The diabetes management experiences questionnaire: Psychometric validation among adults with type 1 diabetes

AIMS

To examine the psychometric properties of the Diabetes Management Experiences Questionnaire (DME-Q). Adapted from the validated Glucose Monitoring Experiences Questionnaire, the DME-Q captures satisfaction with diabetes management irrespective of treatment modalities.

METHODS

The DME-Q was completed by adults with type 1 diabetes as part of a randomized controlled trial comparing hybrid closed loop (HCL) to standard therapy. Most psychometric properties were examined with pre-randomization data (n = 149); responsiveness was examined using baseline and 26-week follow-up data (n = 120).

RESULTS

Pre-randomization, participants' mean age was 44 ± 12 years, 52% were women. HbA1c was 61 ± 11 mmol/mol (7.8 ± 1.0%), diabetes duration was 24 ± 12 years and 47% used an insulin pump prior to the trial. A forced three-factor analysis revealed three expected domains, that is, 'Convenience', 'Effectiveness' and 'Intrusiveness', and a forced one-factor solution was also satisfactory. Internal consistency reliability was strong for the three subscales (α range = 0.74-0.84) and 'Total satisfaction'( α  = 0.85). Convergent validity was demonstrated with moderate correlations between DME-Q 'Total satisfaction' and diabetes distress (PAID: rs  = -0.57) and treatment satisfaction (DTSQ; rs  = 0.58). Divergent validity was demonstrated with a weak correlation with prospective/retrospective memory (PRMQ: rs  = -0.16 and - 0.13 respectively). Responsiveness was demonstrated, as participants randomized to HCL had higher 'Effectiveness' and 'Total satisfaction' scores than those randomized to standard therapy.

CONCLUSIONS

The 22-item DME-Q is a brief, acceptable, reliable measure with satisfactory structural and construct validity, which is responsive to intervention. The DME-Q is likely to be useful for evaluation of new pharmaceutical agents and technologies in research and clinical settings.

Abstract WMP13: Delayed Stimulation Of Angiotensin II Type 2 Receptor Ameliorates Sensorimotor Deficits And Cognitive Decline After Stroke In Aged Hypertensive Rats

Hypertension and aging are leading risk factors for stroke and cognitive decline. Animal models fail to capture the complex interplay between these two pathophysiologic processes, limiting human translation of interventions. In the current study, we investigated the development of cognitive impairment in 18-month-old spontaneously hypertensive rats (SHRs) prior to and following a 30-minute tMCAO or SHAM. Sixty SHRs were kept for 18 months with cognitive assessments performed prior to and post-surgery. Baseline brain MRI was done at 18 months and then at day 3 and week 8 post-surgery. At day 3, rats were randomly assigned to blindly receive either C21 or normal drinking water for 8 weeks.

Results: Over 18 months, SHRs demonstrated a progressive cognitive decline and significant abnormalities on MRI. Aged SHRs demonstrated an acceptably low 14% peri-operative mortality within 72 hours of tMCAO. Stroke resulted in sustained, significant sensorimotor deficits and C21 effectively enhanced sensorimotor recovery at week 8. Progressive cognitive decline continued after surgery, but C21 enhanced post-stroke, subacute associative and reference memory at week 5. There was no evidence of anhedonia at 8 weeks. MRI scans revealed no difference in ischemic lesion resolution between C21 and control. However, C21 treated rats had less cortical atrophy and reduced WM injury at 8 weeks.

Conclusions: Aged SHRs with minor stroke demonstrated persistent sensorimotor deficits, which were significantly lessened with C21. The dramatic decline in exploration time with age was ameliorated with C21 treatment, evidence of preserved cognition.

Use of remote monitoring with continuous glucose monitoring in young children with Type 1 diabetes: the parents' perspective

AIM

Remote monitoring with continuous glucose monitoring (CGM) in children with Type 1 diabetes mellitus has recently become available, but little is known about caregivers' experiences of its use, particularly in younger children. The aim of this study was to explore parents' everyday experiences of using this technology.

METHODS

The parents of children with Type 1 diabetes diagnosed for > 1 year, aged 2-12 years were invited to participate in a semi-structured interview. Interviews were the second phase of a randomized cross-over study using standard insulin therapy with or without CGM and remote monitoring for two 3-month periods. Open-ended questions were used to explore parents' real-life experiences of the remote monitoring and CGM system. Interviews were analysed using thematic analysis.

RESULTS

Five themes related to remote monitoring emerged: (i) impact on sleep quality for the parents, (ii) peace of mind, (iii) impact on anxiety, (iv) freedom and confidence for the parents and children, and (v) impact on relationships. Furthermore, parents reported on themes related to CGM in general, such as better understanding of how to manage and control their child's diabetes and experiences related to physical or technical aspects.

