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A Stewart

Publications and source records attributed to A Stewart.

At least 19 recordsLinked to original sources
PubMed2007

Analgesia with sevoflurane during labour: i. Determination of the optimum concentration.

BACKGROUND: Sevoflurane has favourable physical qualities for inhaled analgesia during labour pain. The aim of this preliminary study was to identify its optimum concentration. METHODS: In this open-labelled escalating-dose study, 22 parturients in labour self-administered sevoflurane at 10 contractions using an Oxford Miniature Vaporiser. The inspired concentration was increased by 0.2% after each contraction from 0% to 1.4% or decreased if sedation occurred. Visual analogue scores (0-100 mm) for pain intensity, pain relief, sedation, mood and coping were measured after each contraction. RESULTS: The median (IQR [range]) pain relief and sedation scores increased from 44 (43-56 [4-93]) mm and 55 (43-56 [0-98]) mm at 0.2% sevoflurane, to 74 (72-78 [50-80]) mm and 71 (71-73 [33-97]) mm at 1.2% sevoflurane, respectively. Pain relief scores did not show any significant increase above 0.8% whilst sedation continued to increase, with excessive sedation occurring at 1.2% sevoflurane. No significant changes in other scores were measured. CONCLUSIONS: We concluded that the optimal sevoflurane concentration in labour was 0.8%. This concentration allows a safety margin and balances the risk of sedation with the benefit of pain relief in labour.

Adaptation, Psychological↗
PubMed2007

Analgesia with sevoflurane during labour: ii. Sevoflurane compared with Entonox for labour analgesia.

BACKGROUND: We determined the optimal inspired sevoflurane concentration for use during labour as 0.8% in our previous study. This study compared sevoflurane at a concentration of 0.8% and Entonox((R)) (nitrous oxide 50%: oxygen 50%) for analgesia during labour in 32 healthy parturients. METHODS: Each mother underwent two open-label, three-part sequences in random order, Entonox-sevoflurane-Entonox or sevoflurane-Entonox-sevoflurane. In each part the agent was self-administered during 10 contractions. A 100 mm visual analogue scores for pain relief and sedation was completed immediately after each contraction. RESULTS: Two patients withdrew during administration of sevoflurane (because of its odour) and five during Entonox (requesting epidural analgesia). Of the remaining women, data were available for analysis from 29 participants: median (IQR [range]) pain relief scores were significantly higher for sevoflurane 67 (55-74 [33-100]) mm than for Entonox 51 (40-69.5 [13-100]) mm (P<0.037). Nausea and vomiting were more common in the Entonox group [relative risk 2.7 (95% CI 1.3-5.7); P=0.004]. No other adverse effects were observed in the mothers or babies. There was significantly more sedation with sevoflurane than with Entonox {74 (66.5-81 [32.5-100]) and 51 (41-69.5 [13-100]) mm, respectively; P<0.001}. Twenty-nine patients preferred sevoflurane to Entonox and found its sedative effects helpful. CONCLUSIONS: We conclude that self-administered sevoflurane at subanaesthetic concentration (0.8%) can provide useful pain relief during the first stage of labour, and to a greater extent than Entonox. Although greater sedative effects were experienced with sevoflurane, it was preferred to Entonox.

Adult↗
PubMed2006

Prevention of infection in arterial reconstruction.

