Effectiveness of Nonmydriatic Ultra-Widefield Retinal Imaging to Screen for Diabetic Eye Disease: A Randomized Controlled Trial (Clearsight)

OBJECTIVE

Suboptimal diabetic eye disease screening is a major cause of preventable vision loss. Screening barriers include mydriasis and the need for dedicated screening appointments. The Clearsight trial assessed whether nonmydriatic ultra-widefield (NM UWF) screening on the day of a diabetes clinic visit improved detection of clinically important eye disease versus usual screening.

RESEARCH DESIGN AND METHODS

This single-center, randomized, parallel-group controlled trial was conducted at St. Joseph's Health Care, London, Ontario, Canada. Adults with diabetes due for screening were randomized to same-day, on-site screening (NM UWF imaging) on the day of a scheduled diabetes clinic visit or usual screening (encouraged to arrange optometrist screening). The primary outcome was detection of actionable eye disease (AED), defined as the need for an ophthalmology referral or increased ocular surveillance. The primary analysis (modified intention-to-screen) compared the proportions of AED between groups within 1 year of enrollment.

RESULTS

Of 740 participants randomized between 7 March 2016 and 17 April 2019, 335 on-site screening and 323 usual screening participants met criteria for the primary analysis. More AED was detected in the on-site screening group than in the usual screening group (50 of 335 [14.9%] vs. 22 of 323 [6.8%]; adjusted odds ratio 2.51; 95% CI 1.49-4.36). The number needed to screen by on-site screening in order to detect 1 additional patient with AED was 13 (95% CI 8-29).

CONCLUSIONS

Same-day, on-site screening by NM UWF imaging increased the detection of clinically important diabetic eye disease versus usual screening. Integration of NM UWF imaging into routine diabetes clinic visits improved screening adherence and has the potential to prevent vision loss.

Hypoglycemia requiring paramedic assistance among adults in southwestern Ontario, Canada: a population-based retrospective cohort study

BACKGROUND

People with diabetes mellitus commonly experience hypoglycemia, but they may not necessarily present to hospital after severe hypoglycemia requiring paramedic assistance. We sought to describe the incidence and characteristics of calls for hypoglycemia requiring paramedic assistance among adults in southwestern Ontario, Canada, and to determine predictors of hospital transport.

METHODS

This population-based retrospective cohort study used data extracted from ambulance call reports (ACRs) of 8 paramedic services of the Southwest Ontario Regional Base Hospital Program from January 2008 to June 2014. We described calls in which treatment for hypoglycemia was administered, summarized the incidence of hypoglycemia calls and performed logistic regression to determine predictors of hospital transport.

RESULTS

Out of 470 467 ACRs during the study period, 9185 paramedic calls occurred in which hypoglycemia treatment was administered to an adult (mean age 60.2 yr, 56.8% male, 81.1% with documented diabetes). Refusal of hospital transport occurred in 2243 (24.4%) of calls. Documented diabetes diagnosis (adjusted odds ratio [OR] 0.82, 95% confidence interval [CI] 0.69-0.96), higher capillary blood glucose (adjusted OR 0.31, 95% CI 0.22-0.44) and overnight calls (adjusted OR 0.80, 95% CI 0.72-0.91) were associated with lower odds of hospital transport. Higher-acuity calls (adjusted OR 2.05, 95% CI 1.58-2.66) were associated with higher odds of transport. The estimated annual incidence rate of hypoglycemia requiring paramedic assistance was 108 per 10 000 people with diabetes per year.

INTERPRETATION

Hypoglycemia requiring paramedic assistance in southwestern Ontario is common, and close to 25% of calls do not result in hospital transport. Physicians managing diabetes care may be unaware of patients' hypoglycemia requiring paramedic care, suggesting a potential gap in follow-up care; we suggest that paramedics play an important role in identifying those at high recurrence risk and communicating with their care providers.

Patient and paramedic experiences with a direct electronic referral programme for focused hypoglycaemia education following paramedic service assist-requiring hypoglycaemia in London and Middlesex County, Ontario, Canada

AIMS

Hypoglycaemia is a common treatment consequence in diabetes mellitus. Prior studies have shown that a large proportion of people with paramedic assist-requiring hypoglycaemia prefer not to be transported to hospital. Thus, these episodes are "invisible" to their usual diabetes care providers. A direct electronic referral programme where paramedics sent referrals focused hypoglycaemia education at the time of paramedic assessment was implemented in our region for 18 months; however, referral programme uptake was low. In this study, we examined patient and paramedic experiences with a direct electronic referral programme for hypoglycaemia education postparamedic assist-requiring hypoglycaemia, including barriers to programme referral and education attendance.

METHODS

We surveyed paramedics and conducted semistructured telephone interviews of patients with paramedic-assisted hypoglycaemia who consented to the referral programme and were scheduled for an education session in London and Middlesex County, Canada.

RESULTS

Paramedics and patient participants felt that the direct referral programme was beneficial. A third of paramedics who responded to our survey used the referral programme for each encounter where they treated patients for hypoglycaemia. Patients felt very positive about the referral programme and their paramedic encounter; however, they described embarrassment, guilt and prior negative experience as key barriers to attending education.

CONCLUSIONS

Paramedics and patients felt that direct referral for focused hypoglycaemia education postparamedic assist-requiring hypoglycaemia was an excellent strategy. Despite this, referral programme participation was low and thus there remain ongoing barriers to implementation and attendance. Future iterations should consider how best to meet patient needs through innovative delivery methods.

Effect of Hydrolyzed Infant Formula vs Conventional Formula on Risk of Type 1 Diabetes: The TRIGR Randomized Clinical Trial

IMPORTANCE

Early exposure to complex dietary proteins may increase the risk of type 1 diabetes in children with genetic disease susceptibility. There are no intact proteins in extensively hydrolyzed formulas.

OBJECTIVE

To test the hypothesis that weaning to an extensively hydrolyzed formula decreases the cumulative incidence of type 1 diabetes in young children.

DESIGN, SETTING, AND PARTICIPANTS

An international double-blind randomized clinical trial of 2159 infants with human leukocyte antigen-conferred disease susceptibility and a first-degree relative with type 1 diabetes recruited from May 2002 to January 2007 in 78 study centers in 15 countries; 1081 were randomized to be weaned to the extensively hydrolyzed casein formula and 1078 to a conventional formula. The follow-up of the participants ended on February 28, 2017.