CONCLUSION

Overall, parents of primary school children reported that using remote monitoring and CGM was a mostly beneficial experience. However, negative aspects within the themes were also reported. These findings will help to provide a structure to discuss parent and child expectations and provide targeted education at the start of using remote monitoring and CGM.

Effect of combining pre-exercise carbohydrate intake and repeated short sprints on the blood glucose response to moderate-intensity exercise in young individuals with Type 1 diabetes

AIMS

To determine whether pre-exercise ingestion of carbohydrates to maintain stable glycaemia during moderate-intensity exercise results in excessive hyperglycaemia if combined with repeated sprints in individuals with Type 1 diabetes.

METHODS

Eight overnight-fasted people with Type 1 diabetes completed the following four 40-min exercise sessions on separate days in a randomized counterbalanced order under basal insulinaemic conditions: continuous moderate-intensity exercise at 50% V ˙ O 2 peak; intermittent high-intensity exercise (moderate-intensity exercise interspersed with 4-s sprints every 2 min and a final 10-s sprint); continuous moderate-intensity exercise with prior carbohydrate intake (~10 g per person); and intermittent high-intensity exercise with prior carbohydrate intake. Venous blood was sampled during and 2 h after exercise to measure glucose and lactate levels.

RESULTS

The difference in marginal mean time-averaged area under the blood glucose curve between continuous moderate-intensity exercise + prior carbohydrate and intermittent high-intensity exercise + prior carbohydrate during exercise and recovery was not significant [0.2 mmol/l (95% CI -0.7, 1.1); P = 0.635], nor was the difference in peak blood glucose level after adjusting for baseline level [0.2 mmol/l (95% CI -0.7, 1.1); P = 0.695]. The difference in marginal mean time-averaged area under the blood glucose curve between continuous moderate-intensity and intermittent high-intensity exercise during exercise and recovery was also not significant [-0.2 mmol/l (95% CI -1.2, 0.8); P = 0.651].

CONCLUSIONS

When carbohydrates are ingested prior to moderate-intensity exercise, adding repeated sprints is not significantly detrimental to glycaemic management in overnight fasted people with Type 1 diabetes under basal insulin conditions.

Dietary protein affects both the dose and pattern of insulin delivery required to achieve postprandial euglycaemia in Type 1 diabetes: a randomized trial

AIM

To quantify the insulin requirement for a high-protein meal compared with a low-protein meal, controlling for carbohydrate and fat content.

METHODS

In this crossover study, young people with Type 1 diabetes were randomized to consume a high- (60 g) or low-protein meal (5 g), each containing 30 g carbohydrate and 8 g fat. A variation of the insulin clamp technique was used to determine the insulin requirements to maintain euglycaemia for the following 5 h.

RESULTS

A total of 11 participants (mean ± sd age 16.5 ± 2.7 years, HbA_1c 52 ± 8.7 mmol/mol [6.9 ± 0.8%], diabetes duration 6.9±5.1 years) completed the study. The mean insulin requirements for the high-protein meal were higher than for the low-protein meal [10.3 (CI 8.2, 12.57) vs 6.7 units (CI 4.7, 8.8); P=0.001], with inter-individual requirements ranging from 0.9 to six times the low-protein meal requirement. Approximately half the additional insulin [1.1 units/h (CI 0.5, 1.8; P=0.001)] was given in the first 2 h, compared with an additional 0.5 units/h (CI -0.2, 1.2; P=0.148) in the second 2 h and 0.1 units (CI -0.6, 0.8; P=0.769) in the final hour.

CONCLUSIONS

A high-protein meal requires ~50% more insulin to maintain euglycaemia than a low-protein meal that contains the same quantity of carbohydrate. The majority is required within the first 2 h. Inter-individual differences exist in insulin requirements for dietary protein.

A randomized comparison of three prandial insulin dosing algorithms for children and adolescents with Type 1 diabetes

AIM

To compare systematically the impact of two novel insulin-dosing algorithms (the Pankowska Equation and the Food Insulin Index) with carbohydrate counting on postprandial glucose excursions following a high fat and a high protein meal.

METHODS

A randomized, crossover trial at two Paediatric Diabetes centres was conducted. On each day, participants consumed a high protein or high fat meal with similar carbohydrate amounts. Insulin was delivered according to carbohydrate counting, the Pankowska Equation or the Food Insulin Index. Subjects fasted for 5 h following the test meal and physical activity was standardized. Postprandial glycaemia was measured for 300 min using continuous glucose monitoring.

