The effect of short-term calcitonin administration on biochemical bone markers in patients with acute immobilization following hip fracture

Improvement of Osteoporosis in Rats With Hind-Limb Unloading Treated With Pulsed Electromagnetic Field and Whole-Body Vibration

OBJECTIVE

Physical factors have been used to address disuse osteoporosis, but their effects and mechanism remain unclear. The purpose of this study was to determine the effects of pulsed electromagnetic field (PEMF) and whole-body vibration (WBV) on disuse osteoporosis to increase knowledge about treating osteoporosis.

METHODS

A disuse osteoporosis rat model was developed by hind-limb unloading (HU) for 6 weeks. Forty 4-month-old female Sprague-Dawley rats were divided into 5 groups and given the following interventions: HU, HU treated with PEMF (HUP), HU treated with WBV (HUW), HU treated with both PEMF and WBV (HUPW), and no intervention (controls). After 8 weeks of intervention, measurements were taken.

RESULTS

HU induced a decrease in bone mineral density (BMD), whereas HUP, HUW, and HUPW increased it. Moreover, the bone resorption markers tartrate-resistant acid phosphatase (TRAP) and C-terminal peptide of type 1 collagen in the HU group significantly increased, whereas the osteogenesis markers osteocalcin and N-terminal propeptide of type 1 procollagen significantly decreased. The markers osteocalcin and N-terminal propeptide of type 1 procollagen significantly increased, but TRAP and C-terminal peptide of type 1 collagen significantly decreased in the HUPW, HUP, and HUW groups compared with the HU group. In particular, HUPW effectively increased osteocalcin and decreased TRAP compared with HUP and WBV. Microcomputed tomography analysis of the femur indicated that HUPW improved trabecular number, bone volume over total volume, bone surface over bone volume, trabecular separation, and the structure model index compared with HUP and that it improved bone surface over bone volume, trabecular separation, and structure model index compared with HUW. The HUPW group showed a significant increase in maximum load compared with the HUW group and a significant increase in elastic modulus compared with the HUP group.

CONCLUSION

PEMF, WBV, and their combination all attenuated bone resorption and enhanced osteogenesis. WBV and the combination of treatments have great potential to improve osteogenesis compared with PEMF. In addition, HUPW significantly attenuated bone resorption compared with HUW and HUP.

IMPACT

The results of this study indicated that HUPW could effectively improve disuse osteoporosis compared with HUP, given that trabecular number and bone volume over total volume are associated with disuse osteoporosis. Moreover, BMD recovered well with HUP, HUW, and HUPW but the bone structure-especially mechanical performance-did not, indicating that osteoporosis should be evaluated with BMD and mechanical performance, not with BMD in isolation.

The "Three in One" Bone Repair Strategy for Osteoporotic Fractures

In aging society, osteoporotic fractures have become one major social problem threatening the health of the elderly population in China. Compared with conventional fractures, low bone mass, bone defect and retarded healing issues of osteoporotic fractures lead to great difficulties in treatment and rehabilitation. Addressing major concerns in clinical settings, we proposed the "three in one" bone repair strategy focusing on anti-osteoporosis therapies, appropriate bone grafting and fracture healing accelerating. We summarize misconceptions and repair strategies for osteoporotic fracture management, expecting improvement of prognosis and clinical outcomes for osteoporotic fractures, to further improve therapeutic effect and living quality of patients.

Patients Undergoing Surgery for Hip Fractures Suffer from Severe Oxidative Stress as Compared to Patients with Hip Osteoarthritis Undergoing Total Hip Arthroplasty

Hip fractures are associated with the highest degree of morbidity and mortality of all fractures in elderly patients and pose a major risk for subsequent fractures. Patients with hip fractures also present accelerated bone turnover despite early stable fracture fixation and early mobilization. We aimed to evaluate oxidative stress in two groups of patients (25 patients each, matched for age, side, and BMI) who underwent internal fixation of hip fractures and total hip arthroplasty for hip osteoarthritis. Blood samples were taken from all patients during admission, the day of surgery, the 4^th postoperative day, and the 15^th postoperative day. Reduced (GSH) and oxidized (GSSG) glutathione, GSH/GSSG, catalase (CAT), thiobarbituric acid reactive substances (TBARS), protein carbonyls (PC), and total antioxidant capacity (TAC) as a widely used battery of redox biomarkers were recorded from blood samples. Patients with hip fractures who undergo fixation surgery, compared to those with hip osteoarthritis, suffer significant oxidative stress with an active but insufficient first line of oxidative defense, an intensive first line reaction, a very active second line of oxidative defense, and a low plasma antioxidant capacity. Surgery worsened already present lipid- and protein-related tissue damage. The severe oxidative stress observed may explain high morbidity and mortality rates and high bone turnover status, as well as the high incidence of refractures. Furthermore, the question of whether antioxidant therapy measures should be introduced in the management of hip fracture patients is raised.

