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D Hartwell

Publications and source records attributed to D Hartwell.

At least 19 recordsLinked to original sources
PubMed2005

Clinical effectiveness and cost-effectiveness of drotrecogin alfa (activated) (Xigris) for the treatment of severe sepsis in adults: a systematic review and economic evaluation.

OBJECTIVES: To assess the clinical and cost-effectiveness of drotrecogin alfa (activated) for the treatment of adults with severe sepsis in a UK context. DATA SOURCES: Electronic databases. Data from the commercial use of the drug up to April 2002. Data from the manufacturer submission to the National Institute for Clinical Excellence (NICE). REVIEW METHODS: A systematic review of the literature and an economic evaluation were undertaken. Data were synthesised through a narrative review with full tabulation of results from included studies. RESULTS: The evidence on the effectiveness of drotrecogin alfa (activated) for the treatment of severe sepsis came primarily from one large pivotal randomised controlled trial, the PROWESS study. This study demonstrated a statistically significant absolute reduction in 28-day mortality of 6.5%. Longer term survival benefit was maintained to 90 days. By 9 months, the trend towards increased median survival was non-significant, although the survival curves did not cross. Results presented by the number of organ dysfunctions were not statistically significant, but when mortality rates for those with two or more organ failures were combined, the relative risk of death was significantly lower in those treated with drotrecogin alfa (activated) compared with placebo. However, this report highlights a number of considerations relevant to the subgroup analyses reported for the PROWESS study. Published cost-effectiveness studies of treatment with drotrecogin alfa (activated) have applied a range of methods to the estimation of benefits, estimating an incremental gain per treated patient of between 0.38 and 0.68 life-years (for patients with severe sepsis). For patients with severe sepsis and multiple organ dysfunction, the manufacturer (Eli Lilly) estimated an incremental gain of 1.115 life-years per treated patient, compared to 1.351 life-years per treated patient estimated by the Southampton Health Technology Assessments Centre (SHTAC). These latter UK analyses are based on a patient group that is more severely affected by disease, where effectiveness is greater and the baseline risk of all-cause mortality is much higher (SHTAC analysis), these factors are associated with the noted difference in effect. The three published cost-effectiveness studies report cost for US and Canadian patient groups; for those patients with severe sepsis they report the additional cost per patient treated in a range around 10,000-16,000 dollars. The manufacturer's submission reports analysis for the UK, based on 28-day survival data in patients with severe sepsis and multiple organ dysfunction (the European licence indication), with the additional mean cost per treated patient estimated to be 5106 pounds. The analysis undertaken by SHTAC, for a UK group of patients with severe sepsis and multiple organ dysfunction, estimates an additional mean cost per patient treated of 6661 pounds. The manufacturer's submission to NICE presents cost-effectiveness estimates for drotrecogin alfa (activated) in the UK, in patients with severe sepsis and multiple organ dysfunction, at 6637 pounds per quality-adjusted life-year (QALY) based on 28-day effectiveness data, and 10,937 pounds per QALY based on longer term follow-up data. SHTAC developed an independent cost-effectiveness model and estimated a base-case cost per QALY of 8228 pounds in patients with severe sepsis and multiple organ failure (based on 28-day survival data). Simulation results indicate that where the NHS is willing to pay 20,000 pounds per QALY, drotrecogin alfa (activated) is a cost-effective use of resources in 98.7% of cases. Published economic evaluations report various sensitivity analyses, with results sensitive to changes in the measure of treatment effect, but otherwise studies reported that results were robust to variations in most assumptions used in the cost-effectiveness analysis. CONCLUSIONS: Drotrecogin alfa (activated) plus best supportive care appears clinically and cost-effective compared with best supportive care alone, in a UK cohort of severe sepsis patients, and in the subgroup of more severely affected patients with severe sepsis and multiple organ failure. The introduction of drotrecogin alfa (activated) will involve a substantial additional cost to the NHS. The treatment-eligible population in England and Wales may comprise up to 16,570 patients, with an estimated annual drug acquisition cost of over 80 million pounds, excluding VAT. Further research is required on the longer term impact of drotrecogin alfa (activated) on both mortality and morbidity in UK patients with severe sepsis, on the clinical and cost-effectiveness of drotrecogin alfa (activated) in children (under 18 years) with severe sepsis, and on the effect of the timing of dosage and duration of treatment on outcomes in severe sepsis.

