Barry Widmer

A genome-wide association study of nonsynonymous SNPs identifies a type 1 diabetes locus in the interferon-induced helicase (IFIH1) region.

In this study we report convincing statistical support for a sixth type 1 diabetes (T1D) locus in the innate immunity viral RNA receptor gene region IFIH1 (also known as mda-5 or Helicard) on chromosome 2q24.3. We found the association in an interim analysis of a genome-wide nonsynonymous SNP (nsSNP) scan, and we validated it in a case-control collection and replicated it in an independent family collection. In 4,253 cases, 5,842 controls and 2,134 parent-child trio genotypes, the risk ratio for the minor allele of the nsSNP rs1990760 A → G (A946T) was 0.86 (95% confidence interval = 0.82–0.90) at P = 1.42 × 10−10.

Localization of a type 1 diabetes locus in the IL2RA/CD25 region by use of tag single-nucleotide polymorphisms

As part of an ongoing search for genes associated with type 1 diabetes (T1D), a common autoimmune disease, we tested the biological candidate gene IL2RA (CD25), which encodes a subunit (IL-2R alpha) of the high-affinity interleukin-2 (IL-2) receptor complex. We employed a tag single-nucleotide polymorphism (tag SNP) approach in large T1D sample collections consisting of 7,457 cases and controls and 725 multiplex families. Tag SNPs were analyzed using a multilocus test to provide a regional test for association. We found strong statistical evidence in the case-control collection (P=6.5x10(-8)) for a T1D locus in the CD25 region of chromosome 10p15 and replicated the association in the family collection (P=7.3x10(-3); combined P=1.3x10(-10)). These results illustrate the utility of tag SNPs in a chromosome-regional test of disease association and justify future fine mapping of the causal variant in the region.

Risk of microalbuminuria and progression to macroalbuminuria in a cohort with childhood onset type 1 diabetes: prospective observational study

Objectives To describe independent predictors for the development of microalbuminuria and progression to macroalbuminuria in those with childhood onset type 1 diabetes. Design Prospective observational study with follow-up for 9.8 (SD 3.8) years. Setting Oxford regional prospective study. Participants 527 participants with a diagnosis of type 1 diabetes at mean age 8.8 (SD 4.0) years. Main outcome measures Annual measurement of glycated haemoglobin (HbA1c) and assessment of urinary albumin:creatinine ratio. Results Cumulative prevalence of microalbuminuria was 25.7% (95% confidence interval 21.3% to 30.1%) after 10 years of diabetes and 50.7% (40.5% to 60.9%) after 19 years of diabetes and 5182 patient years of follow-up. The only modifiable adjusted predictor for microalbuminuria was high HbA1c concentrations (hazard ratio per 1% rise in HbA1c 1.39, 1.27 to 1.52). Blood pressure and history of smoking were not predictors. Microalbuminuria was persistent in 48% of patients. Cumulative prevalence of progression from microalbuminuria to macroalbuminuria was 13.9% (12.9% to 14.9%); progression occurred at a mean age of 18.5 (5.8) years. Although the sample size was small, modifiable predictors of macroalbuminuria were higher HbA1c levels and both persistent and intermittent microalbuminuria (hazard ratios 1.42 (1.22 to 1.78), 27.72 (7.99 to 96.12), and 8.76 (2.44 to 31.44), respectively). Conclusion In childhood onset type 1 diabetes, the only modifiable predictors were poor glycaemic control for the development of microalbuminuria and poor control and microalbuminuria (both persistent and intermittent) for progression to macroalbuminuria. Risk for macroalbuminuria is similar to that observed in cohorts with adult onset disease but as it occurs in young adult life early intervention in normotensive adolescents might be needed to improve prognosis.