BACKGROUND: Arterial reconstructions with prosthetic graft materials or vein are susceptible to infection with a resultant high patient mortality and risk of limb loss. To reduce the risk of infection effective perioperative measures are essential. OBJECTIVES: To determine the effectiveness of perioperative strategies to prevent infection in patients undergoing peripheral arterial reconstruction. SEARCH STRATEGY: We searched the Cochrane Peripheral Vascular Diseases Group trials register (last searched May 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL) (last searched Issue 2, 2006), and reference lists of relevant articles. SELECTION CRITERIA: All randomised controlled trials (RCTs) evaluating measures intended to reduce or prevent infection in arterial surgery. DATA COLLECTION AND ANALYSIS: AS and PSE independently selected and assessed the quality of included trials. Relative risk was used as a measure of effect for each dichotomous outcome. MAIN RESULTS: Thirty-five RCTs were included. Of these, 23 were trials of prophylactic systemic antibiotics, three of rifampicin-bonded grafts, three of preoperative skin antisepsis, two of suction wound drainage, two of minimally invasive in situ bypass techniques, and individual trials of intraoperative glove change and wound closure techniques. Wound infection or early graft infection outcomes were recorded in all trials. Only two trials, both of rifampicin bonding, followed up graft infection outcomes to two years. Trials of antibiotics versus placebo were of highest quality with six double-blind studies of the ten included. Prophylactic systemic antibiotics reduced the risk of wound infection (Relative Risk (RR) 0.25, 95% Confidence Interval (CI) 0.17 to 0.38) and early graft infection in a fixed-effect model (RR 0.31, 95% CI 0.11 to 0.85, P = 0.02). Antibiotic prophylaxis for greater than 24 hours appears to be of no added benefit (RR 1.28, 95% CI 0.82 to 1.98). There was no evidence that prophylactic rifampicin bonding to dacron grafts reduced graft infection at either one month (RR 0.63, 95% CI 0.27 to 1.49) or two years (RR 1.05, 95% CI 0.46 to 2.40). There was no evidence of a beneficial or detrimental effect on rates of wound infection with suction groin-wound drainage (RR 0.96 95% CI 0.50 to 1.86) or of any benefit from a preoperative bathing or shower regimen with antiseptic agents over unmedicated bathing (RR 0.97, 95% CI 0.70 to 1.36). AUTHORS' CONCLUSIONS: There is clear evidence of the benefits of prophylactic broad spectrum antibiotics. Many other interventions intended to reduce the risk of infection in arterial reconstruction lack evidence of effectiveness.

Antibiotic Prophylaxis↗
PubMed2006

Manmade and natural radionuclides in north east Atlantic shelf and slope sediments: Implications for rates of sedimentary processes and for contaminant dispersion.

Results are presented for a study of manmade and natural radionuclides in north east Atlantic continental shelf and slope sediments to the west of Scotland. The data are interpreted in the context of sediment mixing and accumulation processes and are used to establish the westward extent of contamination of the sediment system. Offshore shelf and slope sediments were found to have post-glacial sedimentation rates of the order of 1 cm ky(-1) but nearshore sediments had much higher accumulation rates of the order of 0.1 cm y(-1). Surface mixed layer depths of up to 6 cm were observed and non-local mixing affected most of the slope sediments, resulting in advective transport of surface sediment to depths of up to 10 cm. Biodiffusion coefficients for offshore shelf and slope sediments were dominantly in the range 10(-8) to 10(-9) cm2 s(-1). The study confirmed that seawater contaminated with Sellafield waste radionuclides is dominantly entrained to the east of 7 degrees W and, consistent with this, higher levels of Sellafield derived radionuclides were confined to nearshore sediments, with lower levels to the west of 7 degrees W. 238Pu/(239,240)Pu data indicated that Sellafield contributed 75-91% of the total plutonium in coastal sediment but only about 4-8% of the total in slope sediments. By analogy, it can be concluded that a similar situation will apply to other contaminants in seawater entering the north east Atlantic via the North Channel.

Atlantic Ocean↗
PubMed2006

Relationship between risk factors and QUS in a European Population: The OPUS study.