INTERVENTIONS

The participants received either a casein hydrolysate or a conventional adapted cow's milk formula supplemented with 20% of the casein hydrolysate. The minimum duration of study formula exposure was 60 days by 6 to 8 months of age.

MAIN OUTCOMES AND MEASURES

Primary outcome was type 1 diabetes diagnosed according to World Health Organization criteria. Secondary outcomes included age at diabetes diagnosis and safety (adverse events).

RESULTS

Among 2159 newborn infants (1021 female [47.3%]) who were randomized, 1744 (80.8%) completed the trial. The participants were observed for a median of 11.5 years (quartile [Q] 1-Q3, 10.2-12.8). The absolute risk of type 1 diabetes was 8.4% among those randomized to the casein hydrolysate (n = 91) vs 7.6% among those randomized to the conventional formula (n = 82) (difference, 0.8% [95% CI, -1.6% to 3.2%]). The hazard ratio for type 1 diabetes adjusted for human leukocyte antigen risk group, duration of breastfeeding, duration of study formula consumption, sex, and region while treating study center as a random effect was 1.1 (95% CI, 0.8 to 1.5; P = .46). The median age at diagnosis of type 1 diabetes was similar in the 2 groups (6.0 years [Q1-Q3, 3.1-8.9] vs 5.8 years [Q1-Q3, 2.6-9.1]; difference, 0.2 years [95% CI, -0.9 to 1.2]). Upper respiratory infections were the most common adverse event reported (frequency, 0.48 events/year in the hydrolysate group and 0.50 events/year in the control group).

CONCLUSIONS AND RELEVANCE

Among infants at risk for type 1 diabetes, weaning to a hydrolyzed formula compared with a conventional formula did not reduce the cumulative incidence of type 1 diabetes after median follow-up for 11.5 years. These findings do not support a need to revise the dietary recommendations for infants at risk for type 1 diabetes.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00179777.

A randomised trial of non-mydriatic ultra-wide field retinal imaging versus usual care to screen for diabetic eye disease: rationale and protocol for the Clearsight trial

INTRODUCTION

Suboptimal screening for diabetic eye disease is a major cause of preventable vision loss. Screening barriers include mydriasis and the extra time patients need to attend dedicated eye screening appointments. In the Clearsight trial, we are testing whether screening by non-mydriatic ultra-wide field (NM UWF) imaging on the day patients attend their diabetes outpatient clinic visit improves detection of clinically important eye disease compared with usual screening.

METHODS AND ANALYSIS

Patients with diabetes due for a screening eye exam by the 2013 Canadian Diabetes Association (CDA) practice guidelines are being randomised to on-site screening by NM UWF imaging on the day of their clinic visit or to usual screening where, per CDA guidelines, they are encouraged to arrange an exam by an optometrist. The primary outcome is actionable eye disease (AED) based on a need for referral to ophthalmology and/or increased ocular surveillance. The primary analysis will use an intention-to-screen approach that compares the proportions of detected AED between on-site and usual screening groups under a superiority hypothesis in favour of on-site screening. With 740 randomised participants, the study will have 80% power to detect ≥5% absolute increase in the AED rate among on-site screening versus usual screening participants. This difference translates into a number-needed-to-screen by on-site screening of 20 to detect 1 additional person with AED.

ETHICS AND DISSEMINATION

The protocol was approved by the institutional review board of Western University. The findings of the trial will be disseminated directly to participants and through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.Gov NCT02579837 (registered 16 October 2015).

PROTOCOL ISSUE DATE

18 November 2015.

Use of n-of-1 (single patient) trials to assess the effect of age of transfused blood on health-related quality of life in transfusion-dependent patients

BACKGROUND

The impact of age of red blood cells on health-related quality of life (HRQL) in patients who require chronic transfusions is not known. We assessed this using n-of-1 trials in patient populations where large randomized trials have not been done to date.

STUDY DESIGN AND METHODS

Chronically transfusion-dependent adult patients were randomly assigned over time to four fresh (<7 days of storage) and four standard-issue (up to 42 days of storage) blood transfusions in prospective double-blinded multicrossover studies (n-of-1 trials). HRQL questionnaires were completed before and at 24 hours after each transfusion. Hemoglobin (Hb) levels were measured before each subsequent transfusion.

RESULTS

Twenty transfusion-dependent patients were enrolled, of whom nine (five myelodysplastic syndromes, two myelofibrosis, one β-thalassemia major, one Diamond-Blackfan anemia) completed at least six transfusions. Mean ages of fresh and standard-issue blood transfused were 4.0 and 23.2 days, respectively. There were no significant differences in the effect of standard and fresh blood on follow-up Hb levels or the eight HRQL dimensions assessed in all analyses.

CONCLUSIONS

In chronically transfused patients, there were no significant differences in HRQL or Hb levels between fresh versus standard blood. While larger trials are needed, these results support current practices in hospital blood transfusion laboratories using a first-in, first-out model of blood utilization for these transfusion-dependent patients. Use of n-of-1 trials to determine the benefits of transfusions in single patients appears to be feasible.

Trends in Antihyperglycemic Medication Prescriptions and Hypoglycemia in Older Adults: 2002-2013

Background

Over the last decade, several new antihyperglycemic medications have been introduced including those associated with a lower hypoglycemia risk. We aimed to investigate how these medications are being prescribed to older adults in our region.

Methods

We conducted population-based cross-sectional analyses of older adults (mean age 75 years) with treated diabetes in Ontario, Canada from 2002 until 2013, to examine the percentage prescribed insulin, sulphonylureas, alpha-glucosidase inhibitors, metformin, thiazolidinediones, meglitinides, and dipeptidyl peptidase-4 inhibitors. Over the study period, we also examined their hospital encounters for hypoglycemia (emergency room or inpatient encounter).

Results

The mean age of treated patients increased slightly over the study quarters and the proportion that were women declined. With the exception of chronic kidney disease, cancer, dementia, and neuropathy, the percentage with a comorbidity appeared to decline. The percentage of treated patients prescribed metformin, gliclazide and dipeptidyl peptidase-4 inhibitors increased as did combination therapy. Glyburide and thiazolidinedione prescriptions declined, and insulin use remained stable. In those with newly treated diabetes, the majority were prescribed metformin, with smaller percentages prescribed insulin and other oral agents. Although the absolute number of treated patients with a hypoglycemia encounter increased until mid-2006 and then decreased, the overall percentage with an encounter declined over the study period (0.8% with an event in the first quarter, 0.4% with an event in the last quarter).