Prevalence of Abnormal Lipid Profiles and the Relationship With the Development of Microalbuminuria in Adolescents With Type 1 Diabetes

OBJECTIVE To explore the prevalence of lipid abnormalities and their relationship with albumin excretion and microalbuminuria in adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS The study population comprised 895 young subjects with type 1 diabetes (490 males); median age at the baseline assessment was 14.5 years (range 10–21.1), and median diabetes duration was 4.8 years (0.2–17). A total of 2,194 nonfasting blood samples were collected longitudinally for determination of total cholesterol, LDL cholesterol, HDL cholesterol, TG, and non-HDL cholesterol. Additional annually collected data on anthropometric parameters, A1C, and albumin-to-creatinine ratio (ACR) were available. RESULTS Total cholesterol, LDL cholesterol, HDL cholesterol, and non-HDL cholesterol were higher in females than in males (all P < 0.001). A significant proportion of subjects presented sustained lipid abnormalities during follow-up: total cholesterol >5.2 mmol/l (18.6%), non-HDL cholesterol >3.4 mmol/l (25.9%), TG >1.7 mmol/l (20.1%), and LDL cholesterol >3.4 mmol/l (9.6%). Age and duration were significantly related to all lipid parameters (P < 0.001); A1C was independently related to all parameters (P < 0.001) except HDL cholesterol, whereas BMI SD scores were related to all parameters (P < 0.05) except total cholesterol. Total cholesterol and non-HDL cholesterol were independently related to longitudinal changes in ACR (B coefficient ± SE): 0.03 ± 0.01/1 mmol/l, P = 0.009, and 0.32 ± 0.014/1 mmol/l, P = 0.02, respectively. Overall mean total cholesterol and non-HDL cholesterol were higher in microalbuminuria positive (n = 115) than in normoalbuminuric subjects (n = 780): total cholesterol 4.7 ± 1.2 vs. 4.5 ± 0.8 mmol/l (P = 0.04) and non-HDL cholesterol 3.2 ± 1.2 vs. 2.9 ± 0.8 mmol/l (P = 0.03). CONCLUSIONS In this longitudinal study of adolescents with type 1 diabetes, sustained lipid abnormalities were related to age, duration, BMI, and A1C. Furthermore, ACR was related to both total cholesterol and non-HDL cholesterol, indicating a potential role in the pathogenesis of diabetic nephropathy.

Ambulatory blood pressure measurements are related to albumin excretion and are predictive for risk of microalbuminuria in young people with type 1 diabetes

Aims/hypothesisThe relationship between BP and microalbuminuria in young people with type 1 diabetes is not completely clear. As microalbuminuria is preceded by a gradual rise in albumin excretion within the normal range, we hypothesised that ambulatory BP (ABP) may be closely related to albumin excretion and progression to microalbuminuria.MethodsABP monitoring (ABPM) was performed in 509 young people with type 1 diabetes (age median [range]: 15.7 [10.7–22.6] years) followed with annual assessments of three early morning urinary albumin:creatinine ratios (ACRs) and HbA1c. Systolic BP (SBP) and diastolic BP (DBP) and the nocturnal fall in BP were analysed in relation to ACR.ResultsAll ABPM variables were significantly related to baseline log10 ACR (p < 0.001). After the ABPM evaluation, 287 patients were followed for a median of 2.2 (1.0–5.5) years. ABP at baseline was independently related to mean ACR during follow-up. Nineteen initially normoalbuminuric patients developed microalbuminuria after 2.0 (0.2–4.0) years and their baseline daytime DBP was higher than in normoalbuminuric patients (p < 0.001). After adjusting for baseline ACR and HbA1c, there was an 11% increased risk of microalbuminuria for each 1 mmHg increase in daytime DBP. Forty-eight per cent of patients were non-dippers for SBP and 60% for DBP; however, ACR was not different between dippers and non-dippers and there were no differences in the nocturnal fall in BP between normoalbuminuric and future microalbuminuric patients.Conclusions/interpretationIn this cohort of young people with type 1 diabetes, ABP was significantly related to ACR, and daytime DBP was independently associated with progression to microalbuminuria. Increasing albumin excretion, even in the normal range, may be associated with parallel rises in BP.

Can we identify adolescents at high risk for nephropathy before the development of microalbuminuria

Aims  To determine whether higher than average albumin excretion during early puberty identifies subjects who will subsequently develop microalbuminuria (MA) and clinical proteinuria.

