Evaluation of bone mineral density in children with diabetes mellitus

Osteocalcin serum concentrations and markers of energetic metabolism in pediatric patients. Systematic review and metanalysis

Background

Osteocalcin plays a role in glucose metabolism in mice, but its relevance in human energetic metabolism is controversial. Its relationship with markers of energetic metabolism in the pediatric population has not been systematically addressed in infants and adolescents.

Objective

This study aims to assess the mean differences between tOC, ucOC, and cOC among healthy children and children with type 1 or type 2 diabetes (T1D or T2D) and the correlation of these bone molecules with metabolic markers.

Methods

A systematic review and metanalysis were performed following PRISMA criteria to identify relevant observational studies published in English and Spanish using PubMed, Scopus, EBSCO, and Web of Science databases. The risk of bias was assessed using New Castle-Ottawa scale. Effect size measures comprised standardized mean difference (SMD) and Pearson correlations. Heterogeneity and meta-regressions were performed.

Results

The 20 studies included were of high quality and comprised 3,000 pediatric patients who underwent tOC, cOC, or ucOC measurements. Among healthy subjects, there was a positive correlation of ucOC with WC and weight, a positive correlation of tOC with FPG, HDL-c, WC, height, and weight, and a negative correlation between tOC and HbA1c. Among diabetic subjects, a negative correlation of ucOC with HbA1c and glycemia in both T1D and T2D was found and a negative correlation between tOC and HbA1c in T1D but not in T2D. The ucOC concentrations were lower in T2D, T1D, and patients with abnormal glucose status than among controls. The serum concentrations of tOC concentrations were lower among T1D than in controls. The patient's age, altitude, and HbA1c influenced the levels of serum tOC.

Conclusion

Osteocalcin is involved in energy metabolism in pediatric subjects because it is consistently related to metabolic and anthropometric parameters.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42019138283.

Decreased markers of bone turnover in children and adolescents with type 1 diabetes

BACKGROUND AND AIM

Adults with type 1 diabetes (T1D) have increased risk of bone fractures and decreased bone mineral density (BMD). Alterations in bone turnover have been suggested as the link between T1D and the impaired bone health. Furthermore, bone turnover has been suggested to have beneficial effects on glucose metabolism. This study aimed at describing bone turnover markers (BTM), and the relationship with glycemic control, in children and adolescents with T1D.

METHODS

A total of 173 (47% girls) children and adolescents aged 7.7 to 17.5 years with T1D for more than 1 year were included. Participants were evaluated by BMD together with measurements of selected BTM; two formation markers: osteocalcin (OCN) and procollagen type-1 amino-terminal propeptide (P1NP) and one resorption marker, C-terminal cross-linked telopeptide of type-1 collagen (CTX). BTM were converted into Z-scores utilizing new national references.

RESULTS

Mean OCN Z-score (-0.68 ± 1.31), P1NP Z-score (-0.33 ± 1.03) and CTX Z-score (-0.43 ± 1.10) were all significantly lower than the reference population (P < .001). No associations were seen between BTM and T1D duration. BMD Z-score was comparable to the reference population and associated with none of individual BTMs. CTX Z-score was negatively associated with HbA1c (P = .007) independent of both exogenous and residual endogenous insulin.

CONCLUSIONS

Markers of bone formation and resorption were decreased in children and adolescents with T1D. CTX Z-score associated negatively with HbA1c adjusted for insulin treatment and endogenous insulin production indicating a potential association between CTX and insulin sensitivity. The long-term consequences of decreased BTM on BMD need further attention.

Unaffected bone mineral density in Danish children and adolescents with type 1 diabetes

AIMS

Adults with type 1 diabetes mellitus (T1D) have decreased bone mineral density (BMD). Our study aimed at determining BMD and the association to metabolic control in children and adolescents with T1D.

METHODS

244 patients (113 girls) with a median age of 14.3 years and T1D duration of 1-16 years were included. A dual-energy X-ray absorptiometry scan assessed BMD Z-scores excluding the head (total body less head, TBLH). TBLH-BMD were then investigated for associations to diabetes relevant variables such as HbA1c, insulin treatment, anthropometry and physical activity.

