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Biomedical subjects

G Pearce

Publications and source records attributed to G Pearce.

At least 19 recordsLinked to original sources

Critical path analysis in head and neck cancer: a management technique for surgical oncology.

This paper describes a study of critical path analysis (CPA) as applied to the process of care for patients with head and neck cancer. CPA is a management technique, which has been developed in both the Armed Forces and a wide range of industries. It identifies the parts of a process where improvements are most likely to make an impact on the overall time for that process. There is evidence that reducing the overall times for an oncology care process has a major impact on outcome for patients. This paper describes an appraisal of a formal application of CPA in the setting of oncology. The technique was applied to a single head and neck unit. The results were compared with published standards for times in the care process and with the comparable times for the whole of the South and West of England. The critical path (the combination of processes that limits the total time taken for the whole process) at this unit ran through the combined oncology clinic, leading to a decision to increase the frequency of these clinics, which lead to a reduction in overall process time for patients. A randomised controlled trial in five centres in the South and West region will follow which includes patient quality of life outcomes and collaborative practice to assess the impact of CPA on the patient care process.

Journal Article↗

RALF, a 5-kDa ubiquitous polypeptide in plants, arrests root growth and development.

A 5-kDa polypeptide was isolated from tobacco leaves that induced a rapid alkalinization of the culture medium of tobacco suspension-cultured cells and a concomitant activation of an intracellular mitogen-activated protein kinase. An N-terminal sequence was obtained, and a cDNA coding for the 49-aa polypeptide was isolated from a tobacco cDNA library. The cDNA encoded a preproprotein of 115 amino acids that contained the polypeptide at its C terminus. A search among known expressed sequence tags revealed that genes encoding Rapid ALkalinization Factor (RALF) preproproteins were present in various tissues and organs from 16 species of plants representing 9 families. A tomato homolog of the polypeptide was synthesized and, when supplied to germinating tomato and Arabidopsis seeds, it caused an arrest of root growth and development. Although its specific role in growth has not been established, the polypeptide joins the ranks of the increasing number of polypeptide hormones that are known to regulate plant stress, growth, and development.

Amino Acid Sequence↗

Production of multiple plant hormones from a single polyprotein precursor.

Some animal and yeast hormone genes produce prohormone polypeptides that are proteolytically processed to produce multiple copies of hormones with the same or different functions. In plants, four polypeptides have been identified that can be classed as hormones (intercellular chemical messengers) but none are known to be produced as multiple copies from a single precursor. Here we describe a polyprotein hormone precursor, present in tobacco plants, that gives rise to two polypeptide hormones, as often found in animals and yeast. The tobacco polypeptides activate the synthesis of defensive proteinase-inhibitor proteins in a manner similar to that of systemin, an 18-amino-acid polypeptide found in tomato plants. The two tobacco polypeptides are derived from each end of a 165-amino-acid precursor that bears no homology to tomato prosystemin. The data show that structurally diverse polypeptide hormones in different plant species can serve similar signalling roles, a condition not found in animals or yeast.

Amino Acid Sequence↗

Radon levels in abandoned metalliferous mines, Devon, southwest England.

Radon levels underground in two abandoned mines in Devon, United Kingdom, are reported and analyzed. Extremely high levels have been noted, 7,100,000 Bq m(-3) being the highest level recorded. This is approximately 89 times higher than the highest published radon level for caves and mines in Devon and Cornwall, England, which is 80,000 Bq m(-3). These levels have significant health implications for both casual and occupational mine explorers.

Air Pollutants, Radioactive↗

Hypersensitivity reactions during therapy with the nucleoside reverse transcriptase inhibitor abacavir.

