What factors influence concordance with medications? Findings from the U.K. Asian Diabetes study.

AIMS: To investigate concordance with medication, as assessed at baseline and at 1- and 2-year follow-up, and to examine factors associated with non-concordance in a UK-resident South-Asian population. METHODS: Data from the UK Asian Diabetes Study were analysed. Concordance with medications was assessed and recorded at three time points during the study. Multiple logistic regression was used to investigate the factors associated with non-concordance; the associations of baseline factors with year 1 concordance and baseline plus year 1 factors with year 2 concordance. RESULTS: Data for 403 patients from seven practices participating in the UK Asian Diabetes Study were analysed. The numbers of patients who were non-concordant were: 63 (16%) at baseline; 101 (25%) at year 1; and 122 (30%) at year 2. The baseline-measured variables that were significantly associated with year 1 non-concordance included diabetes duration, history of cardiovascular disease, components of the EuroQol quality of life questionnaire, the EQ-5D score, and number of medications prescribed. In multivariable analyses, the most important determinant of year 1 non-concordance was baseline non-concordance: odds ratio 13.6 (95% confidence limits 4.7, 39.9). Number of medications prescribed for blood pressure control was also significant: odds ratio 1.8 (95% confidence limits 1.4, 2.4). Similar results were observed for year 2 non-concordance. CONCLUSIONS: Non-concordance with medications was common and more likely in people prescribed more medications. The current target-driven management of risk factor levels may lead to increasing numbers and doses of medications. Considering the high cost of medications and the implications of poor health behaviours on morbidity and mortality, further investigation of prescribing behaviours and the factors affecting patient concordance are required.

Replication of 13 genome-wide association (GWA)-validated risk variants for type 2 diabetes in Pakistani populations.

AIMS/HYPOTHESIS: Recent genome-wide association (GWA) studies and subsequent replication studies have greatly increased the number of validated type 2 diabetes susceptibility variants, but most of these have been conducted in European populations. Despite the high prevalence of the disease in South Asians, studies investigating GWA-validated type 2 diabetes risk variants in this ethnic group are limited. We investigated 30 single nucleotide polymorphisms (SNPs), predominantly derived from recent GWA studies, to determine if and to what extent these variants affect type 2 diabetes risk in two Punjabi populations, originating predominantly from the District of Mirpur, Pakistan. METHODS: Thirty SNPs were genotyped in 1,678 participants with type 2 diabetes and 1,584 normoglycaemic control participants from two populations; one resident in the UK and one indigenous to the District of Mirpur. RESULTS: SNPs in or near PPARG, TCF7L2, FTO, CDKN2A/2B, HHEX/IDE, IGF2BP2, SLC30A8, KCNQ1, JAZF1, IRS1, KLF14, CHCHD9 and DUSP9 displayed significant (p < 0.05) associations with type 2 diabetes, with similar effect sizes to those seen in European populations. A constructed genetic risk score was associated with type 2 diabetes (p = 5.46 × 10(-12)), BMI (p = 2.25 × 10(-4)) and age at onset of diabetes (p = 0.002). CONCLUSIONS/INTERPRETATION: We have demonstrated that 13 variants confer an increased risk of type 2 diabetes in our Pakistani populations; to our knowledge this is the first time that SNPs in or near KCNQ1, JAZF1, IRS1, KLF14, CHCHD9 and DUSP9 have been significantly associated with the disease in South Asians. Large-scale studies and meta-analyses of South Asian populations are needed to further confirm the effect of these variants in this ethnic group.

An FTO variant is associated with Type 2 diabetes in South Asian populations after accounting for body mass index and waist circumference.

