Biomedical subjects

Aliya Khan

Publications and source records attributed to Aliya Khan.

7 recordsLinked to original sources

PubMed2006

Anabolic agents: a new chapter in the management of osteoporosis.

Osteoporosis in postmenopausal women has until now been treated with antiresorptive agents, reducing the incidence of fragility fracture by approximately 50%. Clinical research has led to the development of new anabolic therapies capable of increasing the production of bone matrix by osteoblasts and reversing microarchitectural deterioration, resulting in major improvements in both bone quality and bone quantity. Teriparatide, a recombinant human parathyroid hormone consisting of the first 34 of 84 amino acids in human parathyroid hormone, has been shown to reduce significantly the risk of both vertebral and non-vertebral fractures in postmenopausal women. This agent was recently approved for use in Canada. Strontium ranelate is a new oral agent capable of uncoupling bone resorption from bone formation, which results in increases in bone formation with reductions in bone resorption. This agent has also been shown to reduce the risk of both vertebral and non-vertebral fracture while improving bone structure. Anabolic therapies represent a major advance in the management of postmenopausal osteoporosis, and they may provide significant benefit to those patients with severe osteoporosis in whom antiresorptive therapy has proven insufficient. Anabolic therapies should complement the antiresorptive treatments currently available for use in women with postmenopausal osteoporosis.

Anabolic Agents↗

PubMed2006

Premenopausal women and low bone density.

OBJECTIVE: To review the evidence and provide an approach to management of low bone density among premenopausal women. QUALITY OF EVIDENCE MEDLINE: was searched from January 1990 to November 2004 and articles graded by level of evidence (I to III). Diagnosis and management recommendations were based on evidence from randomized controlled trials and expert consensus. MAIN MESSAGE: Bone mineral density (BMD) testing among premenopausal women should be completed only in the presence of approved indications. Current evidence does not support screening for osteoporosis among premenopausal women. Low BMD in premenopausal women is associated with a lower fracture risk than seen in postmenopausal women. In the absence of fragility fractures, low BMD might reflect low peak bone mass based on genetic predisposition, environment, and lifestyle factors. Clinical evaluation enables distinction between low peak bone mass and a systemic disorder resulting in low BMD and skeletal fragility. Common causes of low bone density among premenopausal women include ovulatory disturbances and low body weight. CONCLUSION: Bone mineral density alone is insufficient for diagnosis of osteoporosis among premenopausal women in the absence of fragility fractures. Antiresorptive therapy has been evaluated and shown to benefit premenopausal women using glucocorticoid therapy or those with primary hyperparathyroidism.

Bone Resorption↗

PubMed2005

Prevalence of Vitamin D inadequacy among postmenopausal North American women receiving osteoporosis therapy.

PURPOSE: To evaluate serum 25-hydroxyvitamin D [25(OH)D] concentrations and factors related to vitamin D inadequacy in postmenopausal North American women receiving therapy to treat or prevent osteoporosis. METHODS: Serum 25(OH)D and PTH were obtained in 1536 community-dwelling women between November 2003 and March 2004. Multivariate logistic regression was used to assess risk factors for suboptimal (<30 ng/ml) 25(OH)D. RESULTS: Ninety-two percent of study subjects were Caucasian, with a mean age of 71 yr. Thirty-five percent resided at or above latitude 42 degrees north, and 24% resided less than 35 degrees north. Mean (sd) serum 25(OH)D was 30.4 (13.2) ng/ml: serum 25(OH)D was less than 20 ng/ml in 18%; less than 25 ng/ml in 36%; and less than 30 ng/ml in 52%. Prevalence of suboptimal 25(OH)D was significantly higher in subjects who took less than 400 vs. 400 IU/d or more vitamin D. There was a significant negative correlation between serum PTH concentrations and 25(OH)D. Risk factors related to vitamin D inadequacy included age, race, body mass index, medications known to affect vitamin D metabolism, vitamin D supplementation, exercise, education, and physician counseling regarding vitamin D. CONCLUSIONS: More than half of North American women receiving therapy to treat or prevent osteoporosis have vitamin D inadequacy, underscoring the need for improved physician and public education regarding optimization of vitamin D status in this population.

Accidental Falls↗

PubMed2005

Management of low bone mineral density in premenopausal women.

OBJECTIVE: To review evidence for management of low bone density in premenopausal women and to establish practical guidelines for management of low bone density in this population by family physicians. METHOD: A search of MEDLINE for relevant articles published between January 1990 and May 2004 was conducted. Articles retrieved were graded by level of evidence. Recommendations for diagnosis and therapy were based on evidence from randomized controlled trials and expert consensus. RESULTS: Low bone density in premenopausal women is not associated with the same increased risk of fracture seen in older women. In the absence of fragility fractures and loss of height, it may be a reflection of low peak bone mass and may represent the normal variation in bone mineral density (BMD). Women may have low bone density secondary to an underlying skeletal or systemic disorder. Common causes of low bone density in premenopausal women include ovulatory disturbances and low body weight. CONCLUSION: Osteoporosis is diagnosed in the premenopausal female population in the presence of fragility fractures and is not based solely on the results of BMD testing. Secondary causes of bone loss should be excluded, and any underlying condition contributing to low bone density should be corrected. Antiresorptive therapy has been evaluated only in those premenopausal women who are on glucocorticoid therapy and in those with primary hyperparathyroidism. Only in these conditions has antiresorptive therapy been shown to improve BMD.