Adolescent↗
PubMed2005

Clinical effectiveness and cost-effectiveness of immediate angioplasty for acute myocardial infarction: systematic review and economic evaluation.

OBJECTIVES: To review the clinical evidence comparing immediate angioplasty with thrombolysis, and to consider whether it would be cost-effective. DATA SOURCES: Electronic databases. Experts in the field. REVIEW METHODS: For clinical effectiveness, a comprehensive review of randomised control trials (RCTs) was used for efficacy, and a selection of observational studies such as case series or audit data used for effectiveness in routine practice. RCTs of thrombolysis were used to assess the relative value of prehospital and hospital thrombolysis. Observational studies were used to assess the representativeness of patients in the RCTs, and to determine whether different groups have different capacity to benefit. Clinical effectiveness was synthesised through a narrative review with full tabulation of results of all included studies and a meta-analysis to provide a precise estimate of absolute clinical benefit. Consideration was given to the effect of the growing use of stents. The economic modelling adopted an NHS perspective to develop a decision-analytical model of cost-effectiveness focusing on opportunity costs over the short term (6 months). RESULTS: The results were consistent in showing an advantage of immediate angioplasty over hospital thrombolysis. The updated meta-analysis showed that mortality is reduced by about one-third, from 7.6% to 4.9% in the first 6 months, and by about the same in studies of up to 24 months. Reinfarction is reduced by over half, from 7.6% to 3.1%. Stroke is reduced by about two-thirds, from 2.3% with thrombolysis to 0.7% with percutaneous coronary intervention (PCI), with the difference being due to haemorrhagic stroke. The need for coronary artery bypass graft is reduced by about one-third, from 13.2% to 8.4%. Caution is needed in interpreting some of the older trials, as changes such as an increase in stenting and the use of the glycoprotein IIb/IIa inhibitors may improve the results of PCI. There is little evidence comparing prehospital thrombolysis with immediate PCI. Research on thrombolysis followed by PCI, known as 'facilitated PCI', is underway, but results are not yet available. Trials may be done in select centres and results may not be as good in lower volume centres, or out of normal working hours. In addition, much of the marginal mortality benefit of PCI over hospital thrombolysis may be lost if door-to-balloon time were more than an hour longer than door-to-needle time. Conversely, within the initial 6 hours, the later patients present, the greater the relative advantage of PCI. Results suggest that PCI is more cost-effective than thrombolysis, providing additional benefits in health status at some extra cost. In the longer term, the cost difference is expected to be reduced because of higher recurrence and reintervention rates among those who had thrombolysis. CONCLUSIONS: If both interventions were routinely available, the economic analysis favours PCI, given the assumptions of the model. However, very few units in England could offer a routine immediate PCI service at present, and there would be considerable resource implications of setting up such services. Without a detailed survey of existing provision, it is not possible to quantify the implications, but they include both capital and revenue: an increase in catheter laboratory provision and running costs. The greatest problem would be staffing, and that would take some years to resolve. A gradual incrementalist approach based on clinical networks, with transfer to centres able to offer PCI, may be used. In rural areas, one option may be to promote an increase in prehospital thrombolysis, with PCI for thrombolysis failures. There is a need for data on the long-term consequences of treatment, the quality of life of patients after treatment, and the effects of PCI following thrombolysis failure.

Angioplasty↗
PubMed2004

Clinical and cost-effectiveness of continuous subcutaneous insulin infusion for diabetes.