BACKGROUND: Hypersensitivity reactions consist of a variable group of clinical findings and have been described for a wide variety of chemical compounds. OBJECTIVE: This review characterizes the clinical profile of hypersensitivity to the nucleoside reverse transcriptase inhibitor abacavir sulfate. METHODS: We performed a retrospective medical review of pooled adverse events data from approximately 200,000 patients who received abacavir in clinical trials, through expanded-access programs, or by prescription from 1996 through 2000. Screened cases of hypersensitivity were classified as either definitive or probable. Definitive cases were identified when initial symptoms resolved on interruption of abacavir therapy and returned on reintroduction of abacavir therapy. RESULTS: A total of 1803 cases were identified, 1302 in the 30,595 patients participating in clinical trials or the expanded-access program and 501 in patients from the post-marketing experience. On review, 176 (9.8%) of these cases were considered definitive and the remainder probable. Based on the 1302 cases identified in clinical trials or the expanded-access program, the calculated incidence of hypersensitivity was 4.3%. Symptoms reported in > or = 20% of cases of this multiorgan reaction included fever, rash, malaise/fatigue, and gastrointestinal symptoms such as nausea, vomiting, and diarrhea, among others. Respiratory symptoms occurred in 30% of cases and included dyspnea (12%), cough (10%), and pharyngitis (6%). In 90% of cases, hypersensitivity reactions occurred within the first 6 weeks after initiation of abacavir (median time, 11 days); after an initial reaction, rechallenge with abacavir resulted in the reappearance of symptoms within hours of reexposure. Hypotension was present in 25% of these rechallenge reactions. Among patients who received abacavir in clinical trials, the mortality rate was 0.03% (3 per 10,000 patients). CONCLUSIONS: Hypersensitivity to abacavir is an idiosyncratic reaction and a distinct clinical syndrome characterized predominantly by systemic involvement. It can be expected to appear as a treatment-limiting event in approximately 5% of patients. The appearance of clinical symptoms consistent with this syndrome mandates immediate discontinuation of abacavir. Hypersensitivity to abacavir is an absolute contraindication to subsequent treatment with any formulation that includes this agent.

Clinical Trials, Phase II as Topic↗

Finasteride and tamsulosin used in benign prostatic hypertrophy: a review of the prescription-event monitoring data.

OBJECTIVE: To review the results of non-interventional observational cohort studies of 14 772 patients treated with finasteride and 12 484 patients treated with tamsulosin, both studies being of national proportions and undertaken in general medical practice in England. METHODS: Both studies were undertaken by prescription-event monitoring (PEM), whereby the exposure data are derived from information provided in strict confidence by the Prescription Pricing Authority of the National Health Service. The outcome data are derived from 'green form' questionnaires completed by the prescribing general practitioners (GPs). Additional data are obtained by medical follow-up with the attending practitioners. Adverse experience was measured in three ways; as reports of events which the doctors considered to represent adverse drug reactions; as reports of reasons for stopping the drug; and by studying the incidence density of each reported event. For these purposes a computerized dictionary containing 1430 higher level terms was used. The duration of exposure in the finasteride study was approximately 1 year and was approximately 6 months in the tamsulosin study. RESULTS: The outcome data on the 14 772 and 12 484 patients treated in the finasteride and tamsulosin studies were derived from the 63% and 57.4% of the green forms sent out and returned, respectively. The finasteride cohort included two women and the tamsulosin cohort 70 women. The mean (SD) age of the men in the two cohorts was, respectively, 69.0 (9.2) and 66.2 (11.7) years. Both drugs were well tolerated on long-term therapy and 69.6% (10 274 patients) of the total finasteride and 62.0% (7739 patients) of the total tamsulosin cohort were still receiving the drug at the end of 6 months. In the finasteride study, impotence or ejaculatory failure was reported in 2.0% of the patients still receiving the drug; there were reports of decreased libido in 1.0% and gynaecomastia was reported whilst the drug was still being prescribed in 39 patients (0.3% of the cohort). With tamsulosin, uncommon cases of dizziness, headache, malaise and hypotension (89 reports in 12 484 patients, i.e. 0.7% of the cohort) were common to the findings of reported adverse reactions, reasons for stopping the drug and events of highest incidence density. None of the deaths which occurred in either of these large cohorts was attributed by either the reporting GPs or the PEM medical staff to the drugs examined. Conclusion The GPs rated the drugs effective in most patients; tolerance and adverse experience was consistent with the known pharmacology of the two drugs. No serious, unexpected adverse effects were identified.

