Insulin enhancement of in vitro wound healing in fetal rat parietal bones

Importance of gestational hypoglycaemia for foetal malformations and skeletal development in rats

The aim was to investigate embryo-foetal effects of continuous maternal insulin-induced hypoglycaemia extending throughout gestation or until gestation day (GD)17 (typical last day of dosing during pre-clinical evaluation) providing comparator data for safety assessment of longer-acting insulin analogues in non-diabetic rats. Pregnant rats received human insulin (HI)-infusion during gestation until either GD20 or GD17 (HI-GD20; HI-GD17). On GD20, foetal abnormalities and skeletal ossification/mineralisation were evaluated. HI-infusion induced continuous hypoglycaemia. Foetal skeletal and eye malformations (e.g. bent ribs, microphthalmia) were common in both groups. Foetal size and skeletal ossification/mineralisation decreased, particularly with infusion throughout gestation. Concluding, insulin-induced hypoglycaemia during gestation in non-diabetic rats is damaging to embryo-foetal growth and skeletal development, particularly after GD17. Three days without HI-infusion after GD17 allows for some developmental catch-up. Eye development is sensitive to HI-infusion before GD17. These results should serve as a benchmark during pre-clinical safety assessment of longer-acting insulin analogues tested in rats.

Insulin and wound healing

Skin is a dynamic and complex organ that relies on the interaction of different cell types, biomacromolecules and signaling molecules. Injury triggers a cascade of events designed to quickly restore skin integrity. Depending on the size and severity of the wound, extensive physiological and metabolic changes can occur, resulting in impaired wound healing and increased morbidity resulting in higher rates of death. While wound dressings provide a temporary barrier, they are inherently incapable of significantly restoring metabolic upsets, post-burn insulin resistance, and impaired wound healing in patients with extensive burns. Exogenous insulin application has therefore been investigated as a potential therapeutic intervention for nearly a century to improve wound recovery. This review will highlight the important achievements that demonstrate insulin's ability to stimulate cellular migration and burn wound recovery, as well as providing a perspective on future therapeutic applications and research directions.

Prevalence and predictors of osteopenia and osteoporosis in postmenopausal Chinese women with type 2 diabetes

AIMS

To determine the prevalence and biochemical/hormonal determinants of osteopenia/osteoporosis in postmenopausal Chinese women with type 2 diabetes.

METHODS

This cross-sectional study was carried out in 890 postmenopausal women with type 2 diabetes and 689 age-matched non-diabetic women. Of the total subjects included in both groups were classified as obese (BMI ≥ 25 kg/m²) and non-obese (BMI< 25 kg/m²). Bone mineral density (BMD) at the sites (lumbar spine, femoral neck, and hip), obtained by dual X-ray absorptiometry and some other relevant clinical and laboratory indices of bone mineral metabolism were investigated. The prevalence of osteopenia and that of osteoporosis were evaluated.

RESULTS

BMDs, T- and Z-scores at the total hip, femoral neck and ward's triangle were significantly lower in non-obese diabetic women than those in BMI-matched control subjects (P < 0.038). Obese diabetic patients and control subjects had similar BMDs and T- and Z-scores at various skeletal regions. Osteopenia/osteoporosis was more common at the hip and femoral neck in non-obese diabetic women than in obese diabetic women and control subjects (P = 0.026). On multiple linear regression analysis, which was adjusted for the sex hormone concentration, BMI, fasting insulin level, and serum osteocalcin were positively associated with BMDs at the hip and lumbar spine. Age, mean HbA₁(c) levels, and NTx/Cr showed negative correlation (P < 0.0284) with BMD at the lumbar spine and femoral neck.

CONCLUSIONS

Postmenopausal non-obese women with type 2 diabetes have lower BMD levels and higher osteopenia/osteoporosis rate than BMI-matched control subjects. Impaired bone formation may occur in Chinese postmenopausal women with type 2 diabetes.

Prevalence of osteoporosis and factors affecting bone mineral density among postmenopausal Turkish women with type 2 diabetes

OBJECTIVES

Controversy remains as to the effects of type 2 diabetes on bone metabolism. The aims of this study were to assess the association between type 2 diabetes and bone mineral density (BMD) and to evaluate the possible relationship between chronic diabetic complications and bone density.

METHODS

Bone mineral densities at the lumbar spine, femur, and radius in 206 postmenopausal Turkish women with type 2 diabetes were evaluated by dual-energy X-ray absorptiometry and compared with those in 61 age-matched postmenopausal nondiabetic women. Medical and lifestyle characteristics, body mass index (BMI), hemoglobin A1c level, and status of microvascular and macrovascular diabetic complications were recorded. Frequency of osteoporosis and that of osteopenia as well as the relationship between microvascular and macrovascular complications and BMD were evaluated.

RESULTS

The groups did not differ on BMDs and T scores at the hip, lumbar spine, and radius. Patients with radial and/or lumbar and/or hip osteoporosis had a longer duration of diabetes (P=.000), were older (P=.000), and had a lower BMI (P=.000). No correlation was found between osteopenia or osteoporosis and hemoglobin A1c level, presence of microalbuminuria, retinopathy, neuropathy, peripheral artery disease, cerebrovascular event, and coronary artery disease. Among the three sites, BMD at the hip was positively correlated with BMI (P=.000) but negatively correlated with age (P=.000) and duration of diabetes (P=.000). Presence of microalbuminuria revealed a negative correlation with BMD at the femoral neck (P=.042).

CONCLUSION

There is no evidence that type 2 diabetes influenced BMD in our postmenopausal patient group.

Decreased bone mineral density at the distal radius, but not at the lumbar spine or the femoral neck, in Japanese type 2 diabetic patients

The purpose of this study is to assess the association between type 2 diabetes and bone mineral density. This study included 145 Japanese patients (64 men and 81 women) with type 2 diabetes and 95 non-diabetic control subjects (41 men and 54 women) of similar age. We measured bone mineral density (BMD) at the sites with different cortical/cancellous bone ratio (lumbar spine, femoral neck, and distal radius) using dual-energy X-ray absorptiometry. BMD and Z score at the distal radius were significantly lower in type 2 diabetic patients than those in control subjects, and in type 2 diabetic patients, the Z score at the distal radius was lower than that at their own lumbar spine and femoral neck. In type 2 diabetic patients, negative correlation between BMD and the mean HbA1c during the previous 2 years was found significantly at the distal radius in both genders and at the femoral neck in women. These results indicate the selective cortical bone loss in type 2 diabetes and suggest the importance of also determining BMD at the radius and keeping good metabolic control to prevent bone loss in type 2 diabetic patients.

Colchicine inhibits fracture union and reduces bone strength--in vivo study

INTRODUCTION

Recent studies have demonstrated that Colchicine (CO) prevents heterotopic ossification (HO) after total hip replacement in patients suffering from familial Mediterranean fever (FMF). Other investigators have proved that CO is an in vitro inhibitor of proliferation of osteoblasts and osteosarcoma cells, and is a non-selective mitosis inhibitor and selective inhibitor of mineralization.

METHODS

A double blind prospective study comprised four groups of adult rats. The left posterior tibia in each rat was fractured except in one of the control groups. The study groups were treated with CO 1 mg/kg/day 1 week before, or on the fracture day. The control groups did not receive CO treatment. Six weeks after fracture induction the groups were compared radiographically mechanically and histologically.

RESULTS

Prolonged CO treatment had a significant negative influence on fracture healing according to radiological, clinical, mechanical (p<0.02), and pathological parameters (p<0.0001).

CONCLUSIONS

We were able to demonstrate that prolonged CO treatment reduced bone healing.