RESULTS

In all participants the TBLH-BMD Z-score (0.22 ± 0.96) was significantly higher than the references. Separated by sex, TBLH-BMD Z-score in boys (0.11 ± 0.84) was no different from healthy peers whereas TBLH-BMD Z-score was significantly higher in girls (0.36 ± 1.09). The higher TBLH-BMD Z-score in girls were explained by higher BMI Z-scores. Participants with assumed final height (based on age) had an average TBLH-BMD Z-score of 0.78 ± 1.06, significantly higher than references independent of gender, HbA1c, height- and weight Z-scores. Multiple regression analyses showed that TBLH BMD Z-score associated negatively to HbA1c (P = 0.003), pump treatment (P = 0.019) and screen-time (P = 0.005) and positively to weight Z-score (P < 0.001). Physical activity, sex and puberty did not significantly associate to TBLH-BMD Z-score.

CONCLUSION

Unlike adults with T1D, BMD is not decreased in children and adolescents with T1D and even elevated after attained final height. As HbA1c negatively associates to BMD, decreased BMD may progress over time. Whether changes in microarchitecture or bone metabolism precede changes in BMD needs further investigation.

Bone turnover markers in children and adolescents with type 1 diabetes-A systematic review

Type 1 diabetes (T1D) is associated with impaired bone health and both osteocalcin (OCN) and procollagen type 1 amino terminal propetide (P1NP) (markers of bone formation) and C-terminal cross-linked telopeptide (CTX) (marker of bone resorption) are decreased in adult patients with T1D. We review the existing literature characterizing these bone turnover markers in children and adolescents with T1D and by meta-analysis examine whether alterations in OCN, P1NP, and CTX are evident and if potential changes correlate to the metabolic control (hemoglobin A1c, HbA1c). Systematic searches at MEDLINE and EMBASE were conducted in January 2018 identifying all studies describing OCN, P1NP, or CTX in children and adolescents with T1D. A total of 26 studies were included, representing data from more than 1000 patients with T1D. Pooled analyses of standard mean difference and summary effects analysis were performed when sufficient data were available. Pooled analysis revealed mean OCN to be significantly lower in children and adolescents with T1D compared to healthy controls (standard mean difference: -1.87, 95% confidence interval, CI: -2.83; -0.91) whereas both P1NP and CTX did not differ from the controls. Only data on OCN was sufficient to make pooled correlation analysis revealing a negative correlation between OCN and HbA1c (-0.31 95% CI: -0.45; -0.16). In conclusion, OCN is decreased in children and adolescents with T1D, whether CTX and P1NP are affected as well is unclear, due to very limited data available. New and large studies including OCN, P1NP, and CTX (preferably as z-scores adjusting for age variability) is needed to further elucidate the status of bone turnover in children and adolescents with T1D.

Association between metabolic syndrome and bone mineral density in a Taiwanese elderly population

Previous studies have demonstrated uncertainty regarding the effect of metabolic syndrome (MetS) on bone. In the present work, we investigated the association between MetS, its components, and decreased bone mineral density (BMD) in a cross-sectional study of patients who underwent BMD measurement by dual-energy X-ray absorptiometry during a health examination. Decreased BMD was defined as either osteopenia or osteoporosis. MetS components and body mass index (BMI) were compared between individuals with normal and decreased BMD, and simple and multivariate logistic regression analyses were used to evaluate the association between the variables and decreased BMD in women and men. Among 1162 subjects in the study, the mean age was 59.9 ± 7.3 years, and 59.5% were men. The prevalence of MetS and osteoporosis was 34.2 and 19.6%, respectively. MetS was positively associated with BMD in men, while in women it was negatively associated with BMD. Regarding the relationship between MetS components and BMD, we found that in women, waist circumference (WC) and systolic and diastolic blood pressure were negatively associated with BMD, while high-density lipoprotein cholesterol (HDL-C) was positively associated. In men, WC and fasting glucose were positively associated with BMD, while HDL-C was negatively associated. We also found that an increase in the number of MetS components resulted in a significantly increased positive association with BMD, both before and after adjusting for age, in men but not in women, revealing a gender difference in the correlation between MetS components and BMD.

Higher levels of s-RANKL and osteoprotegerin in children and adolescents with type 1 diabetes mellitus may indicate increased osteoclast signaling and predisposition to lower bone mass: a multivariate cross-sectional analysis

Simultaneous lower bone mineral density, metabolic bone markers, parathyroid hormone (PTH), magnesium, insulin-like growth factor 1 (IGF1), and higher levels of total soluble receptor activator of nuclear factor-kappa B ligand (s-RANKL), osteoprotegerin (OPG), and alkaline phosphatase (ALP) are indicative of lower osteoblast and increased osteoclast signaling in children and adolescents with type 1 diabetes mellitus, predisposing to adult osteopenia and osteoporosis.