RESULTS

33 children participated in the study. When compared to carbohydrate counting, the Pankowska Equation resulted in lower glycaemic excursion for 90-240 min after the high protein meal (p < 0.05) and lower peak glycaemic excursion (p < 0.05). The risk of hypoglycaemia was significantly lower for carbohydrate counting and the Food Insulin Index compared to the Pankowska Equation (OR 0.76 carbohydrate counting vs. the Pankowska Equation and 0.81 the Food Insulin Index vs. the Pankowska Equation). There was no significant difference in glycaemic excursions when carbohydrate counting was compared to the Food Insulin Index.

CONCLUSION

The Pankowska Equation resulted in reduced postprandial hyperglycaemia at the expense of an increase in hypoglycaemia. There were no significant differences when carbohydrate counting was compared to the Food Insulin Index. Further research is required to optimize prandial insulin dosing.

The time lag prior to the rise in glucose requirements to maintain stable glycaemia during moderate exercise in a fasted insulinaemic state is of short duration and unaffected by the level at which glycaemia is maintained in Type 1 diabetes

AIMS

To determine the duration of the low hypoglycaemia risk period after the start of moderate-intensity exercise performed under basal insulinaemic conditions and whether this period is affected by the level at which glycaemia is maintained under these conditions.

METHODS

This was a prospective, randomized counterbalanced study. Eight participants with Type 1 diabetes (mean ± sd age 21.5 ± 4.0 years) underwent either a euglycaemic (5-6 mmol/l) or hyperglycaemic clamp (9-10 mmol/l) on separate days and were infused with insulin at basal rates and [6,6-² H]glucose while cycling for 40 min at 50% maximum oxygen consumption rate. The main outcome measures were the glucose infusion rates required to maintain stable glycaemia and glucoregulatory hormone levels, and rates of glucose appearance and disappearance.

RESULTS

During the first 20 min of exercise, the glucose infusion rate did not increase significantly, irrespective of the level at which glycaemia was maintained, but increased acutely between 20 and 25 min under both conditions. Maintaining higher glycaemia resulted in higher glucose infusion rate during, but not early post-exercise. With the exception of epinephrine, the glucoregulatory hormone levels and rates of glucose appearance and disappearance were similar between conditions.

CONCLUSION

Irrespective of the levels at which glycaemia is maintained, there is a 20-min low exogenous glucose demand period during which the exogenous glucose requirements to maintain stable glycaemia do not increase during moderate exercise performed at basal insulin level.

The glycaemic benefits of a very-low-carbohydrate ketogenic diet in adults with Type 1 diabetes mellitus may be opposed by increased hypoglycaemia risk and dyslipidaemia

AIMS

To investigate whether very-low-carbohydrate high-fat diets, typical of ketogenic diets, can improve glycaemic control without causing any ill health effects in adults with Type 1 diabetes.

METHODS

In this observational study, 11 adults with Type 1 diabetes (seven men, four women, mean ± sd age 36.1± 6.8 years, mean ± sd duration of diabetes 12.8 ± 10.3 years), who followed a ketogenic diet (< 55 g carbohydrate per day) for a mean ± sd of 2.6 ± 3.3 years (β-hydroxybutyrate 1.6 ± 1.3 mmol/l), underwent sampling and analysis of fasting blood, and were fitted with a blinded continuous glucose monitor for 7 days to measure glycaemic variability.

RESULTS

The mean ± sd HbA1c levels were 35±4 mmol/mol (5.3±0.4%), and participants spent 74±20 and 3±8% of their time in the euglycaemic (4-8 mmol/l) and hyperglycaemic (>10 mmol/l) ranges, respectively, with little daily glycaemic variability (sd 1.5±0.7 mmol/l; coefficient of variation 26±8%). Blood glucose levels were <3.0 mmol/l for 3.6% of the time, and participants experienced a median (range) of 0.9 (0.0-2.0) daily episodes of hypoglycaemia. Total cholesterol, LDL cholesterol, total cholesterol/HDL cholesterol ratio, and triglycerides were above the recommended range in 82%, 82%, 64% and 27% of participants, respectively; however, HDL cholesterol levels were within the recommended range for all participants. Participants displayed no or little evidence of hepatic or renal dysfunction.

CONCLUSION

This study provides the first evidence that, ketogenic diets in adults with Type 1 diabetes are associated with excellent HbA1c levels and little glycaemic variability, but may also be associated with dyslipidaemia and a high number of hypoglycaemic episodes.

The Adolescent Cardio-Renal Intervention Trial (AdDIT): retinal vascular geometry and renal function in adolescents with type 1 diabetes

AIMS/HYPOTHESIS

We examined the hypothesis that elevation in urinary albumin creatinine ratio (ACR) in adolescents with type 1 diabetes is associated with abnormal retinal vascular geometry (RVG) phenotypes.

