Prevalence, glucose control and relative survival of people with Type 2 diabetes in the UK from 1991 to 2013.

AIMS: To characterize the prevalence of Type 2 diabetes between 1991 and 2013 in the UK and to determine whether corresponding glucose control and survival had changed in the diabetic population during this period. METHODS: For this retrospective cohort study, people diagnosed with Type 2 diabetes between 1991 and 2013 were identified from the Clinical Practice Research Datalink (CPRD) and the annual point prevalence calculated. Mean HbA1c by year was estimated. The Cox proportional hazards model was used to calculate the risk of all-cause mortality by year for incident cases of Type 2 diabetes treated with glucose-lowering therapy. RESULTS: Crude prevalence of diagnosed Type 2 diabetes increased from 1.32% [95% confidence interval (95% CI) 1.30% to 1.34%] in 1991 to 4.54% (4.52% to 4.56%) in 2013. Mean HbA1c for people with diagnosed Type 2 diabetes was 71 mmol/mol (8.6%) in 1991, 59 mmol/mol (7.5%) in 2003 and 58 mmol/mol (7.5%) in 2013. For diagnosed Type 2 diabetes treated with glucose-lowering therapy, when compared with 1991, the hazard ratio for all-cause mortality was 0.33 (0.27-0.41) in 2013. CONCLUSION: The prevalence of diagnosed Type 2 diabetes trebled in the UK between 1991 and 2013. Improved survival in people with diagnosed Type 2 diabetes is likely to account, at least in part, for the increase in prevalence observed.

The incidence of type 2 diabetes in the United Kingdom from 1991 to 2010.

AIMS: To characterize the incidence of type 2 diabetes in the UK over the previous 20 years; and determine if there has been an increase in people aged 40 years or less at diagnosis. METHODS: For this retrospective cohort study, patients newly diagnosed with type 2 diabetes between 1991 and 2010 were identified from the UK Clinical Practice Research Datalink (CPRD). Patient data were grouped into 5-year intervals by year of diagnosis and age at diagnosis. A standardized incidence ratio (SIR) was determined (1991-1995 = 100). The percentage of newly diagnosed patients for each age group and aged ≤40 years was calculated for each 5-year calendar period. The incidence rate by age and 5-year calendar period was also determined. RESULTS: In 2010, the crude incidence rate of type 2 diabetes was 515 per 100,000 population. The overall SIR increased to 158 (95% CI 157-160, p < 0.001), 237 (235-238, p < 0.001) and 275 (273-276, p < 0.001) for 1996-2000, 2001-2005 and 2006-2010, respectively. For those ≤40, the respective values were 217 (209-226, p < 0.001), 327 (320-335, p < 0.001) and 598 (589-608, p < 0.001). An increase in incidence occurred with increasing 5-year calendar period. The incidence of type 2 diabetes was higher for males after the age of 40 and higher for females aged ≤40. The percentage of patients aged ≤40 years at diagnosis increased with each increasing 5-year calendar period (5.9, 8.4, 8.5 and 12.4%, respectively). CONCLUSIONS: There was a significant increase in the incidence of diagnosed type 2 diabetes between 1991 and 2010 and the proportion of people diagnosed at a relatively early age has increased markedly.

Estimated costs of acute hospital care for people with diabetes in the United Kingdom: a routine record linkage study in a large region.

