Comparative absorption of calcium sources and calcium citrate malate for the prevention of osteoporosis.
(17/3580)
Anthropologically speaking, humans were high consumers of calcium until the onset of the Agricultural Age, 10,000 years ago. Current calcium intake is one-quarter to one-third that of our evolutionary diet and, if we are genetically identical to the Late Paleolithic Homo sapiens, we may be consuming a calcium-deficient diet our bodies cannot adjust to by physiologic mechanisms. Meta-analyses of calcium and bone mass studies demonstrate supplementation of 500 to 1500 mg calcium daily improves bone mass in adolescents, young adults, older men, and postmenopausal women. Calcium citrate malate has high bioavailability and thus has been the subject of calcium studies in these populations. Positive effects have been seen in prepubertal girls, adolescents, and postmenopausal women. The addition of trace minerals and vitamin D in separate trials has improved the effect of calcium citrate malate on bone density and shown a reduction of fracture risk. (+info)
Translating research into practice: a personal case study.
(18/3580)
Although much will change in the National Health Service as a result of the publication of the new White Paper, The new NHS: modern, dependable, the challenges of translating research into practice and ensuring evidence-based policy and practice will remain. This case study demonstrates some of the challenges and has important lessons for the future practice of public health medicine. (+info)
Effects of total coumarins of Cnidium monnieri on bone density and biomechanics of glucocorticoids-induced osteoporosis in rats.
(19/3580)
AIM: To evaluate the effects of total coumarins from dried fruits of Cnidium monnieri (TCCM) on glucocorticoids (GC)-induced osteoporosis (OP) in rats. METHODS: Single photon absorptiometric and biomechanical character measurements of femurs were used. RESULTS: The bone density (BD) indices in proximal, middle, and distal segments in GC group were decreased by 12% (P < 0.05), 14% (P < 0.05), and 12% (P < 0.05), respectively vs control group. The BD on proximal, middle, and distal segments in GC-TCCM group were increased by 26% (P < 0.01), 34% (P < 0.01), and 31% (P < 0.01), respectively vs GC group. The biomechanical competence in femoral middle segments in GC group tended to decrease vs control group. In GC-TCCM group, the torsional strength, energy, maximal torsional angle, and rigidity were increased by 15% (P < 0.05), 32% (P < 0.05), 14% (P > 0.05), and 13% (P > 0.05), respectively vs the GC group. CONCLUSION: TCCM not only prevented glucocorticoids-induced osteoporosis but also increased the torsional strength of femurs in rats. (+info)
Clinic visits and hospital admissions for care of acid-related upper gastrointestinal disorders in women using alendronate for osteoporosis.
(20/3580)
CONTEXT: About 1 in 3 women taking alendronate for osteoporosis report gastrointestinal symptoms, a rate much higher than that found during clinical trials. OBJECTIVE: To establish the frequency of outpatient visits and hospital admissions for acid-related upper gastrointestinal disorder (ARD) among women taking alendronate and to identify potential risk factors. METHODS: A retrospective database analysis identified 812 women with osteoporosis who had filled one or more 10-mg alendronate prescriptions from October 1995 through October 1996. RESULTS: One hundred (12.3%) of the 812 women received healthcare for ARD, a clinical encounter rate of 28.5 per 100 person-years. A reference group of 362,109 women from the same health plan had 17.6 ARD encounters per 100 person-years. Excluding women who had ARDs before receiving alendronate, alendronate users were 1.6 (95% CI = 1.2, 2.7) times more likely to have an ARD encounter than nonusers. Risk of having ARD increased with age [users aged 70 years and older had a relative risk of 1.5 (95% confidence interval (CI) 1.0-2.30) compared with younger women] and with concurrent use of nonsteroidal anti-inflammatory drugs (NSAIDS) (relative risk 1.7, 95% CI 1.1-2.6). CONCLUSIONS: Elderly alendronate users or those concurrently taking NSAIDS should be carefully monitored because of their high risk of having ARD. Cost/benefit analyses of alendronate treatment for osteoporosis should include costs of treating ARD. (+info)
Differential patterns of altered bone formation in different bone compartments in established osteoporosis.
(21/3580)
AIM: To investigate the level of bone formation in the different bone compartments in cases of established osteoporosis, as previous work has concentrated on trabecular bone alone. METHODS: Bone formation rates were measured histomorphometrically, in the periosteal (P), cortical (C), subcortical (SC), and trabecular (T) compartments in iliac crest biopsies from 159 patients with established osteoporosis. The values were standardised using age and sex matched control data and patterns of differential change determined by analysis of parametric status (increased, normal, reduced). RESULTS: Mean bone formation was reduced in all four compartments. This was more marked (4.4/4.1 standard deviations below the mean in C/T, v 2.3/0.9 in P/SC) and more frequent (reduced in 81.5%/78.3% in T/C, v 43.3%/44% in P/SC) in the trabecular and cortical compartments than in the periosteal or subcortical bone. Parametric status was equal in trabecular and cortical bone in 85.4% of cases, and in periosteal and subcortical bone in 65.7%, but in all four compartments in only 35.1%, indicating differential alteration of bone formation in the two sets of compartments (T/C v P/SC). CONCLUSIONS: Altered trabecular bone formation is important in osteoporosis, but there are differential patterns of alteration in the other three compartments, emphasising the presence of different microenvironments in bone; thus the effect on the cortical compartment was similar to that on the trabecular, while the subcortical and periosteal compartments also showed linkage. The linkage between the two pairs was divergent, indicating different control of bone formation, with resultant different patterns of perturbation in osteoporosis. (+info)
Femoral trabecular bone of osteoarthritic and normal subjects in an age and sex matched group.
