Monthly Archives: July 2014

Nicotine Not Responsible for Negative Effects of Smoking on Bone Density in Rats


The effect of long-term nicotine exposure on bone mineral density and oxidative stress in female Swiss Albino rats.

To evaluate the effect of long-term low or high-dose nicotine exposure on bone mass via measuring bone mineral density (BMD) and oxidant-antioxidant status markers.
Thirty-five female Swiss Albino rats weighing 70 ± 10 g were divided as the control group (n = 12), low-dose nicotine group (n = 12) and high-dose nicotine group (n = 11). While the control group was given only normal drinking water, the low-dose nicotine group had 0.4 mg/kg per day and the high-dose nicotine group, 6.0 mg/kg per day of nicotine added to their water for the period of 1 year. BMD was determined with X-ray absorptiometry of lumbar vertebra, corpus femoris, proximal and distal femur. To evaluate oxidant-antioxidant status malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activities were determined.
When comparing the nicotine groups and controls, neither BMD nor oxidant-antioxidant status markers showed any statistically significant difference. In comparison to the controls, 12 months of high-dose oral nicotine exposure did not have a significant effect on BMD and low-dose nicotine exposure led to a statistically insignificant increase in BMD.
Contrary to common belief, the results of this study show that nicotine is not responsible for the decrease in BMD leading to osteoporosis frequently seen in smokers. However, there is a need to explore the other harmful materials in tobacco which may be responsible for the alterations seen in BMD of smokers.

Turan V, Mizrak S, Yurekli B, Yilmaz C…
Arch. Gynecol. Obstet. Feb 2013
PMID: 22955292

Strontium Ranelate Associated with Unfavorable Cardiac Risk


Nationwide registry-based analysis of cardiovascular risk factors and adverse outcomes in patients treated with strontium ranelate.

National registers showed that a large proportion of patients treated with strontium ranelate have conditions that may now contraindicate use. The risk of death in strontium ranelate-treated patients was significantly higher than that seen in users of other osteoporosis drugs even after adjusting for cardiovascular risk factor profile.
The European Medicines Agency (EMA) recently warned that strontium ranelate should be avoided in patients with ischaemic heart disease (IHD), peripheral vascular disease (PVD) or cerebrovascular disease (CVD), and in patients with uncontrolled hypertension. We investigated to what extent patients beginning strontium ranelate had cardiovascular conditions and determined the rates of MI, stroke and death.
Using the Danish National Prescription Database, we identified all 3,252 patients aged 50+ who began strontium ranelate in 2005-2007 and 35,606 users of other osteoporosis drugs as controls. Hospital contacts and causes of death were retrieved from national registers.
Patients starting strontium were older than patients treated with other osteoporosis drugs and more likely to suffer from IHD, PVD or CVD (combined prevalence 19.2 % in female users and 29.5 % in male users). The adjusted risk of MI was not significantly increased (women: HR 1.05 [95 % CI 0.79-1.41, p = 0.73]; men: 1.28 [0.74-2.20, p = 0.38]). For stroke, the adjusted HR was 1.23 (0.98-1.55, p = 0.07) in women and 1.64 (0.99-2.70, p = 0.05) in men. All-cause mortality was higher in strontium users (women: adjusted HR 1.20 [1.10-1.30, p < 0.001]; men: adjusted HR 1.22 [1.03-1.45, p < 0.05]).
Patients treated with strontium ranelate have an unfavourable cardiovascular risk profile compared with users of other osteoporosis drugs. However, only the risk of death differed significantly from the rates observed in users of other osteoporosis drugs adjusted for risk factor profile. A large proportion of patients currently treated with strontium ranelate have conditions that would now be considered contraindications according to EMA.

Abrahamsen B, Grove EL, Vestergaard P
Osteoporos Int Feb 2014
PMID: 24322475

Strontium Ranelate Not Associated with Heart Attacks or Other Cardiac Events


Ischaemic cardiac events and use of strontium ranelate in postmenopausal osteoporosis: a nested case-control study in the CPRD.