AIMS: Diabetes represents a notable burden to health payers. The purpose of this study was to estimate acute hospital care costs of treating people with diabetes with reference to the costs of treating those without. METHODS: This was a retrospective study. Data from routine hospital practice were available from a large health region (439 000 people), with an estimated prevalence of diabetes of 3.4%. Common records were identified using probabilistic record linkage. Cost estimates were attributed to admissions using healthcare resource group software. Outpatient costs were attributed using published values. Data described are for 2004, and prices in pounds sterling for 2005. Standardised cost ratios were estimated to compare the costs observed in the diabetes population with those expected from the non-diabetic reference population. RESULTS: The total annual cost of admissions was pound28 944 811 per 100 000 people, of which pound3 650 869 per 100 000 (12.6%) was diabetes related. The standardised cost rate of inpatient treatment was 2.9. The total cost of outpatient attendances was pound6 589 971 per 100 000, of which pound711 431 per 100 000 (10.8%) was diabetes related. The standardised cost ratio for outpatient care was 4.1. The total cost of hospital care for patients with diabetes was pound11 206 986 per 100 000, or 12.3% of acute hospital expenditure. The combined standardised cost ratio was 3.1. Costs of care for inpatient treatment increased from 8.7% of revenue in 1994 to 12.3% in 2004. CONCLUSIONS: The costs of acute hospital care for treating people with diabetes increased markedly over a decade, and now exceed 12% of revenue.

Dispensing patterns and financial costs of glucose-lowering therapies in the UK from 2000 to 2008.

INTRODUCTION: A variety of influences determine prescribing behaviour. The purpose of this study was to characterize the pattern of dispensing for glucose-lowering and monitoring in the UK from 2000 to 2008, inclusively. METHODS: Open source data were used from the four UK prescription pricing agencies. Historical patterns of dispensing change were analysed in England, thus data are for England unless otherwise stated. Costs were adjusted for price inflation and reported in UK pound at 2008 prices. RESULTS: The total cost in the UK in 2008 was 702 239 000 UK pounds: 22 897 000 pounds (3.2%) for Northern Ireland, 37 681 000 pounds (5.3%) for Wales, 57 146 000 pounds (8.1%) for Scotland and 590 514 000 pounds (83.4%) for England. As a per cent of the overall primary care drug budget for each region, this represented 6.9% overall and then 5.8, 6.5, 5.9 and 7.1%, respectively. In England, diabetes-related dispensing costs increased from 290m to 591m UK pounds. All glucose-lowering drug classes increased in volume, except the alpha-glucoside inhibitors and the prandial glucose regulators. Insulin costs increased from 128m to 286m UK pounds. Insulin glargine metrics increased year-on-year, whereas neutral protamine Hagedorn (NPH) declined. Analogue insulin increased (2.6 million to 33.9 million prescription items), whereas human insulin declined (21.0 million to 10.3 million). DISCUSSION: The costs of dispensing for diabetes increased markedly between 2000 and 2008 to represent an annual cost to the NHS of 708m UK pounds, or 7% of budget. Costs increased at a higher rate than volume. Changes in prescribing appeared to reflect commercial factors more than clinical evidence. Diabetes dispensing patterns need to be better controlled and costs contained.

Prolonged space flight-induced alterations in the structure and function of human skeletal muscle fibres.

The primary goal of this study was to determine the effects of prolonged space flight (180 days) on the structure and function of slow and fast fibres in human skeletal muscle. Biopsies were obtained from the gastrocnemius and soleus muscles of nine International Space Station crew members 45 days pre- and on landing day (R+0) post-flight. The main findings were that prolonged weightlessness produced substantial loss of fibre mass, force and power with the hierarchy of the effects being soleus type I > soleus type II > gastrocnemius type I > gastrocnemius type II. Structurally, the quantitatively most important adaptation was fibre atrophy, which averaged 20% in the soleus type I fibres (98 to 79 µm diameter). Atrophy was the main contributor to the loss of peak force (P(0)), which for the soleus type I fibre declined 35% from 0.86 to 0.56 mN. The percentage decrease in fibre diameter was correlated with the initial pre-flight fibre size (r = 0.87), inversely with the amount of treadmill running (r = 0.68), and was associated with an increase in thin filament density (r = 0.92). The latter correlated with reduced maximal velocity (V(0)) (r = 0.51), and is likely to have contributed to the 21 and 18% decline in V(0) in the soleus and gastrocnemius type I fibres. Peak power was depressed in all fibre types with the greatest loss (55%) in the soleus. An obvious conclusion is that the exercise countermeasures employed were incapable of providing the high intensity needed to adequately protect fibre and muscle mass, and that the crew's ability to perform strenuous exercise might be seriously compromised. Our results highlight the need to study new exercise programmes on the ISS that employ high resistance and contractions over a wide range of motion to mimic the range occurring in Earth's 1 g environment.