Adrenergic alpha-Antagonists↗

HIV-1 reverse transcriptase (RT) genotype and susceptibility to RT inhibitors during abacavir monotherapy and combination therapy.

OBJECTIVE: To examine changes in HIV-1 susceptibility (genotype and phenotype) during an initial abacavir monotherapy phase followed by the addition of zidovudine and lamivudine. DESIGN: Sixty HIV-1 infected, antiretroviral therapy-naive subjects were randomized to receive 100, 300 or 600 mg abacavir twice daily. Subjects completing 24 weeks of randomized therapy or meeting a protocol defined switch criterion could switch to open label abacavir/zidovudine/lamivudine. METHODS: Plasma HIV-1 reverse transcriptase was genotyped at baseline, week 12, and at the last time point on ABC monotherapy. Drug susceptibility was analysed at baseline and on subsequent samples with sufficient HIV-1 RNA levels using the recombinant virus assay. Virological responses (week 24) were correlated to week 24 genotypes. RESULTS: Mutant viruses were not detected before week 12 with the exception of one subject. At the latest time point on abacavir monotherapy (range, weeks 6-48), 21 out of 43 subjects harboured virus with resistance conferring mutations including single, double and triple combinations of K65R, L74V, Y115F and M184V. The most common mutational pattern was L74V + M184V (11/21 cases). Twenty of the 21 subjects with isolates containing abacavir-associated mutations reached week 48, and upon addition of lamivudine/zidovudiine, 16 out of 20 (80%) had week 48 plasma HIV-1 -RNA below 400 copies/ml. At week 48, 16 out of 46 genotypes were obtained; one of these was wild-type; 15 contained M184V either alone, in combination with K65R and/or L74V and/or Y115F or with thymidine analogue-associated mutations. Week 48 viral load levels for these 15 subjects was low (median 3.43 log10 copies/ml or -1.99 log10 copies reduction from baseline). Genotype correlated well with phenotypic resistance to ABC; four samples with three abacavir-associated mutations had high level abacavir resistance (> 8-fold) and six samples with two or three mutations showed intermediate (4-8-fold) resistance. All samples with single mutations retained full ABC susceptibility. CONCLUSIONS: Resistance conferring mutations to abacavir were relatively slow to develop during the monotherapy phase, and did not preclude durable efficacy of abacavir/lamivudine/zidovudine up to 48 weeks.

Cohort Studies↗

Short stature and delayed puberty in gymnasts: influence of selection bias on leg length and the duration of training on trunk length.

BACKGROUND: Delays in bone age, the onset of puberty, and skeletal growth in gymnasts could be, in part, the reason for an interest in gymnastics, rather than being the result of vigorous exercise. We hypothesized that short stature and delayed bone age are present at the start of gymnastics, and training delays growth, producing short stature, even after retirement. METHODS: Sitting height and leg length were measured in 83 active female gymnasts, 42 retired gymnasts, and 154 healthy control subjects. Results were expressed as age-specific SD scores (mean +/- SEM). RESULTS: In the cross-sectional data, active gymnasts had delayed bone age (1.3 +/- 0.1 years), reduced height -1.32 +/- 0.08 SD, sitting height -1.24 +/- 0.09 SD, and leg length, -1.25 +/- 0.08 SD (all P <.001). However, in those training for less than 2 years, the deficit was confined to leg length (-0.8 +/- 0.2 SD). During 2 years of follow-up of 21 gymnasts, only the deficit in sitting height worsened (by 0.4 +/- 0.1 SD). In 13 gymnasts followed up in the immediate 12 months after retirement, sitting height accelerated, resulting in a lessening of the deficit in sitting height by 0.46 +/- 0.14 SD (P <.01). Adult gymnasts who had been retired for 8 years had no deficit in sitting height, leg length, or menstrual dysfunction. CONCLUSIONS: Short stature in active gymnasts is partly due to selection of individuals with reduced leg length. Reduced sitting height is likely to be acquired but is reversible with cessation of gymnastics. A history of gymnastic training does not appear to result in reduced stature or menstrual dysfunction in adulthood.

