Osteoporosis in men with diabetes mellitus

Potential biomarkers of abnormal osseointegration of implants in type II diabetes mellitus

Background

Type II diabetes mellitus (T2DM) is an important risk factor for osseointegration of implants. The aim of this study was to explore key genes of T2DM affecting bone metabolism through bioinformatic analysis of published RNA sequencing data, identify potential biomarkers, and provide a reference for finding the molecular mechanism of abnormal osseointegration caused by T2DM.

Methods

We identified differentially expressed mRNAs and miRNAs from the Gene Expression Omnibus database using the R package ‘limma’ and analysed the predicted target genes using Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis and Gene Ontology analysis. At the same time, miRNA–mRNA interactions were explored using miRWalk 2.0.

Results

We constructed an miRNA-gene regulatory network and a protein–protein interaction network. The enrichment pathways of differentially expressed mRNAs included extracellular matrix receptor interactions, protein digestion and absorption, the PI3K-Akt signalling pathway, cytokine–cytokine receptor interactions, chemokine signalling pathways, and haematopoietic cell lineage functions. We analysed the expression of these differentially expressed mRNAs and miRNAs in T2DM rats and normal rats with bone implants and identified Smpd3, Itga10, and rno-mir-207 as possible key players in osseointegration in T2DM.

Conclusion

Smpd3, Itga10, and rno-mir-207 are possible biomarkers of osseointegration in T2DM. This study sheds light on the possible molecular mechanism of abnormal osseointegration caused by bone metabolism disorder in T2DM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01939-9.

Evidence of impaired bone quality in men with type 1 diabetes: a cross-sectional study

OBJECTIVE

Type 1 diabetes (T1D) is associated with substantial fracture risk. Bone mineral density (BMD) is, however, only modestly reduced, suggesting impaired bone microarchitecture and/or bone material properties. Yet, the skeletal abnormalities have not been uncovered. Men with T1D seem to experience a more pronounced bone loss than their female counterparts. Hence, we aimed to examine different aspects of bone quality in men with T1D.

DESIGN AND METHODS

In this cross-sectional study, men with T1D and healthy male controls were enrolled. BMD (femoral neck, total hip, lumbar spine, whole body) and spine trabecular bone score (TBS) were measured by dual x-ray absorptiometry, and bone material strength index (BMSi) was measured by in vivo impact microindentation. HbA1c and bone turnover markers were analyzed.

RESULTS

Altogether, 33 men with T1D (43 ± 12 years) and 28 healthy male controls (42 ± 12 years) were included. Subjects with T1D exhibited lower whole-body BMD than controls (P = 0.04). TBS and BMSi were attenuated in men with T1D vs controls (P = 0.016 and P = 0.004, respectively), and T1D subjects also had a lower bone turnover. The bone parameters did not differ between subjects with or without diabetic complications. Duration of disease correlated negatively with femoral neck BMD but not with TBS or BMSi.

CONCLUSIONS

This study revealed compromised bone material strength and microarchitecture in men with T1D. Moreover, our data confirm previous studies which found a modest decrease in BMD and low bone turnover in subjects with T1D. Accordingly, bone should be recognized as a target of diabetic complications.

The Prevalence of Osteopenia and Osteoporosis Among Malaysian Type 2 Diabetic Patients Using Quantitative Ultrasound Densitometer

Background:

Type 2 Diabetes Mellitus (T2DM) and osteoporosis are both chronic conditions and the relationship between them is complex.

Objective:

The aims of this study were to assess the prevalence of Low Bone Mineral density (LBMD, i.e., osteopenia and osteoporosis), as well as, the difference and associations between Quantitative Ultrasound Scan (QUS) parameters with socio-demographic data and clinical related data among T2DM in Penang, Malaysia.

Method:

An observational, cross-sectional study with a convenient sample of 450 T2DM patients were recruited from the outpatient diabetes clinic at Hospital Pulau Pinang (HPP) to measure Bone Mineral Density (BMD) at the heel bone using QUS. In addition, a self-reported structured questionnaire about the socio-demographic data and osteoporosis risk factors were collected. Moreover, the study included the retrospective collection of clinical data from patients’ medical records.