There are many risk factors associated with low bone mineral density. Quantitative ultrasound (QUS) is a generally accepted method for measurement of bone and has been shown to be strongly associated with future fracture risk. The Osteoporosis and Ultrasound Study (OPUS) is a multi-centre European wide study examining 5 different QUS scanners (4 calcaneal, 1 finger device). The aim of this paper was to examine the relationship between risk factors (as assessed by questionnaire) and QUS measurements. 449 younger women (aged 20 to 39 years) and 2283 older women (aged 55 to 79 years) were included in this analysis. As expected, those with a self-reported previous fracture had lower QUS measurements than those without (P < 0.001). However, no significant difference was seen between those reporting a maternal hip fracture and those who did not report such an event. Differences were found for smokers vs. non-smokers for SOS but not for BUA measurements. Weight was positively correlated with all BUA variables but only with some SOS variables. We determined which risk factors were most strongly associated with QUS measurements by using step-wise multiple regression. Models for each QUS measurement were calculated, and the R2 values ranged from 0.18 to 0.28 for SOS, 0.27 to 0.32 for BUA and 0.31 to 0.42 for the finger QUS device. The most common risk factors across all models were age, use of hormone replacement therapy, self-reported previous fracture, self-reported diagnosis of osteoporosis, current weight, pulse rate and self-reported estimated height at age 20 years. We analysed relationships across the 5 centres and detected some geographical differences in the prevalence of the risk factors. In conclusion, similar relationships are seen with QUS measurements as are found for bone mineral density. However, the strength of the association is dependent on the type of QUS device and variable measured.

Adult↗
PubMed2006

Relationship between point gene mutation, chromosomal abnormality, and tumour suppressor gene methylation status in colorectal adenomas.

Epigenetic mechanisms in carcinogenesis may have a significant role in the development of colorectal cancer. To investigate this phenomenon in early-stage disease, promoter methylation status in the tumour suppressor genes APC, MGMT, hMLH1, P14/P14ARF, and CDKN2A/P16 was investigated in 78 colorectal adenomas. These had previously been characterized for mutations of APC, KRAS, and TP53 genes and for chromosomal abnormality by comparative genomic hybridization (CGH). APC hypermethylation was seen in 52 tumours (66.7%). APC showed either methylation or mutation in 66 lesions (84.6%), but these events were not statistically associated. MGMT methylation was detected in 39 cases (50%). Adenomas with this abnormality showed a significantly lower number of chromosomal changes by CGH (p < 0.02), confirming that DNA repair defect of this type is associated with a lower level of chromosomal instability. An hMLH1 methylation defect was seen in only one adenoma (1.3%), from a patient who had a synchronous cancer showing the same defect. Methylation of P14 (P14ARF) was seen in 31 adenomas (39.7%) and CDKN2A (P16) abnormality in 25 (32.1%). DNA methylation at two or more loci was seen in 46 tumours (59%), while 11 lesions (14.1%) showed no evidence of hypermethylation at any of the loci studied. Methylation at any or all of MGMT, P14 or P16 was significantly associated with APC methylation (p = 0.01). Those neoplasms with more than two methylated genes showed significantly fewer chromosomal abnormalities than adenomas with one or no methylated loci (p < 0.001). There was no association between specific individual chromosomal abnormalities, APC, KRAS or TP53 mutations and any pattern of methylation abnormality. We conclude that methylation abnormality is very common in pre-invasive colorectal neoplasia, and that high level methylation is associated with low level chromosomal instability.

Adaptor Proteins, Signal Transducing↗
PubMed2006

Respiratory failure of two sp gastric bypass patients and subsequent rescue with extracorporeal membrane oxygenation.

Severe obesity is a chronic condition that is difficult to treat through diet and exercise alone. Gastrointestinal surgery for obesity (bariatric surgery) alters the digestive process by either restrictive surgical alterations or malabsorptive operations. Some 10-20% of patients who have weight-loss surgery require follow-up operations to correct complications. Hypoxemia after gastric bypass surgery for morbid obesity, a reported complication, can occur as early as 24 h post surgery. Two patients presented with severe hypoxia and were placed on veno-venous extracorporeal membrane oxygenation (ECMO). Patient No. 1 had an obstruction of the alimentary limb of the gastric bypass due to suture adhesions, and patient No. 2 had an incarcerated diaphragmatic hernia. While on ECMO, ventilation using a protective strategy (60% FiO2, pressure-controlled ventilation inspiratory pressure (PCV) IP 25-27, positive end-expiratory pressure (PEEP) 10-14, permissive hypercapnia) was employed. An inflow cannula to the level of the right atrium served as arterial outflow from the circuit to the patient, while the femoral vein served as venous inflow to the ECMO circuit. Although ECMO in adult respiratory failure is often used as the last resort due to serious associated adverse events, we report two patients with life-threatening complications from gastric bypass who were rescued, resuscitated to day 7, and uneventfully discharged from the hospital to home.