Conclusions

Antihyperglycemic medications with safer profiles are being increasingly prescribed to older adults. In this setting there has been a decrease in the percentage of treated patients with a hospital encounter for hypoglycemia.

The development and utility of a novel scale that quantifies the glycemic progression toward type 1 diabetes over 6 months

OBJECTIVE

We developed a scale to serve as a potential end point for 6-month glycemic progression (PS6M) toward type 1 diabetes (T1D) in autoantibody-positive relatives of individuals with T1D.

RESEARCH DESIGN AND METHODS

The PS6M was developed from Diabetes Prevention Trial-Type 1 (DPT-1) data and tested in the TrialNet Pathway to Prevention Study (PTP). It is the difference between 6-month glucose sum values (30-120 min oral glucose tolerance test values) and values predicted for nonprogressors.

RESULTS

The PS6M predicted T1D in the PTP (P < 0.001). The area under the receiver operating chacteristic curve was greater (P < 0.001) for the PS6M than for the baseline-to-6-month difference. PS6M values were higher in those with two or more autoantibodies, 30-0 min C-peptide values <2.00 ng/mL, or DPT-1 Risk Scores >7.00 (P < 0.001 for all).

CONCLUSIONS

The PS6M is an indicator of short-term glycemic progression to T1D that could be a useful tool for assessing preventive treatments and biomarkers.

N-of-1 (single-patient) trials for statin-related myalgia

BACKGROUND

Statin-related myalgia is difficult to distinguish from other conditions causing myalgia and may often lead to statin discontinuation.

OBJECTIVE

To compare the effect of statin rechallenge with placebo in patients with prior statin-related myalgia and to determine whether patients resumed statin therapy after evaluating the results.

DESIGN

N-of-1 trial with 3 double-blind, crossover comparisons separated by 3-week washout periods. (Clinicaltrials.gov: NCT01259791) SETTING: Tertiary care lipid clinic.

PATIENTS

Patients with prior statin-related myalgia with or without mild elevation of creatine kinase levels.

INTERVENTION

Rechallenge with the statin that was previously associated with myalgia within 3 weeks of open-label use versus matching placebo.

MEASUREMENTS

Weekly visual analogue scale (VAS) scores for myalgia and specific symptoms (VAS myalgia score and symptom-specific VAS score, respectively), pain interference scores, and pain severity scores were recorded during the 3-week periods when patients were receiving placebo or statin. The primary outcome was the VAS myalgia score (range, 0 to 100 mm).

RESULTS

Eight patients (mean age, 66 years [SD, 8 years]; 88% women, all with high 10-year Framingham cardiovascular risk) participated in n-of-1 trials. Seven patients completed 3 treatment pairs, and 1 completed 2 treatment pairs. For each n-of-1 trial, no statistically significant differences were seen between statin and placebo in the VAS myalgia score, symptom-specific VAS score, pain interference score, and pain severity score. Five patients resumed open-label statin treatment, with a median posttrial follow-up of 10 months.

LIMITATION

Results are limited by the small sample size and cannot be extended to patients with longer onset of myalgia after statin initiation.

CONCLUSION

In selected patients with a history of statin-related myalgia whose symptoms are difficult to evaluate, n-of-1 trials may be a useful method for determining statin tolerability.

PRIMARY FUNDING SOURCE

Western University, London, Ontario, Canada.

Zinc transporter-8 autoantibodies improve prediction of type 1 diabetes in relatives positive for the standard biochemical autoantibodies

OBJECTIVE

We assessed diabetes risk associated with zinc transporter-8 antibodies (ZnT8A), islet cell antibodies (ICA), and HLA type and age in relatives of people with type 1 diabetes with the standard biochemical autoantibodies (BAA) to insulin (IAA), GAD65 (GAD65A), and/or insulinoma-associated protein 2 antigen (IA-2A).

RESEARCH DESIGN AND METHODS

For this analysis, 2,256 relatives positive for at least one BAA, of whom 142 developed diabetes, were tested for ZnT8A, ICA, and HLA genotype followed by biannual oral glucose tolerance tests. ZnT8A were also tested in 911 randomly chosen antibody-negative relatives.

RESULTS

ZnT8A were associated with the other BAA (548 of 2,256 [24.3%] BAA(+) vs. 8 of 911 [0.8%] BAA(-), P < 0.001) and BAA number (177 of 1,683 [10.5%] single-, 221 of 384 [57.6%] double-, and 150 of 189 [79.4%] triple-BAA positivity, P < 0.001). The 4-year diabetes risk was higher in single BAA(+) relatives with ZnT8A than ZnT8A(-) relatives (31 vs. 7%, P < 0.001). In multivariable analysis, age ≤ 20 years (hazard ratio 2.13, P = 0.03), IA-2A (2.15, P = 0.005), IAA (1.73, P = 0.01), ICA (2.37, P = 0.002), and ZnT8A (1.87, P = 0.03) independently predicted diabetes, whereas HLA type (high and moderate vs. low risk) and GAD65A did not (P = 0.81 and 0.86, respectively).

CONCLUSIONS

In relatives with one standard BAA, ZnT8A identified a subset at higher diabetes risk. ZnT8A predicted diabetes independently of ICA, the standard BAA, age, and HLA type. ZnT8A should be included in type 1 diabetes prediction and prevention studies.

Development of autoantibodies in the TrialNet Natural History Study

OBJECTIVE

Understanding the relationship between age and islet autoantibody (Ab) seroconversion can establish the optimal screening interval(s) to assess risk for type 1 diabetes, identify subjects who can participate in prevention trials, and determine associated costs. This study assessed the rates of seroconversion to glutamic acid decarboxylase positive (GAD65(+)), insulin positive (mIAA(+)), and insulinoma-associated protein 2 positive (ICA512(+)) in a large cohort of relatives of type 1 diabetes probands undergoing Ab rescreening in the TrialNet Natural History Study.

