Protective effect of amlodipine on rat bone tissue after orchidectomy

Association of antihypertensive drugs with fracture and bone mineral density: A comprehensive drug-target Mendelian randomization study

Background

Observational studies have investigated the associations between antihypertensive drugs and fracture risk as well as bone mineral density (BMD), but yielding controversial results.

Methods

In this study, a comprehensive drug-target Mendelian randomization (MR) analysis was conducted to systematically examine the associations between genetic proxies for eight common antihypertensive drugs and three bone health-related traits (fracture, total body BMD [TB-BMD], and estimated heel BMD [eBMD]). The main analysis used the inverse-variance weighted (IVW) method to estimate the causal effect. Multiple MR methods were also employed to test the robustness of the results.

Results

The genetic proxies for angiotensin receptor blockers (ARBs) were associated with a reduced risk of fracture (odds ratio [OR] = 0.67, 95% confidence interval [CI]: 0.54 to 0.84; P = 4.42 × 10-4; P-adjusted = 0.004), higher TB-BMD (β = 0.36, 95% CI: 0.11 to 0.61; P = 0.005; P-adjusted = 0.022), and higher eBMD (β = 0.30, 95% CI: 0.21 to 0.38; P = 3.59 × 10-12; P-adjusted = 6.55 × 10-11). Meanwhile, genetic proxies for calcium channel blockers (CCBs) were associated with an increased risk of fracture (OR = 1.07, 95% CI: 1.03 to 1.12; P = 0.002; P-adjusted = 0.013). Genetic proxies for potassium sparing diuretics (PSDs) showed negative associations with TB-BMD (β = -0.61, 95% CI: -0.88 to -0.33; P = 1.55 × 10-5; P-adjusted = 1.86 × 10-4). Genetic proxies for thiazide diuretics had positive associations with eBMD (β = 0.11, 95% CI: 0.03 to 0.18; P = 0.006; P-adjusted = 0.022). No significant heterogeneity or pleiotropy was identified. The results were consistent across different MR methods.

Conclusions

These findings suggest that genetic proxies for ARBs and thiazide diuretics may have a protective effect on bone health, while genetic proxies for CCBs and PSDs may have a negative effect.

Effects of Amlodipine on Bone Metabolism in Orchidectomised Spontaneously Hypertensive Rats

Spontaneously hypertensive rats (SHR) represent a model of essential hypertension. We studied the effect of amlodipine (AML) on bone markers, bone mineral density (BMD), and biomechanical properties of osteopenic bone induced by orchidectomy in male SHR. Rats were allocated to 3 groups and were sacrificed after 12 weeks: sham-operated control; orchidectomised control; and orchidectomised receiving a diet supplemented with AML. Indicators of bone turnover were assessed in bone homogenate, BMD was measured by dual energy X-ray absorptiometry, and the femurs were subjected to biomechanical testing. Long-term AML administration does not have a negative impact on bone metabolism and density in male SHR.

Changes in Bone Metabolism in Young Castrated Male Rats

PURPOSE

To determine the window of time during which osteoporosis affects the management of spinal surgery and the mechanism of bone metabolism changes in males with osteoporosis by examining changes in bone metabolism in young castrated male rats.

MATERIALS AND METHODS

A total of 30 Sprague-Dawley rats were randomly allocated into two study groups. Group 1 (control) received a sham surgery and Group 2 received bilateral orchiectomy to change bone mineral density (BMD). Serum osteocalcin, alkaline phosphatase (ALP), and collagen type 1 cross-linked C-telopeptide (CTX) were analyzed at postoperative date (POD) 8, 10, and 12 weeks. BMDs were measured using micro computed tomography scans.

RESULTS

Femoral and lumbar BMDs were decreased in the orchiectomy groups. BMDs in the sham and orchiectomy groups showed statistically differences at POD 8, 10, and 12 weeks for the femur (p=0.032, 0.008, 0.008) and lumbar spine (p=0.151, 0.008, 0.008, respectively). Serum osteocalcin, ALP, and CTX decreased gradually; however, N-terminal type 1 procollagen (P1NP) showed a slight increase yet no significant change.

CONCLUSION

In young castrated male rats, a significant decrease in BMD was observed after orchiectomy due to the mixture of two detrimental factors. Young castrated male rats did not reach peak BMD. Increased bone turnover causes bone resorption to exceed bone formation. This study may contribute to the creation of a valuable model for studies of male osteoporosis and the spinal surgery field.

Risk of hip fracture among older people using antihypertensive drugs: a nationwide cohort study

Background

Many people with a high risk of hip fracture have coexisting cardiovascular diseases. We aimed to examine associations between exposure to antihypertensive drugs and the risk of hip fracture among older people.