OBJECTIVES: To assess the clinical and cost-effectiveness of continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) in the delivery of intensive insulin therapy for the treatment of diabetes mellitus. DATA SOURCES: Electronic databases, references of retrieved articles and manufacturer submissions. Experts in the field were consulted. REVIEW METHODS: For the systematic review of clinical and cost-effectiveness, studies were assessed for inclusion according to predefined criteria by two reviewers. Data extraction and quality assessment were undertaken by one reviewer and checked by a second reviewer. Data on clinical effectiveness were synthesised through a narrative review with full tabulation of all eligible studies, with meta-analysis performed where appropriate. RESULTS: Twenty studies comparing CSII with MDI were identified. Quality was generally poor. In adults with Type 1 diabetes, glycated haemoglobin improved by 0.61% (95% CI -1.29 to 0.07) in longer term studies, although this improvement was smaller when a study using bovine ultralente was excluded. A reduction in insulin dose with CSII of about 12 units per day (-11.90, 95% CI -18.16 to 5.63) was found in short-term studies, with smaller differences in longer term studies. Body weight and cholesterol levels were similar between treatments. Hypoglycaemic events did not differ significantly between CSII and MDI in most trials, but some found fewer events with CSII and one found more hypoglycaemia and hypoglycaemic coma with CSII. There was no consistency between the studies in patient preference, but progress has been made both with insulin pumps and injector pens since the publication of many of the older studies. No difference in glycated haemoglobin between CSII and MDI was found in pregnancy; one study found less insulin was required by patients with CSII, but two other studies found no significant difference. One study of adolescents found lower glycated haemoglobin and insulin dose with CSII whereas a second study found no significant difference. In CSII analogue insulin was associated with lower glycated haemoglobin levels than soluble insulin. No economic evaluations comparing CSII with MDI were identified. The estimated additional cost of CSII compared to MDI varies from GBP1091 per annum to GBP1680 per annum, according to the make of the insulin pump and the estimated life of the device. These estimates include the costs for the insulin pump, the consumables associated with delivery of CSII, and an allowance for the initial education required when patients switch from MDI to CSII. The largest component of the annual cost for CSII is the cost of consumable items (e.g. infusion sets). CONCLUSIONS: When compared with optimised MDI, CSII results in a modest but worthwhile improvement in glycated haemoglobin in adults with Type 1 diabetes. It has not been possible to establish the longer term benefits of such a difference in glycated haemoglobin, although there is an expectation that it would be reflected in a reduction in long-term complications. More immediate primary benefits from CSII may be associated with an impact on the incidence of hypoglycaemic events and the dawn phenomenon, and greater flexibility of lifestyle. However, there is limited evidence on this, and information presented to offer context on quality-of-life is based on testimonies from those patients who have had a positive experience of CSII. The estimated cost to the NHS per year for CSII would be around GBP3.5 million in England and Wales if 1% of people with Type 1 diabetes used CSII, GBP10.5 million for 3%, and GBP17.5 million for 5%. Further research should focus on wider benefits of CSII, such as flexibility of lifestyle and quality of life, and on the psychological impact of wearing a device for 24 hours every day. Research into the use of CSII in children of different ages is also needed.

Cost-Benefit Analysis↗
PubMed2000

Pro-coagulant state resulting from high levels of soluble P-selectin in blood.