AIMS: A common variant, rs9939609, in the FTO (fat mass and obesity) gene is associated with adiposity in Europeans, explaining its relationship with diabetes. However, data are inconsistent in South Asians. Our aim was to investigate the association of the FTO rs9939609 variant with obesity, obesity-related traits and Type 2 diabetes in South Asian individuals, and to use meta-analyses to attempt to clarify to what extent BMI influences the association of FTO variants with diabetes in South Asians. METHODS: We analysed rs9939609 in two studies of Pakistani individuals: 1666 adults aged ≥40 years from the Karachi population-based Control of Blood Pressure and Risk Attenuation (COBRA) study and 2745 individuals of Punjabi ancestry who were part of a Type 2 diabetes case-control study (UK Asian Diabetes Study/Diabetes Genetics in Pakistan; UKADS/DGP). The main outcomes were BMI, waist circumference and diabetes. Regression analyses were performed to determine associations between FTO alleles and outcomes. Summary estimates were combined in a meta-analysis of 8091 South Asian individuals (3919 patients with Type 2 diabetes and 4172 control subjects), including those from two previous studies. RESULTS: In the 4411 Pakistani individuals from this study, the age-, sex- and diabetes-adjusted association of FTO variant rs9939609 with BMI was 0.45 (95%CI 0.24-0.67) kg/m(2) per A-allele (P=3.0 × 10(-5) ) and with waist circumference was 0.88 (95% CI 0.36-1.41) cm per A-allele (P=0.001). The A-allele (30% frequency) was also significantly associated with Type 2 diabetes [per A-allele odds ratio (95%CI) 1.18 (1.07-1.30); P=0.0009]. A meta-analysis of four South Asian studies with 8091 subjects showed that the FTO A-allele predisposes to Type 2 diabetes [1.22 (95%CI 1.14-1.31); P=1.07 × 10(-8) ] even after adjusting for BMI [1.18 (95%CI 1.10-1.27); P=1.02 × 10(-5) ] or waist circumference [1.18 (95%CI 1.10-1.27); P=3.97 × 10(-5) ]. CONCLUSIONS: The strong association between FTO genotype and BMI and waist circumference in South Asians is similar to that observed in Europeans. In contrast, the strong association of FTO genotype with diabetes is only partly accounted for by BMI.

Impact of acute hyperglycaemia on endothelial function and retinal vascular reactivity in patients with Type 2 diabetes.

AIM: In diabetes, endothelial dysfunction and an altered retinal blood flow have been reported and precede overt macrovascular and microvascular disease. Furthermore, an association between postprandial hyperglycaemia, retinopathy and cardiovascular disease has been observed. METHODS: Endothelial function and retinal vascular reactivity have been measured in baseline conditions in 10 healthy control subjects and 21 patients with Type 2 diabetes. In the patients with Type 2 diabetes, endothelial function and retinal vascular reactivity have been also measured every hour, for 4 h, during an oral glucose tolerance test. Endothelial function has been evaluated by measuring flow-mediated vasodilation of the brachial artery, while retinal vascular reactivity has been measured using a retinal vessel analyser, during a flicker. RESULTS: At 1 and 2 h after glucose ingestion, endothelial function decreased (P<0.05), while retinal vascular reactivity increased, even at 3 h (P<0.05), vs. the baseline values. CONCLUSION: Our data highlight that acute hyperglycaemia impacts on endothelial function simultaneously at both macrovascular and at microvascular levels, inducing functional change, which could contribute towards explaining the clinical evidence of a strong association between postprandial hyperglycaemia, cardiovascular disease and retinopathy.

DPP-IV inhibition enhances the antilipolytic action of NPY in human adipose tissue.

CONTEXT: Dipeptidyl peptidase IV (DPP-IV) inactivates the incretin hormone glucagon-like peptide. It can also affect the orexigenic hormone neuropeptide Y (NPY(1-36)) which is truncated by DPP-IV to NPY(3-36), as a consequence NPY's affinity changes from receptor Y1, which mediates the antilipolytic function of NPY, to other NPY receptors. Little is known whether DPP-IV inhibitors for the treatment of type 2 diabetic (T2DM) patients could influence these pathways. AIMS: To investigate the in vitro effects of NPY with DPP-IV inhibition in isolated abdominal subcutaneous (AbdSc) adipocytes on fat metabolism, and assessment of NPY receptor and DPP-IV expression in adipose tissue (AT). METHODS: Ex vivo human AT was taken from women undergoing elective surgery (body mass index: 27.5 (mean +/- s.d.) +/- 5 kg/m2, age: 43.7 +/- 10 years, n = 36). Isolated AbdSc adipocytes were treated with human recombinant (rh)NPY (1-100 nM) with and without DPP-IV inhibitor (1 M); glycerol release and tissue distribution of DPP-IV, Y1 and Y5 messenger RNA (mRNA) were measured and compared between lean and obese subjects. RESULTS AND CONCLUSION: rhNPY reduced glycerol release, an effect that was further enhanced by co-incubation with a DPP-IV inhibitor [control: 224 (mean +/- s.e.) +/- 37 micromol/l; NPY, 100 nM: 161 +/- 27 micromol/l**; NPY 100 nM/DPP-IV inhibitor, 1 M: 127 +/- 14 micromol/l**; **p < 0.01, n = 14]. DPP-IV was expressed in AbdSc AT and omental AT with relative DPP-IV mRNA expression lower in AbdSc AT taken from obese [77 +/- 6 signal units (SU)] vs. lean subjects (186 +/- 29 SU*, n = 10). Y1 was predominantly expressed in fat and present in all fat depots but higher in obese subjects, particularly the AbdSc AT-depot (obese: 1944 +/- 111 SU vs. lean: 711 +/- 112 SU**, n = 10). NPY appears to be regulated by AT-derived DPP-IV. DPP-IV inhibitors augment the antilipolytic effect of NPY in AT. Further studies are required to show whether this explains the lack of weight loss in T2DM patients treated with DPP-IV inhibitors.