The changing prevalence of diagnosed diabetes and its associated vascular complications in a large region of the UK.

AIMS: To characterize the prevalence of diabetes in a large health district in 2004 and compare it with a previous estimate made in 1996. METHODS: The study population comprised the resident population of Cardiff and the Vale of Glamorgan. Routine record linkage was used to identify patients from various sources of hospital and mortality data. Patients with diabetes were identified according to biochemistry test results, coding on routine data or attendance at a diabetes-related clinic. Diabetes-related complications were ascribed according to coding on routine data. RESULTS: It was possible to identify 17 088 people with diabetes alive on 1 January 2005. Of these patients, 9064 (53.0%) were male and 8024 (47.0%) were female. Mean age (+/- sd) was 59.6 +/- 18.9 years for males and 61.2 +/- 20.4 years for females. The crude prevalence of diabetes in 2005 was 3.9% (3.4% adjusted) compared with 2.5% in 1996 (2.3% adjusted). With the exception of females aged > or = 75 years, the prevalence of diabetes increased in all age- and sex-specific subgroups. Within the 2005 cohort, over two-thirds has no recorded complications compared with approximately one half of the 1996 cohort. The prevalence of individual complications decreased, with the exception of renal complications. CONCLUSIONS: The prevalence of identified diabetes appears to have increased substantially over a relatively short period of 9 years to 2004. The increase in prevalence was 46%, with an increase in numbers of patients with diabetes of 53%. A number of factors are likely to have contributed to this, including an increase in case ascertainment.

Molecular detection of exercise-induced free radicals following ascorbate prophylaxis in type 1 diabetes mellitus: a randomised controlled trial.

AIMS/HYPOTHESIS: Patients with type 1 diabetes mellitus are more susceptible than healthy individuals to exercise-induced oxidative stress and vascular endothelial dysfunction, which has important implications for the progression of disease. Thus, in the present study, we designed a randomised double-blind, placebo-controlled trial to test the original hypothesis that oral prophylaxis with vitamin C attenuates rest and exercise-induced free radical-mediated lipid peroxidation in type 1 diabetes mellitus. METHODS: All data were collected from hospitalised diabetic patients. The electron paramagnetic resonance spectroscopic detection of spin-trapped alpha-phenyl-tert-butylnitrone (PBN) adducts was combined with the use of supporting markers of lipid peroxidation and non-enzymatic antioxidants to assess exercise-induced oxidative stress in male patients with type 1 diabetes (HbA(1c) 7.9 +/- 1%, n = 12) and healthy controls (HbA(1c) 4.6 +/- 0.5%, n = 14). Following participant randomisation using numbers in a sealed envelope, venous blood samples were obtained at rest, after a maximal exercise challenge and before and 2 h after oral ingestion of 1 g ascorbate or placebo. Participants and lead investigators were blinded to the administration of either placebo or ascorbate treatments. Primary outcome was the difference in changes in free radicals following ascorbate ingestion. RESULTS: Six diabetic patients and seven healthy control participants were randomised to each of the placebo and ascorbate groups. Diabetic patients (n = 12) exhibited an elevated concentration of PBN adducts (p < 0.05 vs healthy, n = 14), which were confirmed as secondary, lipid-derived oxygen-centred alkoxyl (RO.) radicals (a(nitrogen) = 1.37 mT and abeta(hydrogen) = 0.18 mT). Lipid hydroperoxides were also selectively elevated and associated with a depression of retinol and lycopene (p < 0.05 vs healthy). Vitamin C supplementation increased plasma vitamin C concentration to a similar degree in both groups (p < 0.05 vs pre-supplementation) and attenuated the exercise-induced oxidative stress response (p < 0.05 vs healthy). There were no selective treatment differences between groups in the primary outcome variable. CONCLUSIONS/INTERPRETATION: These findings are the first to suggest that oral vitamin C supplementation provides an effective prophylaxis against exercise-induced free radical-mediated lipid peroxidation in human diabetic blood. CLINICAL TRIALS REGISTRATION NUMBER: ISRCTN96164937.