INTRODUCTION

Type 1 diabetes mellitus (T1DM) is a risk factor for reduced bone mass, disrupting several bone metabolic pathways. We aimed at identifying association patterns between bone metabolic markers, particularly OPG, s-RANKL, and bone mineral density (BMD) in T1DM children and adolescents, in order to study possible underlying pathophysiologic mechanisms of bone loss.

METHODS

We evaluated 40 children and adolescents with T1DM (mean ± SD age 13.04 ± 3.53 years, T1DM duration 5.15 ± 3.33 years) and 40 healthy age- and gender-matched controls (aged12.99 ± 3.3 years). OPG, s-RANKL, osteocalcin, C-telopeptide cross-links (CTX), IGF1, electrolytes, PTH, and total 25(OH)D were measured, and total body along with lumbar spine BMD were evaluated with dual energy X-ray absorptiometry (DXA). Multivariate regression and factor analysis were performed after classic inference.

RESULTS

Patients had significantly lower BMD, with lower bone turnover markers, PTH, magnesium, and IGF1 than controls, indicating lower osteoblast signaling. Higher levels of total s-RANKL, OPG, and total ALP were observed in patients, with log(s-RANKL) and OPG correlation found only in controls, possibly indicating increased osteoclast signaling in patients. Coupling of bone resorption and formation was observed in both groups. Multivariate regression confirmed simultaneous lower bone turnover, IGF1, magnesium, and higher total s-RANKL, OPG, and ALP in patients, while factor analysis indicated possible activation of RANK/RANKL/OPG system in patients and its association with magnesium and IGF1. Patients with longer disease duration or worse metabolic control had lower BMD.

CONCLUSIONS

T1DM children and adolescents have impaired bone metabolism which seems to be multifactorial. Reduced osteoblast and increased osteoclast signaling, resulting from multiple simultaneous disturbances, could lead to reduced peak bone accrual in early adulthood, predisposing to adult osteopenia and osteoporosis.

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

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

IGF-1 and IGF-binding proteins and bone mass, geometry, and strength: relation to metabolic control in adolescent girls with type 1 diabetes

Children and adolescents with poorly controlled type 1 diabetes mellitus (T1DM) are at risk for decreased bone mass. Growth hormone (GH) and its mediator, IGF-1, promote skeletal growth. Recent observations have suggested that children and adolescents with T1DM are at risk for decreased bone mineral acquisition. We examined the relationships between metabolic control, IGF-1 and its binding proteins (IGFBP-1, -3, -5), and bone mass in T1DM in adolescent girls 12-15 yr of age with T1DM (n = 11) and matched controls (n = 10). Subjects were admitted overnight and given a standardized diet. Periodic blood samples were obtained, and bone measurements were performed. Serum GH, IGFBP-1 and -5, glycosylated hemoglobin (HbA(1c)), glucose, and urine magnesium levels were higher and IGF-1 values were lower in T1DM compared with controls (p < 0.05). Whole body BMC/bone area (BA), femoral neck areal BMD (aBMD) and bone mineral apparent density (BMAD), and tibia cortical BMC were lower in T1DM (p < 0.05). Poor diabetes control predicted lower IGF-1 (r(2) = 0.21) and greater IGFBP-1 (r(2) = 0.39), IGFBP-5 (r(2) = 0.38), and bone-specific alkaline phosphatase (BALP; r(2) = 0.41, p < 0.05). Higher urine magnesium excretion predicted an overall shorter, lighter skeleton, and lower tibia cortical bone size, mineral, and density (r(2) = 0.44-0.75, p < 0.05). In the T1DM cohort, earlier age at diagnosis was predictive of lower IGF-1, higher urine magnesium excretion, and lighter, thinner cortical bone (r(2) >or=0.45, p < 0.01). We conclude that poor metabolic control alters the GH/IGF-1 axis, whereas greater urine magnesium excretion may reflect subtle changes in renal function and/or glucosuria leading to altered bone size and density in adolescent girls with T1DM.

[Evolution of bone mass in children and adolescents with type 1 diabetes mellitus]

BACKGROUND AND OBJECTIVE

There is some controversy over bone mineral density (BMD) in children and teenagers with type 1 diabetes mellitus (DM1). We evaluated BMD by dual-energy X-ray absorptiometry (DXA) and correlated it with anthropometric, biochemical and hormonal parameters related to bone metabolism.

PATIENTS AND METHOD

Sixty-six patients with DM1 (26 males and 40 females) aged between 3 and 17 years, and 327 controls with a similar age were studied.