The effect of nephrectomy on Klotho, FGF-23 and bone metabolism

Background

Increased concentration of fibroblast growth factor 23 (FGF-23) and decreased levels of soluble Klotho (sKL) are linked to negative clinical outcomes among patients with chronic kidney disease and acute kidney injury. Therefore, it is reasonable to hypothesize that GFR reduction caused by nephrectomy might alter mineral metabolism and induces adverse consequences. Whether nephrectomy due to urological indications causes derangements in FGF-23 and sKL has not been studied. The aim of the study was to evaluate the effect of acute GFR decline due to unilateral nephrectomy on bone metabolism, FGF-23 and sKL levels.

Methods

This is a prospective, single-centre observational study of patients undergoing nephrectomy due to urological indications. Levels of C-terminal FGF-23 (c-FGF-23), sKL and bone turnover markers [β-crosslaps (CTX), bone-specific alkaline phosphatase (bALP) and tartrate-resistant acid phosphatase 5b (TRAP 5b)] were measured before and after surgery (5 ± 2 days).

Results

Twenty-nine patients were studied (14 females, age 63.0 ± 11.6, eGFR 87.3 ± 19.2 ml/min/1.73 m²). After surgery, eGFR significantly declined (p < 0.0001). Nephrectomy significantly decreased sKL level [709.8 (599.9–831.2) vs. 583.0 (411.7–752.6) pg/ml, p < 0.001] and did not change c-FGF-23 concentration [70.5 (49.8–103.3) vs. 77.1 (60.5–109.1) RU/ml, p = 0.9]. Simultaneously, alterations in bone turnover markers were observed. Serum concentration of CTX increased [0.49 (0.4–0.64) vs. 0.59 (0.46–0.85) ng/ml, p = 0.001], while bALP and TRAP 5b decreased [23.6 (18.8–31.4) vs. 17.9 (15.0–22.0) U/l, p < 0.0001 and 3.3 (3.0–3.7) vs. 2.8 (2.3–3.2) U/l, p < 0.001, respectively].

Conclusions

Nephrectomy among patients with preserved renal function before surgery does not increase c-FGF-23 but reduces sKL. Moreover, nephrectomy results in derangements in bone turnover markers in short-term follow-up. These changes may participate in pathogenesis of bone disease after nephrectomy.

Evolutionary medicine and bone loss in chronic inflammatory diseases--A theory of inflammation-related osteopenia

OBJECTIVE

Bone loss is typical in chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, ankylosing spondylitis, systemic lupus erythematosus, multiple sclerosis, inflammatory bowel diseases, pemphigus vulgaris, and others. It is also typical in transplantation-related inflammation and during the process of aging. While we recognized that bone loss is tightly linked to immune system activation or inflamm-aging in the form of acute, chronic active, or chronic smoldering inflammation, bone loss is typically discussed to be an "accident of inflammation."

METHODS

Extensive literature search in PubMed central.

RESULTS

Using elements of evolutionary medicine, energy regulation, and neuroendocrine regulation of homeostasis and immune function, we work out that bone waste is an adaptive, evolutionarily positively selected program that is absolutely necessary during acute inflammation. However, when acute inflammation enters a chronic state due to the inability to terminate inflammation (e.g., in autoimmunity or in continuous immunity against microbes), the acute program of bone loss is a misguided adaptive program.

CONCLUSIONS

The article highlights the complexity of interwoven pathways of osteopenia.

Atypical femoral fractures: a review of the literature

Bisphosphonates are the most commonly used drugs worldwide for treating osteoporosis. Atypical femoral fractures most commonly are associated with prolonged bisphosphonate use. They also may occur with denosumab use or in patients without a history of using these drugs. In this article, we provide a comprehensive review of the mechanism of action of bisphosphonate and the definition, incidence, epidemiology, pathogenesis, diagnosis, management, and prevention of atypical femoral fractures.

Calcitonin: physiological actions and clinical applications

Calcitonin (CT) was first reported as a hypocalcemic principle, initially thought to originate from the parathyroid gland, a view subsequently corrected to an origin from parafollicular C-cells. Human CT is a 32 amino acid peptide with an N-terminal disulphide bridge and a C-terminal prolineamide residue, shown to potently inhibit bone resorption. More recent studies have demonstrated that this may take place through a direct osteoclastic action. A number of osteoclast CT receptors have subsequently been characterized and particular receptor regions necessary for ligand binding and intracellular signaling identified. Its potent anti-resorptive effect has led to its use in treating Paget's bone disease, osteoporosis, hypercalcaemia and osteogenesis imperfecta. This review summarises some key aspects of its synthesis, structure and its actions at the cellular and molecular levels, and leads on to its therapeutic uses that have emerged since its discovery as well as possibilities for future clinical applications.