Gestational diabetes screening and glycaemic management; national survey on behalf of the Association of British Clinical Diabetologists.

BACKGROUND: There is no UK consensus for screening methodology, diagnosis and management of gestational diabetes mellitus (GDM). AIM: To evaluate routine practice for GDM management across the UK. METHODS: Questionnaires were sent to all members of the Association of British Clinical Diabetologists. They were asked to describe how patients were screened for GDM, the diagnostic criteria and subsequent management and clinical targets. Centres that did not respond were followed up by personal communication. Variability trends within regions were assessed. RESULTS: The response rate averaged 46% nationally (35-67%). Most (85%) units hold a joint clinic, regardless of the size. Most (82%) centres routinely screen for GDM; half universally and half screening high risk pregnancies only. Screening tests, cut-off values, timings and subsequent action vary widely. The first screening test to be used varies, with 40% using glycosuria, followed by random plasma glucose (RPG)(28%), high risk features (11%) then FPG in 6%. Cut-off values for both random and plasma glucose as screening methods also vary. The 75 g oral glucose tolerance test (OGTT) is the most likely confirmatory test to be used if initial screening is positive; however, clinicians rely on different cut-off values and timing. Most (95%) centres routinely assess foetal growth. Postpartum screening is undertaken by 90%, using a 75 g OGTT (93%). Most (90%) centres counsel patients about their high risk for further GDM and type 2 diabetes mellitus. Variability trends in any of the responses could not be detected between different regions in the UK. CONCLUSION: Standards for GDM screening and management vary significantly across the UK. Although most centres utilize the 75 g OGTT to confirm the diagnosis, there is no consistency in its interpretation. This survey confirms the urgent need for consensus guideline development.

The deleterious effects of bed rest on human skeletal muscle fibers are exacerbated by hypercortisolemia and ameliorated by dietary supplementation.

Prolonged inactivity associated with bed rest in a clinical setting or spaceflight is frequently associated with hypercortisolemia and inadequate caloric intake. Here, we determined the effect of 28 days of bed rest (BR); bed rest plus hypercortisolemia (BRHC); and bed rest plus essential amino acid (AA) and carbohydrate (CHO) supplement (BRAA) on the size and function of single slow- and fast-twitch muscle fibers. Supplementing meals, the BRAA group consumed 16.5 g essential amino acids and 30 g sucrose at 1100, 1600, and 2100 h, and the BRHC subjects received 5 daily doses of 10-15 mg of oral hydrocortisone sodium succinate throughout bed rest. Bed rest induced atrophy and loss of force (mN) and power (muN.FL.s(-1)) in single fibers was exacerbated by hypercortisolemia where soleus peak force declined by 23% in the type I fiber from a prevalue of 0.78 +/- 0.02 to 0.60 +/- 0.02 mN post bed rest (compared to a 7% decline with bed rest alone) and 27% in the type II fiber (1.10 +/- 0.08 vs. 0.81 +/- 0.05 mN). In the BRHC group, peak power dropped by 19, 15, and 11% in the soleus type I, and vastus lateralis (VL) type I and II fibers, respectively. The AA/CHO supplement protected against the bed rest-induced loss of peak force in the type I soleus and peak power in the VL type II fibers. These results provide evidence that an AA/CHO supplement might serve as a successful countermeasure to help preserve muscle function during periods of relative inactivity.