The plasma concentration of soluble adhesion receptors is increased under pathological circumstances, but their function remains enigmatic. Soluble P-selectin (sP-sel) is shed from activated platelets and endothelial cells. Mice genetically engineered to express P-selectin without the cytoplasmic tail (DeltaCT) constitutively show a 3- to 4-fold increase of sP-sel in plasma. We observed that the DeltaCT mice formed fibrin very readily. In an ex vivo perfusion chamber, there was more fibrin deposited at the site of platelet thrombus formation than in wild type (WT), whereas no fibrin deposits were detected using P-selectin-deficient blood during the same interval. Similarly, in vivo, the hemorrhage produced by local Shwartzman reaction was smaller in the DeltaCT mice than in WT. In contrast, we previously showed hemorrhage to be more prominent in P-selectin knock-out mice. Infusion of mouse P-sel-Ig chimera produced the same protective effect in WT mice as seen in the DeltaCT mice, indicating that the effect was due to increased levels of sP-sel. Mice infused with P-sel-Ig showed significantly more fibrin deposited on the luminal face of the injured vessels than control mice. Plasma from DeltaCT mice or mice infused with P-sel-Ig contained higher concentration of pro-coagulant microparticles and clotted one minute faster than WT. This pro-coagulant phenotype of DeltaCT mice could be reversed by a 4-day treatment with PSGL-Ig, a P-selectin inhibitor. We propose that sP-sel should no longer be considered only as a marker of inflammation or platelet activation, but also as a direct inducer of pro-coagulant activity associated with vascular and thrombotic diseases.

Animals↗
PubMed2000

Soluble P-selectin moderates complement dependent injury.

P-selectin is an adhesion molecule expressed on activated endothelial and platelet membranes containing 9 short consensus repeats (SCRs) similar to the composition of complement regulatory proteins. In our murine model of intestinal ischemia and reperfusion where local injury is mediated by the classical complement pathway we hypothesized the SCRs would moderate the complement response. Confirmatory data were sought following hindlimb ischemia and reperfusion where injury is both complement- and neutrophil-mediated. Mice deficient in P-selectin (P-/-) were found to have similar intestinal and hindlimb permeability compared to normal wild types mice (P+/+). When reconstituted with P+/+ platelets, but not P-/- platelets, P-/- mice subjected to intestinal ischemia had a significant 29% decrease in permeability (P < 0.05) and after hindlimb ischemia the decrease was 33% (P<0.05). Reperfusion after intestinal ischemia led to a 76% fall in CH50 in P-/- compared to sham animals (P < 0.05) indicating complement activation and consumption, but only a 36% fall in animals reconstituted with P+/+ platelets (P < 0.05). Full-length, soluble P-selectin (sPsel) derived from processed platelets, but not the truncated version of sPsel has been shown to adhere to a heat labile fraction of serum and sensitized red blood cells thereby reducing Clq adherence to the sensitized red cell. From these data we conclude that sPsel moderates complement activation by competing with C1q binding to antibody, thereby limiting activation of the classical pathway that mediates murine reperfusion injury.

Animals↗
PubMed1998

Adhesion elicits an intrinsic defect in interleukin-1 expression by macrophages from autoimmune-prone MRL mice.

Macrophages (m phi) from prediseased autoimmune-prone MRL/+ and MRL/ lpr mice have a marked defect in endotoxin (LPS)-induced expression of several cytokines including interleukin 1 (IL-1). The progressive nature of this defect over time suggests that it may develop in response to specific extracellular stimuli. In this report, we show that adhesion is an essential factor for the development of aberrant IL-1 expression by m phi from autoimmune-prone MRL mice. Thus, when MRL/+ m phi were allowed to adhere before being stimulated with LPS, they demonstrated a striking defect in expression of both IL-1 message and protein in comparison with multiple normal strains. In marked contrast, when MRL/+ m phi were maintained in a non-adherent state by culture on agarose, the IL-1 defect was not evident and IL-1 expression was restored to nearly normal levels. Since an identical defect in IL-1 expression was found when MRL/+ m phi were cultured on a variety of extracellular matrix proteins (including laminin, fibronectin, type I collagen, and type IV collagen), it appears that IL-1 underexpression is dependent on the adhesive state per se rather than on engagement of any one specific adhesion receptor. Moreover, the cytoskeletal inhibitor cytochalasin D had no effect on the magnitude of the defect, indicating that the adhesion-dependent signaling events necessary to elicit IL-1 underexpression are independent of cytoskeletal rearrangement. Taken together, these results indicate that m phi from autoimmune prone MRL/+ mice have an adhesion-dependent signaling abnormality that leads to profound underexpression of the cytokine IL-1.

