PubMed Health⌕ Search

Biomedical subjects

M R McClung

Publications and source records attributed to M R McClung.

At least 19 recordsLinked to original sources
PubMed2003

The efficacy of 48-week oral ibandronate treatment in postmenopausal osteoporosis when taken 30 versus 60 minutes before breakfast.

Since effective prevention and treatment of osteoporosis demands a high degree of long-term compliance, optimization of the dosing regimen in terms of efficacy and convenience of drug intake is a critical issue of oral bisphosphonate treatment. The purpose of the present study was to investigate whether the efficacy of the treatment with oral ibandronate, 2.5 mg daily, can be maintained if changing the postdose fast from 60 to 30 min. This was a 48-week, multicenter, open-label, randomized, parallel-group noninferiority study. Subjects were postmenopausal women 55-80 years old with lumbar spine (L1-L4) bone mineral density (BMD) corresponding to a T score < or =2.5. Women were randomly assigned to take 2.5 mg ibandronate exactly 30 or 60 min before breakfast. Lumbar spine and proximal femur (trochanter, femoral neck, total hip) BMD were measured by dual energy X-ray absorptiometry; serum osteocalcin and creatinine-corrected urinary C-telopeptide of type I collagen (u-CTX/Cr) excretion were measured by ELISA. After 48 weeks of treatment, the relative increase in lumbar spine BMD from baseline in the 30-min fast group was lower than that in the 60-min fast group (3.07% versus 4.95%, one-sided 97.5% CI = -2.89%) such that the prespecified noninferiority criteria were not met. The mean relative increases in BMD at the trochanter (3.04% versus 4.36%), femoral neck (1.82% versus 2.19%), and total hip (2.35% versus 3.21%) in the 30-min fast group were also lower than those in the 60-min fast group. Less suppression of the markers of bone turnover (u-CTX/Cr, -48.5% vs -61.8%; serum osteocalcin, -34.8% vs 43.8%) was observed in the 30-min compared with the 60-min group. In conclusion, if reducing the postdose fasting interval, dose-increase compensation would likely to be required to maintain efficacy of oral ibandronate treatment. Another potential solution for improving the convenience with bisphosphonate treatment is expected from weekly or monthly dosing regimens currently under clinical investigations.

Absorptiometry, Photon↗
PubMed2002

The efficacy and tolerability of risedronate once a week for the treatment of postmenopausal osteoporosis.

This study evaluated the efficacy and tolerability of risedronate once a week (35 mg and 50 mg) compared with risedronate 5 mg once daily in women with osteoporosis. We conducted a randomized, double-blind, active-controlled, 2-year study; the primary efficacy assessment was performed after 1 year. Subjects were women aged 50 years or older who had been postmenopausal for at least 5 years, with either a bone mineral density (BMD) T-score of -2.5 or lower (lumbar spine or proximal femur) or a T-score lower than -2 and at least one prevalent vertebral fracture. Subjects received risedronate 5 mg once daily, 35 mg once a week or 50 mg once a week. All subjects also received 1 g daily of elemental calcium supplementation and supplemental vitamin D if the baseline serum levels were low. The primary efficacy measure was percent change in lumbar spine BMD at 12 months. A total of 1,456 women were randomized and received medication; 1,209 (83%) women completed 12 months. The mean percent change (SE) in lumbar spine BMD after 12 months was 4.0% (0.2%) in the 5 mg daily group, 3.9% (0.2%) in the 35 mg group, and 4.2% (0.2%) in the 50 mg group; each once-a-week treatment was determined to be as effective as the daily treatment. Outcomes of the secondary efficacy measurements and safety assessments were also similar in all 3 groups after 12 months. Risedronate 35 mg and 50 mg once a week provide the same efficacy and safety as the daily 5 mg regimen; therefore, the lower dose, 35 mg once a week, is considered optimal for women with postmenopausal osteoporosis who desire a once-a-week regimen.

Administration, Oral↗
PubMed2001

Effect of risedronate on the risk of hip fracture in elderly women. Hip Intervention Program Study Group.