Adolescent↗

The pharmacovigilance of tamsulosin: event data on 12484 patients.

OBJECTIVE: To determine drug effectiveness and adverse effects in a noninterventional observational cohort study of over 10 000 patients treated with tamsulosin in general medical practice. METHODS: Using prescription-event monitoring, data were collected of all prescriptions for tamsulosin issued nationally during June 1996 to January 1998. For each patient entered into the cohort a computerized longitudinal record of exposure was constructed. The outcome data, patient information and an opinion about the effectiveness of the drug were provided by the prescriber, using a standard questionnaire sent 6 months after the initial prescription for tamsulosin. The incidence of each of almost 2000 events listed in the Drug Safety Research Unit computerized dictionary was calculated and scrutinized by medical assessors for possible adverse reactions, and any difference determined between the incidence of each event in the first month and subsequent months of exposure. All deaths were followed up to detect possibly drug-related causes. RESULTS: Event data were obtained on 12484 patients, from the 52.9% of questionnaires returned and that contained valid event data. Tamsulosin was reported to have been effective in 7428 (78.3%) of the 9487 patients in whom the general practitioners expressed an opinion about effectiveness. Suspected adverse drug reactions were reported in only 171 (1.4%) of the cohort. Dizziness, headache, malaise and hypotension were common to the reported adverse reactions, reasons for stopping the drug and events of greatest incidence density. None of the 282 deaths that occurred in this elderly cohort were attributed to the drug. CONCLUSION: This study suggests that tamsulosin has a highly acceptable benefit-to-risk ratio. No untoward features not already mentioned in the prescribing guidance were identified.

Adolescent↗

Proteinase inhibitor-inducing activity of the prohormone prosystemin resides exclusively in the C-terminal systemin domain.

Prosystemin is the 200-amino acid precursor of the 18-amino acid polypeptide defense hormone, systemin. Herein, we report that prosystemin was found to be as biologically active as systemin when assayed for proteinase inhibitor induction in young tomato plants and nearly as active in the alkalinization response in Lycopersicon esculentum suspension-cultured cells. Similar to many animal prohormones that harbor multiple signals, the systemin precursor contains five imperfect repetitive domains N-terminal to a single systemin domain. Whether the five repetitive domains contain defense signals has not been established. N-terminal deletions of prosystemin had little effect on its activity in tomato plants or suspension-cultured cells. Deletion of the C-terminal region of prosystemin containing the 18-amino acid systemin domain completely abolished its proteinase inhibitor induction and alkalinization activities. The apoplastic fluid from tomato leaves and the medium of cultured cells were analyzed for proteolytic activity that could process prosystemin to systemin. These experiments showed that proteolytic enzymes present in the apoplasm and medium could cleave prosystemin into large fragments, but the enzymes did not produce detectable levels of systemin. Additionally, inhibitors of these proteolytic enzymes did not affect the biological activity of prosystemin. The cumulative data indicated that prosystemin and/or large fragments of prosystemin can be active inducers of defense responses in both tomato leaves and suspension-cultured cells and that the only region of prosystemin that is responsible for activating the defense response resides in the systemin domain.

Journal Article↗

Losartan: a study of pharmacovigilance data on 14,522 patients.