Animals↗
PubMed1996

Dysregulated cytokine expression in vivo in prediseased and diseased autoimmune-prone MRL mice.

Macrophages (mø) from prediseased autoimmune-prone MRL/ + and MRL/lpr mice produce markedly decreased levels of IL-1 in vitro in response to LPS. In contrast, tissues from diseased MRL/lpr mice overexpress IL-1 in vivo. To determine whether IL-1 underproduction in the MRL strains is solely an in vitro phenomenon, we compared in vivo cytokine mRNA expression from prediseased age-matched MRL/ + and MRL/lpr mice to that from normal BALB/c and C3HeB/FeJ mice. Like mø in vitro, whole organ RNA from the spleen, liver, and kidney of MRL/ + and MRL/lpr mice showed down-regulation of IL-1 RNA following intraperitoneal injection of LPS. This abnormality in inducible IL-1 expression was present in all MRL mice, irrespective of disease stage or the presence of the lpr gene. On the other hand, only diseased MRL/lpr mice displayed elevated and constitutive expression of IL-1 in their livers and kidneys. We suggest that inducible expression is most indicative of the intrinsic, or genetic, capacity of cells to produce cytokine, whereas constitutive expression reflects extracellular disease-related inflammatory stimuli present only in the diseased MRL/lpr strains. By restricting our studies to prediseased MRL mice, we have tried to eliminate the effects of disease and to focus on the predisposing genetic background. The existence both in vitro and in vivo of a defect in inducible IL-1 expression by prediseased MRL mice suggests that the molecular abnormality underlying this defect may be a part of this predisposing background to autoimmunity.

Animals↗
PubMed1994

Cytokine dysregulation and the initiation of systemic autoimmunity.

Autoimmunity (AI) exemplifies the potent and destructive activity expressed by the immune system when normal constraints against self-reactivity are lost or compromised. We have previously described a dramatic and intrinsic defect in cytokine expression in macrophages (M phi) from young AI-prone mice [1-3]. There are two points in particular that we believe speak to the importance of this observation: (i) Cytokine dysregulation is distinguished from many of the aberrancies reported in AI-prone mouse strains in that, as an inherent trait, it cannot arise as a consequence of the disease process. (ii) This defect is a remarkably consistent characteristic of M phi from strains that develop manifestations of systemic AI, including MRL/+, NZB, NZB/W F1, BXSB, and NOD, and distinguishes these strains from mice whose disease is predicated on defects in apoptosis (e.g., the lpr and gld mutations). The multigenic basis for disease and renal pathology in the former strains more closely mirror human lupus than do the disease manifestations of lpr and gld mice. In light of clear evidence that cytokines are key mediators of lymphocyte growth and function, a defect in the cytokine network has the potential to disrupt the normal regulation of self-reactivity, leading to the initiation of systemic AI.

Animals↗
PubMed1993

Interleukin-1 dysregulation is an intrinsic defect in macrophages from MRL autoimmune-prone mice.

Macrophages (M phi) from pre-diseased autoimmune-prone MRL mice (both MRL/+ and MRL/lpr) dramatically underproduce the cytokine interleukin-1 (IL-1) in comparison to M phi from a number of normal strains. In this study we show that IL-1 dysregulation by MRL M phi is fully expressed at birth, and that this defect does not change with time or the development of disease. We also constructed adult irradiation chimeras (consisting of A/J-->MRL and MRL-->A/J mice), and show that M phi isolated from these chimeras display a pattern of IL-1 production indistinguishable from that of the donor strain controls. Moreover, when we constructed a mixed chimera (A/J + MRL-->A/J, the A/J and MRL M phi coexisting within the same animal retained their individual patterns of IL-1 production when isolated by negative selection. Taken together, these results provide the first substantive evidence for an intrinsic defect (IL-1 dysregulation) in M phi from MRL autoimmune-prone mice.