Adult↗
PubMed2006

Prevalence of exercise-induced bronchospasm in Thokoza schoolchildren.

BACKGROUND: Asthma is a common childhood illness, with a prevalence of 1 in 10 children. Exercise-induced bronchospasm (EIB) is a common feature of asthma and is found more often in children than in adults. OBJECTIVE: To determine the prevalence and potential impact of various factors on the prevalence of EIB in Thokoza schoolchildren. METHODS: Data were collected on respiratory health and the home environment of children living in Thokoza, Gauteng. A total of 475 9- and 10-year-old children performed the free-running asthma screening test (FRAST). An abnormal response to FRAST was defined as a reduction in the post-exercise peak flow of more than 15% of the pre-exercise value, at 3- and 10- minute intervals. All children who had a fall in post-exercise flow rate (PEFR) of more than 15% on 2 occasions after FRAST were classified as having EIB. RESULTS: Using the above criteria to diagnose EIB, an overall prevalence rate of 7.26% (95% confidence interval (CI): 4.5 - 10.3%) was recorded. A less rigorous definition of EIB is a fall in PEFR of more than 10% on 2 occasions after FRAST, and if this was used then the prevalence of EIB was 15.69% (95% CI: 10.6 - 20.8%). Difficulty breathing and a tight chest were the most prevalent respiratory symptoms in children with EIB (odds ratio (OR): 1.79, 95% CI: 0.49 - 6.49 and OR 1.69, 95% CI: 0.72 - 3.99, respectively). The use of gas and electricity as domestic fuels was the strongest risk factor associated with EIB, as shown by logistical regression analysis using an adjusted OR in a reduced model (OR 2.44, 95% CI: 0.71 - 8.44 and OR 2.33, 95% CI: 0.59 - 9.24, respectively). CONCLUSION: The prevalence of EIB reported in this study is higher than that reported in studies from other African countries, with the exception of a study from Kenya. Findings of the present study suggest that there may be a trend towards increasing prevalence of EIB in South African urban areas.

Asthma, Exercise-Induced↗
PubMed2005

Seminal tissue factor revisited.

Studies of seminal tissue factor (TF) are few and mostly based on small numbers. Due to the reported lack of factor (F) X in semen, it has been suggested that TF may not have a role in seminal coagulum formation. However, recent identification of a number of haemostatic factors in semen justifies a re-evaluation of its occurrence. Semen specimens were collected from sub-fertile (n = 19), normally fertile (n = 33), semen donors (n = 30) and vasectomized subjects (n = 62), some fractionated into sperm, a prostasome-rich fraction and seminal plasma. Functional and antigenic TF levels were measured and related to conventional fertility parameters. Semen contains high concentration of functional and antigenic TF. Most TF was found in seminal plasma prepared by low-speed centrifugation. When further fractionated by ultracentrifugation much of this may reside in the pellet (prostasomal fraction). It was also detectable on sperm. TF antigen levels were higher in vasectomized subjects than sub-fertile, normally fertile, donor (p = 0.02) and a 'pooled normal semen parameters' (PNSP) stratification (derived from a combination of measurements) (p = 0.06). The sub-fertile group showed a wider variation than normal, donor or the PNSP subjects. Seminal TF antigen levels correlated significantly with sperm agglutination (p = 0.03) and abnormal sperm morphology (p = 0.04). Subjects with anti-sperm antibodies also showed high TF antigen levels. In conclusion, semen contains functional and antigenic TF at high concentrations. A full complement of clotting factors probably exists in semen, so some pro-coagulant role for TF should not be excluded. Decreased seminal TF levels appear to be associated with seminal parameters that are known to favour male fertility.