Comparison of maternal ghrelin and leptin in healthy mothers and mothers with Type 1 diabetes.

AIMS: Maternal leptin affects placental growth hormone (GH), whereas ghrelin, a natural ligand of the growth-hormone-secretagogue receptor, modulates GH action. Both hormones may affect fetal growth, and dysregulation in diabetes may lead to fetal growth disturbances. The aim was to investigate changes in maternal ghrelin during pregnancy with diabetes and to establish reference leptin levels. METHODS: Twelve healthy non-diabetic (ND) and 12 pregnant women with Type 1 diabetes (T1DM) were recruited. Age and body mass index (BMI) [ND: age 29.9 +/- 4.7 years (mean +/- sd), BMI 25.2 +/- 3.7 kg/m2; T1DM: age 31 +/- 5.5 years, BMI 27 +/- 3.1 kg/m2] were similar in the groups. HbA1c in T1DM was 6.2 +/- 1.1% at 20 weeks, 6.3 +/- 1.1% at 30 weeks' gestation and 7.8 +/- 2.1% postpartum. Fasting plasma ghrelin, total leptin, free leptin (FL) and soluble leptin receptor (sOB-R) levels were measured at 20 and 30 weeks' gestation and postpartum and determined by radioimmunoassay. RESULTS: All pregnancies resulted in full-term singleton births with no differences in birth weight between groups [T1DM: 3.4 +/- 0.56 kg (mean +/- SE); ND: 3.6 +/- 0.3 kg, P = NS]. Ghrelin levels were lower in T1DM when corrected for age and mothers' weight (T1DM: 458 +/- 36 pg/ml and 432.9 +/- 26.6 pg/ml; ND: 562 +/- 52 pg/ml and 515.8 +/- 63 pg/ml at 20 and 30 weeks, respectively, P < 0.05). T1DM mothers had higher levels of sOB-R and FL levels declined at 30 weeks' gestation in T1DM (P = 0.04) but not in ND. CONCLUSION: In a population of pregnant women with expected changes in leptin levels as previously reported, ghrelin levels were lower in T1DM pregnancies at 20 and 30 weeks. This may have implications for fetal development and requires further study in diabetes, particularly in pregnancies that result in macrosomia.

Enhanced diabetes care to patients of south Asian ethnic origin (the United Kingdom Asian Diabetes Study): a cluster randomised controlled trial.