(22/3580)
OBJECTIVE: To describe changes to the cancellous structure of femoral bone from patients with severe primary osteoarthritis by comparison with age and sex matched controls. METHOD: Specimens were taken from 18 male and 18 female pairs. One of each pair was a normal control, the other having severe primary osteoarthritis which required hip arthroplasty. Undecalcified cancellous bone blocks were embedded in resin, sectioned and impregnated with silver. Histoquantitation was performed using image analysis. Using a plate model for the trabecular structure of bone, an estimate was made of bone volume, bone surface, trabecular thickness, trabecular separation and trabecular number. RESULTS: In osteoarthritis, pooled male and female data show a significant decrease in trabecular number together with an increase in trabecular thickness and separation. The statistical variance in the histomorphometric variables for each of the study groups was calculated and expressed as the ratio of osteoarthritic to control. This ratio shows that the variance of the osteoarthritic groups is significantly increased for each variable in the pooled data. The same trend is evident in the male and female groups. CONCLUSIONS: This quantitative study of cancellous bone architecture in the femoral head, infero-medial to the fovea, has found increased trabecular thickness and decreased trabecular number in patients with primary osteoarthritis. Increased morphometric variance has shown that severe osteoarthritis, contrary to osteoporosis, is associated with heterogeneous bone structures. These findings provide some basis for understanding how osteoarthritis may contribute to the prevention of osteoporotic fracture. (+info)
The benefits of hormone replacement therapy in pre-menopausal women with oestrogen deficiency on haemodialysis.
(23/3580)
BACKGROUND: Impaired sexual function is an important cause of depression in uraemic females. Hyperprolactinaemia is frequent, and often associated with decreased serum oestradiol concentration, which can significantly contribute to accelerated bone loss. The aim of the study was to evaluate the effect of hormone replacement therapy (HRT) on sexual function, serum 17beta-oestradiol and prolactin, and bone mineral density (BMD) in pre-menopausal women undergoing haemodialysis. METHODS: Among 63 women on haemodialysis, aged 18-45 years, 23 with secondary amenorrhoea and serum oestradiol < 30 pg/ml were enrolled into the 1 year study. They were divided into: group I (n = 13) treated with transdermal oestradiol with cyclic addition of noretisterone acetate, and control group II (n = 10). BMD was measured with dual energy X-ray absorptiometry (DEXA). RESULTS: No important changes in sexual function and hormonal profile were observed in the control group, whereas in all women from group I the treatment induced regular menses and a marked improvement of libido and sexual activity. Serum 17beta-oestradiol increased after the first month from 20.5 +/- 11.7 to 46.8 +/- 13.6 pg/ml (P < 0.001) and remained at that level until the end of the study, accompanied by a decrease of serum prolactin (from 1457 +/- 1045 to 691 +/- 116 mIU/ml after 12 months; P < 0.001). In group I, the treatment induced an increase in BMD, although significant only in L2-L4 (P < 0.05), whereas in group II a mild insignificant decrease was observed. However, a comparison of BMD values after 12 months in both groups revealed marked (P < 0.01-P < 0.05) differences at all studied sites. CONCLUSIONS: Transdermal HRT allows sustained physiological serum oestradiol concentrations in pre-menopausal women with oestrogen deficiency on haemodialysis, with the restoration of regular menses and a marked improvement in their sexual function. The treatment inhibits bone demineralization and can play an important role in the prevention of early osteoporosis in this group of patients. (+info)
Lactose malabsorption and rate of bone loss in older women.
(24/3580)
OBJECTIVES: to study the prevalence of lactose malabsorption with increasing age and to determine whether lactose malabsorbers consume less dietary calcium, have lower bone mineral density or display faster bone loss than lactose absorbers. DESIGN: 80 healthy Caucasian women aged 40-79 years (20 per decade) were studied for 1 year. METHODS: breath hydrogen exhalation was measured for 3 after a 50 g oral lactose challenge. Bone density was assessed in the radius, femoral neck, lumbar spine and total body by dual energy x-ray absorptiometry and dietary calcium intake was estimated by 4-day diet records and food-frequency questionnaires. RESULTS: lactose malabsorption rose with age (15% in those aged 40-59 years versus 50% in those aged 60-79; P < 0.01). Malabsorbers aged 70-79 years consumed significantly less calcium than lactose absorbers of this age (P < 0.05). Baseline total body calcium values were lower in lactose malabsorbers (n=26) than in lactose absorbers (n=54) but age-adjustment eliminated this difference. Bone change (% per year) was correlated with dietary calcium intake at the femoral neck and trochanter (P < 0.05) but was not statistically greater in malabsorbers than in absorbers. CONCLUSIONS: the ability to absorb lactose declines in the 7th decade. This may contribute to decreased dietary intakes of milk products and calcium in elderly women. However, lactose malabsorption without reduction in calcium intake has little effect on bone mineral density or the rate of bone loss. (+info)