The objective of this study was to undertake a post- marketing safety surveillance study of losartan, the first specific angiotensin-II receptor antagonist to be marketed in England. It is a non-interventional observational cohort study using the technique of prescription-event monitoring. Subjects who took part in the study were from 14 522 patients treated by general practitioners in England. We recorded adverse drug reactions, adverse events, reasons for stopping the drug, pregnancies and deaths. The results were that general practitioners considered the drug to have been effective in 85.9% of the patients evaluated for effectiveness. Dizziness, malaise, lassitude, nausea, cough and headache were among the most frequently reported adverse drug reactions, reasons for stopping the drug and events of highest incidence density. None of the deaths that occurred were attributed to losartan and no serious unexpected adverse reactions or interactions were identified. In conclusion losartan has an acceptable safety profile and the study confirms the safety information given in the current Summary of Product characteristics for losartan.

Age Distribution↗

The differing tempo of growth in bone size, mass, and density in girls is region-specific.

The differing tempo and direction of growth of the periosteal and endocortical surfaces, and the differing tempo of growth of the axial and appendicular skeleton, may predispose to regional deficits in bone size, bone mineral content (BMC), and volumetric bone mineral density (vBMD). These traits were measured during 2 years by dual x-ray absorptiometry in 109 girls. By 7 years of age, bone size was approximately 80% of its maturational peak, and BMC was approximately 40% of its peak. Before puberty, the legs grew more rapidly than the trunk. During puberty, the growth spurt was truncal. Between 7 and 17 years, femoral and lumbar spine BMC increased by 50-150% because bone size increased. vBMD increased by 10-30%. Thus, growth builds a bigger, but only moderately denser, skeleton. Regions growing rapidly, or distant from their peak, may be more severely affected by illness than those growing slowly or nearer completion of growth. Depending on the age of exposure to disease, deficits may occur in limb dimensions (prepuberty), spine dimensions (early puberty), or vBMD by interference with mineral accrual (late puberty). As vBMD is independent of age before puberty, the position of an individual's vBMD in the population distribution is established early in life. Bone fragility in old age may have its foundations in growth.

Adolescent↗

A dose-ranging study to evaluate the safety and efficacy of abacavir alone or in combination with zidovudine and lamivudine in antiretroviral treatment-naive subjects.

OBJECTIVE: To compare antiretroviral efficacy, safety and tolerance of three dosing regimens of the novel nucleoside reverse transcriptase inhibitor, abacavir (1592U89) over 24 weeks and its efficacy in open-label combination with zidovudine and lamivudine. DESIGN: Sixty HIV-1-infected antiretroviral therapy naive subjects (entry criteria; CD4+ cell count > or = 100 cells/mm(3), plasma HIV-1 RNA > or = 30 000 copies/ml), randomized into 20 subjects per cohort received 100, 300 or 600 mg abacavir twice daily. Subjects successfully completing 24 weeks' randomized therapy could switch to open label therapy (abacavir, zidovudine, lamivudine at 300, 300 and 150 mg twice daily, respectively) for a further 24 weeks of studly, as could subjects meeting one or more switch criteria. METHODS: Subjects were assessed for antiretroviral activity by measuring changes in plasma HIV-1 RNA load and CD4+ cell counts. Evaluation of safety and tolerance was based on clinical adverse events and laboratory analyses. RESULTS: At week 4, subjects receiving 300 or 600 mg abacavir twice daily had greater reductions in plasma HIV-1 RNA (median changes -1.55 and -1.61 log10) copies/ml, respectively); differences (P = 0.007 and P < or = 0.001, respectively) than subjects receiving 100 mg abacavir twice daily (median change, -0.63 log10 copies/ml). Differences between the 300 and 600 mg twice daily groups were not clinically or statistically significant. At 24 weeks, analysis showed a median change in plasma HIV-1 RNA of -0.70 and -1.30 log10 copies/ml in the 300 and 600 mg twice daily groups, respectively. During the open label phase in which zidovudine/lamivudine was added to 300 mg abacavir twice daily, a further median reduction in plasma HIV-1 RNA of 1.74 log10 copies/ml was seen. At 48 weeks pooled data from all abacavir-treated subjects showed a sustained reduction in plasma HIV-1 RNA of 2.8 log10) copies/ml; 65% and 43% of subjects had < or = 400 and < or = 50 HIV-1 RNA copies/ml, respectively, and a further median increase of 111 CD4+ cells/mm3 were seen. Abacavir was generally well tolerated with few clinically significant adverse events. Two subjects (3.3%) developed hypersensitivity reactions to abacavir. There were no differences between the groups with regard to serious adverse events. CONCLUSIONS: In terms of antiretroviral therapy naive subjects, treatment with 300 or 600 mg abacavir twice daily was statistically superior to a 100 mg twice daily dose at 4 weeks. Combinations therapy containing abacavir-zidovudine-lamivudine was a highly effective antiretroviral regimen, resulting in substantial reductions in plasma HIV-1 RNA which may be comparable to combinations containing protease inhibitors. Abacavir was generally tolerated.