BACKGROUND: Risedronate increases bone mineral density in elderly women, but whether it prevents hip fracture is not known. METHODS: We studied 5445 women 70 to 79 years old who had osteoporosis (indicated by a T score for bone mineral density at the femoral neck that was more than 4 SD below the mean peak value in young adults [-4] or lower than -3 plus a nonskeletal risk factor for hip fracture, such as poor gait or a propensity to fall) and 3886 women at least 80 years old who had at least one nonskeletal risk factor for hip fracture or low bone mineral density at the femoral neck (T score, lower than -4 or lower than -3 plus a hip-axis length of 11.1 cm or greater). The women were randomly assigned to receive treatment with oral risedronate (2.5 or 5.0 mg daily) or placebo for three years. The primary end point was the occurrence of hip fracture. RESULTS: Overall, the incidence of hip fracture among all the women assigned to risedronate was 2.8 percent, as compared with 3.9 percent among those assigned to placebo (relative risk, 0.7; 95 percent confidence interval, 0.6 to 0.9; P=0.02). In the group of women with osteoporosis (those 70 to 79 years old), the incidence of hip fracture among those assigned to risedronate was 1.9 percent, as compared with 3.2 percent among those assigned to placebo (relative risk, 0.6; 95 percent confidence interval, 0.4 to 0.9; P=0.009). In the group of women selected primarily on the basis of nonskeletal risk factors (those at least 80 years of age), the incidence of hip fracture was 4.2 percent among those assigned to risedronate and 5.1 percent among those assigned to placebo (P=0.35). CONCLUSIONS: Risedronate significantly reduces the risk of hip fracture among elderly women with confirmed osteoporosis but not among elderly women selected primarily on the basis of risk factors other than low bone mineral density.

Aged↗
PubMed2000

Alendronate in early postmenopausal women: effects on bone mass during long-term treatment and after withdrawal. Alendronate Osteoporosis Prevention Study Group.

We studied the effect on bone mass of alendronate treatment for 5 yr and its withdrawal. Four hundred and forty-seven postmenopausal women with normal bone mass entered a 3-yr randomized trial followed by a 2-yr open label extension. Three hundred and eleven women completed the first 3 yr, and 263 consented to continue and completed the extension. We are reporting data from groups using the dose of alendronate currently approved for osteoporosis prevention (5 mg) or from the group in which alendronate treatment was withdrawn: 52 women received alendronate (5 mg) for 5 yr (group I), 56 received 3 yr of placebo followed by alendronate (5 mg) for 2 yr (group II), and 52 received alendronate (20 mg) for 2 yr followed by 3 yr off therapy (group III). In group I, alendronate (5 mg) increased bone mineral density (BMD) at the spine and trochanter by 2.5-3.2% (P < 0.001 vs. baseline) and stabilized total body and femoral neck BMD (change vs. baseline, P = NS) over 5 yr. By the end of 5 yr, BMD was comparable at the spine, hip, and total body in groups I and III. The 3-yr decrease in BMD after withdrawal of alendronate (20 mg) in group III was 1.8-5.7% (P < 0.01 vs. baseline) and similar to the 3-yr decrease in BMD in group II during the initial 3 yr. In conclusion, alendronate (5 mg) for 5 yr or alendronate (20 mg) for 2 yr followed by 3 yr off therapy prevented postmenopausal bone loss. After withdrawal of alendronate (20 mg), bone loss resumed at the normal early postmenopausal rate.

Absorptiometry, Photon↗
PubMed2000

Bisphosphonates in osteoporosis: recent clinical experience.

Bisphosphonates are potent inhibitors of bone resorption that have come to play a prominent role in the prevention and treatment of various forms of osteoporosis and other metabolic bone disorders. Therapy in women with osteoporosis and at high fracture risk substantially reduces the incidence of vertebral and non-vertebral fractures. In younger postmenopausal women, bisphosphonates are attractive alternatives to oestrogen to prevent bone loss and the subsequent development of osteoporosis. Bisphosphonates have recently become the treatment of choice to prevent and treat the skeletal consequences of chronic corticosteroid therapy. When administered appropriately, these drugs are very well tolerated and have an excellent safety profile. The challenges now to clinicians are to identify the patients for whom bisphosphonate therapy is indicated and to devise dosing and monitoring strategies to enhance the long-term adherence to therapy required to realise the full benefits of these treatments.