The financial costs of healthcare treatment for people with Type 1 or Type 2 diabetes in the UK with particular reference to differing severity of peripheral neuropathy.

AIMS: To characterize symptom severity of diabetic peripheral neuropathy (DPN) in people with diabetes and to characterize its association with healthcare resource use. METHODS: The study was undertaken in Cardiff and the Vale of Glamorgan, UK. A postal survey was posted to subjects identified as having diabetes. Demography, quality of life (EQ-5D and SF-36) and symptoms of neuropathy (NTSS-6 and QOL-DN) data were collected. These data were linked to routine healthcare data coded into healthcare resource groups (HRGs) and subsequently costed according to UK National reference costs. RESULTS: Survey responses were received from 1298 patients, a 32% response rate. For patients with a clinically confirmed diagnosis of DPN, the mean NTSS-6-SA score was 6.16 vs. 3.19 (P < 0.001). Duration of diabetes did not change across groups defined by severity of neuropathy symptoms, but mean HbA(1c) and body mass index values did increase with symptom severity (range 7.6-8.1%, P = 0.023; and 28.0-30.9 kg/m(2), P < 0.001, respectively). General linear modelling showed that the NTSS-6-SA score was a significant predictor of both annual health resource costs and yearly prescribed drug costs. On average, each 1-point increase in NTSS-6-SA score predicted a 6% increase in primary and secondary care costs and a 3% increase in log transformed drug costs. CONCLUSION: This study demonstrated that severity of DPN symptoms was associated with increased healthcare resource use, thus costs.

The health-related utility and health-related quality of life of hospital-treated subjects with type 1 or type 2 diabetes with particular reference to differing severity of peripheral neuropathy.

AIMS/HYPOTHESIS: We characterised symptom severity of diabetic peripheral neuropathy (DPN) in people with diabetes, and correlated this with health-related utility and health-related quality of life. MATERIALS AND METHODS: The study was undertaken in Cardiff and the Vale of Glamorgan, Wales. A postal survey was mailed to a random sample of subjects identified as having diabetes. Data were collected on the symptoms of neuropathy using the Neuropathic Total Symptom Score (self-administered) (NTSS-6-6A) and on quality of life using the Quality of Life in Diabetes Neuropathy Instrument (QoL-DN), EueroQoL five dimensions (EQ5D) and Short Form 36 (SF36). Other information, such as demographics and self-reported drug use, was also collected. The anonymised data were linked to routine inpatient and outpatient healthcare data. RESULTS: Responses were received from 1,298 patients. For patients with a clinically confirmed diagnosis of DPN, the mean NTSS-6-SA score was 6.16 vs 3.19 in patients without DPN (p<0.001). Four categories of severity were defined, ranging from none to severe. All quality of life measures showed a deterioration between these groups: the EQ5D(index) fell from an average of 0.81 in those without symptoms to 0.25 in those with severe symptoms, the SF36 general health profile fell from 59.9 to 25.5 (p<0.001) and the QoL-DN increased from 25.8 to 48.1 (p<0.001). Multivariate models also demonstrated that this relationship remained after controlling for other factors. CONCLUSIONS/INTERPRETATION: This study demonstrated that severity of DPN symptoms was predictive of poor health-related utility and decreased quality of life. Furthermore, it provides detailed utility data for economic evaluation of treatment of typical diabetes-related morbidity states. Reducing DPN morbidity should be a priority.

Characterization and comparison of health-related utility in people with diabetes with various single and multiple vascular complications.