Adult↗

PubMed2005

Recommendations for bone mineral density reporting in Canada.

OBJECTIVE: To propose a set of recommendations for optimal bone mineral density (BMD) reporting in postmenopausal women and older men and to provide clinicians with both a BMD diagnostic category and a useful tool to assess an individual's risk of osteoporotic fracture. OPTIONS: The current methods of BMD reporting were reviewed. In this document, we propose that an individual's 10-year absolute fracture risk, rather than BMD alone, be used for fracture risk categorization. Consequently, age, sex, BMD, fragility fracture history, and glucocorticoid use are the basis for the approach outlined in this document. OUTCOMES: An optimal BMD report as proposed in this document will provide clinicians with both a BMD diagnostic category and a useful tool to assess an individual's risk of osteoporotic fracture. A BMD report format, a checklist, and a patient questionnaire are meant to further encourage its use. EVIDENCE: All recommendations were developed using a consensus from clinicians and experts in the field of BMD testing and a standard method for the evaluation and citation of the supporting evidence. VALUES: These recommendations were developed by a multidisciplinary working group under the auspices of the Scientific Advisory Council of the Osteoporosis Society of Canada and the Canadian Association of Radiologists. BENEFITS, HARM, AND COSTS: Optimal BMD reports help the practitioner to assess an individual's risk for osteoporotic fracture and to decide whether medical therapy is warranted. RECOMMENDATIONS: The BMD report should include: patient identifiers. Dual-energy X-ray absorptiometry (DXA) scanner identifier. BMD results expressed in absolute values (g/cm2; 3 decimal places) and T-score (1 decimal place) for lumbar spine; proximal femur (total hip, femoral neck, and trochanter); and an alternate site (forearm BMD preferred: 1/3 radius, 33% radius or proximal radius) if either hip or spine is not valid. A statement about any limitations due to artifacts, if present. The fracture risk category (low, moderate, or high) as determined by using Tables 3 and 4 and by including major clinical factors that modify absolute fracture risk probability (with an indication of the corresponding absolute 10-year fracture risk of <10%, 10-20%, or >20%). A statement as to whether the change is statistically significant or not for serial measurements. The BMD centre's least significant change for each skeletal site (in g/cm2) should be included. VALIDATION: Recommendations were based on consensus opinion. Since these are the first Canadian recommendations integrating clinical risk factors in a quantitative fracture risk assessment, it is anticipated that these "Recommendations for BMD Reporting in Canada" will be a work in progress and will be updated periodically to accommodate advances in this field.

Absorptiometry, Photon↗

PubMed2003

Advances in osteoporosis therapy. 2003 update of practical guidelines.

OBJECTIVE: To review evidence for current therapies for postmenopausal osteoporosis and to establish practical guidelines for management of osteoporosis by family physicians. QUALITY OF EVIDENCE: MEDLINE was searched from January 1990 to January 2003. Articles retrieved were graded by level of evidence (I to III). Recommendations for diagnosis and therapy were based on evidence from randomized controlled trials and meta-analyses. MAIN MESSAGE: Osteoporosis is treatable. Early diagnosis and intervention is recommended. After excluding secondary causes of osteoporosis, physicians should advise patients to take appropriate calcium and vitamin D supplementation. Those with osteopenia at risk of fractures and those with established osteoporosis need additional therapy. CONCLUSION: Approved pharmacologic therapies include alendronate, risedronate, raloxifene, calcitonin, cyclical etidronate, and hormone replacement therapy. Family physicians can help with early diagnosis and intervention and should discuss lifestyle modification with patients.

Aged↗

PubMed2002

Bone densitometry: applications and limitations.

Osteoporosis is clinically diagnosed in its advanced stages, usually following a fracture. Accurate, precise, and noninvasive skeletal assessment is now possible for early detection of osteoporosis at a preclinical stage. Currently, the gold standard in bone mass measurement and fracture prediction is dual energy X-ray absorptiometry (DEXA) of the hip and spine. Exponential increases in fracture risk have been observed with small decreases in bone mineral density. Bone mineral density (BMD) should be considered in conjunction with independent clinical risk factors for fracture, including: low body weight, history of postmenopausal fracture, family history of fracture, and poor neuromuscular function. The World Health Organization (WHO) diagnostic criteria for osteoporosis and osteopenia are appropriate for postmenopausal Caucasian women and are applicable to DEXA assessments at the hip, spine, or forearm. This review explores the relationship between BMD and fracture risk, the principles of bone densitometry interpretation, and the applications as well as the limitations of DEXA technology, and presents cases illustrating common errors seen in the interpretation of DEXA studies.

Absorptiometry, Photon↗