BACKGROUND: Delivery of high-quality, evidence-based health care to deprived sectors of the community is a major goal for society. We investigated the effectiveness of a culturally sensitive, enhanced care package in UK general practices for improvement of cardiovascular risk factors in patients of south Asian origin with type 2 diabetes. METHODS: In this cluster randomised controlled trial, 21 inner-city practices in the UK were assigned by simple randomisation to intervention (enhanced care including additional time with practice nurse and support from a link worker and diabetes-specialist nurse [nine practices; n=868]) or control (standard care [12 practices; n=618]) groups. All adult patients of south Asian origin with type 2 diabetes were eligible. Prescribing algorithms with clearly defined targets were provided for all practices. Primary outcomes were changes in blood pressure, total cholesterol, and glycaemic control (haemoglobin A1c) after 2 years. Analysis was by intention to treat. This trial is registered, number ISRCTN 38297969. FINDINGS: We recorded significant differences between treatment groups in diastolic blood pressure (1.91 [95% CI -2.88 to -0.94] mm Hg, p=0.0001) and mean arterial pressure (1.36 [-2.49 to -0.23] mm Hg, p=0.0180), after adjustment for confounders and clustering. We noted no significant differences between groups for total cholesterol (0.03 [-0.04 to 0.11] mmol/L), systolic blood pressure (-0.33 [-2.41 to 1.75] mm Hg), or HbA1c (-0.15% [-0.33 to 0.03]). Economic analysis suggests that the nurse-led intervention was not cost effective (incremental cost-effectiveness ratio pound28 933 per QALY gained). Across the whole study population over the 2 years of the trial, systolic blood pressure, diastolic blood pressure, and cholesterol decreased significantly by 4.9 (95% CI 4.0-5.9) mm Hg, 3.8 (3.2-4.4) mm Hg, and 0.45 (0.40-0.51) mmol/L, respectively, and we recorded a small and non-significant increase for haemoglobin A1c (0.04% [-0.04 to 0.13]), p=0.290). INTERPRETATION: We recorded additional, although small, benefits from our culturally tailored care package that were greater than the secular changes achieved in the UK in recent years. Stricter targets in general practice and further measures to motivate patients are needed to achieve best possible health-care outcomes in south Asian patients with diabetes.

Adiponectin complexes in human cerebrospinal fluid: distinct complex distribution from serum.

AIMS/HYPOTHESIS: Adiponectin is an adipocyte-derived secretory factor that is specifically produced in adipocytes. It exerts effects on energy homeostasis via peripheral and central mechanisms. However, it is not clear whether adiponectin crosses the blood-brain barrier in humans. In serum, adiponectin circulates in several different complexes, each of which has distinct functions. Here, we wanted to test whether adiponectin can be found in human cerebrospinal fluid (CSF) and whether specific adiponectin complexes are enriched in CSF compared with peripheral serum samples. We also wanted to establish whether there is a sex-related difference with regard to the distribution of adiponectin oligomers in CSF. MATERIALS AND METHODS: We studied 22 subjects (11 men, 11 women) in this study. Their average BMI was 28.0+/-4.7 kg/m2; average age was 70+/-7 years. RESULTS: Analysis of total adiponectin revealed that adiponectin protein is present in human CSF at approximately 0.1% of serum concentration. The distribution of adiponectin oligomers differs considerably in CSF from that of serum within matched samples from the same patients. Only the adiponectin trimeric and low-molecular-mass hexameric complexes are found in CSF, with a bias towards the trimeric form in most patients. Male subjects have a higher CSF:serum ratio of total adiponectin (p<0.05; n=20) and have slightly higher trimer levels in serum and CSF than female subjects. CONCLUSIONS/INTERPRETATION: We conclude that the adiponectin trimer is the predominant oligomer in human CSF.

Type 2 diabetes and cardiovascular risk in the UK south Asian community.

A popular hypothesis for the greater prevalence of type 2 diabetes and cardiovascular disease in UK south Asians is that they have an increased susceptibility of developing insulin resistance in response to certain environmental factors, including obesity and adoption of a sedentary lifestyle. Insulin resistance is postulated as a central feature of the metabolic syndrome, culminating in type 2 diabetes, atherosclerotic vascular disease and CHD; a pathway potentially accelerated by migration/urbanisation. We describe and compare the prevalence of type 2 diabetes, cardiovascular disease and their associated risk factors in UK south Asian and white Caucasian populations to determine possible reasons for the increased preponderance of these diseases in south Asians, and highlight key evidence for optimal risk factor management. Finally, we describe a UK community-based programme that attempts to reduce the morbidity and mortality from type 2 diabetes and cardiovascular disease in south Asians through a new approach to management.

Evaluation of delivery of enhanced diabetes care to patients of South Asian ethnicity: the United Kingdom Asian Diabetes Study (UKADS).