Adult↗
PubMed2005

Postoperative fractures of the lingual plate after bilateral sagittal split osteotomies.

We encountered the unusual complication of postoperative fracture of the lingual plate in four patients after bilateral sagittal split osteotomy. We then did a retrospective review to identify possible risk factors. Over a 1-year period we did 52 bilateral split osteotomies. The patients' casenotes were examined and a number of variables were recorded, including surgical technique, and the patient's sex, age, presence or absence of third molars, and the height of the mandible in the region of the osteotomy. Significant risk factors were a vertical mandibular height of 2 cm or less distal to the last molar tooth (p=0.02), and a depth of 0.6 cm or less from the apex of last molar root or impacted third molar to the lower border (p=0.005).

Adolescent↗
PubMed2005

Use of digital x ray radiogrammetry in the assessment of joint damage in rheumatoid arthritis.

OBJECTIVE: To compare digital x ray radiogrammetry (DXR) with manual radiography for assessing bone loss in RA and examine the relationship of the scores obtained with other disease indices. METHODS: 225 consecutive consenting subjects attending the RA clinic were enrolled. An x ray examination was carried out; demographic details recorded; a self assessment questionnaire completed; blood taken for ESR measurement; and an assessment made by a trained nurse. All x ray films were scored manually using the modified Sharp technique by a single observer; 20 films were rescored by three readers. Films were assessed with the Pronosco X-Posure system, version 2.0. Analysis included chi2 tests, independent t tests, multiple linear regression, and partial correlations, as appropriate. The smallest detectable difference (SDD), coefficient of variation (CV), and coefficient of repeatability (CR) were determined from Bland and Altman plots. RESULTS: The DXR precision varied: SDD = 0.002-0.9; CV = 0.09-5.9%; CR = 0.002-0.792, but was better than that of the intra- and interobserver Sharp scores: SDD = 73.9; CV = 27.8%; CR = 33.0-47.6. The DXR measurements, bone mineral density (R2 = 0.210), metacarpal index (R2 = 0.222), and cortical thickness (R2 = 0.215), significantly predicted Sharp scores. In women, DXR measurements significantly correlated with modified HAQ scores but with no other disease indices. Sharp scores significantly correlated with assessor's global assessment, swollen and tender joint counts, pain, HAQ, and DAS28. CONCLUSION: DXR measurements are more precise than Sharp scores; both are related to long term disease activity in RA. DXR is simple to use, does not require intensive training, and may identify subjects not responding to standard treatment.

Absorptiometry, Photon↗
PubMed2005

Modelling and experimental studies on the transfer of radionuclides to fruit.

Although fruit is an important component of the diet, the extent to which it contributes to radiological exposure remains unclear, partially as a consequence of uncertainties in models and data used to assess transfer of radionuclides in the food chain. A Fruits Working Group operated as part of the IAEA BIOMASS (BIOsphere Modelling and ASSessment) programme from 1997 to 2000, with the aim of improving the robustness of the models that are used for radiological assessment. The Group completed a number of modelling and experimental activities including: (i) a review of experimental, field and modelling information on the transfer of radionuclides to fruit; (ii) discussion of recently completed or ongoing experimental studies; (iii) development of a database on the transfer of radionuclides to fruit; (iv) development of a conceptual model for fruit and (v) two model intercomparison studies and a model validation study. The Group achieved significant advances in understanding the processes involved in transfer of radionuclides to fruit. The work demonstrated that further experimental and modelling studies are required to ensure that the current generation of models can be applied to a wide range of scenarios.

Fruit↗
PubMed2005

Screening elderly women for risk of future fractures--participation rates and impact on incidence of falls and fractures.

