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Osteoporosis


Recent Management Controversies in Osteoporosis Susan M DeLange Hudec1


and Pauline M Camacho2


1. Endocrinology Fellow, Loyola University Medical Center; 2. Associate Professor of Medicine and Director, Loyola University Osteoporosis and Metabolic Bone Disease Center, Loyola University Medical Center


Abstract


Osteoporosis is a important health concern that leads to significant morbidity for millions of Americans. Most recently, several areas of osteoporosis treatment have been debated, including calcium and vitamin D supplementation, duration of bisphosphonate therapy, and frequency of bone mineral density measurement. This article reviews the recent studies on these controversial topics and presents the current practice guidelines.


Keywords Osteoporosis, vitamin D, calcium, bisphosphonates


Disclosure: The authors have no conflicts of interest to declare. Received: 23 June 2011 Accepted: 5 September 2011 Citation: European Endocrinology, 2012;8(1):61–4 Correspondence: Pauline M Camacho, Division of Endocrinology, Loyola Medical Center, 2160 S First Avenue, Bldg 54, Maywood, IL 60153, US. E: pcamach@lumc.edu


Osteoporosis is a significant health concern that currently affects more than 10 million Americans, with an additional 34 million Americans at risk due to low bone mass. Osteoporotic fractures can lead to disabling pain, and nearly 30 % of patients with hip fractures require nursing home admission. In addition, 20 % of patients with hip fractures are no longer living one year after fracture. In 1994, the World Health Organization (WHO) defined osteoporosis as a T-score based on bone mineral density (BMD). Osteoporosis is present when BMD lies 2.5 standard deviations (SDs) or more below the mean value for young healthy women (i.e. a T-score of <-2.5 SDs). Osteoporosis is further defined by the American Association of Clinical Endocrinologists (AACE) as a T-score of -2.5 or below in the spine (anteroposterior), femoral neck, or total hip, or the presence of fracture of the hip or spine (in the absence of other bone conditions).1 Once osteoporosis has been diagnosed it is classified as either primary or secondary. Primary osteoporosis occurs later in life, in women often following the menopause. Secondary osteoporosis results from medications, concomitant conditions or disease processes2


(a list of secondary causes can be seen in Table 1).1 These


secondary causes must be fully evaluated and excluded prior to initiating treatment.1


There are several topics for debate in the current treatment of osteoporosis, which will be addressed in this article. These include the use of calcium and vitamin D supplements, duration of pharmacological therapy, and the appropriate method for monitoring therapy.


Calcium Supplementation


Calcium and vitamin D are important in successful osteoporosis treatment. Randomised clinical trials have demonstrated that adequate calcium intake increased BMD and decreased the incidence of fractures.3,4


age group, for adequate bone health.5


Over the past several years,


however, research studies have demonstrated a possible link between calcium supplementation and increased risk of cardiovascular disease,6


making the choice of an appropriate dose of calcium the subject of increasing controversy.


In a randomised controlled trial designed to evaluate the effect of calcium supplementation on the risk of cardiovascular disease, 1,471 postmenopausal women were recruited and randomized to receive either 1,000 mg elemental calcium or placebo. After five years of follow-up, the women randomized to calcium were found to have a statistically significant (p=0.0099) increased incidence of myocardial infarction (MI).7


Following the results of this study, a


meta-analysis was performed to evaluate the risk of calcium supplements on cardiovascular events.8


It included 15 studies in


which patients received >500 mg calcium per day. The mean calcium intake was 1,800 mg/day, patients were followed for a minimum of two years, and mean follow-up was 45 months. Cardiovascular outcomes were taken from self reports and hospital records. This analysis revealed an increased risk of MI in patients who received calcium supplementation;8


however, the studies included did not


In these trials, women who received calcium supplements of 1,000–1,200mg/day had fewer fractures than women who did not receive calcium supplementation. Guidelines therefore recommend a daily calcium intake of 800–1,200 mg/day, depending on


© TOUCH BRIEFINGS 2012


have cardiovascular outcomes as primary or secondary outcomes, nor did patients receive vitamin D supplementation. Therefore, a repeat meta-analysis was performed that included two further randomised controlled studies in which patients had received calcium and vitamin D plus Women’s Health Initiative (WHI) data. This meta-analysis also demonstrated a statistically significant (p=0.05) increase in the risk of MI in the calcium group versus placebo. This study was limited by the WHI data, which were obtained from a publicly accessible dataset and accounted for the majority (75–80 %) of the data included in the meta-analysis.9


In the WHI trial, 36,282 post-menopausal women were randomised to calcium carbonate 1,000 mg/day plus vitamin D 800 units daily


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