29
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      The Ovariectomized Rat as a Model for Studying Alveolar Bone Loss in Postmenopausal Women

      review-article
      1 , 1 , 2 , *
      BioMed Research International
      Hindawi Publishing Corporation

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          In postmenopausal women, reduced bone mineral density at the hip and spine is associated with an increased risk of tooth loss, possibly due to a loss of alveolar bone. In turn, having fewer natural teeth may lead to compromised food choices resulting in a poor diet that can contribute to chronic disease risk. The tight link between alveolar bone preservation, tooth retention, better nutritional status, and reduced risk of developing a chronic disease begins with the mitigation of postmenopausal bone loss. The ovariectomized rat, a widely used preclinical model for studying postmenopausal bone loss that mimics deterioration of bone tissue in the hip and spine, can also be used to study mineral and structural changes in alveolar bone to develop drug and/or dietary strategies aimed at tooth retention. This review discusses key findings from studies investigating mandible health and alveolar bone in the ovariectomized rat model. Considerations to maximize the benefits of this model are also included. These include the measurement techniques used, the age at ovariectomy, the duration that a rat is studied after ovariectomy and habitual diet consumed.

          Related collections

          Most cited references52

          • Record: found
          • Abstract: found
          • Article: not found

          The recent prevalence of osteoporosis and low bone mass in the United States based on bone mineral density at the femoral neck or lumbar spine.

          The goal of our study was to estimate the prevalence of osteoporosis and low bone mass based on bone mineral density (BMD) at the femoral neck and the lumbar spine in adults 50 years and older in the United States (US). We applied prevalence estimates of osteoporosis or low bone mass at the femoral neck or lumbar spine (adjusted by age, sex, and race/ethnicity to the 2010 Census) for the noninstitutionalized population aged 50 years and older from the National Health and Nutrition Examination Survey 2005-2010 to 2010 US Census population counts to determine the total number of older US residents with osteoporosis and low bone mass. There were more than 99 million adults aged 50 years and older in the US in 2010. Based on an overall 10.3% prevalence of osteoporosis, we estimated that in 2010, 10.2 million older adults had osteoporosis. The overall low bone mass prevalence was 43.9%, from which we estimated that 43.4 million older adults had low bone mass. We estimated that 7.7 million non-Hispanic white, 0.5 million non-Hispanic black, and 0.6 million Mexican American adults had osteoporosis, and another 33.8, 2.9, and 2.0 million had low bone mass, respectively. When combined, osteoporosis and low bone mass at the femoral neck or lumbar spine affected an estimated 53.6 million older US adults in 2010. Although most of the individuals with osteoporosis or low bone mass were non-Hispanic white women, a substantial number of men and women from other racial/ethnic groups also had osteoporotic BMD or low bone mass. © 2014 American Society for Bone and Mineral Research.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            The ovariectomized rat model of postmenopausal bone loss.

            Dike Kalu (1991)
            An animal model of postmenopausal bone loss can be defined as a living animal in which spontaneous or induced bone loss due to ovarian hormone deficiency can be studied, and in which the characteristics of the bone loss and its sequalae resemble those found in postmenopausal women in one or more respects. Although in comparison to humans, the skeletal mass of rats remains stable for a protracted period during their lifespan, rats can be ovariectomized to make them sex-hormone deficient, and to stimulate the accelerated loss of bone that occurs in women following menopause. Ovariectomy induced bone loss in the rat and postmenopausal bone loss share many similar characteristics. These include: increased rate of bone turnover with resorption exceeding formation; and initial rapid phase of bone loss followed by a much slower phase; greater loss of cancellous than cortical bone; decreased intestinal absorption of calcium; some protection against bone loss by obesity; and similar skeletal response to therapy with estrogen, tamoxifen, bisphosphonates, parathyroid hormone, calcitonin and exercise. These wide-ranging similarities are strong evidence that the ovariectomized rat bone loss model is suitable for studying problems that are relevant to postmenopausal bone loss.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Effects of estrogen plus progestin on risk of fracture and bone mineral density: the Women's Health Initiative randomized trial.

              In the Women's Health Initiative trial of estrogen-plus-progestin therapy, women assigned to active treatment had fewer fractures. To test the hypothesis that the relative risk reduction of estrogen plus progestin on fractures differs according to risk factors for fractures. Randomized controlled trial (September 1993-July 2002) in which 16 608 postmenopausal women aged 50 to 79 years with an intact uterus at baseline were recruited at 40 US clinical centers and followed up for an average of 5.6 years. Women were randomly assigned to receive conjugated equine estrogen, 0.625 mg/d, plus medroxyprogesterone acetate, 2.5 mg/d, in 1 tablet (n = 8506) or placebo (n = 8102). All confirmed osteoporotic fracture events that occurred from enrollment to discontinuation of the trial (July 7, 2002); bone mineral density (BMD), measured in a subset of women (n = 1024) at baseline and years 1 and 3; and a global index, developed to summarize the balance of risks and benefits to test whether the risk-benefit profile differed across tertiles of fracture risk. Seven hundred thirty-three women (8.6%) in the estrogen-plus-progestin group and 896 women (11.1%) in the placebo group experienced a fracture (hazard ratio [HR], 0.76; 95% confidence interval [CI], 0.69-0.83). The effect did not differ in women stratified by age, body mass index, smoking status, history of falls, personal and family history of fracture, total calcium intake, past use of hormone therapy, BMD, or summary fracture risk score. Total hip BMD increased 3.7% after 3 years of treatment with estrogen plus progestin compared with 0.14% in the placebo group (P<.001). The HR for the global index was similar across tertiles of the fracture risk scale (lowest fracture risk tertile, HR, 1.20; 95% CI, 0.93-1.58; middle tertile, HR, 1.23; 95% CI, 1.04-1.46; highest tertile, HR, 1.03; 95% CI, 0.88-1.24) (P for interaction =.54). This study demonstrates that estrogen plus progestin increases BMD and reduces the risk of fracture in healthy postmenopausal women. The decreased risk of fracture attributed to estrogen plus progestin appeared to be present in all subgroups of women examined. When considering the effects of hormone therapy on other important disease outcomes in a global model, there was no net benefit, even in women considered to be at high risk of fracture.
                Bookmark

                Author and article information

                Journal
                Biomed Res Int
                Biomed Res Int
                BMRI
                BioMed Research International
                Hindawi Publishing Corporation
                2314-6133
                2314-6141
                2015
                28 April 2015
                : 2015
                : 635023
                Affiliations
                1Faculty of Applied Health Sciences, Brock University, St. Catharines, ON, Canada L2S 3A1
                2Centre for Bone and Muscle Health, Brock University, St. Catharines, ON, Canada L2S 3A1
                Author notes
                *Wendy E. Ward: wward@ 123456brocku.ca

                Academic Editor: Andrea Vecchione

                Article
                10.1155/2015/635023
                4427799
                26060817
                356a8bae-d2ee-4b9a-aece-785602b37005
                Copyright © 2015 B. D. Johnston and W. E. Ward.

                This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                : 7 October 2014
                : 2 March 2015
                Categories
                Review Article

                Comments

                Comment on this article