We have assessed the acceptability of a method for screening for risk of future hip fracture in elderly women. After receipt of an initial response to a mailed risk-factor questionnaire sent out to 5,306 women, women were randomly assigned to active or control groups. The active group was invited to participate in a screening visit that comprised a life-style questionnaire and a quantitative ultrasound heel scan. General practitioners (GPs) of women who were found to be in the lowest quartile of broadband ultrasound attenuation and/or who had two or more risk factors for hip fracture were advised to prescribe a calcium and vitamin D supplement. A second mailed questionnaire was sent to both groups 1 to 3 years later. Compared with the control group, the active group had a 56% lower risk of fracture (odds ratio [OR], 0.44; 95% confidence interval [CI], 0.24-0.81 adjusted age, weight, and treatment status). At follow-up, the proportion of fallers in the active group (25.3%) was lower than that in the control group (29.6%) (P = 0.064). The control group was found to have a higher rate of falls at follow-up than the active group (95% CI, 0.02-0.22); no difference was found at baseline (95% CI, -0.08 to +0.14). The screening method used was found to be acceptable to the majority of elderly women in this study. Screening the elderly in this way together with simple advice on treatment appears to reduce the age-associated increase in fall rates and the number of subsequent fractures. This form of screening may provide a cost-effective method to reduce falls and fractures in free-living elderly women. However, no such cost-effectiveness analysis has been performed to date.

Accidental Falls↗
PubMed2005

Axial BMD, change in BMD and bone turnover do not predict breast cancer incidence in early postmenopausal women.

Previous studies have indicated a relationship between bone mineral density and the incidence of breast cancer in middle-aged and elderly women, with women with higher BMD being at significant increased risk. We investigated whether there was such a relationship in younger women who were perimenopausal or in their early postmenopausal years. As part of a population-screening program for osteoporosis, 5,119 women aged between 45 and 54 years were scanned between 1990-1994 at the Osteoporosis Research Unit. In 1997-2001, 3,884 returned for follow-up scans and questionnaires, and 3,144 returned a postal questionnaire in 2002. All cases of incident breast cancer were noted. One hundred sixty-six women indicated that they had suffered from breast cancer, of which 87 were incident cases (59 had prevalent breast cancer at baseline and 20 had benign or unconfirmed diagnosis and were excluded because of the use of agents that may interfere with BMD, e.g., tamoxifen). We compared therefore the incident breast cancer group (BC group; n=87) with a control group (C group; n=3,013). There were no significant differences using a t-test between the BC group and C group for baseline DXA of the spine or femoral neck. Further changes in BMD over a mean period of 6.9 years demonstrated no significant hazard ratio for the lumbar spine or femoral neck. No relationship was seen between the bone turnover markers pyridinoline/creatinine or deoxypyridinoline/creatinine assessed at their second study visit and incidence of breast cancer. In conclusion, in perimenopausal or early postmenopausal women there is no relationship between the incidence of breast cancer and BMD, change in BMD or bone turnover.

Biomarkers↗
PubMed2005

Can peripheral DXA measurements be used to predict fractures in elderly women living in the community?

While axial dual energy X-ray absorptiometry (DXA) is the accepted "gold standard" method both for diagnosing osteoporosis and predicting fractures, appropriate equipment is not universally available. Peripheral bone mass measurements may have the potential to identify patients at risk of fracture and to be used to target appropriate treatment. We assessed the effectiveness of peripheral DXA (PIXI, GELunar) in the assessment of risk and targeting treatment to prevent future fracture in 7,604 women aged 60-80 from five centres across Britain. At enrolment women completed a lifestyle and risk factor questionnaire and had a PIXI DXA scan of the heel. Women were categorised by PIXI DXA bone mineral density (BMD) into high, medium or low risk of future osteoporotic fracture. Treatment was recommended to those at highest risk. Follow-up was by simple questionnaire 18-24 months after baseline assessment. Seventy-four percent returned the follow-up questionnaire. The area under the receiver operator characteristic (ROC) curves for any fracture and osteoporotic fracture were comparable to those published using other sites and technologies. A 1-SD decrease in PIXI BMD was associated with an 86% increase in risk of osteoporotic fracture. Of the women identified as high risk, 74% had started treatment following their heel scan and 84.7% continued to take treatment at follow-up. No significant difference was noted in fracture rates in those who started treatment after assessment compared to those who did not. While peripheral DXA is highly effective for predicting older women who are at increased risk of future fracture, it has yet to be established as an effective method for targeting bisphosphonate or other therapy.