RESULTS

The BMD of all diabetic patients was not different from that of the controls. However, the subgroup of older males (between 15 and 17 years) had a significantly inferior BMD than controls of the same age: mean (standard deviation), 0.888 (0.13) versus 0.994 (0.11) (p = 0.027). BMD was inferior to -1 standard deviation (Z-score) in 21.2% of diabetic children. All the biochemical and hormonal parameters were within the normality rank. There was a negative correlation between the evolution time of the disease and the levels of 25-hydroxycholecalciferol (r = -0.345; p = 0.006). We did not observe any correlation between BMD and the remaining studied parameters.

CONCLUSIONS

These results confirm that initially children and adolescents with non-complicated DM1 have no alteration of the bone mass. Yet the BMD physiological increase is smaller in the diabetic population than in controls during the adolescence period, which may cause a lower peak of bone mass in these patients.

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.

Role of hemoglobin A(1c), duration and puberty on bone mineral density in diabetic children

BACKGROUND

The aim of the present was to determine bone mineral density (BMD) in type 1 diabetic children and the roles of hemoglobin A(1c), disease duration and pubertal stage on BMD changes.

METHODS

Fifty-eight patients were investigated: 16 had been newly diagnosed (Diabetes(New)) and 42 were already on follow up (Diabetes(Follow up)). BMD of the lumbar vertebrae, HbA1c(HbA1c(last)), Ca, P, Mg were measured. Mean HbA1c of the previous year (HbA1c(1year)), the whole duration of diabetes (HbA1c(whole)), and diabetic impact index (HbA1c(whole) x diabetes duration) were calculated in the Diabetes(Follow up) group.

RESULTS

Mean BMD-Z score (-0.61 +/- 0.99 g/cm(2)) of the whole group was significantly lower than zero. Osteopenia was present in 14 (24.1%), and osteoporosis in three (5.2%). HbA1c(whole) was the most important determinant effecting BMD-Z (r = -0.35, P < 0.05) with the cut-off for osteopenia and osteoporosis being 9.8% and 12.1%, respectively. The cut-off of diabetes duration for osteopenia was 3.6 years and it was more predictive for osteopenia compared to HbA1c(whole). In the Diabetes(New) group, the BMD-Z score of the early pubertal group was significantly lower than those in other pubertal groups.

CONCLUSION

BMD is affected in diabetic children, and HbA1c(whole) and diabetes duration are the most important determinants. Pubertal stage is another determinant of BMD, especially in newly diagnosed patients.

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.

Lower bone mineral content in children with type 1 diabetes mellitus is linked to female sex, low insulin-like growth factor type I levels, and high insulin requirement

CONTEXT

Studies on bone mineral characteristics in children with type 1 diabetes mellitus (T1DM) have generated conflicting results.

OBJECTIVE

Our objective was to investigate bone mineral characteristics in children with T1DM and to analyze their associations with bone metabolism and the IGF-I system.

DESIGN

We recruited a cohort of Caucasian patients with T1DM for at least 3 yr and healthy children between January 2003 and June 2004.

SETTING

This was a university hospital-based study.

PARTICIPANTS

A total of 127 patients and 319 controls aged 6 to 20 yr participated.

METHODS

Dual-energy x-ray absorptiometry was performed in patients and controls. Serum bone alkaline phosphatase, CrossLaps, IGF-I, and IGF-binding protein 3 levels were determined in patients with values analyzed using our normative data from 1150 healthy children.

RESULTS

After adjustment for age, sex, pubertal stage, and body mass index sd score, total body bone mineral content (BMC)/lean body mass was significantly lower in patients than in controls (P < 0.04). This difference was a result of the differences between the girls of the two groups. Girls with T1DM had significantly lower lumbar spine and total body BMC than control girls (P = 0.002), whereas no such difference was observed in boys. Serum bone alkaline phosphatase level was significantly lower in girls than in boys (P = 0.04). Low serum IGF-I levels and the administration of large amounts of insulin were found to have independent deleterious effects on BMC for children of all ages and both sexes, whereas disease duration and glycosylated hemoglobin levels did not.

CONCLUSIONS

A sex-related difference in the impairment of bone mineral characteristics was identified in children with T1DM. Longitudinal studies are required to investigate whether boys may gain slightly less bone mass during skeletal growth.

Early manifestation of type 1 diabetes in children is a risk factor for changed bone geometry: data using peripheral quantitative computed tomography

OBJECTIVE

Normal to severely decreased bone mineral density has been reported in children with type 1 diabetes. To detect possible abnormalities in bone mineralization, geometry, and muscle bone unit, we measured selective parameters in children with type 1 diabetes using peripheral quantitative computed tomography.

