The efficacy of calcitriol therapy in the management of bone loss and fractures: a qualitative review

Osteoporosis, a skeletal disorder characterized by a reduction in bone strength, increases fracture risk. Primary osteoporosis is usually a result of reduced bone mineral density as a consequence of natural aging. Secondary osteoporosis is usually a result of a disease, such as cystic fibrosis, or medical treatment, such as corticosteroids or cancer treatment.

INTRODUCTION

Currently, ten million Americans are osteoporotic and an additional 34 million have the precursor condition, osteopenia. Osteoporosis leads to 1.5 million fractures and 500,000 hospitalizations annually. Osteoporosis-related fractures increase mortality and reduce quality of life. Calcitriol, the active form of vitamin D, regulates intestinal calcium absorption, among other actions. During the past four decades, many clinical trials investigating the effect of calcitriol on bone loss have been performed.

METHODS

We conducted a systematic qualitative review of clinical trials that assessed calcitriol for the treatment of osteoporosis and bone loss. In these clinical trials, calcitriol was used as a monotherapy and in combination with other therapeutic bone agents.

RESULTS AND CONCLUSION

Studies using calcitriol monotherapy, although not conclusive, found that calcitriol slowed the rate of bone loss in a variety of populations. Calcitriol in combination with other therapeutic bone agents was shown to have additional bone-preserving effects when compared to the use of therapeutic bone agents alone. A common side-effect of calcitriol therapy was hypercalcemia and hypercalciuria, but the degree of hypercalcemia was mild. Recent research found that intermittent dosing can reduce hypercalcemia rates. Calcitriol, alone or in combination with other agents, should be considered for the therapy of osteoporosis.

Association of cytokines with quality of life among breast cancer survivors: A randomized pilot study exploring the effect of Tai Chi Chuan

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Background: While advances in cancer treatment can increase breast cancer (BC) survival, cancer treatment side effects can decrease quality of life (QOL). Cancer cardiotoxicity is a major side effect of chemotherapy and radiotherapy that leads to cardiovascular disease (CVD). The combined burden of cancer and cancer cardiotoxicity drastically affects QOL. Cytokine-mediated inflammatory profiles are dysregulated by cancer treatments and are implicated in the pathogenesis of CVD. Tai Chi Chuan (TCC), an exercise mode with an energy expenditure equivalent to brisk walking, has been shown to improve cardiovascular function and QOL among BC survivors. The purpose of this pilot study was to explore how TCC affects cytokines and how cytokine changes are related to QOL changes among BC survivors. Methods: This pilot study compared the effects of 12 weeks (3, 60 min. sessions/week) of TCC with support therapy on IL-2 and IL-8 and on QOL among 21 BC survivors (mean age=51; range 33–78). Cytokine responses were obtained via serum ELISA and QOL were assessed via the FACIT measurement system pre- and post-intervention. Results: Mean levels of IL-2 decreased in the TCC group (CS=-8.82) but increased in the control group (CS=4.60). Mean levels of IL-8 increased in the TCC group (CS=0.32) but decreased in the control group (CS=-3.82). ANCOVA, controlling for baseline, revealed no treatment effect for IL-2 but there was a statistical trend suggesting a possible treatment effect and baseline interaction for IL-8 (p=0.1). Bivariate analyses revealed a negative association between overall QOL and IL-8 (p=0.07), functional QOL (e.g. ability to work) and IL-8 (p=0.03), as well as physical QOL (e.g. energy level) and IL-8 (p=0.01) in the TCC group. Correlations also showed a negative association between overall QOL and IL-2 (p=0.05) and between functional QOL and IL-2 (p=0.005) among the control group. Conclusions: These findings suggest that TCC-induced changes in cytokines may be associated with changes in QOL, specifically in the physical and functional domains. Future research is needed to verify these pilot study findings and should focus on cardiotoxic effects associated with physical and functional QOL. NCI grant 1R25-CA102618 and Sally Schindel Cone.