RESEARCH DESIGN AND METHODS

Of 32,845 children aged <18 years screened for Abs, 1,287 (3.9%) were GAD65(+), 778 (2.4%) were mIAA(+), 677 (2.1%) were ICA512(+), and 31,038 were Ab-negative. Ab-negative children were offered annual rescreening up to 18 years of age. Cox regression was used to estimate the risk for GAD65, mIAA, and ICA512 seroconversion. RESULTS There were 205 children who seroconverted to GAD65(+), 155 who seroconverted to mIAA(+), and 53 who seroconverted to ICA512(+) over 5.8 years of follow-up. The risk of mIAA (hazard ratio 0.89 [95% CI 0.85-0.92]) and GAD65 (0.96 [0.93-0.99]) seroconversion significantly decreased with increasing age (i.e., for each 1-year increase in age, the risk of seroconversion decreased by 11% [P < 0.0001] for mIAA and 4% [P = 0.04] for GAD65) across all ages. The cumulative Ab seroconversion was 2% for those <10 years of age versus 0.7% for those ≥10 years of age.

CONCLUSIONS

The risk of development of islet Abs declines with increasing age in type 1 diabetes relatives. These data support annual screening for children <10 years of age and one additional screening in adolescence.

Comparison of two insulin assays for first-phase insulin release in type 1 diabetes prediction and prevention studies

BACKGROUND

Detection of below-threshold first-phase insulin release or FPIR (1+3 minute insulin concentrations during an intravenous glucose tolerance test [IVGTT]) is important in type 1 diabetes prediction and prevention studies including the TrialNet Oral Insulin Prevention Trial. We assessed whether an insulin immunoenzymometric assay (IEMA) could replace the less practical but current standard of a radioimmunoassay (RIA) for FPIR.

METHODS

One hundred thirty-three islet autoantibody positive relatives of persons with type 1 diabetes underwent 161 IVGTTs. Insulin concentrations were measured by both assays in 1056 paired samples. A rule classifying FPIR (below-threshold, above-threshold, uncertain) by the IEMA was derived and validated against FPIR by the RIA.

RESULTS

The insulin IEMA-based rule accurately classified below- and above-threshold FPIRs by the RIA in 110/161 (68%) IVGTTs, but was uncertain in 51/161 (32%) tests for which FPIR by RIA is needed. An uncertain FPIR by the IEMA was more likely among below-threshold vs above-threshold FPIRs by the RIA (64% [30/47] vs. 18% [21/114], respectively; p<0.05).

CONCLUSIONS

An insulin IEMA for FPIR in subjects at risk for type 1 diabetes accurately determined below- and above-threshold FPIRs in 2/3 of tests relative to the current standard of the insulin RIA, but could not reliably classify the remaining FPIRs. TrialNet is limiting the insulin RIA for FPIR to the latter given the practical advantages of the more specific IEMA.

Barriers to blood pressure control: a STITCH substudy

Despite improvements in blood pressure (BP) control, a substantial percentage of patients do not achieve target. The relative importance of determinants of poor BP control is unclear. Therefore, the authors conducted a post hoc exploratory analysis to assess determinants of BP control. Data were collected in 45 general practices, which enrolled patients with uncontrolled hypertension. Antihypertensive medication changes throughout the 6-month follow-up period were documented. Baseline and 6-month BPs were recorded. Of the 2030 patients analyzed, 320 had diabetes. Overall, 42% of patients did not achieve BP control. In multivariate analysis, failure to intensify therapy was identified as a significant independent predictor of lesser BP reduction. Of patients unable to reach target after 6 months, only 25% were prescribed ≥ 3 drugs. Patients with diabetes were significantly less likely to reach target than those without (26% vs 64%, P<.001). Antihypertensive therapy prescribed to patients with diabetes was only marginally more intensive than to those without. In patients with hypertension, whether with or without coexisting diabetes, poor BP control appears to be at least partially due to failure to uptitrate antihypertensive therapy. Clinical inertia is likely an important barrier to BP control.

Fate of the mate: the influence of delayed graft function in renal transplantation on the mate recipient

Delayed graft function (DGF) in a deceased-donor renal recipient is associated with allograft dysfunction 1-year posttransplant. There is limited research about the influence to allograft function on the mate of a DGF recipient over time. Using a retrospective cohort design, we studied 55 recipients from a single center. The primary outcome was the change in glomerular filtration rate (GFR) 1-year posttransplant. The secondary outcome was the GFR at baseline. We found that mates to DGF recipients had a mean change in GFR 1-year posttransplant of -11.2 mL/min, while the control group had a mean change of -0.4 mL/min. The difference in the primary outcome was significant (p = 0.025) in a multivariate analysis, adjusting for cold ischemic time, panel reactive antibody level, allograft loss, human leukocyte antibody (HLA)-B mismatches and HLA-DR mismatches. No significant difference between groups was found in baseline GFR. In conclusion, mates to DGF recipients had a significantly larger decline in allograft function 1-year posttransplant compared to controls with similar renal function at baseline. We believe strategies that may preserve allograft function in these'at-risk'recipients should be developed and tested.

The TrialNet Natural History Study of the Development of Type 1 Diabetes: objectives, design, and initial results

OBJECTIVES

TrialNet's goal to test preventions for type 1 diabetes has created an opportunity to gain new insights into the natural history of pre-type 1 diabetes. The TrialNet Natural History Study (NHS) will assess the predictive value of existing and novel risk markers for type 1 diabetes and will find subjects for prevention trials.

RESEARCH DESIGN AND METHODS

The NHS is a three-phase, prospective cohort study. In phase 1 (screening), pancreatic autoantibodies (glutamic acid decarboxylase, insulin, ICA-512, and islet cell antibodies) are measured. Phase 2 (baseline risk assessment) includes oral glucose tolerance tests (OGTTs) in antibody-positive subjects and estimation of 5-yr diabetes risks according to the OGTT and number of confirmed positive antibody tests. Phase 3 (follow-up risk assessments) requires OGTTs every 6 months. In phases 2 and 3, samples are collected for future tests of T-lymphocyte function, autoantibody isotypes, RNA gene expression, and proteomics. The primary outcome is diabetes onset.

RESULTS

Of 12 636 relatives screened between March 2004 and December 2006, 605 (4.8%) were positive for at least one biochemical antibody. Of these, 322 were confirmed antibody positive and completed phase 2, of whom 296 subjects were given preliminary 5-yr diabetes risks of <25% (n = 132), > or =25% (n = 36), and > or =50% (n = 128) where the latter two categories represent different subjects based on number of confirmed positive antibodies (2, > or =25%; 3 or more, > or =50%) and/or an abnormal OGTT (> or =50%).