Acquired Immunodeficiency Syndrome↗

The deleterious effects of low-dose corticosteroids on bone density in patients with polymyalgia rheumatica.

The beneficial effects of corticosteroid therapy in the treatment of rheumatic diseases may be offset by the occurrence of corticosteroid-related osteoporosis. This problem may be overcome by using low-dose corticosteroids; however, the dose of corticosteroids that is both efficacious and skeletal sparing is uncertain. Therefore, the aim of this study was to determine whether low-dose prednisolone treatment results in bone loss and modifies bone turnover. Nineteen patients (12 female, seven male) suffering from polymyalgia rheumatica received 10 mg or less daily, given in reducing dosage, with a range of 2.5-10 mg and an average of 6.0+/-0.2 mg daily (+/-S.E.M.). Prior to the commencement of therapy and at regular intervals during treatment, bone mineral density (BMD) using dual X-ray absorptiometry and circulating biochemical and hormonal determinants of bone turnover were measured. The patients were followed for 14.4+/-1.6 months (range 6-27). They were compared to 19 age-matched controls. Despite a mean exposure dose of 6 mg/day and disease remission, BMD decreased in the patients at the lumbar spine (2.6+/-0.8%, P < 0.01), femoral neck (2.9+/-1.5%, P=0.06), Ward's triangle (5.5+/-2.9%, P=0.06) and the trochanter (4.3+/-1.9%, P < 0.05). Total body bone mass decreased by 50+/-19 g in the first 6 months (P < 0.02), and by 39+/-30 g in the remaining 8 months of follow-up [not significant (NS)]. In the first 6 months, BMD decreased at the lumbar spine (1.7+/-0.9%, P = 0.06). From 6 months to the end of follow-up, BMD decreased by 8.5+/-3.5% at Ward's triangle (P < 0.05) and by 4.8+/-2.5% at the femoral neck (P=0.08). The fall in BMD correlated with the cumulative prednisolone dose at trabecular-rich regions (trunk r=-0.72, P < 0.001; ribs r=-0.53, P < 0.05). Bone resorption, assessed by urinary cross-laps, was 54.7% higher than controls before treatment was started (P < 0.05) and decreased by 23.5+/-7.1% in the first month of treatment when the mean prednisolone dose was 9.1 mg/day, range 5-10 (P < 0.0001). Serum osteocalcin was not suppressed by disease before treatment, decreased by 27.4+/-5.1% during the first month of treatment (P < 0.001), remained suppressed while the daily dose of prednisolone was > 5 mg/day, but returned to baseline below this dose. Serum parathyroid hormone was 19.3% lower in the patients than controls at baseline (NS), and increased by 46.1% (P < 0.05) but was no higher than controls at any time. Muscle strength increased by 20-60% (P < 0.05 to < 0.01). Prophylaxis should be considered in patients receiving > or = 5 mg/day prednisolone daily as bone loss is 2- to 3-fold expected rates. Earlier trabecular bone loss may predispose to spine and rib fracture; later cortical bone loss may predispose to hip fractures. Doses of prednisolone of < 5 mg daily may be skeletal sparing, but may not be efficacious.

