The change of bone mineral density in secondary osteoporosis and vertebral fracture incidence

Diabetes mellitus, thyroid dysfunctions and osteoporosis: is there an association?

BACKGROUND

Osteoporosis is the most common metabolic bone disease with complicated, multifactorial and heterogenic nature that has no known pathological cause. As the role of Diabetes Mellitus (DM) and thyroid dysfunctions in the prevalence of osteoporosis is not exactly known, therefore this study was designed to evaluate the probable association between osteoporosis with DM and thyroid dysfunctions in Iranian patients.

METHODS

In this cross-sectional study, 300 subjects out of the total number of patients referring to Gorgan bone densitometry centers (3000subjects) were selected via random sampling method in 2009. Individual characteristics, DM, thyroid dysfunctions and densitometry results were collected from densitometry records. Data analysis was carried out by SPSS version 16 software and by using Chi square and T-test. The level of significance in all tests was considered 0.05.

RESULTS

The mean of T-score in lumbar and femoral areas of diabetic patients were -0.87 ± 1.08 and -1.94 ± 1.33 and in patient with thyroid dysfunctions was -0.80 ± 1.09 and -1.64 ± 1.24 respectively. The mean of BMD in lumbar and femoral areas of diabetic patients were 0.96 ± 0.19 and 0.75 ± 0.19 and in patient with thyroid dysfunctions were 0.96 ± 0.17 and 0.76 ±0.19 respectively. The mean of BMI in osteoporotic subjects in the lumbar and femoral areas were 25.94 ± 5.62 and 26.95 ± 5.20 respectively. The association between BMI and BMD in the lumbar and femoral areas were statistically significant, but the association between DM and thyroid dysfunctions with BMD and T-score in the femoral and lumbar areas was not statistically significant (P-value > 0.05).

CONCLUSION

The results of current study show that there is no association between DM and thyroid dysfunctions with osteoporosis.

Mechanism by Sambucus nigra Extract Improves Bone Mineral Density in Experimental Diabetes

The effects of polyphenols extracted from Sambucus nigra fruit were studied in streptozotocin- (STZ-) induced hyperglycemic rats to evaluate its possible antioxidant, anti-inflammatory, antiglycosylation activity, and antiosteoporosis effects in diabetes. DEXA bone mineral density tests were performed in order to determine bone mineral density (BMD), bone mineral content (BMC), and fat (%Fat) in control and diabetic animals, before and after polyphenol delivery. As compared to the normoglycemic group, the rats treated with STZ (60 mg/kg body weight) revealed a significant malondialdehyde (MDA) increase, as an index of the lipid peroxidation level, by 69%, while the total antioxidant activity (TAS) dropped by 36%, with a consistently significant decrease (P < 0.05) in the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPX). Also, the treatment of rats with STZ revealed a significant increase of IL-6, glycosylated haemoglobin (HbA_1c), and osteopenia detected by DEXA bone mineral density tests. The recorded results highlight a significant improvement (P < 0.001) in the antioxidative capacity of the serum in diabetic rats treated with natural polyphenols, bringing back to normal the concentration of reduced glutathione (GSH), as well as an important decrease in the serum concentration of MDA, with improved osteoporosis status. Knowing the effects of polyphenols could lead to the use of the polyphenolic extract of Sambucus nigra as a dietary supplement in diabetic osteoporosis.

Chronic non-cholestatic liver disease is not associated with an increased fracture rate in children

Chronic liver disease in adults is a risk factor of osteoporosis, but little is known about risk of fractures in children with non-cholestatic liver disease. The aim of this study was to investigate associations among the severity of liver fibrosis, bone mass and low-energy fractures in children. History of fractures, anthropometry, and bone mass and size were examined in 39 Caucasian children (25 boys, 14 girls) aged 7.1-18 years (mean 11.9 ± 3.1) with chronic hepatitis B and liver fibrosis evidenced by liver biopsy. Severity of liver fibrosis was based on histological classification according to the method of Batts and Ludwig (mild, 1-2 scores; advanced, 3 scores) and Ishak (1-3 and 4-5 scores, respectively). Bone mineral content (BMC), density (BMD) and body composition were determined in the total body and lumbar spine using dual energy X-ray absorptiometry. Seven subjects (4 girls, 3 boys; 18% of the sample) had low BMD in the total body and lumbar spine region (Z-scores below -2.0). No associations were found among BMC, BMD, bone size and the severity of liver fibrosis. Nine boys (36% of all boys) and one girl reported repeated fractures (forearm, wrist, tibia, ankle, humerus), showing trends similar to the prevalence in general population. Fractures were neither associated with lower BMD/BMC nor with scores of liver fibrosis. Deficits in BMD in children with chronic hepatitis B are not associated with the severity of liver fibrosis. This study suggests that non-cholestatic liver disease does not increase the risk of low-energy fractures during growth. From the practical perspective, however, children with chronic liver disease should be screened for history and clinical risk factors for fractures rather than referred to bone density testing.