Animals↗
PubMed2000

Clinical risk factors and evaluation of the risk of osteoporosis in clinical practice.

Bone health is determined by influences that accumulate over one's entire lifetime. Numerous factors including age, heredity, nutrition, physical activity, sex steroids and other medical problems all influence the possibility of an individual developing osteoporosis. Fractures due to minimal trauma are the important consequence of osteoporosis, but the risk of fractures is also determined by many non-skeletal risk factors such as body size and the frequency of injury. We now have effective therapeutic options to prevent bone loss and to reduce fracture risk. Assessing risk factors for both osteoporosis and for fractures allows clinicians to identify individuals for whom these therapies are most appropriate.

Age Distribution↗
PubMed1999

Alendronate and estrogen-progestin in the long-term prevention of bone loss: four-year results from the early postmenopausal intervention cohort study. A randomized, controlled trial.

BACKGROUND: Up to 3 years of treatment with alendronate, 5 mg/d, prevents postmenopausal bone loss. OBJECTIVE: To determine whether the effect of alendronate is sustained at 4 years of treatment and persists after treatment is discontinued. DESIGN: Randomized, controlled trial. SETTING: United States and Europe. PARTICIPANTS: 1609 postmenopausal women 45 to 59 years of age. INTERVENTION: Participants were randomly assigned to receive oral alendronate, 5 mg/d or 2.5 mg/d; placebo; or open-label estrogen-progestin. Women in the alendronate groups received alendronate for the first 2 years of the study. Treatment was then continued without change or replaced with placebo for the last 2 years of the study. MEASUREMENTS: Annual measurement of bone mineral density. RESULTS: By year 4, the bone mineral density of participants in the placebo group had decreased by 1% to 6% (P < 0.001). Four years of treatment with 5 mg of alendronate per day increased bone mineral density at the spine (mean change [+/-SE], 3.8%+/-0.3%), hip (mean, 2.9%+/-0.2%), and total body (mean, 0.9%+/-0.2%) (P < 0.001 overall). By year 4, bone mineral density at most skeletal sites was greater in participants who switched from alendronate to placebo than in those who continuously received placebo. In years 3 and 4, bone loss in participants who switched from alendronate to placebo was similar to that seen during years 1 and 2 in those who continuously received placebo. Compared with 5 mg of alendronate per day, estrogen-medroxyprogesterone acetate produced similar increases in bone mineral density and estradiol-norethisterone acetate produced increases that were substantially greater. CONCLUSIONS: Four years of treatment with alendronate or estrogen-progestin prevented postmenopausal bone loss. A residual effect was seen 2 years after alendronate therapy was stopped; however, continuous alendronate treatment was more effective in preventing postmenopausal bone loss than 2 years of alendronate followed by 2 years of placebo.

Alendronate↗
PubMed1999

Diagnosis and management of osteoporosis in postmenopausal women: clinical guidelines. International Committee for Osteoporosis Clinical Guidelines.

The authors, all physicians involved in clinical research on bone and practicing clinicians, propose practical guidelines for identifying persons with osteoporosis or those at high risk of developing the disease and for managing patients who may benefit from therapy. These guidelines are based on an analysis of peer-reviewed articles published before November 1998. A flowchart of women who might benefit from treatment is provided, including clinical presentation (recent fracture of the spine, hip, or other bone or no fracture; risk factors for osteoporosis); relevant investigations (bone mineral density measurement and laboratory tests required for the differential diagnosis); and therapeutic management (general measures such as calcium and vitamin D supplementation and specific pharmacologic interventions such as estrogen, bisphosphonates, intranasal calcitonin, raloxifene, fluoride salts, and other compounds that have been assessed in randomized clinical trials). The strongest evidence for antifracture efficacy (reduction of vertebral and nonvertebral fracture risk) was observed with alendronate.