CONCLUSIONS

The NHS is identifying potential prevention trial subjects and is assembling a large cohort that will provide new natural history information about pre-type 1 diabetes. Follow-up to diabetes will help establish the biological significance and clinical value of novel type 1 diabetes risk markers.

Relationship between Escherichia coli O157:H7 and diabetes mellitus

Ingestion of Escherichia coli O157:H7 can cause a spectrum of acute illness, ranging from overt hemolytic-uremic syndrome (HUS), to gastroenteritis with bloody diarrhea, to no symptoms. This organism has been responsible for dozens of outbreaks of gastroenteritis and HUS in industrialized nations, and thus is a major public health concern. Although the acute effects of E. coli O157:H7 ingestion are well understood, the long-term complications are less well known. Here, we review the biological and empirical evidence supporting a link between E. coli O157:H7 and long-term diabetes mellitus. Survivors with diarrhea-associated HUS have a significantly increased incidence of diabetes due to complete insulin deficiency, which may recur several years after the initial infection. However, less severe forms of infection, such as E. coli O157:H7 gastroenteritis without overt HUS, do not appear to result in an increased risk of type 2 diabetes.

Insulin resistance and progression to type 1 diabetes in the European Nicotinamide Diabetes Intervention Trial (ENDIT)

OBJECTIVE

Insulin resistance can modulate progression to type 1 diabetes in individuals with ongoing islet autoimmunity. We wanted to see whether measures of insulin resistance improved risk assessment in islet cell antibody (ICA)-positive relatives when added to other immune and metabolic markers.

RESEARCH DESIGN AND METHODS

The retrospective cohort analysis included 213 family members participating in the European Nicotinamide Diabetes Intervention Trial. All were aged <25 years, with at least one islet antibody in addition to ICA >or=20 Juvenile Diabetes Foundation units. Median length of follow-up was 4.21 years, and 105 individuals developed diabetes. Oral and intravenous glucose tolerance tests were performed at baseline; antibodies to GAD, IA-2, and insulin were determined by radioimmunoassay; and insulin resistance was estimated by homeostasis model assessment. Risk was assessed by Cox regression analysis

RESULTS

The overall cumulative risk of diabetes within 5 years was 54.1% (95% CI 46.0-62.3). Multivariate analysis confirmed that baseline first-phase insulin response (FPIR) quartile (P < 0.0001), number of additional antibody markers (P < 0.0001), and 120-min glucose in the oral glucose tolerance test (P < 0.0001) were independent determinants of risk of progression, whereas addition of homeostasis model assessment of insulin resistance (HOMA2-IR) achieved only borderline significance (P = 0.06). HOMA2-IR was an independent determinant in participants with loss of FPIR (P = 0.025) but not in those with preserved FPIR (P = 0.3).

CONCLUSIONS

These data suggest that insulin resistance accelerates progression to type 1 diabetes in antibody-positive relatives in whom insulin secretion is markedly reduced but does not affect progression when insulin secretion is relatively well preserved.

Reduced IFN-alpha secretion by blood dendritic cells in human diabetes

Characterization of dendritic cells (DC) in human diabetes has been restricted to monocyte-derived DC in type 1 diabetes, whose physiological relevance to endogenous DC is uncertain. Here, we provide the first report characterizing the phenotype and function of endogenous DC subsets in type 1 and type 2 diabetes. We show that DC subsets in each diabetic group exhibit normal properties concerning frequency and activation state, as determined using 4-color flow cytometry of whole blood cells. DC maturation is also intact as confirmed by their efficacious ability to stimulate T cell proliferation in an allogeneic MLR assay. Yet we found that DC are poor producers of IFN-alpha (P < 0.05) in human diabetes. IFN-alpha is a potent antiviral agent and therefore its reduced levels may interfere with T cell-mediated immune responses leading to increased susceptibility and persistence of infections in persons with diabetes.

Diabetes during diarrhea-associated hemolytic uremic syndrome: a systematic review and meta-analysis

OBJECTIVE

To quantify the incidence of diabetes during the acute phase of diarrhea-associated hemolytic uremic syndrome (D + HUS) and to identify features associated with its development.

RESEARCH DESIGN AND METHODS

A systematic review and meta-analysis of articles assessing diabetes during D + HUS was conducted. Relevant citations were identified from Medline, Embase, and Institute for Scientific Information Citation Index databases. Bibliographies of relevant articles were hand searched. All articles were independently reviewed for inclusion and data abstraction by two authors.

RESULTS

Twenty-one studies from six countries were included. Only 2 studies reported a standard definition of diabetes; 14 defined diabetes as hyperglycemia requiring insulin. The incidence of diabetes during the acute phase of D + HUS could be quantified in a subset of 1,139 children from 13 studies (1966-1998, age 0.2-16 years) and ranged from 0 to 15%, with a pooled incidence of 3.2% (95% CI 1.3-5.1, random-effects model, significant heterogeneity among studies, P = 0.007). Children who developed diabetes were more likely to have severe disease (e.g., presence of coma or seizures, need for dialysis) and had higher mortality than those without diabetes. Twenty-three percent of those who developed diabetes acutely died, and 38% of survivors required long-term insulin (median follow-up 12 months). Recurrence of diabetes was possible up to 60 months after initial recovery.

CONCLUSIONS

Children with D + HUS should be observed for diabetes during their acute illness. Consideration should be given to long-term screening of D + HUS survivors for diabetes.

The effectiveness of beta-blockers after myocardial infarction in patients with type 2 diabetes

OBJECTIVE

Beta-blocker therapy has been proven to reduce mortality and reinfarction after myocardial infarction (MI), but the impact of beta-blockers on cardiac outcomes in patients with type 2 diabetes in routine practice is not clear. The purpose of this study was to determine the effectiveness of beta-blockers after MI in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

Using the Saskatchewan Health Databases, 12,272 patients with newly treated diabetes were identified between 1991 and 1996; 625 patients were subsequently admitted for MI. Beta-blocker exposure within 30 days of discharge was identified in 298 patients, and all were followed until death, coverage termination, or 31 December 1999. Multivariate proportional hazards models were used to assess differences in all-cause mortality, recurrent MI, and 30-day all-cause rehospitalization (the latter a proxy measure for drug safety).