Exendin-4 exerts osteogenic actions in insulin-resistant and type 2 diabetic states

Poor control of glucose homeostasis accounts for diabetes-related bone loss. Incretins - GLP-1 and GIP - have been proposed to affect bone turnover. GLP-1, apart from its anti-diabetic and other actions, has shown to exert a bone anabolic effect in streptozotocin-induced type 2 diabetic (T2D) and fructose-induced insulin-resistant (IR) rats. Exendin-4 (Ex-4), a peptide of non-mammalian nature, is sharing with GLP-1 part of its structural sequence, and also several glucoregulatory effects in mammals in an even more efficient manner. We have explored the effect of continuous administration (3 days by osmotic pump) of Ex-4 or saline (control) on bone turnover factors and bone structure in T2D and IR rats, compared to N, and the possible interaction of Ex-4 with the Wnt signalling pathway. Blood was taken before and after treatment for plasma measurements; tibiae and femurs were collected for gene expression of bone markers (RT-PCR) and structure (microCT) analysis; we also measured the mRNA levels of LRP5 - an activator of the Wnt pathway - and those of DKK1 and sclerostin (SOST) - both blockers of LRP5 activity. Compared to N-control, plasma glucose and insulin were respectively higher and lower in T2D; osteocalcin (OC) and tartrate-resistant alkaline phosphatase 5b (TRAP5b) were lower; after Ex-4, these turnover markers were further reduced in T2D and IR, while TRAP5b increased in N. Bone OC, osteoprogeterin (OPG) and receptor activator of NF-kB ligand (RANKL) mRNA were lower in T2D and IR; Ex-4 increased OC in all groups and OPG in N and IR, reduced RANKL in N and T2D but increased it in IR; the LRP5/DKK1 and LRP5/SOST mRNA ratios were similarly decreased in T2D, but in IR, the latter ratio was reduced while the former was increased; after Ex-4, both ratios augmented in N, and that of LRP5/DKK1 tended to normalize in T2D and IR. In conclusion, Ex-4 exerts osteogenic effects in T2D and IR models, and interacts with the Wnt pathway to promote bone formation.

Effect of GLP-1 treatment on bone turnover in normal, type 2 diabetic, and insulin-resistant states

It has been suggested that hormones released after nutrient absorption, such as glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide 2 (GLP-2), could be responsible for changes in bone resorption. However, information about the role of GLP-1 in this regard is scanty. Diabetes-related bone loss occurs as a consequence of poor control of glucose homeostasis, but the relationship between osteoporosis and type 2 diabetes remains unclear. Since GLP-1 is decreased in the latter condition, we evaluated some bone characteristics in streptozotocin-induced type 2 diabetic (T2D) and fructose-induced insulin-resistant (IR) rat models compared to normal (N) and the effect of GLP-1 or saline (control) treatment (3 days by osmotic pump). Blood was taken before and after treatment for plasma measurements; tibiae and femora were collected for gene expression of bone markers (RT-PCR) and structure (microCT) analysis. Compared to N, plasma glucose and insulin were, respectively, higher and lower in T2D; osteocalcin (OC) and tartrate-resistant alkaline phosphatase 5b were lower; phosphate in IR showed a tendency to be higher; PTH was not different in T2D and IR; all parameters were unchanged after GLP-1 infusion. Bone OC, osteoprotegerin (OPG) and RANKL mRNA were lower in T2D and IR; GLP-1 increased OC and OPG in all groups and RANKL in T2D. Compared to N, trabecular bone parameters showed an increased degree of anisotropy in T2D and IR, which was reduced after GLP-1. These findings show an insulin-independent anabolic effect of GLP-1 and suggest that GLP-1 could be a useful therapeutic agent for improving the deficient bone formation and bone structure associated with glucose intolerance.