Age Factors↗
PubMed1991

Imbalanced cytokine production by macrophages from autoimmune-prone mice.

Peritoneal macrophages from multiple autoimmune-prone strains of mice (MRL/lpr, MRL/+, NZB/W, BXSB, and B6/gld) show defective expression of the cytokines IL-1 and IL-6. Autoimmune mice were all used between 1 and 6 weeks of age, the earliest times being well before the onset of overt disease. Northern blot analysis reveals a parallel reduction in the levels of IL-1 alpha, IL-1 beta, and IL-6 mRNA. In contrast, the production of other proteins, including the cytokine TNF-alpha, appears to be normal. These findings imply an imbalance within the cytokine network of autoimmune macrophages. Studies on bone marrow-derived macrophage precursors, as well as macrophages from chimeric mice, suggest an intrinsic macrophage defect as opposed to conditioning by the autoimmune environment. This defect appears to be constant throughout the lifespan of autoimmune MRL/lpr mice, being equally apparent in 1-week old mice as in fully diseased 6-12-month-old mice. Aberrant regulation of IL-1 and IL-6 represents a novel defect in the function of autoimmune macrophages that is both intrinsic and substantial, and has the potential to contribute to the immune dysregulation that characterizes autoimmunity.

Animals↗
PubMed1990

Comparison of vitamin D metabolism in early healthy and late osteoporotic postmenopausal women.

We studied 20 healthy premenopausal women aged 36.5 +/- 4.0 years (mean +/- 1 SD), 123 healthy postmenopausal women aged 50.0 +/- 2.4 years, and 103 postmenopausal women aged 65.1 +/- 5.6 years with symptomatic osteoporosis (forearm and spinal fracture). Serum levels of vitamin D metabolites [25(OH)D, 24,25(OH)2D3, and 1,25-(OH)2D] were compared with (1) bone mass in the forearm (single photon absorptiometry) and in the spine (dual photon absorptiometry); (2) biochemical indices of bone formation (serum alkaline phosphatase, plasma bone Gla protein), and bone resorption (fasting urinary hydroxyproline); and (3) other biochemical estimates of calcium metabolism (serum calcium, serum phosphate, 24-hour urinary calcium, intestinal absorption of calcium). The present study revealed no difference in any of the vitamin D metabolites between the premenopausal women, the healthy postmenopausal women and the osteoporotic women as a group. The concentrations of 1,25(OH)2D and 25(OH)D were significantly lower in patients with spinal fracture than in those with forearm fracture. In the early postmenopausal women serum 1,25(OH)D was related to forearm bone mass (r = -0.20; P less than 0.05), intestinal calcium absorption (r = 0.18; P less than 0.05), and 24-hour urinary calcium (r = 0.21; P less than 0.05); serum 25(OH)D was related to spinal bone mass (r = 0.23; P less than 0.01). In the osteoporotic women, serum vitamin D metabolites were not related to bone mass, but 1,25(OH)2D was related to bone Gla protein (r = 0.33; P less than 0.001), serum phosphate (r = -0.27; P less than 0.01), and 24-hour urinary calcium (r = 0.43; P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

24,25-Dihydroxyvitamin D 3↗
PubMed1990

Changes in vitamin D metabolism during natural and medical menopause.