AIMS: To characterize and compare health-related utility in a large cohort of patients treated in hospital with diabetes and with single and multiple comorbidities. METHODS: The study was conducted in Cardiff and the Vale of Glamorgan, UK. Health-related utility was measured using the EQ5D(index), a standardized instrument for measuring health outcome. Patients from the Health Outcomes Data Repository (HODaR) were surveyed by postal questionnaire 6 weeks post discharge for in-patients and during clinics for patients attending as out-patients between January 2002 and July 2005. Patients with diabetes were identified by a previous history of in-patient admission with diabetes or as an out-patient with diabetes recorded as a coexisting diagnosis. RESULTS: We identified 4502 patients with diabetes. Mean ages were 65.4 and 64.2 years for males and females, respectively. Of these, 2003 (45%) had no recorded vascular complication. Overall, the EQ5D(index) was 0.584 (sd 0.325) for males and 0.533 (sd 0.351) for females. For those without any vascular complications the mean EQ5D(index) was 0.735 (sd 0.288). In a general linear model, the presence of single and multiple complications had a detrimental impact on the EQ5D(index). CONCLUSION: The results of this study provide an indication of the true impact of diabetes in terms of health-related utility. There was a decrease in the mean EQ5D(index) for those with vascular complications. Economic models of diabetes that have used additive or multiplicative methods to assess utility in individuals with several complications may be unreliable, and direct measurements, such as this, are recommended.

Low cell pH depresses peak power in rat skeletal muscle fibres at both 30 degrees C and 15 degrees C: implications for muscle fatigue.

Historically, an increase in intracellular H(+) (decrease in cell pH) was thought to contribute to muscle fatigue by direct inhibition of the cross-bridge leading to a reduction in velocity and force. More recently, due to the observation that the effects were less at temperatures closer to those observed in vivo, the importance of H(+) as a fatigue agent has been questioned. The purpose of this work was to re-evaluate the role of H(+) in muscle fatigue by studying the effect of low pH (6.2) on force, velocity and peak power in rat fast- and slow-twitch muscle fibres at 15 degrees C and 30 degrees C. Skinned fast type IIa and slow type I fibres were prepared from the gastrocnemius and soleus, respectively, mounted between a force transducer and position motor, and studied at 15 degrees C and 30 degrees C and pH 7.0 and 6.2, and fibre force (P(0)), unloaded shortening velocity (V(0)), force-velocity, and force-power relationships determined. Consistent with previous observations, low pH depressed the P(0) of both fast and slow fibres, less at 30 degrees C (4-12%) than at 15 degrees C (30%). However, the low pH-induced depressions in slow type I fibre V(0) and peak power were both significantly greater at 30 degrees C (25% versus 9% for V(0) and 34% versus 17% for peak power). For the fast type IIa fibre type, the inhibitory effect of low pH on V(0) was unaltered by temperature, while for peak power the inhibition was reduced at 30 degrees C (37% versus 18%). The curvature of the force-velocity relationship was temperature sensitive, and showed a higher a/P(0) ratio (less curvature) at 30 degrees C. Importantly, at 30 degrees C low pH significantly depressed the ratio of the slow type I fibre, leading to less force and velocity at peak power. These data demonstrate that the direct effect of low pH on peak power in both slow- and fast-twitch fibres at near-in vivo temperatures (30 degrees C) is greater than would be predicted based on changes in P(0), and that the fatigue-inducing effects of low pH on cross-bridge function are still substantial and important at temperatures approaching those observed in vivo.

Evaluation of survival and ischaemic and thromboembolic event rates in patients with non-valvar atrial fibrillation in the general population when treated and untreated with warfarin.