AIMS: We tested the hypothesis that enhanced care for diabetes, tailored to the needs of the South Asian community with Type 2 diabetes, would improve risk factors for diabetic vascular complications and ultimately reduce morbidity and mortality. PATIENTS AND METHODS: The study was a cluster randomized controlled trial (RCT) with general practice the unit of randomization. Six West Midlands general practices with a high proportion of South Asian patients were randomized to 'enhanced care' using Asian link workers and extra community diabetes specialist nurse sessions (intervention) or continued standard practice care (control). RESULTS: Of 401 patients recruited to the study, 361 (90%), comprising 178 from Coventry and 183 from Birmingham were eligible and included in the analyses. The mean age at baseline (standard deviation, SD) was 58.9 (11.7 years) with median (interquartile range; IQR) duration of diabetes 6.5 (3-11) years. At one year follow-up there was a significant difference in reduction of systolic (4.6 mmHg, P = 0.035) and diastolic blood pressure (3.4 mmHg, P = 0.003) and total cholesterol (0.4 mmol/l, P = 0.005), comparing the intervention and control groups. After adjusting for baseline measurement and age, only differential reduction in diastolic blood pressure remained significant. There was no significant change in HbA(1c) and no difference between the groups. CONCLUSIONS: Using link workers and extra community diabetes specialist nurse input together with treatment protocols in primary care might prove a useful strategy in working towards NSF targets for diabetes management. In this study, small reductions in blood pressure and cholesterol were achieved. Improvement in glycaemic control may require longer and possibly different strategies. Further research is required to evaluate fully the effectiveness, including the costs and longer term sustainability of culturally sensitive initiatives.

Effect of head-out water immersion on serum sodium transport inhibitor and urinary nonadrenaline excretion in pre-menopausal women.

The effect of head out water immersion on the excretion of catecholamines and serum sodium transport inhibitor (STI) was studied in healthy young women during the follicular and leuteal phases. Two way ANOVA showed that menstrual cycle had no effect on the excretion of noradrenaline (NA), dopamine (DA) or serum STI. Analysis of pooled data from follicular and leuteal phases showed that immersion caused a significant increase in sodium excretion and serum STI and a significant decrease in urinary NA excretion in healthy young women. After immersion, sodium excretion, DA excretion and serum STI decreased and NA increased.

Cardiorespiratory responses to underwater treadmill walking in healthy females.

This study compared the cardiorespiratory responses of eight healthy women (mean age 30.25 years) to submaximal exercise on land (LTm) and water treadmills (WTm) in chest-deep water (Aquaciser). In addition, the effects of two different water temperatures were examined (28 and 36 degrees C). Each exercise test consisted of three consecutive 5-min bouts at 3.5, 4.5 and 5.5 km x h(-1). Oxygen consumption (VO2) and heart rate (HR), measured using open-circuit spirometry and telemetry, respectively, increased linearly with increasing speed both in water and on land. At 3.5 km x h(-1) VO2 was similar across procedures [chi = 0.6 (0.05) l x min(-1)]. At 4.5 and 5.5 km x h(-1) VO2 was significantly higher in water than on land, but there was no temperature effect (WTm: 0.9 and 1.4, respectively; LTm: 0.8 and 0.9 l x min(-1), respectively). HR was significantly higher in WTm at 36 degrees C compared to WTm at 28 degrees C at all speeds, and compared to LTm at 4.5 and 5.5 km x h(-1) (P < or = 0.003). The HR-VO2 relationship showed that at a VO2 of 0.9 l x min(-1) x HR was higher in water at 36 degrees C (115 beats x min[-1]) than either on land (100 beats min[-1]) or in water at 28 degrees C (99 beats x min[-1]). The Borg scale of perceived exertion showed that walking in water at 4.5 and 5.5 km x h(-1) was significantly harder than on land (WTm: 11.4 and 14, respectively; LTm: 9.9 and 11, respectively; P < or = 0.001). These cardiorespiratory changes occurred despite a slower cadence in water (the mean difference at all speeds was 27 steps/min). Thus, walking in chest-deep water yields higher energy costs than walking at similar speeds on land. This data has implications for therapists working in hydrotherapy pools.

Screening for diabetic retinopathy in primary care: retinal photography alone can be used efficiently and effectively to exclude those with sight threatening lesions.