Absorptiometry, Photon↗
PubMed2005

Association of oestrogen receptor alpha gene polymorphisms with postmenopausal bone loss, bone mass, and quantitative ultrasound properties of bone.

BACKGROUND: The gene encoding oestrogen receptor alpha (ESR1) appears to regulate bone mineral density (BMD) and other determinants of osteoporotic fracture risk. OBJECTIVE: To investigate the relation between common polymorphisms and haplotypes of the ESR1 gene and osteoporosis related phenotypes in a population based cohort of 3054 Scottish women. RESULTS: There was a significant association between a common haplotype "px", defined by the PvuII and XbaI restriction fragment length polymorphisms within intron 1 of the ESR1 gene, and femoral neck bone loss in postmenopausal women who had not received hormone replacement therapy (n = 945; p = 0.009). Annual rates of femoral neck bone loss were approximately 14% higher in subjects who carried one copy of px and 22% higher in those who carried two copies, compared with those who did not carry the px haplotype. The px haplotype was associated with lower femoral neck BMD in the postmenopausal women (p = 0.02), and with reduced calcaneal broadband ultrasound attenuation (BUA) values in the whole study population (p = 0.005). There was no association between a TA repeat polymorphism in the ESR1 promoter and any phenotype studied, though on long range haplotype analysis subjects with a smaller number of TA repeats who also carried the px haplotype had reduced BUA values. CONCLUSIONS: The ESR1px haplotype is associated with reduced hip BMD values and increased rates of femoral neck bone loss in postmenopausal women. An association with BUA may explain the fact that ESR1 intron 1 alleles predict osteoporotic fractures by a mechanism partly independent of differences in BMD.

Alleles↗
PubMed2004

Predicting erosive disease in rheumatoid arthritis. A longitudinal study of changes in bone density using digital X-ray radiogrammetry: a pilot study.

OBJECTIVE: Periarticular osteoporosis is one of the first radiological signs of rheumatoid arthritis (RA). Osteoporosis is now quantified using dual-energy X-ray absorptiometry (DXA), although it was originally assessed by radiogrammetry. A new updated system of radiogrammetry has been developed: digitized X-ray radiogrammetry (DXR). We used this DXR system to identify whether changes seen in hand X-rays of RA patients can predict those who subsequently develop erosions. METHODS: We enrolled 24 patients with early RA and they attended for hand radiographs at baseline, 12, 24 and 48 months. The hand radiographs were analysed using a Pronosco X-Posure system which measures bone mineral density, and other parameters using DXR. DXA of the hand was also performed to measure bone mineral density. Sharp and Larsen radiographic scores were calculated and other disease activity markers were measured. RESULTS: DXR bone mineral density fell significantly throughout the study. The group of RA subjects were divided according to the change in erosive status. Change in DXR bone mineral density after 1 yr was very specific (100%) and highly sensitive (63%) in predicting those who either became erosive or whose erosions significantly worsened. In contrast, of the other disease activity markers, only baseline ESR (sensitivity 67%, specificity 80%) significantly predicted the erosive status of subjects at 4 yr. CONCLUSION: Computerized radiogrammetry from digitized images can predict at 1 yr those patients with RA who will become erosive at 4 yr. A larger prospective study is required to confirm these findings; however, these results show some promise as a method of targeting those patients who require more aggressive, expensive therapy.

Absorptiometry, Photon↗