Thirty-nine women were studied longitudinally for 3 yr, during which period 10 women passed a natural menopause. Vitamin D metabolites were determined every 3 months in these 10 women. The same variables were studied in 42 premenopausal women with endometriosis treated for 6 months with nafarelin acetate (a LHRH agonist) given alone in a dose of 200 or 400 micrograms or in a dose of 400 micrograms combined with 1.2 mg norethisterone (NET)/day and followed-up for a further 6 months. No changes were seen in 1,25-dihydroxyvitamin D [1,25-(OH)2D], vitamin D-binding protein, or the free index of 1,25-(OH)2D during the natural menopause. A small increase was found in 25-hydroxyvitamin D [25OHD] and 24,25-(OH)2D3 after correction for seasonal variation. All three nafarelin groups had a significantly decreased free index of 1,25-(OH)2D, which returned to the baseline value on withdrawal of the treatment. Serum 25OHD and 24,25-(OH)2D3 were increased at 6 months and thereafter decreased to baseline values. These changes were still visible after correction for seasonal variation. Vitamin D-binding protein showed a small transient increase in the nafarelin plus NET group, but was unchanged in the other two groups. The 24-h urinary excretion of calcium increased significantly in the groups receiving nafarelin alone, whereas it remained unchanged in the nafarelin plus NET group. We conclude that detectable changes in 1,25-(OH)2D do not occur in natural menopause. Treatment with LHRH agonists produces a significant decrease in serum 1,25-(OH)2D, which does not seem to be dependent on increased bone resorption. This suggests that LHRH agonists may induce a change in other pituitary hormones involved in vitamin D regulation.

24,25-Dihydroxyvitamin D 3↗
PubMed1990

Vitamin D metabolism in osteoporotic women during treatment with estrogen, an anabolic steroid, or calcitonin.

We assessed the effects of a continuous oral combination of estradiol and norethisterone acetate, nandrolone decanoate, or salmon calcitonin on the vitamin D endocrine system. One hundred and nineteen postmenopausal women, aged 55-75 years, with at least one osteoporotic fracture, were randomly allocated to one year of treatment with estradiol and norethisterone acetate, nandrolone decanoate, or calcitonin, all drugs with a beneficial effect on bone. All three trials were double-blind and placebo-controlled; 104 women (87%) completed the study. We measured the total serum concentration of 1,25-dihydroxyvitamin D (1,25(OH)2D) and vitamin D-binding protein, and estimated the free 1,25(OH)2D index and the "24-hydroxylase activity" initially, and at 6 and 12 months. Furthermore, the 24-h urinary excretions of calcium, phosphate, and adenosine 3'-5'-cyclic monophosphate were assessed initially and at 12 months. The serum concentration of vitamin D-binding protein and 1,25(OH)2D increased transiently during estradiol and norethisterone acetate treatment and vitamin D-binding protein decreased transiently during nandrolone decanoate treatment. None of the other parameters were significantly affected by any of the three treatments. The risk of type II errors was below 10 per cent for all vitamin D measurements. We conclude that the vitamin D metabolites are unlikely to be of major importance for the mechanism by which these drugs exert their positive skeletal effects.

Aged↗
PubMed1990

Vitamin D metabolites--relation to age, menopause and endometriosis.

We investigated the influence of menopause, age and sex on vitamin D metabolism in a large group of healthy women (n = 113) and men (n = 108) and in a group of early postmenopausal women (n = 124). Furthermore, we studied the vitamin D metabolism in 42 women with endometriosis. The vitamin D metabolites did not show dependence on age or on duration of menopause. The serum concentrations of vitamin D metabolites did not differ in normal men and women. There were highly significant seasonal oscillations for 25(OH)D and 24,25(OH)2D3 but not for 1,25(OH)2D. Women with endometriosis had significantly elevated serum 1,25(OH)2D compared to the normal women. Our study indicates that ageing is not associated with a significant depletion of 25(OH)D, 24,25(OH)2D or 1,25(OH)2D in normal men and women up to the age of 75 years. Furthermore, changes in vitamin D metabolism seem not to be an important factor in early postmenopausal bone loss. Our results on patients with endometriosis indicate that these patients may have some calcium-metabolic disturbances.

24,25-Dihydroxyvitamin D 3↗
PubMed1989

Treatment of postmenopausal osteoporosis: is the anabolic steroid nandrolone decanoate a candidate?