RESULTS

Patients were aged 69 +/- 11 years old, 66% were male, and mean follow-up was 2.7 +/- 2.1 years. Overall, beta-blockers were prescribed for 48% of patients. There were fewer deaths in the beta-blocker group versus control subjects (55 of 298 [18.5%] vs. 126 of 327 [38.5%], respectively, P < 0.001). However, beta-blockers were not associated with improved survival in multivariate analyses (hazard ratio [HR] 0.89 [95% CI 0.63-1.25]). There were no differences in rates of recurrent MI (adjusted HR 1.35 [0.93-1.95]) or rehospitalizations (adjusted odds ratio 1.40 [0.83-2.37]) between the groups.

CONCLUSIONS

Beta-blocker therapy post-MI was not associated with reduced mortality or fewer recurrent events in people with type 2 diabetes in routine practice, although these medications were safe in this population.

The stability of utility scores: test-retest reliability and the interpretation of utility scores in elective total hip arthroplasty

PURPOSES

Are utility scores for hypothetical health states stable over time even when the health of the patient changes dramatically? Can investigators who use scores for hypothetical states be confident about the stability of those scores? The first purpose is to assess the stability of standard gamble utility scores for three hypothetical health states describing mild, moderate, and severe osteoarthritis (OA) (test-retest reliability). How should investigators interpret utility scores? The second purpose is to provide evidence on the marker-state approach to assist in interpreting utility scores.

BACKGROUND

SG scores for three hypothetical marker states and the patient's current state were obtained at multiple times in a longitudinal study of elective total hip arthroplasty (THA). SG scores for current health increased from a mean of 0.59 pre-surgery to 0.76 post-surgery.

METHODS

Test-retest reliability was assessed using the intra-class correlation coefficient (ICC). The effects of time on scores were analysed using an analysis of covariance.

RESULTS

At the group level the marker-state scores were stable. Mean scores for mild, moderate, and severe OA were 0.69, 0.61, and 0.41. With respect to test-retest reliability, ICCs varied from 0.49 to 0.62. In general, time did not affect the scores for the three marker states.

CONCLUSIONS

Group-level standard gamble scores are stable. At the individual level scores for hypothetical health states are somewhat stable over time. The marker states assist in interpretation indicating that, on average, THA converted moderate OA to better than mild.

Is the Health Utilities Index valid in total hip arthroplasty patients?

PURPOSE

The purpose of the study was to examine the construct validity of the Health Utilities Index Mark 2 (HU12) and Mark 3 (HU13) in patients with osteoarthritis (OA) needing total hip arthroplasty (THA).

BACKGROUND

One hundred and fourteen OA patients (mean age = 69.2; SD = 8.9) who were waiting to see a surgeon for an evaluation for THA completed baseline measures that included the HU12, HU13, SF-36, Harris Hip Scale, WOMAC, MACTAR, State-Trait Anxiety Inventory, and the 6-min walk test.

METHODS

We examined 87 a priori hypotheses by correlating (one-tailed zero-order correlations) the single-attribute utility scores for the pain, emotion, mobility, ambulation, self-care, dexterity, vision, hearing, and speech attributes of the HU12 and HU13 and the overall HU12 and HU13 utility scores to specified subscales of the other measures.

RESULTS

The zero-order correlations confirmed 75% of our a priori hypotheses suggesting that the constructs within the HU12 and HU13 were, in general, related to similar constructs in other measures as expected.

CONCLUSIONS

The evidence suggests that HU12 and HU13 are valid for use in OA and THA studies.

Insulin resistance in latent autoimmune diabetes of adulthood

Insulin resistance in patients with latent autoimmune diabetes of adulthood (LADA) was determined by homeostasis model assessment (HOMA). LADA was identified by a clinical phenotype of type 2 diabetes with antibodies to GAD65 and/or IA-2/ICA512. All patients were managed with insulin therapy. Insulin resistance in LADA was lower than in antibody-negative type 2 diabetes, higher than in normal humans and in recent-onset type 1 diabetes, and similar to that in long-term type 1 diabetes. Mean values for HOMA varied linearly with mean values for BMI, which accounted for much of the insulin resistance in these forms of diabetes. LADA resembles long-term type 1 diabetes with respect to insulin resistance and BMI, but occurs at an older age.

Is the health utilities index responsive in total hip arthroplasty patients?

OBJECTIVE

The purpose is to examine the responsiveness of the Health Utilities Index Mark 2 (HUI2), Mark 3 (HUI3), and other generic and disease-specific measures in osteoarthritis patients undergoing total hip arthroplasty (THA).

METHODS

Ninety patients (mean age=68.13; SD=8.15) on a waiting list for THA completed measures that included the standard gamble, HUI2, HUI3, SF-36, Harris Hip Scale, WOMAC, and MACTAR. before and after THA. Responsiveness statistics (effect size, standardized response mean, Guyatt's responsiveness statistic, paired-sample t-tests, and relative efficiency statistic) were calculated.

RESULTS

The disease-specific measures were more responsive than the generic measures. Rankings of the degree of responsiveness varied depending on the responsiveness statistic used.

CONCLUSIONS

Disease-specific measures are the most responsive in THA patients. However, the SF-36, HUI2, and HUI3 had summary scores and domain/attributes scores that were also responsive and provided additional information. Among the generic measures, HUI3 was the most responsive.

Comparing community-preference-based and direct standard gamble utility scores: evidence from elective total hip arthroplasty

OBJECTIVES

Do utility scores based on patient preferences and scores based on community preferences agree? The purpose is to assess agreement between directly measured standard gamble (SG) utility scores and utility scores from the Health Utilities Index Mark 2 (HUI2) and Mark 3 (HUI3) systems.

METHODS

Patients were assessed repeatedly throughout the process of waiting to see a surgeon, waiting for surgery, and recovery after total hip arthroplasty (THA). Group mean scores are compared using paired t-tests. Agreement is assessed using the intraclass correlation coefficient (ICC).

RESULTS

The mean SG, HUI2, and HUI3 (SD) scores at assessment 1 are 0.62 (0.31), 0.62 (0.19), and 0.52 (0.21); n=103. At assessment 2, the means are 0.67 (0.30), 0.68 (0.30), and 0.58 (0.22); n=84. There are no statistically significant differences between group mean SG and HUI2 scores. Mean SG and HUI3 scores are significantly different. ICCs are low.