BACKGROUND: Good screening performance of retinal photography and ophthalmoscopy together in screening for diabetic retinopathy in primary care have been reported. This study reanalysed the data to evaluate the screening performance of photography alone. METHODS: One thousand and ten patients screened by fundal photography and ophthalmoscopy were studied retrospectively. Fundal photographs were quality graded with poor quality pictures being excluded from the analysis. Each patient was reviewed initially by both retinal photographs and ophthalmoscopy by an ophthalmologist, the "gold standard". Six months later the fundal photographs were reviewed and reported in a blinded manner by the ophthalmologist. RESULTS: Two thousand and fourteen photographs were obtained, of which 162 (8%) had to be excluded because of poor quality. On review of the remaining 1852 photographs in isolation, of 77 cases of severe retinopathy as determined by the "gold standard", 67 had severe changes on photography--detection rate 87%. Of the 1775 cases without sight threatening retinopathy only five were judged to have sight threatening changes on photography--false positive rate 0.3%. Considering sight threatening and background retinopathy together, the detection rate was 69% (257 of 375) and the false positive rate 1.6% (23 of 1477). CONCLUSION: Good quality fundal photographs alone seem specific enough to screen for sight threatening diabetic retinopathy, but will underdetect background retinopathy.

Functional importance of platelet-derived growth factor (PDGF) receptor extracellular immunoglobulin-like domains. Identification of PDGF binding site and neutralizing monoclonal antibodies.

The biological effects of platelet-derived growth factor (PDGF) are mediated by alpha- and beta-PDGF receptors (PDGFR), which have an intracellular tyrosine kinase domain and an extracellular region comprising five immunoglobulin-like domains (D1-D5). Using deletion mutagenesis we mapped the PDGF binding site in each PDGFR to the D2-D3 region. In the case of alpha-PDGFR, 125I-PDGF AA and 125I-PDGF BB bound to the full-length extracellular domain, D1-D5, and D2-D3 with equal affinity (Kd = 0.21-0.42 nM). Identical results were obtained for 125I-PDGF BB binding to beta-PDGFR mutants D1-D5 and D2-D3, establishing that D1, D4, and D5 do not contribute to PDGF binding. Monoclonal antibodies (mAb) directed against individual PDGFR Ig-like domains were used to extend these observations. The anti-D1 mAb 1E10E2 and anti-D5 mAb 2D4G10 had no effect on alpha- or beta-PDGFR function, respectively. In contrast, mAb 2H7C5 and 2A1E2 directed against D2 of the alpha- and beta-receptor, respectively, blocked PDGF binding, receptor autophosphorylation and mitogenic signaling with IC50 values of 0.1-3.0 nM. An anti-D4 mAb 1C7D5 blocked beta-receptor autophosphorylation and signaling without inhibiting PDGF binding consistent with the observation that D4 is essential for PDGFR dimerization (Omura, T., Heldin, C.-H., and Ostman, A. (1997) J. Biol. Chem. 272, 12676-12682). mAbs identified here act as potent PDGFR antagonists that can be used as research tools and potentially as therapeutic agents for the treatment of diseases involving unwanted PDGFR signaling.

Adding retinal photography to screening for diabetic retinopathy: a prospective study in primary care.

OBJECTIVE: To evaluate whether adding retinal photography improved community screening for diabetic retinopathy. SETTING: Mobile screening unit at rural and urban general practices in south west England. SUBJECTS: 1010 diabetic patients from primary care. DESIGN: Prospective study; patients were examined by ophthalmoscopy by general practitioners or opticians without fundal photographs and again with photographs, and assessments were compared to those of an ophthalmologist. MAIN OUTCOME MEASURES: Whether fundal photography improved the sensitivity of detection of retinopathy and referrable diabetic retinopathy, and whether this sensitivity could be improved by including a review of the films by the specialist. RESULTS: Diabetic retinopathy was detected by the ophthalmologist in 205 patients (20.5%) and referrable retinopathy in 49 (4.9%). The sensitivity of the general practitioners and opticians for referrable retinopathy with ophthalmoscopy was 65%, and improved to 84% with retinal photographs. General practitioners' sensitivity in detecting background retinopathy improved with photographs from 22% to 65%; opticians' sensitivity in detecting background retinopathy improved from 43% to 71%. The sensitivity of detecting referrable retinopathy by general practitioners improved from 56% to 80% with photographs; for opticians it improved from 75% to 88%. CONCLUSIONS: Combining modalities of screening by providing photography with specialist review of all films in addition to direct ophthalmoscopy through dilated pupils improves assessment and referral for diabetic retinopathy by general practitioners and opticians. With further training and experience, primary care screeners should be able to achieve a sensitivity that will achieve an effective, acceptable, and economical community based screening programme for this condition.