OBJECTIVE: To compare survival and adverse outcome of patients with non-valvar atrial fibrillation (NVAF) treated with or without warfarin. DESIGN: Record linkage method to identify patients with a previous hospital diagnosis of atrial fibrillation and to link these patients to international normalised ratio (INR) test results and mortality data. SETTING: Cardiff and the Vale of Glamorgan, Wales. MAIN OUTCOME MEASURES: Mortality, specifically from ischaemic and thromboembolic events. RESULTS: 6108 patients were identified with NVAF, of whom 36.4% received warfarin. Mean survival in the warfarin and non-warfarin groups was 52.0 months and 38.2 months, respectively (p < 0.001), and 14.4 months (p < 0.001) after adjustment for confounding factors. Warfarin treated patients in the upper quartile of INR control had significantly longer survival (57.5 months) than did those in the lowest quartile of control (38.1 months, p < 0.001). The risk of stroke in the warfarin group when treated was lower than that in the non-warfarin group (relative rate (RR) 0.74, p < 0.001). The risk of death from ischaemic stroke was lower in the warfarin group (RR 0.43, p < 0.001). The risk of all ischaemic and embolic events in the warfarin group was lower when they were taking warfarin (RR 0.74, p < 0.001). The risk of bleeding in the warfarin group when treated was greater (RR 1.78, p = 0.001). CONCLUSIONS: Patients with NVAF within the recommended target INR range of 2.0-3.0 survive longer and have reduced morbidity. Probably too few people are anticoagulated with warfarin in NVAF.

Evaluation of the pattern of treatment, level of anticoagulation control, and outcome of treatment with warfarin in patients with non-valvar atrial fibrillation: a record linkage study in a large British population.

OBJECTIVE: To evaluate how well patients with non-valvar atrial fibrillation (NVAF) were maintained within the recommended international normalised ratio (INR) target of 2.0-3.0 and to explore the relation between achieved INR control and clinical outcomes. DESIGN: Record linkage study of routine activity records and INR measurements. SETTING: Cardiff and the Vale of Glamorgan, South Wales, UK. PARTICIPANTS: 2223 patients with NVAF, no history of heart valve replacement, and with at least five INR measurements. MAIN OUTCOME MEASURES: Mortality, ischaemic stroke, all thromboembolic events, bleeding events, hospitalisation, and patterns of INR monitoring. RESULTS: Patients treated with warfarin were outside the INR target range 32.1% of the time, with 15.4% INR values > 3.0 and 16.7% INR values < 2.0. However, the quartile with worst control spent 71.6% of their time out of target range compared with only 16.3% out of range in the best controlled quartile. The median period between INR tests was 16 days. Time spent outside the target range decreased as the duration of INR monitoring increased, from 52% in the first three months of monitoring to 30% after two years. A multivariate logistic regression model showed that a 10% increase in time out of range was associated with an increased risk of mortality (odds ratio (OR) 1.29, p < 0.001) and of an ischaemic stroke (OR 1.10, p = 0.006) and other thromboembolic events (OR 1.12, p < 0.001). The rate of hospitalisation was higher when INR was outside the target range. CONCLUSIONS: Suboptimal anticoagulation was associated with poor clinical outcomes, even in a well controlled population. However, good control was difficult to achieve and maintain. New measures are needed to improve maintenance anticoagulation in patients with NVAF.

Evaluating the performance of the Framingham risk equations in a population with diabetes.

AIMS: The Framingham risk equations are widely used to estimate risk of coronary heart disease (CHD). The purpose of this study was to evaluate the reliability of these equations in predicting CHD risk in people with diabetes and the reliability of using imputed mean HDL-cholesterol values. METHODS: Data describing the baseline characteristics of recognized CHD risk factors for 938 people aged 30-74 years were extracted from the Cardiff Diabetes Database. Data describing CHD events were available for up to 4 years following the baseline year (1996). Several mathematical techniques were used to assess the reliability of predictions provided by the Framingham equations in this population. RESULTS: Thirty-four percent of males and 25% of females who experienced CHD events had a predicted 10-year CHD risk >/= 30%. Seventy-five percent of males and 58% of females had a predicted 10-year CHD risk >/= 20%. Using imputed HDL-cholesterol values, 26% of males and 6% of females who later developed CHD events had a 10-year CHD risk >/= 30%. Using imputed HDL-cholesterol values, the CHD risk predicted by the Framingham equations consistently underestimated the actual risk of CHD events. However, refitting the Framingham risk equations to the Cardiff data resulted in only marginal improvements in discriminatory capabilities. CONCLUSIONS: The Framingham risk equations can be unreliable when applied to the diabetic population, tending to underestimate an individual's probability of progressing to CHD; the equations perform marginally better in women than in men. The use of imputed mean HDL-cholesterol values improved the reliability of the estimates of risk.