CONCLUSIONS

At the mean level for the group, SG and HUI2 scores match closely. At the individual level, agreement is poor. HUI2 scores were greater than HUI3 scores. HUI2 and HUI3 are appropriate for group level analyses relying on community preferences but are not a good substitute for directly measured utility scores at the individual level.

Type 1 diabetes alters anti-hsp90 autoantibody isotype

The 90-kDa chaperon family includes heat shock protein (hsp) 90 and glucose-regulated protein (grp) 94. These proteins play an important role in normal cellular architecture, in the etiology of some autoimmune and infectious diseases and in antigen presentation to T cells. Owing to its role in autoimmunity, we explored anti-hsp90 autoantibody (hsp90AA) response in the sera of persons with type 1 diabetes, first-degree relatives (FDR) and in normal subjects. Significant high level of hsp90AA was found in FDR, but there was no significant difference between the normal and diabetic persons. The IgG1 and IgG3 isotypes of hsp90AA were higher in persons with type 1 diabetes and FDR than in normal subjects. We found a good correlation between hsp90AA measured by ELISA and RIA. A positive correlation between serum hsp90AA and glutamic acid decarboxylase (GAD65) autoantibody (GAA) was also observed. Hsp90AA positive sera from diabetic persons immunoblotted recombinant hsp90, GAD65 and corresponding proteins in islet lysates. Our study suggests that hsp90AA are present in normal, FDR and diabetic persons. However, there is a higher level of IgG1 and IgG3 isotypes of hsp90AA in FDR and type 1 diabetic subjects. Thus, autoimmunity leading to type 1 diabetes significantly alters the autoantibody isotype to autoantigens, such as hsp90.

Health-related quality of life and mobility of patients awaiting elective total hip arthroplasty: a prospective study

BACKGROUND

Waits for elective total hip arthroplasty for osteoarthritis are common in publicly funded health care systems, but they may lead to poorer postoperative outcomes and loss of health-related quality of life (HRQOL) through progressive pain and immobility during the wait. These issues have not been examined from the time of referral for surgery. Our primary objective was to test whether a longer wait was associated with poorer postoperative HRQOL.

METHODS

Patients needing possible total hip arthroplasty for osteoarthritis were identified upon referral to a surgeon in London, Ont. Outcome measures, including the Western Ontario McMaster (WOMAC) Osteoarthritis Index and mobility in the 6-Minute Walk, were assessed at baseline and every 3-6 months thereafter until at least 3 months after the surgery.

RESULTS

Of 553 potentially eligible patients referred for surgical assessment, 123 were placed on a waiting list for total hip arthroplasty; 114 underwent the procedure, and 99 of them returned for postoperative assessment. No significant differences in HRQOL or mobility were seen postoperatively between patients with short waits and those with long waits (a priori definitions < or = 6 months and > 6 months respectively). At referral, however, patients with short waits had poorer HRQOL and were less mobile than those with long waits (p = 0.002 for WOMAC Osteoarthritis Index total score, 0.001 for pain, 0.009 for stiffness and 0.008 for function; p = 0.006 for 6-Minute Walk results). Patients with short waits experienced larger gains in these measures from the time of referral until the postoperative assessment than did patients with long waits (p = 0.002 for WOMAC Osteoarthritis Index total score, < 0.001 for pain, 0.005 for stiffness and 0.005 for function; p = 0.06 for 6-Minute Walk results). For patients with long waits, increases in the WOMAC Osteoarthritis Index total score exceeded 10% and losses in walking distance exceeded 30 m from the time of referral to surgery.

INTERPRETATION

The length of wait for elective total hip arthroplasty is not associated with postoperative HRQOL and mobility. However, patients who undergo the procedure within 6 months after referral have greater disability at referral, and realize greater gains in HRQOL and mobility after surgery, than patients waiting more than 6 months. Clinically important losses in HRQOL and mobility occur in patients waiting more than 6 months.

Autoantibodies and HLA susceptibility markers in Canadian first-degree relatives of patients with type 1 diabetes

We examined the frequencies of autoantibodies to glutamate decarboxylase, GAD65, protein tyrosine phosphatase, IA-2/ICA512, and insulin, and of HLA class II markers in ICA-positive first-degree relatives of patients with type 1 diabetes. Our results indicate that while the presence of HLA susceptibility markers is associated with anti-islet autoantibodies, protective DQB1 markers do not absolutely prevent development of autoantibodies or progression to autoimmune diabetes.

Quadriceps muscle function and fatigue in women with Addison's disease

In nine patients with Addison's disease (mean +/- SE: 51 +/- 2 years) receiving conventional steroid treatment, and nine age-matched healthy controls (56 +/- 2 years), we investigated maximum voluntary quadriceps force (MVC) and contractile properties evoked with stimulation and central activation both at rest and during a submaximal intermittent fatigue task. The MVC was similar (-3%), but twitch tension (-27%) and central activation were significantly less (-7%), and tetanic half-relaxation time was approximately 40% slower in the patients. Twitch amplitudes were potentiated by 6% in the patients, but unchanged in the control group. The patients self-terminated a submaximal intermittent fatigue protocol (0.6 duty cycle) at approximately 5 +/- 1 min, whereas the controls stopped when they lost 50% of MVC force ( approximately 10 +/- 1 min). Force loss was similar between groups over the first 5 min of the fatigue task. In the patient group, maximal and submaximal relative integrated electromyogram (IEMG) increased significantly in the first minute of fatigue and remained elevated, whereas the controls exhibited a gradual increase in submaximal IEMG with little change in maximal IEMG. These results indicate that conventionally treated Addison's patients have similar MVC strength, but altered contractile properties and decreased endurance compared with controls.