Aged↗

Systemin: a polypeptide signal for plant defensive genes.

Damage to leaves of several plant species by herbivores or by other mechanical wounding induces defense gene activation throughout the plants within hours. An 18-amino acid polypeptide, called systemin, has been isolated from tomato leaves that is a powerful inducer of over 15 defensive genes when supplied to the tomato plants at levels of fmol/plant. Systemin is readily transported from wound sites and is considered to be the primary systemic signal. The polypeptide is processed from a 200-amino acid precursor called prosystemin, analogous to polypeptide hormones in animals. However, the plant prohormone does not possess typical dibasic cleavage sites, nor does it contain a signal sequence or any typical membrane-spanning regions. The signal transduction pathway that mediates systemin signaling involves linolenic acid release from membranes and subsequent conversion to jasmonic acid, a potent activator of defense gene transcription. The pathway exhibits analogies to arachidonic acid/prostaglandin signaling in animals that leads to inflammatory and acute phase responses.

Amino Acid Sequence↗

Corticosteroid-induced bone loss in men.

Lack of consistent information concerning the pathophysiology of corticosteroid-related bone loss may be due to coexisting independent factors that influence bone mineral density (BMD). For example, the disease being treated may increase bone turnover and cause bone loss, and its severity may influence the dose of corticosteroids chosen. Similarly, disease remission due to the treatment or disease progression despite treatment may influence bone turnover and the rate of bone loss. The hormonal changes purportedly responsible for reduced bone formation or increased bone resorption may be the result of the disease, not the corticosteroids. To determine the pathophysiology of corticosteroid-related bone loss, we conducted a controlled, prospective study in men with no systemic illness treated with corticosteroids to reduce antisperm antibodies. We measured BMD using dual x-ray absorptiometry and circulating biochemical and hormonal determinants of bone turnover in 9 men before and during prednisolone treatment and in 10 age-matched controls. The results were expressed as the mean +/- SEM. There were no differences in BMD between the two groups at baseline. The patients received 50 mg prednisolone daily for 3.7 +/- 0.6 months (range, 1-6). BMD decreased by 4.6 +/- 0.8% at the lumbar spine (P = 0.0007), by 2.6 +/- 0.6% at the trochanter (P = 0.004), and by 4.8 +/- 1.9% at the Ward's triangle (P < 0.04). The decrease in lumbar spine BMD correlated with the cumulative dose of corticosteroids (r = -0.49; P = 0.03). Serum osteocalcin and skeletal alkaline phosphatase decreased by 28.5 +/- 15.5% (P = 0.08) and 24.2 +/- 8.6% (P < 0.03), respectively. The decrease in lumbar spine BMD correlated with the decrease in osteocalcin (r = -0.48; P < 0.02). Serum testosterone and sex hormone-binding globulin decreased by 28.6 +/- 4.4% (P < 0.003) and 28.5 +/- 8.3% (P < 0.007), respectively. The testosterone/sex hormone-binding globulin ratio did not change. The decrease in total testosterone correlated with the decrease in osteocalcin (r = -0.40; P = 0.05). There were no detectable changes in urinary C-telopeptide, serum PTH, or serum calcium. Estradiol decreased by 23.5 +/- 11.4% (P < 0.003). Corticosteroid therapy results in rapid bone loss, probably due to reduced bone formation. Neither increased bone resorption nor secondary hyperparathyroidism appears to contribute to the rapid bone loss. Whether the reduction in bone formation may be partly mediated by changes in sex steroids remains unclear.

Absorptiometry, Photon↗