Methods

We conducted a cohort study of the 906,422 people born before 1945 and living in Norway in 2005. We obtained information on all prescriptions of antihypertensive drugs dispensed (the Norwegian Prescription Database) in 2004–2010 and the dates of primary hip fractures (the Norwegian Hip Fracture Registry) in 2005–2010. We compared the incidence rates of hip fracture during the time people were exposed and unexposed to antihypertensive drugs by calculating the standardized incidence ratio (SIR).

Results

Altogether, 39,938 people experienced a primary hip fracture (4.4 %). The risk of hip fracture was decreased among people exposed to thiazides (SIR 0.7, 95 % confidence interval (CI) 0.6–0.7), beta-blockers (SIR 0.7, 95 % CI 0.7–0.8), calcium channel blockers (SIR 0.8, 95 % CI 0.8–0.8), angiotensin II receptor blockers (SIR 0.8, 95 % CI 0.7–0.8), ACE inhibitor/thiazide combination products (SIR 0.7, 95 % CI 0.6–0.7) and angiotensin II receptor blocker/thiazide combination products (SIR 0.6, 95 % CI 0.6–0.6). Use of loop diuretics and ACE inhibitors (plain products) was associated with increased fracture risk in people born after 1924, and with decreased risk in those born before 1925. The protective associations were stronger among exposed men than among exposed women for all drugs except loop diuretics. The SIRs decreased with increasing age among exposed people, except for thiazides and angiotensin II receptor blockers.

Conclusions

We found a reduced risk of hip fracture associated with overall use of most antihypertensive drugs, but an increased risk with loop diuretics and ACE inhibitors among people younger than 80 years and in new users of loop diuretics. This may have great impact at the population level, because the use of antihypertensive drugs is widespread in people at risk of hip fracture. Clinical studies are needed to further explore these associations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12877-015-0154-5) contains supplementary material, which is available to authorized users.

The effects of amlodipine and platelet rich plasma on bone healing in rats

Aim

The aim of this study was to evaluate the effects of calcium channel blocker (CCB) amlodipine (AML), platelet rich plasma (PRP), and a mixture of both materials on bone healing.

Materials and methods

Fifty-six male Wistar rats were randomly divided into four groups: group A, tibia defect model with no treatment; group B, tibia defect model treated with AML, 0.04 mg daily by oral gavage; group C, tibia defect model treated with local PRP; group D, tibia defect model treated with local PRP and AML, 0.04 mg daily by oral gavage.

Results

At day 21, bone healing was significantly better in groups C and D compared to group A (P<0.05), but comparisons showed no statistically significant difference in group B (P>0.05). At day 30, groups B and C showed no statistically significant difference (P>0.05) compared to group A, but bone healing in group D was significantly better than in group A (P<0.05). Statistically, AML did not affect alkaline phosphatase (ALP) activity at 21 and 30 days (P>0.05), but PRP and AML + PRP increased ALP activity statistically (P<0.05).

Conclusion

It can be concluded that AML had neither a positive nor a negative effect on bone healing, but when used in combination with PRP, it may be beneficial.

Antihypertensive medications, bone mineral density, and fractures: a review of old cardiac drugs that provides new insights into osteoporosis

Osteoporosis is increasing in prevalence and importance as society's age, with the clinical consequence of fractures of the hip, spine, and upper extremity, leading to impaired quality of life, loss of function and independence, and increased morbidity and mortality. A major risk factor for osteoporosis is older age, and cardiovascular diseases also share this risk factor; therefore, osteoporosis and cardiovascular disease often coexist and share risk factors. Medications used for the treatment of cardiovascular diseases, in particular antihypertensive drugs, have been shown in a variety of studies of varying designs to modulate bone health in both a positive or negative manner. In this article, we reviewed the pharmacology, potential mechanisms, and possible effects on bone mineral density and fracture risk of commonly prescribed antihypertensive medications, including thiazide and non-thiazide diuretics, beta-blockers, calcium channel blockers, renin-angiotensin-aldosterone system agents, and nitrates.

Amlodipine increases vitamin D levels more than valsartan in newly diagnosed hypertensive patients: pointing to an additional effect on bone metabolism or a novel marker of inflammation?

Hypertension is a major challenge for public health. Appropriate antihypertensive treatment seem to provide a better life with lower morbidity and mortality rates. Another pathologic condition, osteoporosis, mainly affects postmenouposal women, and constitutes a growing body of risks after a particular age. As bone is a dynamic organ system that is directly related to calcium and phosphor metabolism, imbalance in these two parameters upon aging or menopause finally may lead to osteoporosis. Today, both osteoporosis and high blood pressure are major morbidities, especially in the elderly population. There are some intriguing results on the effects of antihypertensive agents on bone metabolism in the literature. In this study, we aimed to investigate the effects of widely used antihypertensive agents, valsartan and amlodipine on vitamin D levels in newly diagnosed hypertensive population. We found that amlodipine increased vitamin D levels significantly in patients with a newly diagnosed hypertension on a 12-week treatment duration compared to valsartan.