Longitudinal relation between limited joint mobility, height, insulin-like growth factor 1 levels, and risk of developing microalbuminuria: the Oxford Regional Prospective Study

Aims: To determine risk factors for development of microalbuminuria (MA) in relation to detection of limited joint mobility (LJM+) of the interphalangeal joints in a longitudinal cohort of type 1 diabetic (T1DM) subjects. Methods: A total of 479 T1DM subjects diagnosed <16 years were followed from diagnosis of diabetes with annual assessments consisting of assessment of LJM, measurement of HbA1c and insulin-like growth factor 1 (IGF-1), and three urine samples for albumin:creatinine ratio (ACR). Results: After a median follow up of 10.9 years, 162 subjects (35.1%) developed LJM at median age 13.0 years and duration 5.2 years. More subjects developed LJM after compared to before puberty (67.6 v 32.4%). In LJM+ compared to LJM− subjects, HbA1c (mean 10.1 (SD 1.6) v 9.6 (1.4) %)) and ACR levels (median 1.1 (range 0.2–242.9) v 0.9 (0.4–70.7) mg/mmol) were higher, and in a Cox model probability of developing LJM was related to puberty and higher HbA1c levels. ACR levels were higher after detection of LJM compared to before (median 1.2 (range 0.4–102.6) v 0.8 (0.2–181.9) mg/mmol). Probability of developing MA was related to puberty, HbA1c, female sex, and presence of LJM (a 1.9-fold increased risk). Both LJM and MA were associated with lower height SDS (LJM: mean 0.0 (SD 1.0) v 0.2 (1.1); MA: 0.0 (1.0) v 0.2 (SD 1.0)) and lower IGF-1 levels. Conclusion: The development of LJM was associated with an increased risk of microalbuminuria, independent of glycaemic control. Risk for both microalbuminuria and LJM was associated with puberty, reduced growth, and reduced IGF-1 levels, and may indicate underlying shared pathogenic mechanisms.

Effect of acute variations of insulin and glucose on plasma concentrations of asymmetric dimethylarginine in young people with Type 1 diabetes

ADMA (asymmetric dimethylarginine), an endogenous inhibitor of nitric oxide synthase, is considered a major risk factor for cardiovascular disease and progression of renal disease. In the present study we aim to investigate the effect of acute variations in plasma glucose and insulin on plasma ADMA levels in young people with T1D (Type 1 diabetes). Fifteen young patients (ten males) with T1D, median age 18.3 (13.2-24.4) years, HbA(1c) (glycated haemoglobin) 9% (6.4-13.6%), underwent an overnight (18:00-08:00 hours) variable insulin infusion for euglycaemia, followed by a hyperinsulinaemic-euglycaemic clamp (08:00-12:00 hours). Blood samples were collected every 15 min for determination of ADMA, SDMA (symmetric dimethylarginine), valine, phenylalanine, arginine, creatinine and glucose. Insulin levels were assessed every 30 min. During the overnight period, glucose levels increased following the evening meal. In response to the protein intake there was a significant increase in ADMA, arginine, valine, phenylalanine and creatinine. For the remaining part of the night, glucose levels progressively decreased reaching 5 mmol/l by 04:00 hours. ADMA and SDMA did not change significantly. During the hyperinsulinaemic clamp, a significant fall in ADMA was observed, from 0.468+/-0.056 to 0.364+/-0.050 micromol/l (P<0.001). A significant fall was also found in SDMA, valine, phenylalanine, arginine and the ADMA/SDMA ratio (all P<0.001), but not in creatinine levels. No correlation was found between insulin sensitivity and ADMA. We conclude that acute changes in glycaemia do not significantly affect plasma ADMA levels whereas infusion of insulin significantly reduces ADMA, suggesting an important role for insulin in the regulation of this cardiovascular risk factor.

Cognitive behavioural therapy and short-term psychoanalytical psychotherapy versus a brief psychosocial intervention in adolescents with unipolar major depressive disorder (IMPACT): a multicentre, pragmatic, observer-blind, randomised controlled superiority trial