Results:

The mean value of T-score for normal BMD, osteopenic and osteoporotic patients’ were (-0.41±0.44), (-1.65±0.39) and (-2.76±0.27), respectively. According to QUS measurements, more than three quarters of T2DM patients (82%) were at high risk of abnormal BMD. The results showed that QUS scores were significantly associated with age, gender, menopausal duration, educational level and diabetic related data. Moreover, the QUS parameters and T-scores demonstrated significant negative correlation with age, menopausal duration, diabetic duration and glycaemic control, as well as, a positive correlation with body mass index and waist to hip ratio. The current study revealed that none of the cardiovascular disease risk factors appear to influence the prevalence of low BMD among T2DM Malaysian patients.

Conclusion:

The study findings revealed that the assessment of T2DM patients’ bone health and related factor are essential and future educational programs are crucial to improve osteoporosis management.

Sclerostin antibody treatment improves fracture outcomes in a Type I diabetic mouse model

Type 1 diabetes mellitus (T1DM) patients have osteopenia and impaired fracture healing due to decreased osteoblast activity. Further, no adequate treatments are currently available that can restore impaired healing in T1DM; hence a significant need exists to investigate new therapeutics for treatment of orthopedic complications. Sclerostin (SOST), a WNT antagonist, negatively regulates bone formation, and SostAb is a potent bone anabolic agent. To determine whether SOST antibody (SostAb) treatment improves fracture healing in streptozotocin (STZ) induced T1DM mice, we administered SostAb twice weekly for up to 21days post-fracture, and examined bone quality and callus outcomes at 21days and 42days post-fracture (11 and 14weeks of age, respectively). Here we show that SostAb treatment improves bone parameters; these improvements persist after cessation of antibody treatment. Markers of osteoblast differentiation such as Runx2, collagen I, osteocalcin, and DMP1 were reduced, while an abundant number of SP7/osterix-positive early osteoblasts were observed on the bone surface of STZ calluses. These results suggest that STZ calluses have poor osteogenesis resulting from failure of osteoblasts to fully differentiate and produce mineralized matrix, which produces a less mineralized callus. SostAb treatment enhanced fracture healing in both normal and STZ groups, and in STZ+SostAb mice, also reversed the lower mineralization seen in STZ calluses. Micro-CT analysis of calluses revealed improved bone parameters with SostAb treatment, and the mineralized bone was comparable to Controls. Additionally, we found sclerostin levels to be elevated in STZ mice and β-catenin activity to be reduced. Consistent with its function as a WNT antagonist, SostAb treatment enhanced β-catenin activity, but also increased the levels of SOST in the callus and in circulation. Our results indicate that SostAb treatment rescues the impaired osteogenesis seen in the STZ induced T1DM fracture model by facilitating osteoblast differentiation and mineralization of bone.

Correlation of serum testosterone with insulin resistance in elderly male type 2 diabetes mellitus patients with osteoporosis

AIMS/INTRODUCTION

The present study was designed to investigate the correlations between the serum testosterone level and insulin sensitivity in elderly male type 2 diabetes patients with osteoporosis.

MATERIALS AND METHODS

A total of 35 elderly male patients with type 2 diabetes (type 2 diabetes group), 30 elderly male type 2 diabetes patients combined with osteoporosis (DO group) and 30 healthy elderly men (normal control group) participated in the present study. The fasting plasma glucose, fasting insulin, testosterone (T) and estradiol (E2) were measured. The insulin sensitivity index (ISI), homeostasis model assessment of insulin resistance (HOMA-IR) and E2/T were calculated. Then, the correlations of serum testosterone level with ISI and HOMA-IR were analyzed by statistical methods.

RESULTS

The HOMA-IR, E2 and E2/T of the type 2 diabetes group and DO group were significantly increased, whereas the bone mineral density, ISI, T and sex hormone binding globulin were decreased compared with those of the normal control group. Serum testosterone levels of the type 2 diabetes group and DO group were negatively correlated to the HOMA-IR (r = -0.496, -0.506; P < 0.05), whereas they were positively correlated to the fasting insulin (r = 0.281, 0.292; P < 0.05) and ISI (r = 0.364, 0.403; P < 0.05).

CONCLUSIONS

The reduced level of serum testosterone in elderly male type 2 diabetes patients with osteoporosis might promote insulin resistance.