Adult↗
PubMed1999

Blood pressure and calcium intake are related to bone density in adult males.

Based on the premise that elevated blood pressure and low bone mass have both been associated with poor Ca nutriture and disturbances in Ca metabolism, a cross-sectional study was employed to determine if blood pressure and dietary Ca intake were significantly related to bone mass. Forty-seven men between 24-77 years of age with blood pressure values ranging from normal to mildly elevated comprised the study group. Blood pressure was measured with a random-zero sphygmomanometer. Bone mineral content (BMC) and density (BMD) of the hip, spine and total body were measured with dual-photon absorptiometry. Dietary intake and physical activity were also assessed. Multiple linear regression analysis was used for statistical analysis. After adjusting for known confounding variables (age, BMI, Ca intake, and others) diastolic blood pressure was negatively related to BMC (P < or = 0.05) and BMD (P < or = 0.01) of the total body, trochanteric region (P < 0.01) and Ward's triangle (P < 0.05), and to BMC of the femoral neck (P < 0.05) and lumbar spine, although the latter was just shy of statistical significance (P = 0.058). Systolic blood pressure was negatively related to trochanteric BMD (P = 0.04) and BMC (P = 0.06). Ca intake was positively related to total body BMD (P = 0.005), and BMC of the lumbar spine (P = 0.05). In this population of men, Ca intake was a positive predictor, and blood pressure was a negative predictor of regional measures of bone mass. These findings support the concept that independent of age, BMI and Ca intake, elevated blood pressure varies indirectly with bone mass and density, known predictors of osteoporotic fractures. Future studies are needed to determine whether elevated blood pressure is causally related to the development of low bone mass, and what role dietary Ca plays in that pathway.

Adult↗
PubMed1998

Risedronate in the treatment of Paget's disease of bone: an open label, multicenter study.

An open-label, multicenter study was conducted to determine the efficacy and safety of oral risedronate (a pyridinyl bisphosphonate) in 162 patients (102 men, 60 postmenopausal women; mean age, 68 years) with moderate to severe Paget's disease of bone (mean serum alkaline phosphatase [ALP] approximately seven times the upper limit of normal). Patients were treated with oral risedronate, 30 mg/day for 84 days, followed by 112 days without treatment. This 196-day cycle was repeated once if serum ALP did not normalize or increased from the nadir value by > or = 25%. At the end of the first and second cycles, the mean percentage decreases for serum ALP were 65.7% and 69.1%, and for urinary hydroxyproline/creatinine 50.4% and 66.9%, respectively. The decreases from baseline in ALP and urinary hydroxyproline/creatinine were significant (p < 0.001). Normalization of serum ALP was observed in 86 patients (53.8%): 53 during the first treatment cycle and 33 during the second. There was a significant proportion of patients reporting a decrease in the pagetic bone pain at days 84 and 196 (p < 0.001). Overall, risedronate was well tolerated. Five patients withdrew due to adverse events, none of which were considered to be drug related. In conclusion, 30 mg of oral risedronate administered daily for 84 days significantly reduced the biochemical indices of disease activity and was associated with pain reduction in patients with moderate to severe Paget's disease of bone. Normalization of ALP was observed in the majority of patients. Repeated administration of risedronate was shown to be beneficial. In general, risedronate was well tolerated and demonstrated a good safety profile.

Administration, Oral↗
PubMed1997

Increments in bone mineral density of the lumbar spine and hip and suppression of bone turnover are maintained after discontinuation of alendronate in postmenopausal women.

