males with type 1 diabetes. Twenty-four non-diabetic subjects served as controls.

RESULTS

In 40% of the patients, osteopenia at the lumbar spine (L1-L4) and/or at the left hip was found, and 7% met criteria for osteoporosis. L1-L4 BMD z-score was correlated with age (r=0.365, P=0.018) and a similar trend was observed at left hip. L1-L4 BMD z-score was negatively correlated with CTX and osteocalcin (r=-0.343, P=0.028; r=-0.376, P=0.024, respectively). A significant correlation was evidenced between BMD z-score at both lumbar spine and left hip and leptin values (r=0.343, P=0.03; r=0.395, P=0.012, respectively) but after adjustment for weight this correlation was no longer significant. Osteocalcin, CTX and leptin concentrations were comparable between patients and controls, while OPG concentrations tend to be higher in diabetic subjects (P=0.08). CTX was negatively correlated with age (r=-0.390, P=0.012) and positively correlated with osteocalcin (r=0.696, P<0.001). OPG was positively correlated with age (r=0.507, P=0.001).

CONCLUSION

Our results suggest that in diabetic subjects osteopenia is a relatively frequent complication but bone loss is attenuated with age progression. Whether this is also mediated by OPG and/or leptin remains to be confirmed.

Leptin levels and body composition in children and adolescents with type 1 diabetes

The purpose of this study was to determine the relationship between serum leptin levels and body composition and to evaluate the variables related to disease in children and adolescents with type 1 diabetes. We studied 49 diabetic patients aged 6-16 years (age: 11.2+/-2.9 years, M/F: 26/23), and 37 healthy controls. Body composition was determined by dual-energy X-ray absorptiometry. Serum leptin, glycated hemoglobin (HbA1c), free thyroxin, thyrotropin, testosterone and estradiol levels were measured in patients and controls. We did not observe significant difference in serum leptin levels between patients and controls. Girls had significantly higher serum leptin levels than boys in both patient and control groups. Serum leptin levels did not correlate significantly with HbA1c, disease duration or daily insulin dose but, correlated positively with body mass index (BMI) and fat mass (FM) in patients as in controls. Body composition in diabetic girls and boys was similar with respective controls. When analyzed by pubertal stage, BMI, lean body mass (LBM), FM, and total bone mineral density (BMD) were significantly higher in pubertal girls with type 1 diabetes compared to prepubertal ones. In pubertal boys with type 1 diabetes, LBM and FM were significantly higher than prepubertal ones. The results of the present study showed that neither serum leptin levels nor body composition was significantly altered in children and adolescents with type 1 diabetes managed with intensive insulin therapy.

Bone mineral density and alterations of bone metabolism in children and adolescents with type 1 diabetes mellitus

OBJECTIVES

To analysis bone mineral density (BMD) and bone turnover markers in children and adolescents with type 1 diabetes mellitus (DM1) and to establish possible correlations with duration of the disease and degree of metabolic control.

PATIENTS AND METHODS

Fifty-eight (26 prepubertal, 32 pubertal) children (29 boys) with DM1 (age: 11.7 +/- 3.1 years) and 44 (20 prepubertal, 24 pubertal) healthy children (21 boys) as controls (age: 10.8 +/- 3.2 years) were included in the study. BMD was measured by dual energy X-ray absorptiometry (DEXA). Scans of the lumbar spine (LS2-4) and femoral neck (FN) were carried out. Serum levels of osteocalcin, amino-terminal propeptide of type I procollagen (PINP), and alkaline phosphatase, as markers of bone formation, and urinary calcium/creatinine (Ca/Cr) ratio and levels of N-telopeptide (Ntx), as markers of bone resorption, were assessed. Anthropometrics, duration of DM1, presence of complications, insulin dose, and degree of metabolic control were obtained from the patients' records.

RESULTS

In children with DM1 and controls, the mean measurements of LS2-4 BMD were 0.698 +/- 0.178 g/cm2 and 0.669 +/- 0.192 g/cm2, respectively (p >0.05), and FN-BMD measurements were 0.743 +/- 0.147 g/cm2 and 0.744 +/- 0.170 g/cm2, respectively (p >0.05). Children with DM1 had lower serum levels of calcium, intact parathyroid hormone, osteocalcin and PINP, and higher serum levels of 25-hydroxyvitamin D and urinary Ca/Cr (p <0.05). BMD was not related to any of the markers of bone resorption or formation, duration of the disease, or degree of metabolic control.

CONCLUSIONS

Although we did not establish decreased LS2-4 and FN-BMD measurements in patients with DM1, we found reduced bone formation and increased bone resorption markers in children with DM1. Measurements of serum osteocalcin, PINP, urinary Ntx and Ca/Cr might be useful for long-term follow-up in children and adolescents with DM1.

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.