METHODS

Measurements of the radius by peripheral quantitative computed tomography were made to assess cortical and trabecular bone characteristics as well as muscle mass in 88 patients (42 girls, 46 boys) at a mean age of 11.7 +/- 3.0 years, a mean disease duration of 5.6 +/- 3.7 years, and a mean manifestation age of type 1 diabetes of 6.1 +/- 3.5 years. Height, weight, Tanner stage, insulin regimen, and glycosylated hemoglobin values were recorded. Bone metabolism was studied by measurement of bone formation and bone resorption parameters. Dynamic muscle force was measured using a grip strength device.

RESULTS

Overall, cortical, trabecular, and total bone mineral density were within the reference range. Total and cortical bone cross-sectional area and muscle mass were low in prepubertal patients, and total cross-sectional area was low in early puberty. Adolescent patients showed normal bone and muscle parameters. Grip strength and recreational physical activity were normal in all in relation to a healthy reference population. In a subgroup of 18 patients, early manifestation of type 1 diabetes was detected as a risk factor for altered bone development with significantly reduced cortical bone mineral density and total, cortical, and muscle cross-sectional area (-0.9 +/- 1.3 SD, -2.1 +/- 1.3 SD, -1.6 +/- 0.7 SD, and -1.0 +/- 0.7 SD, respectively). Bone characteristics were not influenced by metabolic control, disease duration, or insulin regimen.

CONCLUSIONS

Manifestation of type 1 diabetes at an early age may impair bone development. Longitudinal data are needed to determine whether this impairment persists into adolescence and adulthood.

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.

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 acquisition in adolescents with type 1 diabetes

OBJECTIVE

To track bone mineral acquisition in adolescents with type 1 diabetes (DM).

STUDY DESIGN

Subjects were adolescents, ages 12 to 18 years, with DM (n=42) and a healthy regional reference (n=199). Measurements of tibia bone characteristics by peripheral quantitative computed tomography (pQCT) and spine and whole body (WB) by dual-energy x-ray absorptiometry (DEXA), anthropometrics, and lifestyle questionnaires were obtained during a 12-month period. Disease duration, insulin dose, renal function, and glycosylated hemoglobin (HbA1c) values for the previous 12 months were recorded.

RESULTS

Body size and maturation were similar between groups. DM had lower tibia, spine, and WB bone characteristics but greater muscle mass (LBM) and lower bone mineral content (BMC)/LBM at baseline and 12 months. Annual gains for tibia cortical bone and WB BMC/LBM were lower and inversely related to HbA1c levels (R=-0.36 to -0.51), whereas spine area and density and WBLBM were greater and were predicted by pubertal-driven growth. Overall, the DM cohort had 8.5% less WB BMC/LBM, suggesting that bone mineral deposition was not adequately adapted to muscle gains.

CONCLUSIONS

Adolescents with type 1 diabetes continue to have smaller bone mass and bone size despite normal growth and maturation. Poor metabolic control appears to negatively influence bone mineral acquisition.

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.

Alterations in bone characteristics associated with glycemic control in adolescents with type 1 diabetes mellitus

OBJECTIVE

To determine whether bone characteristics in adolescents with type 1 diabetes mellitus (DM) are influenced by blood glucose regulation and disease duration. The subjects were adolescents with type 1 DM (n=55) recruited from the University of Utah's Primary Children's Pediatric Diabetes Treatment Center. A reference database consisting of 95 healthy adolescents from the same geographic area was used for comparison.Study design Measurements of the tibia by peripheral quantitative computed tomography were made to assess cortical and trabecular bone characteristics. Hip, spine, and whole body characteristics were measured by dual-energy x-ray absorptiometry. Height, weight, health histories, Tanner stage, disease duration, insulin regimen, and glycosylated hemoglobin values were recorded.

RESULTS

Age, maturation, and body size and composition values were similar between the subjects with type 1 DM and reference. Subjects with type 1 DM had lower tibia trabecular and femoral neck density and whole body mineral content and density. The mean glycosylated hemoglobin value was inversely related to tibia trabecular bone density (R(2)=-0.30) and whole body bone mineral content (R(2)=-0.25) and accounted for 3.0% to 8.9% of the variance.

CONCLUSIONS

Altered bone mineral acquisition in adolescents with type 1 DM may limit peak bone mass acquisition and increase the risk of osteoporosis in later life.