PURPOSE: Previously we have reported a significant increase in bone mineral density (BMD) of the spine and the hip and reductions in biochemical indices of bone turnover in postmenopausal women with osteoporosis treated with alendronate at various doses over 1 to 2 years. We have followed BMD and biochemical parameters in these patients for 1 or 2 years after discontinuation of alendronate to determine resolution of alendronate effects. PATIENTS AND METHODS: Participants received daily oral doses of placebo, 5 or 10 mg of alendronate for 2 years, or 20 or 40 mg of alendronate for 1 year followed by 1 year of placebo. No treatment was given in the third year of study. RESULTS: Lumbar spine BMD changes in the 5- and 10-mg groups (-1.4 and -0.4%) were similar to those in the placebo group (-1.2%) 1 year after discontinuation of drug and lumbar spine BMD changes in the 20- and 40-mg groups (-1.2% and 0.8%) were similar to those in the placebo group (-0.9%) 2 years after discontinuation of drug. BMD of the total hip followed the same pattern of resolution. The difference in BMD between alendronate and placebo groups at the end of alendronate treatment was maintained up to 2 years. Residual reductions in the bone resorption markers urinary deoxypyridinoline (D-Pyr) and collagen type 1 cross-linked N telopeptides and the bone formation markers serum bone-specific alkaline phosphatase and osteocalcin remained for 1 year after discontinuation of 5 and 10 mg of alendronate and for 2 years after discontinuation of 20 and 40 mg of alendronate, other than return of D-Pyr to baseline 1 year after cessation of treatment with the 5- and 10-mg doses. CONCLUSIONS: A residual decrease in bone turnover may be found up to 2 years after discontinuation of alendronate. Accelerated bone loss is not observed when treatment is discontinued. However, continuous therapy with alendronate is required to achieve a continuous gain in BMD.

Adult↗
PubMed1997

Dose-response relationships for alendronate treatment in osteoporotic elderly women. Alendronate Elderly Osteoporosis Study Centers.

Alendronate (ALN) is an aminobisphosphonate employed as an antiresorptive agent in the treatment of osteoporosis. The present study was carried out to determine dose-response relationships, particularly the effects of relatively low doses of ALN, on bone mineral density (BMD), biochemical indexes of bone and mineral metabolism, and bone histology, with particular attention to effects in elderly women. This prospective, randomized, double blind, 2-yr multicenter study compared the effects of placebo with those of 1.0, 2.5, or 5.0 mg ALN daily. All subjects received supplemental calcium (500 mg daily) as the carbonate. We studied 359 women with lumbar spine BMD at least 2.0 SD below the peak young adult mean. Subjects were stratified by age, with 135 aged 60-69 yr and 224 aged 70-85 yr. Histomorphometry was performed on transiliac bone biopsies obtained from 104 subjects after 1 yr and from 83 subjects after 2 yr. This study elucidated the previously uninvestigated lower region of the dose-response curve for ALN in osteoporosis. Over 2 yr, treatment with 1.0, 2.5, or 5.0 mg/day increased lumbar spine BMD, on the average, by 0.65%, 3.54%, and 5.67%, respectively, compared with that in the placebo group (P < 0.001 vs. placebo for the 2.5 and 5 mg groups). Significant dose-related increases were also seen in BMD at appendicular sites and in total body BMD. Dose-dependent reductions in bone turnover to new steady states were indicated by serum and urine biochemical markers as well as by histomorphometry. There was also a dose-related reduction in the proportion of subjects suffering nonvertebral fractures (P < 0.05). Safety profiles were similar for the ALN and placebo groups and for both age strata. Efficacy was similar for both age strata. There was no evidence of impaired mineralization or other histological abnormalities due to ALN treatment. We conclude that treatment with ALN over a period of 2 yr was well tolerated and produced dose-dependent increases in BMD without evidence of a plateau over the dose range of 1.0-5.0 mg daily. One milligram daily did not result in a significant effect on BMD, and 5.0 mg daily produced favorable effects at all sites measured. Other studies have demonstrated somewhat greater effects on 10 mg daily. ALN, was equally effective and well tolerated in osteoporotic women over 70 yr old as in younger women with the same condition.

Aged↗
PubMed1997

New developments in osteoporosis.

Osteoporosis is no longer a disorder about which nothing can be done. Many of the new developments in this field have already assumed important places in clinical management. The author reviews many of the new developments in treating osteoporosis and attempts to place them in a practical, clinical context.

Absorptiometry, Photon↗
PubMed1996

Discrepancies in normative data between Lunar and Hologic DXA systems.