We explored the cardiac safety of the osteoporosis treatment strontium ranelate in the UK Clinical Practice Research Datalink. While known cardiovascular risk factors like obesity and smoking were associated with increased cardiac risk, use of strontium ranelate was not associated with any increase in myocardial infarction or cardiovascular death.
It has been suggested that strontium ranelate may increase risk for cardiac events in postmenopausal osteoporosis. We set out to explore the cardiac safety of strontium ranelate in the Clinical Practice Research Datalink (CPRD) and linked datasets.
We performed a nested case-control study. Primary outcomes were first definite myocardial infarction, hospitalisation with myocardial infarction, and cardiovascular death. Cases and matched controls were nested in a cohort of women treated for osteoporosis. The association with exposure to strontium ranelate was analysed by multivariate conditional logistic regression.
Of the 112,445 women with treated postmenopausal osteoporosis, 6,487 received strontium ranelate. Annual incidence rates for first definite myocardial infarction (1,352 cases), myocardial infarction with hospitalisation (1,465 cases), and cardiovascular death (3,619 cases) were 3.24, 6.13, and 14.66 per 1,000 patient-years, respectively. Obesity, smoking, and cardiovascular treatments were associated with significant increases in risk for cardiac events. Current or past use of strontium ranelate was not associated with increased risk for first definite myocardial infarction (odds ratio [OR] 1.05, 95 % confidence interval [CI] 0.68-1.61 and OR 1.12, 95 % CI 0.79-1.58, respectively), hospitalisation with myocardial infarction (OR 0.84, 95 % CI 0.54-1.30 and OR 1.17, 95 % CI 0.83-1.66), or cardiovascular death (OR 0.96, 95 % CI 0.76-1.21 and OR 1.16, 95 % CI 0.94-1.43) versus patients who had never used strontium ranelate.
Analysis in the CPRD did not find evidence for a higher risk for cardiac events associated with the use of strontium ranelate in postmenopausal osteoporosis.

Cooper C, Fox KM, Borer JS
Osteoporos Int Feb 2014
PMID: 24322476 | Free Full Text

Bisphosphonates Reduce Mortality in Women


Osteoporosis medication and reduced mortality risk in elderly women and men.

Osteoporotic fractures are associated with premature mortality. Antiresorptive treatment reduces refracture but mortality reduction is unclear.
The objective of the study was to examine the effect of osteoporosis treatment [bisphosphonates (BP), hormone therapy (HT), and calcium ± vitamin D only (CaD)] on mortality risk.
This was a prospective cohort study (April 1989 to May 2007).
The study was conducted with community-dwelling elderly (aged 60+ yr) subjects in Dubbo, a semiurban city, Australia.
Subjects included 1223 and 819 women and men in the Dubbo Osteoporosis Epidemiology Study.
Mortality according to treatment group was recorded.
There were 325 (BP, n = 106; HT, n = 77; CaD, n = 142) women and 37 men (BP, n = 15; CaD, n = 22) on treatment. In women, mortality rates were lower with BP 0.8/100 person-years (0.4, 1.4) and HT 1.2/100 person-years (0.7, 2.1) but not CaD 3.2/100 person-years (2.5, 4.1) vs. no treatment 3.5/100 person-years (3.1, 3.8). Accounting for age, fracture occurrence, comorbidities, quadriceps strength, and bone mineral density, mortality risk remained lower for women on BP [hazard ratio (HR) 0.3 (0.2, 0.6)] but not HT [HR 0.8 (0.4, 1.8)]. For 429 women with fractures, mortality risk was still reduced in the BP group [adjusted HR 0.3 (0.2, 0.7)], not accounted for by a reduction in subsequent fractures. In men, lower mortality rates were observed with BP but not CaD [BP 1.0/100 person-years (0.3, 3.9) and CaD 3.1/100 person-years (1.5, 6.6) vs. no treatment 4.3/100 person-years (3.9, 4.8)]. After adjustment, mortality was similar, although not significant [HR 0.5 (0.1, 2.0)].
Osteoporosis therapy appears to reduce mortality risk in women and possibly men.