Surveying physicians to determine the minimal important difference: implications for sample-size calculation

The minimal important difference (MID) is the smallest benefit of treatment that would result in clinicians recommending it to their patients. The MID is necessary to calculate sample size for randomized clinical trials, but its chosen value is often arbitrary. This study set out to determine the practicability of surveying physicians to elicit the MID for clinical trial sample-size calculation. Using a mail survey, we elicited the MID of different physician specialties (family medicine, internal medicine, vascular surgery) for using propranolol to slow abdominal aortic aneurysm (AAA) growth assuming that propranolol was efficacious in this condition. We used different outcome measures (growth rate or proportion of patients requiring surgery) and different methods of data presentation for the proportion of patients requiring surgery (absolute risk reduction or number needed to treat). The MID varied significantly by physician specialty, experience with AAA and propranolol, and the method used to elicit the MID. Consequently, sample-size calculations using these various MIDs varied from 116 to 3015. Future attempts to elicit the MID need to consider carefully who is surveyed, how data are presented, and how opinions are elicited.

Theophylline for irreversible chronic airflow limitation: a randomized study comparing n of 1 trials to standard practice

STUDY OBJECTIVE

To compare quality of life and exercise capacity (primary aim), and drug usage (secondary aim), between groups of patients with irreversible chronic airflow limitation (CAL) who were undergoing theophylline Theo-Dur; Key Pharmaceuticals; Kenilworth, NJ) therapy guided by n of 1 trials or standard practice.

DESIGN

Randomized study of n of 1 trials vs standard practice.

SETTING

Outpatient departments in two tertiary care centers.

PATIENTS

Sixty-eight patients with irreversible CAL who were symptomatic despite the use of inhaled bronchodilators, and who were unsure whether theophylline was helping them following open treatment, were randomized into n of 1 trials (N=34) or standard practice.

INTERVENTIONS

The n of 1 trials (single-patient, randomized, double-blind, multiple crossover comparisons of the effect on dyspnea of theophylline vs a placebo) followed published guidelines. Standard practice patients stopped taking theophylline but resumed it if their dyspnea worsened. If their dyspnea then improved, theophylline was continued. In both groups, a decision about continuing or stopping the use of theophylline was made within 3 months of randomization.

MEASUREMENTS AND RESULTS

The primary outcomes (the chronic respiratory disease questionnaire [CRQ] and 6-min walk) were measured at baseline, 6 months, and 12 months by personnel blinded to treatment group allocation. No between-group differences (n of 1 minus standard practice) were seen in within-group changes over time (1 year minus baseline) in the CRQ Physical Function score (point estimate on the difference, -2.8; 95% confidence limits [CLs], -8.2, 2.5), CRQ Emotional Function score (point estimate on the difference, 0.5; 95% CLs, -4.7, 5.7), or 6-min walk (point estimate on the difference, 8 m; 95% CLs, -26, 44 m). No differences between groups were seen in the secondary outcome of the proportion of patients taking theophylline at 6 and 12 months. In 7 of 34 n of 1 trial patients (21%), dyspnea improved during theophylline treatment compared with placebo treatment.

CONCLUSIONS

Using n of 1 trials to guide theophylline therapy in patients with irreversible CAL did not improve their quality of life or exercise capacity, or reduce drug usa e, over 1 year compared to standard practice. Under the objective conditions of an n of 1 trial, 21% of patients with CAL responded to theophylline. There remains a rationale for considering theophylline in patients with irreversible CAL who remain symptomatic despite the use of inhaled bronchodilators, but the use of n of 1 trials to guide this decision did not yield clinically important advantages over standard practice.

A randomized study comparing a patient-directed hypertension management strategy with usual office-based care

This study aimed to compare the efficacy of a patient-directed management strategy with office-based management in maintaining blood pressure control in patients with chronic stable hypertension using a randomized trial of two months duration. The subjects had chronic stable essential hypertension without secondary causes or unstable cardiovascular disease and were selected through the offices of 11 family physicians and a tertiary care hypertension research unit. Patients were randomly assigned (2:1 ratio) to either a patient-directed management strategy using home blood pressure monitoring to adjust drug therapy if readings consistently exceeded defined limits, or office-based management through physician visits. The primary endpoint was the change from baseline in mean arterial pressure as determined by automatic ambulatory blood pressure monitoring. Secondary endpoints were changes in compliance, quality of life, and health care resource use. Ninety-one potential subjects were screened and 31 were randomized. Subjects in the patient-directed management group employed the drug adjustment protocols appropriately without complications. A significant difference in change in mean blood pressure was observed, favoring the patient-directed management (-0.95 mm Hg and +1.90 mm Hg, respectively, for patient-directed management and office-based management, P = .039). Compliance rates and quality of life scores were not significantly different between groups. Physician visits were more frequent in the patient-directed management group (1.05 v 0.20 visits/8 weeks, respectively, for patient-directed management and office-based management groups, P = .045). A patient-directed hypertensive management strategy may be feasible for patients with chronic stable hypertension. Such a strategy may improve blood pressure control compared with usual office-based care. However, physician visits may be increased using this strategy, at least in the short term.

The Ontario trial of active compression-decompression cardiopulmonary resuscitation for in-hospital and prehospital cardiac arrest

OBJECTIVE

To compare the impact of active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) and standard CPR on the outcomes of in-hospital and prehospital victims of cardiac arrest.

DESIGN

Randomized controlled trial with blinding of allocation using a sealed container.

SETTINGS

(1) Emergency departments, wards, and intensive care units of 5 university hospitals and (2) all locations outside hospitals in 2 midsized cities.

PATIENTS

A total of 1784 adults who had cardiac arrest.

INTERVENTION

Patients received either standard or ACD CPR throughout resuscitation.

MAIN OUTCOME MEASURES

Survival for 1 hour and to hospital discharge and the modified Mini-Mental State Examination (MMSE).

RESULTS

All characteristics were similar in the standard and ACD CPR groups for the 773 in-hospital patients and the 1011 prehospital patients. For in-hospital patients, there were no significant differences between the standard (n = 368) and ACD (n = 405) CPR groups in survival for 1 hour (35.1% vs 34.6%; P = .89), in survival until hospital discharge (11.4% vs 10.4%; P = .64), or in the median MMSE score of survivors (37 in both groups). For patients who collapsed outside the hospital, there were also no significant differences between the standard (n = 510) and ACD (n = 501) CPR groups in survival for 1 hour (16.5% vs 18.2%; P = .48), in survival to hospital discharge (3.7% vs 4.6%; P = .49), or in the median MMSE score of survivors (35 in both groups). Exploration of clinically important subgroups failed to identify any patients who appeared to benefit from ACD CPR.

CONCLUSIONS

ACD CPR did not improve survival or neurologic outcomes in any group of patients with cardiac arrest.