Many studies have shown the high correlation between Lunar and Hologic DXA bone mineral density (BMD) measurements despite differences in absolute calibration. However, in clinical practice, raw BMD values (in g/cm2) are not normally used for assessing skeletal status and fracture risk. Instead, the BMD values are expressed in terms of the number of standard deviations above or below the young normal value (commonly referred to as the T-score). If the normative populations of the various systems are consistent, the standard deviation scores should also be consistent. For this reason, the World Health Organization (WHO) recently established diagnostic criteria for osteoporosis based on T-scores and not BMD. However, few studies have compared the instruments in terms of their standard deviation scores. In this study, we used linear regression to compare T-scores in 83 women at L1-4 and 120 women at the femoral neck obtained on a Lunar DPX and a Hologic QDR-1000/W system. patient BMD and T-score measurements were highly correlated between the two systems (r > 0.95). No clinically significant difference in L1-4 T-scores was seen (less than 0.1 SD). However, linear regression analysis confirmed a systematic difference of 0.9 SD between the femoral neck T-scores. This discrepancy is caused by: (1) differences in the normal populations, and (2) differences in statistical models used to determine the young normal mean and standard deviation. In an attempt to correct the discrepancy, the female young normal mean and standard deviation were recalculated for the femoral neck using published epidemiological data from NHANES and existing DXA cross-calibration equations. The Hologic young normal value (mean +/- SD) was redefined as 0.85 +/- 0.11 g/cm2, while the Lunar value was redefined as 1.00 +/- 0.11 g/cm2. When the femoral neck T-scores for the study population were recalculated on the basis of these new values, the results were equivalent between manufactures, effectively eliminating the discrepancy. However, the revised values should be confirmed by additional measurements in young normal adults.

Absorptiometry, Photon↗
PubMed1996

Clinical utility of bone mass measurements in adults: consensus of an international panel. The Society for Clinical Densitometry.

Low bone mass predicts future fracture risk as well as high cholesterol or high blood pressure can predict the risk of heart disease or stroke. Prevention of the first fracture should be a clinical goal. In patients without fractures, osteopenia and osteoporosis can be diagnosed based on the extent of reduction in bone mass below mean peak bone mass of young healthy individuals. As bone mass decreases, fracture risk increases exponentially. Clinical situations in which an assessment of bone mass and fracture risk affects therapeutic decisions include estrogen deficiency, vertebral abnormalities, radiographic osteopenia, asymptomatic primary hyperparathyroidism, and long-term corticosteroid therapy. Serial measurements can also be used to monitor the effects of osteoporosis treatments. The appropriate technique and skeletal site for bone mass measurements should be chosen based on the patient's circumstances and the precision of measurement. A clinical interpretation can enhance the value of computer-generated bone mass measurement reports and improve decision making.

Absorptiometry, Photon↗
PubMed1996

Current bone mineral density data on bisphosphonates in postmenopausal osteoporosis.

Osteoporosis is a disorder of skeletal fragility characterized by an imbalance in bone turnover such that bone resorption exceeds bone formation. Accelerated bone resorption is the principal physiological derangement responsible for both postmenopausal and age-related bone loss. Furthermore, increased bone turnover is itself a risk factor for fracture, independent of bone mineral density. Thus, there is a strong rationale for the use of potent antiresorptive drugs for the treatment of postmenopausal osteoporosis. Bisphosphonates are a class of drugs that inhibit osteoclast activity and bone resorption. Recent studies with etidronate, pamidronate, and alendronate demonstrate the ability of these drugs to suppress bone turnover and to preserve or increase bone mass. In large studies with alendronate, in long-term studies with clodronate, and in patients at high fracture risk treated with etidronate, decreased fracture occurrence is observed. Except for upper gastrointestinal intolerance with aminobisphosphonates, these drugs are very well tolerated. Bisphosphonates are promising alternatives to estrogen for the treatment of patients with decreased bone mass and, particularly, those with severe osteoporosis. Further studies are needed to define the optimal long-term dosing regimen and to establish whether more potent members of this drug class are more effective or can be administered by different routes. The effectiveness of bisphosphonates in combination with estrogen or bone growth stimulators also requires evaluation, and the extended long-term safety of these drugs must be determined.

Bone Density↗