Center JR, Bliuc D, Nguyen ND, Nguyen TV…
J. Clin. Endocrinol. Metab. Apr 2011
PMID: 21289270

Low-Dose Alendronate Effect is Similar to Standard-Dose in Chinese Women with Bone Loss


Effect of low-dose alendronate treatment on bone mineral density and bone turnover markers in Chinese postmenopausal women with osteopenia and osteoporosis.

The aim of this study was to evaluate the effect of low-dose alendronate (ALN) treatment on bone mineral density (BMD) and bone turnover markers in Chinese postmenopausal women with osteopenia and osteoporosis.
This study was a large-sample, randomized, open-label, prospective, multicenter, clinical trial with a 12-month follow-up. A total of 639 postmenopausal women (aged 62.2 ± 7.0 y) with osteopenia or osteoporosis were randomized into two groups: low-dose ALN (70 mg every two weeks) and standard-dose ALN (70 mg weekly). All patients were also supplemented with calcium (600 mg) and vitamin D3 (125 IU) daily. BMD (measured by dual-energy x-ray absorptiometry; Hologic and Lunar) and levels of serum bone turnover markers (bone resorption marker, carboxy-telopeptide of type I collagen; bone formation marker, alkaline phosphatase) were assessed at baseline and at 3, 6, and 12 months of treatment. BMD and bone turnover markers were compared between the baseline and the end of treatment, and the changes in BMD and bone turnover markers were also compared between the low-dose ALN group and the standard-dose ALN group.
No significant differences in age, years since menopause, body mass index, BMD, 25-hydroxy vitamin D level, and serum biochemical markers were found at baseline between the two dose groups. A total of 558 (87.3%) and 540 (84.5%) women completed the treatment at the 6th and 12th months, respectively. After the 12-month treatment, lumbar spine and hip BMD increased and serum bone turnover markers decreased significantly in both of the treatment groups (P < 0.01), and no differences in percentage changes in BMD at the lumbar spine, femoral neck, and hip were found between the low-dose group (5.60%, 3.87%, and 3.28%, respectively) and the standard-dose group (5.07%, 2.93%, and 3.80%, respectively; P > 0.05). However, levels of serum alkaline phosphatase and carboxy-telopeptide of type I collagen in the standard-dose group decreased moderately compared with those in the low-dose group (P < 0.05 and P < 0.01). The women tolerated the two doses of ALN quite well. Adverse effects were similar in the two groups.
Treatment with low-dose ALN (70 mg every two weeks) in women with postmenopausal osteopenia or osteoporosis effectively increases lumbar spine and hip BMD, similar to treatment with standard-dose ALN. Low-dose ALN may be a cost-effective and safe protocol for treating osteopenia or osteoporosis in Chinese women.

Li M, Zhang ZL, Liao EY, Chen DC…
Menopause Jan 2013
PMID: 22968256

Jewel Orchid Prebiotic Extract Prevents Bone Loss in Rats


The prebiotic effect of Anoectochilus formosanus and its consequences on bone health.

The present study evaluated the prebiotic effect of a standardised aqueous extract of Anoectochilus formosanus (SAEAF) and its effects on osteoporosis in ovariectomised (OVX) rats. The OVX rats were randomly divided into five groups and orally treated with water, SAEAF (200 and 400 mg/kg daily) and inulin (400 mg/kg daily) for 12 weeks. The sham group was orally treated with water. The SAEAF treatment enhanced the number of faecal bifidobacteria in OVX rats. The results of a Ca-balance experiment showed that SAEAF increased apparent Ca absorption and retention. The OVX rats were killed after SAEAF treatment lasting 12 weeks. The SAEAF decreased the caecal pH values and increased the caecal wall weight, caecal mucosa calbindin-D9k mRNA expression, free-Ca concentration and levels of SCFA in the caecum. The mineral content, density and biomechanical strength of bones were lower in OVX rats than the sham group, but these bone losses were prevented by SAEAF administration. Microtomography scanning showed that the SAEAF-treated rats had higher trabecular bone volume than the OVX rats. These results suggest that SAEAF prevented bone loss associated with ovarian hormone deficiency in the rats.