Summary Background Psychological treatments for adolescents with unipolar major depressive disorder are associated with diagnostic remission within 28 weeks in 65–70% of patients. We aimed to assess the medium-term effects and costs of psychological therapies on maintenance of reduced depression symptoms 12 months after treatment. Methods We did this multicentre, pragmatic, observer-blind, randomised controlled superiority trial (IMPACT) at 15 National Health Service child and adolescent mental health service (CAMHS) clinics in three regions in England. Adolescent patients (aged 11–17 years) with a diagnosis of DSM IV major depressive disorder were randomly assigned (1:1:1), via a web-based randomisation service, to receive cognitive behavioural therapy (CBT) or short-term psychoanalytical therapy versus a reference brief psychological intervention. Randomisation was stochastically minimised by age, sex, self-reported depression sum score, and region. Patients and clinicians were aware of group allocation, but allocation was concealed from outcome assessors. Patients were followed up and reassessed at weeks 6, 12, 36, 52, and 86 post-randomisation. The primary outcome was self-reported depression symptoms at weeks 36, 52, and 86, as measured with the self-reported Mood and Feelings Questionnaire (MFQ). Because our aim was to compare the two psychological therapies with the brief psychosocial intervention, we first established whether CBT was inferior to short-term psychoanalytical psychotherapy for the same outcome. Primary analysis was by intention to treat. This trial is registered with Current Controlled Trials, number ISRCTN83033550. Findings Between June 29, 2010, and Jan 17, 2013, we randomly assigned 470 patients to receive the brief psychosocial intervention (n=158), CBT (n=155), or short-term psychoanalytical therapy (n=157); 465 patients comprised the intention-to-treat population. 392 (84%) patients had available data for primary analysis by the end of follow-up. Treatment fidelity and differentiation were established between the three interventions. The median number of treatment sessions differed significantly between patients in the brief psychosocial intervention group (n=6 [IQR 4–11]), CBT group (n=9 [5–14]), and short-term psychoanalytical therapy group (n=11 [5–23]; p<0·0001), but there was no difference between groups in the average duration of treatment (27·5 [SD 21·5], 24·9 [17·7], 27·9 [16·8] weeks, respectively; Kruskal–Wallis p=0·238). Self-reported depression symptoms did not differ significantly between patients given CBT and those given short-term psychoanalytical therapy at weeks 36 (treatment effect 0·179, 95% CI −3·731 to 4·088; p=0·929), 52 (0·307, −3·161 to 3·774; p=0·862), or 86 (0·578, −2·948 to 4·104; p=0·748). These two psychological treatments had no superiority effect compared with brief psychosocial intervention at weeks 36 (treatment effect −3·234, 95% CI −6·611 to 0·143; p=0·061), 52 (−2·806, −5·790 to 0·177; p=0·065), or 86 (−1·898, −4·922 to 1·126; p=0·219). Physical adverse events (self-reported breathing problems, sleep disturbances, drowsiness or tiredness, nausea, sweating, and being restless or overactive) did not differ between the groups. Total costs of the trial interventions did not differ significantly between treatment groups. Interpretation We found no evidence for the superiority of CBT or short-term psychoanalytical therapy compared with a brief psychosocial intervention in maintenance of reduced depression symptoms 12 months after treatment. Short-term psychoanalytical therapy was as effective as CBT and, together with brief psychosocial intervention, offers additional patient choice for psychological therapy, alongside CBT, for adolescents with moderate to severe depression who are attending routine specialist CAMHS clinics. Funding National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme, and the Department of Health.

C-Reactive Protein in Relation to the Development of Microalbuminuria in Type 1 Diabetes: The Oxford Regional Prospective Study

OBJECTIVES—To perform a longitudinal evaluation of high-sensitivity C-reactive protein (hs-CRP) in young people with type 1 diabetes in relation to the development of microalbuminuria (MA). RESEARCH DESIGN AND METHODS—hs-CRP was measured in 329 blood samples collected from 49 subjects with type 1 diabetes with MA and 49 normoalbuminuric subjects matched for age, sex, and duration of diabetes. RESULTS—In subjects developing MA, a progressive rise in hs-CRP was detected with levels significantly higher in the years after the onset of MA when compared with levels before MA onset (P = 0.003; age-adjusted P = 0.06). After the onset of MA, hs-CRP levels were significantly higher in subjects with MA when compared with normoalbuminuric subjects (median 1.9 mg/l [range 0.2–9.8] vs. 1.1 mg/l [0.2–6.4]; P = 0.02; adjusted P = 0.036). CONCLUSIONS—In this population of young subjects with type 1 diabetes, there was a significant increase in hs-CRP levels after the onset of MA, likely reflecting a general state of inflammation.