Thirty-nine postmenopausal women (aged 55-75 years) with at least one osteoporotic fracture were allocated to one year of treatment with the anabolic steroid nandrolone decanoate (50 mg i.m. every 3 weeks) or placebo injection. Both groups also received a daily intake of 500 mg calcium. Thirty-six women (92%) completed the study. In the nandrolone decanoate-treated group the fat corrected bone mineral content in the proximal part of the distal forearm (measured by single photon absorptiometry) showed a significant increase of 3% compared with placebo (P less than 0.01), and the same tendency was seen in the bone mineral content of the distal part of the distal forearm and density of the lumbar spine (measured by dual photon absorptiometry). However, this did not reach significance. In the placebo group all bone mineral measurements remained unchanged. The biochemical estimates of bone formation (plasma bone Gla protein (BGP), serum alkaline phosphatase) and whole body retention (WBR) of 99mTc-diphosphonates were not statistically significantly changed by the nandrolone decanoate therapy. We conclude that treatment with nandrolone decanoate does increase the bone mineral content; however, this may not be due to a direct increase in bone formation. The mechanism may theoretically be a combination of decreased bone resorption and increased muscle mass, which both play a beneficial role in conserving bone.

Aged↗
PubMed1989

Metabolism of vitamin D2 and vitamin D3 in patients on anticonvulsant therapy.

We examined the effect of short-term treatment with pharmacological doses of vitamin D2 or vitamin D3 on the serum concentration of 1,25(OH)2D metabolites in epileptic patients on chronic anticonvulsant drug therapy. Nine patients were studied before and after treatment with vitamin D2 4000 IU daily for 24 weeks and 10 before and after treatment with vitamin D3 in the same dose. Before treatment the serum concentrations of 1,25(OH)2D and 25(OH)D were significantly lower in epileptics than in normal subjects (P less than 0.01). Vitamin D2 treatment increased the serum concentration of 1,25(OH)2D2, but a corresponding decrease in 1,25(OH)2D3 resulted in an unchanged serum concentration of total 1,25(OH)2D. The serum concentration of 25(OH)D2 and 25(OH)D increased significantly, whereas there was a small decrease in 25(OH)D3. Vitamin D3 treatment did not change the serum concentration of 1,25(OH)2D3 whereas serum 25(OH)D3 increased significantly. The correlation between the serum ratio of 1,25(OH)2D2/1,25(OH)2D3 and 25(OH)D2/25(OH)D3 estimated on vitamin D2-treated epileptic patients and normal subjects was highly significant (P less than 0.01). The data indicate that the serum concentration of 1,25(OH)2D2 and 1,25(OH)2D3 are directly proportional to the amount of their precursors 25(OH)D2 and 25(OH)D3 and that the concentration of total 1,25(OH)2D is tightly regulated.

25-Hydroxyvitamin D 2↗
PubMed1989

Discrepancy between serum concentrations of 1,25-dihydroxyvitamin D metabolites measured by radio-immunoassay and thymus radioreceptor assay during vitamin D2 treatment.

A radio-immunoassay (RIA) for determination of 1,25-dihydroxycholecalciferol (1,25(OH)2D3) and 1,25-dihydroxyergocalciferol (1,25(OH)2D2) in serum was compared with a competitive protein binding assay using calf thymus receptor to clarify the comparability of measurements in subjects treated with either vitamin D2 or vitamin D3 (4000 IU per day for 8 weeks). Before and during treatment with vitamin D3 the two assay techniques were concordant, but during vitamin D2 treatment the serum concentrations of 1,25(OH)2D2 and 1,25(OH)2D3 were higher when measured by RIA. The study demonstrates that during vitamin D2 treatment unknown compounds, recognized only by the antiserum, co-elute with 1,25(OH)2D2 and 1,25(OH)2D3 in high pressure liquid chromatography. It can be concluded that the radio-immunoassay used here cannot replace the calf thymus receptor assay.

Adult↗