Abnormal metabolic fate of nitric oxide in Type I diabetes mellitus.

AIMS/HYPOTHESIS: Reduced bioavailability of endothelium-derived nitric oxide is implicated in diabetic macrovascular and microvascular disease. In patients with diabetes, we hypothesised that protein glycosylation can alter nitric oxide binding affinity of haemoglobin and plasma proteins, hence reducing nitric oxide availability and causing an alteration in nitric oxide metabolism. METHODS: Binding of nitric oxide to haemoglobin was studied across a range of glycosylation levels in vitro (HbA(1c) 5.9 to 9.8%). In clinical studies nitrate, nitrite, nitrosyl haemoglobin and plasma nitrosothiols were measured in venous blood from 23 patients with uncomplicated Type I (insulin-dependent) diabetes mellitus and 17 non-diabetic control subjects. Samples were analysed at baseline and after nitric oxide was added ex vivo. RESULTS: Nitric oxide-haemoglobin binding was increased at a HbA(1c) greater than 8.5% compared with 5.9% (p<0.01). Basal nitrosyl haemoglobin was higher in diabetic patients compared with the control subjects (0.59+/-0.12 micro mol/l vs 0.24+/-0.12 micro mol/l, p<0.05). Plasma nitrosothiols, and nitrite and nitrate (NOx) concentrations were similar in diabetic patients compared with the control subjects (7.64+/-0.79 micro mol/l vs 5.93+/-0.75 micro mol/l, 13.98+/-2.44 micro mol/l vs 12.44+/-2.15 micro mol/l, respectively). In blood from diabetic patients, added nitric oxide was metabolised preferentially to nitrosyl haemoglobin and plasma nitrosothiols, with a twofold increase in nitrosyl haemoglobin observed across all concentrations of nitric oxide (p<0.05). These preferential increases correlated positively with HbA(1c). CONCLUSION/INTERPRETATION: Nitrosyl haemoglobin is increased in patients with Type I diabetes. Preferential metabolism to nitrosyl haemoglobin and nitrosothiols occurs after increases in nitric oxide. Our results show an accentuated association between nitric oxide and glycosylated proteins, especially deoxygenated haem. An altered metabolic fate of nitric oxide could influence microvascular regulation and tissue perfusion.

Screening for gestational diabetes; past, present and future.

Gestational diabetes is carbohydrate intolerance, with onset or first recognition of hyperglycaemia during pregnancy. Several studies have suggested that gestational hyperglycaemia is associated with adverse maternal and fetal outcomes, promoting the case for screening. Conversely, others argue that screening for gestational diabetes may colour the clinical judgement, influencing further management, e.g. more 'unjustified' caesarean sections. Additionally, the lack of definitive data either on a clear-cut glycaemic threshold for the development of adverse outcomes or on the impact of intervention is emphasized by opponents of screening. This review attempts to evaluate the available data on screening for gestational diabetes. Oral glucose tolerance test is promoted on the basis that the diabetogenic stress of pregnancy is encountered during late gestation and is best recognized in the fed state. There are different tests, including the 1 h/50-g, 2 h/75-g and 3 h/100-g tests, with practical limitations, including the time and cost involved and the unpleasant supra-physiological glucose load that is unrelated to body weight, and issues of reproducibility and sensitivity/specificity profiles. Despite its convenience, the poor sensitivity of random glucose has precluded its routine use for screening. Fasting glucose appears to be promising but further testing is required to ensure satisfactory sensitivity/specificity in different populations. Despite its limitations, the oral glucose tolerance test has become established as the 'most acceptable' diagnostic test for gestational diabetes. More convenient methods, e.g. fasting or random or post-load glucose, have to be validated therefore against the oral glucose tolerance test to gain acceptance for routine screening.