Vertebral Fracture Assessment: the 2007 ISCD Official Positions

Vertebral fracture assessment (VFA) is an established, low radiation method for detection of prevalent vertebral fractures. Vertebral fractures are usually not recognized clinically at the time of their occurrence, but their presence indicates a substantial risk for subsequent fractures independent of bone mineral density. Significant evidence supporting VFA use for many post-menopausal women and older men has accumulated since the last ISCD Official Position Statement on VFA was published. The International Society for Clinical Densitometry considered the following issues at the 2007 Position Development Conference: (1) What are appropriate indications for Vertebral Fracture Assessment; (2) What is the most appropriate method of vertebral fracture detection with VFA; (3) What is the sensitivity and specificity for detection of vertebral fractures with this method; (4) When should additional spine imaging be performed following a VFA; and (5) What are the reporting obligations for those interpreting VFA images?

Late low-dose steroid withdrawal in renal transplant recipients increases bone formation and bone mineral density

Corticosteroids have been the most widely used immunosuppressive agents since the first clinical transplantation in the 1950s. There are few studies of late steroid withdrawal in renal transplantation and none have prospectively assessed bone mineral density (BMD). The study aim was to assess the impact of corticosteroid withdrawal, in stable renal transplant recipients, on BMD and bone turnover. BMD, osteocalcin (OC) and cross-linked telopeptide of type I collagen (CTx) were measured in 92 patients randomized into a trial of steroid withdrawal. Patients with functioning renal transplants for more than 1 year with a serum creatinine below 200 micromol/L entered the trial. All patients were on triple immunosuppression (Cyclosporin microemulsion, Azathioprine and prednisolone), corticosteroids were withdrawn at 1 mg/month. BMD was measured twice annually with serum CTx and OC. One year following withdrawal of glucocorticoids there was no significant difference in creatinine. BMD increased in the withdrawal group (2.54% per year L1-L4, p < 0.01), there was a slight reduction in the control group. Mean OC increased from 5.3 to 12.2 ng/mL (p < 0.05) in the withdrawal group, but was unchanged in the controls. No change was seen in CTx. Corticosteroid withdrawal in renal transplant recipients results in an increase in BMD with a corresponding increase in serum OC.

Bone mineral density and cytokine levels during interferon therapy in children with chronic hepatitis B: does interferon therapy prevent from osteoporosis?

BACKGROUND

Our aim was to determinate bone mineral density (BMD), levels of biochemical markers and cytokines in children with chronic hepatitis B treated with interferon (IFN)-alpha and to investigate effect of IFN-alpha therapy on these variables. To the best of our knowledge, this is first study carried out about BMD and cytokine levels in pediatric patients with chronic hepatitis B treated with IFN-alpha.

METHODS

BMD, levels of parathyroid hormone (PTH), osteocalcin, C-terminal cross-linking telopeptide of type I collagen (CTX), calcium, alkaline phosphates (ALP), cytokines as TNF-alpha, interleukin (IL)-1beta, IL-2r, IL-6, and IL-8 were studied in 54 children with chronic hepatitis B (4-15 years old) treated with interferon alone (n = 19) or in combination with lamivudine (n = 35) for six months and as controls in 50 age-matched healthy children.

RESULTS

There was no significant difference in respect to serum IL-1beta, TNF-alpha and osteocalcin levels while serum IL-2r (p = 0.002), IL-6 (p = 0.001), IL-8 (p = 0.013), PTH (p = 0.029), and CTX (p = 0.021) levels were higher in children with chronic hepatitis B than in healthy controls. BMD of femur neck (p = 0.012) and trochanter (p = 0.046) in patients were higher than in healthy controls. There was a statistically significant correlation between serum IL-1beta and osteocalcin (r = -0.355, p < 0.01); between serum IL-8 and CTX levels (r = 0.372, p = 0.01), and ALP (r = 0.361, p = 0.01); between serum ALP and femur neck BMD (r = 0.303, p = 0.05), and trochanter BMD (r = 0.365, p = 0.01); between spine BMD and IL-2R (r = -0.330, p < 0.05).

CONCLUSION

In conclusion, our study suggest that BMD of femur, serum IL-2r, IL-6, IL-8, PTH, and CTX levels were higher in children with chronic hepatitis B treated with IFN-alpha alone or combination with lamivudine than in healthy children. High femur BMD measurements found in patients may suggest that IFN-alpha therapy in children with chronic hepatitis B could contribute indirectly to prevent from hip osteoporosis. Additionally, further investigations on effects of IFN-alpha for bone structure in children should be performed in the future.