No significant financial relationships to disclose.

The effect of tai chi chuan on bone remodeling and cytokines among breast cancer survivors: A feasibility trial

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Background: Weight-bearing exercise may slow the rate of bone loss associated with breast cancer treatment. The purpose of this study is to determine the effect of tai chi chuan (TCC) on bone health, as measured by the changes in the levels of bone resorption and bone formation. This study also aimed to investigate whether changes in bone health were correlated with growth and inflammation markers that serve as regulators of bone cell function. Methods: Female patients (N=16) who completed treatment for breast cancer within the past 30 months were randomly assigned to either the TCC group or the psycho-educational support group without exercise (ST) for 60 minutes, three times a week for a period of 12 weeks. Serum levels of bone resorption (N-telopeptides of type I collagen; NTx) and bone formation (bone specific alkaline phosphatase; BAP) were determined by ELISA at baseline and post-intervention. Using validated methods, a bone remodeling index (BRI) was calculated from levels of NTx and BAP. In addition, pre- and post-intervention levels of insulin-like growth factor binding protein 1 (IGFBP-1) and interleukin-2 (IL-2), markers associated with excessive bone resorption, were measured. Lastly, levels of interleukin-6 (IL-6), believed to enhance bone formation, were measured at both pre- and post-intervention. Results: ANCOVA analyses demonstrated that survivors in the TCC group experienced a greater increase in bone remodeling than those in the ST group (Δ BRITCC=1.6 vs Δ BRIST=0.2; p=0.04). All correlations were determined by Pearson's correlation coefficients. IGFBP-1 was negatively correlated with increasing bone remodeling levels (r=-0.43, p=0.14). IL-2 was also negatively correlated with increasing bone remodeling levels (r=-0.35, p=0.24). IL-6 was positively correlated with increasing bone remodeling levels (r=0.69, p=0.01). Conclusions: This pilot study suggests that TCC has positive effects on bone remodeling through changes in growth and inflammation factors that regulate bone cell function. A larger, more definitive trial examining the influence of TCC on bone remodeling is warranted. Funding: Sally Schindel Cone and R25 CA102618

No significant financial relationships to disclose.

Associations between adult and childhood secondhand smoke exposures and fecundity and fetal loss among women who visited a cancer hospital

BACKGROUND

A large percentage of the population continues to be exposed to secondhand smoke (SHS). Although studies have consistently linked active smoking to various pregnancy outcomes, results from the few studies examining SHS exposure and pregnancy difficulties have been inconsistent.

METHODS

Approximately 4800 women who presented to Roswell Park Cancer Institute between 1982 and 1998 and reported being pregnant at least once were queried about their childhood and adult exposures to SHS using a standardised questionnaire. Women were asked to report on selected prenatal pregnancy outcomes (fetal loss and difficulty becoming pregnant).

RESULTS

Approximately 11.3% of women reported difficulty becoming pregnant, while 32% reported a fetal loss or 12.4% reported multiple fetal losses. 40% reported any prenatal pregnancy difficulty (fetal loss and/or difficulty becoming pregnant). SHS exposures from their parents were associated with difficulty becoming pregnant (OR = 1.27, 95% CI 1.03 to 1.56) and lasting >1 year (OR = 1.34, 95% CI 1.12 to 1.60). Exposure to SHS in both at home during childhood and at the time of survey completion was also associated with fetal loss (OR = 1.39, 95% CI 1.17 to 1.66) and multiple fetal losses (OR = 1.62, 95% CI 1.25 to 2.11). Increasing current daily hours of SHS exposure as an adult was related to the occurrence of both multiple fetal loss and reduced fecundity (p(trend) < 0.05).

CONCLUSIONS

Reports of exposures to SHS during childhood and as an adult were associated with increased odds for prenatal pregnancy difficulties. These findings underscore the public health perspective that all people, especially women in their reproductive years, should be fully protected from tobacco smoke.