Analgesic effects of calcitonin

The analgesic activity of salmon calcitonin (subcutaneous or intranasal) has been demonstrated in several prospective clinical trials, in patients suffering different painful skeletal conditions, including recent nontraumatic osteoporotic vertebral fractures. The mechanism of the analgesic effect of calcitonin is not clear. It is possible that specific binding sites for salmon calcitonin exist in the brain. Another explanation is that changes in descending serotonergic modification on the sensory transmission mediated by C afferents contribute to the analgesic effects of calcitonin on pain in osteoporotic patients. From the clinical point of use, the analgesic effect of calcitonin is beneficial throughout the whole period of medical treatment of osteoporotic patients. Salmon calcitonin in a daily dose of 100 IU subcutaneously or 200 IU intranasally reduces dramatically the back pain (p < 0.0005) after a recent osteoporotic vertebral fracture, and promotes the early mobility of patients. The finding that injectable or intranasally administered salmon calcitonin effectively controls severe pain in osteoporotic patients with a recent vertebral fracture, allowing them earlier mobility in combination with a reduction of the urinary hydroxyproline excretion, and a limitation of the considerable bone loss that may occur during prolonged bed rest, make this therapeutic scheme attractive.

Analgesic effect of salmon calcitonin suppositories in patients with acute pain due to recent osteoporotic vertebral crush fractures: a prospective double-blind, randomized, placebo-controlled clinical study

OBJECTIVE

To evaluate the analgesic efficacy of calcitonin suppositories (200 IU) in comparison with bed rest and paracetamol tablets, as a rescue analgesic.

DESIGN

A prospective, double-blind, randomized, placebo-controlled, clinical trial.

PATIENTS

Forty patients (8 men and 32 postmenopausal women), who had recently (within the last 5 days) suffered a nontraumatic osteoporotic vertebral fracture.

SETTING AND INTERVENTIONS

All patients were admitted to the hospital, divided randomly into two groups and received either one calcitonin or placebo suppository once a day, respectively, for 28 days. All patients were allowed to take paracetamol tablets (500 mg), with a maximum dose of six tablets daily.

OUTCOME MEASURES

Spinal pain evaluation was performed at the beginning of the study (before the initiation of treatment) and then daily until the end of the study (day 28) using the Huskinsson's visual analog scale (VAS) and a painmeter device, by direct pressure on the fractured vertebra. Pain was evaluated with the patients attempting or performing four different locomotor functions, e.g., bed rest, sitting, standing, and walking functions. Biochemical urine and plasma measurements were carried out before the initiation of treatment and on days 14 and 28.

RESULTS

All calcitonin-treated patients experienced an overall statistically significant (all p values < 0.001) decrease of spinal pain as assessed by the VAS and the painmeter device. Pain relief allowed for early mobilization and the gradual restoration of the locomotive functions in the calcitonin-treated group. Placebo-treated patients remained in bed for almost the whole of the observation period. At the end of the study (28th day), fasting osteocalcin, hydroxyproline/creatinine, and calcium/creatinine ratio values were statistically significantly (all p values < 0.001), lower in the calcitonin-treated than in the placebo-treated patients. In the placebo group these values showed a gradual increase. In the calcitonin-treated group side effects mainly included dizziness and enteric irritation caused by the suppositories. Enteric irritation was also present in the placebo-treated group.

CONCLUSIONS

Salmon calcitonin suppositories (200 IU daily) caused a dramatic decrease in spinal pain in patients with recent osteoporotic vertebral fractures and influenced the early mobilization and the gradual restoration of their locomotor functions.

Pain relief from nasal salmon calcitonin in osteoporotic vertebral crush fractures. A double blind, placebo-controlled clinical study

We examined the analgesic effect of nasal salmon calcitonin in patients with acute pain due to recent, nontraumatic osteoporotic vertebral crush fractures. 32 men and 68 postmenopausal women were studied using a prospective, double-blind, placebo-controlled clinical design. Men and women taking 200 IU of nasal salmon calcitonin daily for a period of 28 days had a dramatic decrease of spinal pain. This analgesic effect was accompanied by early mobilization and gradual restoration of the locomotor functions, such as sitting, standing and walking. Patients receiving the placebo nasal spray remained in bed for almost the entire period of observation. The consumption of high doses of paracetamol did not help placebo patients to get out of bed during the 4 weeks of hospitalization. Nasal salmon calcitonin and early mobilization also reduced hydroxyproline excretion, thus preventing massive bone loss during the period of bedrest.

Calcitonin in the Prevention and Therapy of Osteoporotic Syndromes

It is now generally accepted that estrogen status, exercise and adequate calcium intake are the singularly most important factors which guarantee the assumption of genetically programmed peak bone mass. Physicians also recognize that estrogen replacement therapy is not only essential to prevent bone loss in the early postmenopausal female, but also for the long-term preservation of bone mineral density. The efficacy of either continuous or intermittent calmon calcitonin administration in preventing further bone loss and in some instances decreasing fracture incidences in established osteoporotic syndromes is currently well established. As noted during a variety of controlled investigations performed both in the United States and abroad, and in the Physician's Resource Manual on Osteoporosis published by the United States National Osteoporosis Foundation, salmon calcitonin is also effective in early postmenopausal women who are not candidates for estrogen replacement therapy in addition to those patients with established osteoporosis. The practicing physician should acknowledge that of all the anti-resorptive agents recommended for therapy in osteoporotic syndromes, estrogens and salmon calcitonin are currently the only two drugs recommended by the U.S. Food and Drug Administration (USFDA) as safe and effective as treatment modalities in osteoporosis.