Clinical utility of laboratory testing in women with osteoporosis

Clinicians regularly order laboratory tests in women with osteoporosis to assess if an underlying medical condition is contributing to bone loss. To determine which laboratory tests are associated with osteoporosis we conducted a secondary analyses of data collected as part of the Fracture Intervention Trial (FIT), which included 15,316 postmenopausal women. Women had tests of liver and kidney function, mineral metabolism, electrolytes and complete blood count, femoral neck and total body BMD and spinal radiographs. The prevalence of abnormal tests in women with osteoporosis compared to women without was not different, except for low TSH (<0.5 IU/ml). Among women with and without osteoporosis at the femoral neck the prevalence of low TSH was 4.9% (95% CI: 4.4-5.5) and 3.7% (95% CI: 3.3-4.1), respectively, yielding a positive likelihood ratio of 1.2 (95% CI: 1.1-1.3). We observed similar results for women with vertebral fractures compared to women without vertebral fractures; positive likelihood ratio of 1.4 (95% CI: 1.3-1.6). Our data suggests that when assessing healthy women with osteoporosis ordering a routine panel of laboratory tests is not useful but measuring TSH may be informative.

Alendronate reduces the daily consumption of insulin (DCI) in patients with senile type I diabetes and osteoporosis

The use of Alendronate for the treatment of senile diabetes with osteopenia or osteoporosis is a common practice today, although the reasons for the success of this treatment are not completely understood. We investigated 40 elderly female patients, over 70 years of age, divided in two Groups (A and B) 20 cases of each, with insulin-dependent senile diabetes and fair metabolic balance, with an average disease duration of 30 +/- 4 years. They all had osteoporosis shown by the mean T-score of bone mineral densitometry. The Groups were treated as follows, Group A with 10 mg/day of Alendronate per os, with morning fasting plus a supplementation of calcium and vitamin D3, while the Group B received only calcium and vitamin D3 per os. Bone mineral density (BMD) expressed in mg/cm2, and in terms of T-score and Z-score at the spine (L1-L4) was monitored over time after 12 and 24 months, using dexa technique with a Lunar DPX densitometer. Moreover, the variation of daily consumption of insulin (DCI) of all the study population was calculated 12 and 24 months after the start of treatments. The data of Group A showed an improvement of osteoporosis, as evidenced by the increase of BMD at both times of measurement, accompanied by a significant reduction in the DCI (-21.6% by the 12th month, and -36.2% by the end of the observation period). In the Group B only small, statistically insignificant changes were observed in both the BMD and DCI. The most plausible explanation of reduction of DCI in Group A seems to be that Alendronate has improved the clinical symptoms of osteoporosis (pain, rigidity, and reduction of movements) through its action on the bone mass recovery and slowing down the bone turnover and under these conditions the diabetic patients improved their own physical performance. The better and more extensive movements certainly produced a reduction in the DCI, since a correct and adequate physical activity does contribute to an improved glucose metabolism.

Secondary osteoporosis

Bone loss occurs during the normal aging process. The term "primary" osteoporosis refers to osteoporosis that results from the involutional losses associated with aging and, in women, additional losses related to natural menopause. Osteoporosis that is caused or exacerbated by other disorders or medication exposures is referred to as "secondary" osteoporosis. This article describes the major causes and provides a framework for the diagnostic investigation of patients with suspected of having secondary osteoporosis.

Accidents in patients with insulin-treated diabetes: increased risk of low-impact falls but not motor vehicle crashes--a prospective register-based study

BACKGROUND

Patients with diabetes mellitus may be at increased risk of accidents, mainly because of hypoglycemia. A variety of approaches have been adopted in an attempt to quantify this risk, but there has not been, to date, a systematic study using a national trauma register. In this study, we report findings from the Scottish Trauma Audit Group database.

METHODS

The database includes all patients admitted to hospital for 3 or more days, or who died in hospital as a result of their accident. The study includes 11,244 cases aged 15 years or over entered into the database between July 1996 and June 1998. This included 151 patients with insulin-treated diabetes. Using detailed prescribing information from one representative region, we have calculated the rates of different types of accidents for patients treated with insulin and compared this with the control population. We have analyzed information on the mechanism and severity of injury, outcome, and length of hospital stay.