Yang LC, Wu JB, Lu TJ, Lin WC
Br. J. Nutr. May 2013
PMID: 22950799

Boron Increases Strength and Bone Minerals in Rabbits


Boron enhances strength and alters mineral composition of bone in rabbits fed a high energy diet.

An experiment was performed to determine whether boron had a beneficial effect on bone strength and composition in rabbits with apparent adiposity induced by a high energy diet. Sixty female New Zealand rabbits, aged 8 months, were randomly divided into five groups with the following treatments for seven months: control 1, fed alfalfa hay only (5.91 MJ/kg); control 2, high energy diet (11.76 MJ and 3.88 mg boron/kg); B10, high energy diet+10 mg/kg body weight boron gavage/96 h; B30, high energy diet+30 mg/kg body weight boron gavage/96 h; B50, high energy diet+50mg/kg body weight boron gavage/96 h. Bone boron concentrations were lowest in rabbits fed the high energy diet without boron supplementation, which suggested an inferior boron status. Femur maximum breaking force was highest in the B50 rabbits. Tibia compression strength was highest in B30 and B50 rabbits. All boron treatments significantly increased calcium and magnesium concentrations, and the B30 and B50 treatments increased the phosphorus concentration in tibia of rabbits fed the high energy diet. The B30 treatment significantly increased calcium, phosphorus and magnesium concentrations in femur of rabbits fed the high energy diet. Principal component analysis of the tibia minerals showed that the three boron treatments formed a separate cluster from controls. Discriminant analysis suggested that the concentrations of the minerals in femur could predict boron treatment. The findings indicate boron has beneficial effects on bone strength and mineral composition in rabbits fed a high energy diet.

Hakki SS, Dundar N, Kayis SA, Hakki EE…
J Trace Elem Med Biol Apr 2013
PMID: 22944583

PTH(1-84) Increases Bone Density Over 24 Months


Improved adherence with PTH(1-84) in an extension trial for 24 months results in enhanced BMD gains in the treatment of postmenopausal women with osteoporosis.

The purpose of this study is to examine the effect of PTH(1-84) treatment over 24 months followed by 12 months discontinuation on BMD, bone turnover markers, fractures and the impact of adherence on efficacy.
There is limited information about the effect of PTH(1-84) after 18 months and limited data about the impact of compliance on response to anabolic therapy.
Seven hundred and eighty-one subjects who received active PTH(1-84) in the Treatment of Osteoporosis with Parathyroid hormone trial for approximately 18 months were entered into a 6-month open-label extension. Thereafter, they were followed for 12 additional months after discontinuation of treatment. Endpoints examined included changes in BMD and biochemical markers.
PTH(1-84) treatment over 24 months increased BMD at the lumbar spine by 6.8% above baseline (p<0.05). The total corresponding BMD increases at the hip and femoral neck were 1.1 and 2.2% above baseline. Larger increases in spine BMD were observed in participants with ≥80% adherence to daily injections of PTH(1-84) (8.3% in adherent vs 4.9% in poorly adherent patients). Total hip BMD gains were 1.7% in adherent vs 0.6% in poorly adherent participants. Markers of bone turnover (BSAP and NTx) peaked 6 months after starting PTH(1-84) treatment and declined slowly but remained above baseline at 24 months. After discontinuation of PTH(1-84) treatment (at 24 months), bone turnover markers returned to near baseline levels by 30 months. The adherent group sustained significantly fewer fractures than the poorly adherent group.
PTH(1-84) treatment over 24 months results in continued increases in lumbar spine BMD. Adherence to treatment with PTH(1-84) for up to 24 months is also associated with greater efficacy.