RESULTS

Overall, the rate of accidents for insulin-treated patients was estimated at 291.2 per 100,000 population per year compared with 148.4 for the control population (p < 0.001; relative risk, 1.97; 95% confidence interval, 1.68-2.32). Insulin-treated patients were, on average, older (p < 0.005), more likely to be women (p < 0.02), and had longer stay in hospital (p < 0.001). The major excess of injuries related to low falls (< 2 m), which accounted for 62.3% of the injuries in the insulin-treated group compared with 47.1% in the remainder (p < 0.01). Low falls in the insulin-treated group (n = 94) were examined in detail: compared with the control population, there was no difference in age and sex, Injury Severity Score, Revised Trauma Score (a measure of the severity of physiologic disturbance), or calculated probability of survival (TRISS). Length of inpatient stay was higher in the insulin-treated low-fall patients (10 vs. 7 days, p < 0.01). Of the 151 catalogued injuries, the vast majority were fractures at peripheral sites. Only 23 insulin-treated individuals were admitted after a motor vehicle crash during the study period. This represents a slight but not significant increase above the rate for the background population.

CONCLUSION

This study confirms that patients taking insulin are at increased risk of accidents. Among the different types of injury, only low-impact falls were significantly increased. This is most likely related to an increased tendency for insulin-treated patients to fall during a hypoglycemic episode. However, patients with diabetes may also be at higher risk of sustaining a fracture after a fall. The number of car crashes involving drivers with insulin-dependent diabetes is small, and the rate is not significantly greater than that of the background population. Further study of the causes and consequences of falls in diabetic patients is warranted.

Effect of vitamin K(2) on lumbar vertebral bone: histomorphometric analyses in experimental osteoporotic rats

The in-vivo effect of vitamin K(2) on bone metabolism was investigated by histochemical and morphometric methods, using an animal model of osteoporosis. Eighteen female Wistar rats were divided into three groups. Rats in group A had sham ovariectomies, group B were ovariectomized, and group C were ovariectomized and received vitamin K(2), at 10 mg/kg per day, injected subcutaneously. The lumbar vertebral bones were evaluated 8 weeks after the operation by a modified tetrachrome method after decalcification. Mineralized bone areas, osteoid, and defectively mineralized bone areas in group B were markedly decreased compared with findings in group A, but these features in group C were not severely decreased. There was no significant difference in total bone areas and total bone volumes among the three groups. Accordingly, it appeared that vitamin K(2) had an effect in reducing mineralized bone loss after the ovariectomy. In conclusion, vitamin K(2) is thought to be beneficial for the properties of bone microarchitecture in the condition of osteoporosis.

Correlation between the bone mass, psychometric performances, and the levels of autonomy and autosufficiency in an elderly Italian population above 80 years of age

This study was aimed at evaluating the correlation between bone mineral density (BMD) and the psychophysical health status in an elderly study population (62 subjects, mean age 84+/-5 years, 21 males and 41 females), institutionalized (Group A) in various structures of Pozzallo, a marine locality of the Ragusa Province in Sicily. BMD was measured by using ultrasonography of the calcanear area (T-score, Z-score, stiffness). The alterations of the cognitive and affective spheres as well as the levels of autonomy and autosufficiency were estimated by means of psychometric scales like mini-mental state examination (MMSE), geriatric depression scale (GDS), activities of daily living (ADL) and instrumental activities of daily living (IADL). Other biological, social and health-related factors, such as age, sex, body weight and height, nutritional and drug-taking habits, physical activity and previous pathologies, were also considered. These variables were compared to those obtained in a similar, but non-institutionalized controls (Group B) of 63 subjects (mean age 85+/-2 years, 27 males and 36 females), being similar in number and age distribution, frequenting the Geriatric Day Center of the same locality. Statistical analysis revealed significant differences between Groups A and B: the BMD was considerably lower, but also the cognitive and affective performances were strongly reduced in Group A. These findings can be attributed to decreased psychosensorial stimuli and lost interest of the patients in Group A, resulting in a lower physical activity, accompanying the depressive state, and may represent the first signs of a decreased intellectual performance, which can later be transformed into dementia. The functional abilities and the levels of autonomy are also reduced, risking the loss of autosufficiency. Also, the drug usage was different in Group A: more sedative-hypnotics and anticoagulants were consumed. As regards the polymorbidities, arterial hypertension and consequent chronic renal failure, hepatopathies and thyreopathies were most frequent, these latter two being more frequent in the Group A.