Black DM, Bilezikian JP, Greenspan SL, Wüster C…
Osteoporos Int Apr 2013
PMID: 22930240

Cladrin Increases Osteoblast Prolifertion in Rats


Differential effects of formononetin and cladrin on osteoblast function, peak bone mass achievement and bioavailability in rats.

Dietary soy isoflavones including genistein and daidzein have been shown to have favorable effects during estrogen deficiency in experimental animals and humans. We have evaluated osteogenic effect of cladrin and formononetin, two structurally related methoxydaidzeins found in soy food and other natural sources. Cladrin, at as low as 10 nM, maximally stimulated both osteoblast proliferation and differentiation by activating MEK-Erk pathway. On the other hand, formononetin maximally stimulated osteoblast differentiation at 100 nM that involved p38 MAPK pathway but had no effect on osteoblast proliferation. Unlike daidzein, these two compounds neither activated estrogen receptor in osteoblast nor had any effect on osteoclast differentiation. Daily oral administration of each of these compounds at 10.0 mg kg(-1) day(-1) dose to recently weaned female Sprague-Dawley rats for 30 consecutive days, increased bone mineral density at various anatomic positions studied. By dynamic histomorphometry of bone, we observed that rats treated with cladrin exhibited increased mineral apposition and bone formation rates compared with control, while formononetin had no effect. Cladrin had much better plasma bioavailability compared with formononetin. None of these compounds exhibited estrogen agonistic effect in uteri. Our data suggest that cladrin is more potent among the two in promoting parameters of peak bone mass achievement, which could be attributed to its stimulatory effect on osteoblast proliferation and better bioavailability. To the best of our knowledge, this is the first attempt to elucidate structure-activity relationship between the methoxylated forms of daidzein and their osteogenic effects.

Gautam AK, Bhargavan B, Tyagi AM, Srivastava K…
J. Nutr. Biochem. Apr 2011
PMID: 20579866

Cladrin Increases Bone Formation and Strength in Rats


Positive skeletal effects of cladrin, a naturally occurring dimethoxydaidzein, in osteopenic rats that were maintained after treatment discontinuation.

Effects of cladrin treatment and withdrawal in osteopenic rats were studied. Cladrin improved trabecular microarchitecture, increased lumbar vertebral compressive strength, augmented coupled remodeling, and increased bone osteogenic genes. A significant skeletal gain was maintained 4 weeks after cladrin withdrawal. Findings suggest that cladrin has significant positive skeletal effects.
We showed that a standardized extract of Butea monosperma preserved trabecular bone mass in ovariectomized (OVx) rats. Cladrin, the most abundant bioactive compound of the extract, promoted peak bone mass achievement in growing rats by stimulating osteoblast function. Here, we studied the effects of cladrin treatment and withdrawal on the osteopenic bones.
Adult female Sprague-Dawley rats were OVx and left untreated for 12 weeks to allow for significant estrogen deficiency-induced bone loss, at which point cladrin (1 and 10 mg/kg/day) was administered orally for another 12 weeks. Half of the rats were killed at the end of the treatments and the other half at 4 weeks after treatment withdrawal. Sham-operated rats and OVx rats treated with PTH or 17β-estradiol (E2) served as various controls. Efficacy was evaluated by bone microarchitecture using microcomputed tomographic analysis and fluorescent labeling of bone. qPCR and western blotting measured mRNA and protein levels in bone and uterus. Specific ELISA was used for measuring levels of serum PINP and urinary CTx.
In osteopenic rats, cladrin treatment dose dependently improved trabecular microarchitecture, increased lumbar vertebral compression strength, bone formation rate (BFR), cortical thickness (Cs.Th), serum PINP levels, and expression of osteogenic genes in bones; and reduced expression of bone osteoclastogenic genes and urinary CTx levels. Cladrin had no uterine estrogenicity. Cladrin at 10 mg/kg maintained acquired skeletal gains 4 weeks after withdrawal. Cladrin had positive skeletal effects in osteopenic rats that were maintained after treatment withdrawal.

Khan K, Sharan K, Swarnkar G, Chakravarti B…
Osteoporos Int Apr 2013
PMID: 22932734