METHODS

A cross-sectional study at baseline of the relationship between ACR within the normoalbuminuric range and RVG in 963 adolescents aged 14.4 ± 1.6 years with type 1 diabetes (median duration 6.5 years) screened for participation in AdDIT. A validated algorithm was used to categorise log₁₀ ACR into tertiles: upper tertile ACR was defined as 'high-risk' for future albuminuria and the lower two tertiles were deemed 'low-risk'. RVG analysis, using a semi-automated computer program, determined retinal vascular calibres (standard and extended zones) and tortuosity. RVG measures were analysed continuously and categorically (in quintiles: Q1-Q5) for associations with log₁₀ ACR and ACR risk groups.

RESULTS

Greater log₁₀ ACR was associated with narrower vessel calibres and greater tortuosity. The high-risk group was more likely to have extended zone vessel calibres in the lowest quintile (arteriolar Q1 vs Q2-Q5: OR 1.67 [95% CI 1.17, 2.38] and venular OR 1.39 [0.98, 1.99]) and tortuosity in the highest quintile (Q5 vs Q1-Q4: arteriolar OR 2.05 [1.44, 2.92] and venular OR 2.38 [1.67, 3.40]). The effects of retinal vascular calibres and tortuosity were additive such that the participants with the narrowest and most tortuous vessels were more likely to be in the high-risk group (OR 3.32 [1.84, 5.96]). These effects were independent of duration, blood pressure, BMI and blood glucose control.

CONCLUSIONS/INTERPRETATION

Higher ACR in adolescents is associated with narrower and more tortuous retinal vessels. Therefore, RVG phenotypes may serve to identify populations at high risk of diabetes complications during adolescence and well before onset of clinical diabetes complications.

Psychiatric disorders during early adulthood in those with childhood onset type 1 diabetes: Rates and clinical risk factors from population-based follow-up

AIM

To determine the incidence of and risk factors for psychiatric disorders in early adulthood in patients with childhood onset type 1 diabetes (T1D).

METHODS

In this retrospective-cohort study, we identified a population-based childhood onset T1D cohort and an age and sex matched (5:1) non-diabetic comparison cohort. Data linkage was used to access inpatient hospitalization data, mental health support service data, and mortality data to follow-up both cohorts into early adulthood.

RESULTS

The mean age of T1D diagnosis was 9.5 years (SD 4.1), with a mean age at end of follow-up of 26.4 years (SD 5.2, max 37.7). The diagnosis of any psychiatric disorder was observed for 187 of 1302 (14.3%) in the T1D cohort and 400 of 6422 (6.2%) in the comparison cohort [adjusted hazard ratio (HR) 2.3; 95% CI 1.9, 2.7]. Anxiety, eating, mood, and personality and behaviour disorders were observed at higher rates within the T1D cohort. Comorbid psychiatric disorders were more frequent, at the cohort level, within the T1D cohort (2-3 disorders 3.76% vs 1.56%) and service utilization was higher (15+ contacts 6.8% vs 2.8%); though these differences did not remain when restricted to only those individuals diagnosed during follow-up. A history of poor glycaemic control was associated with an increased risk of anxiety, mood, and 'any' disorder (HR ranging from 1.35 to 1.42 for each 1% increase in mean paediatric HbA1c).

CONCLUSION

Our findings highlight the need for access to mental health support services as part of routine patient care for young adults with T1D, and for better predictive tools to facilitate targeting at-risk patients with early intervention programs.

Home-based vs inpatient education for children newly diagnosed with type 1 diabetes

BACKGROUND

Initial management of children diagnosed with type 1 diabetes (T1D) varies worldwide with sparse high quality evidence regarding the impact of different models of care.

AIM

To compare the inpatient model of care with a hybrid home-based alternative, examining metabolic and psychosocial outcomes, diabetes knowledge, length of stay, and patient satisfaction.

SUBJECTS AND METHODS

The study design was a randomized-controlled trial. Inclusion criteria were: newly diagnosed T1D, aged 3 to 16 years, living within approximately 1 hour of the hospital, English-speaking, access to transport, absence of significant medical or psychosocial comorbidity. Patients were randomized to standard care with a 5 to 6 day initial inpatient stay or discharge after 2 days for home-based management. All patients received practical skills training in the first 48 hours. The intervention group was visited twice/day by a nurse for 2 days to assist with injections, then a multi-disciplinary team made 3 home visits over 2 weeks to complete education. Patients were followed up for 12 months. Clinical outcomes included HbA1c, hypoglycemia, and diabetes-related readmissions. Surveys measured patient satisfaction, diabetes knowledge, family impact, and quality of life.

RESULTS

Fifty patients were recruited, 25 to each group. There were no differences in medical or psychosocial outcomes or diabetes knowledge. Average length of admission was 1.9 days shorter for the intervention group. Families indicated that with hindsight, most would choose home- over hospital-based management.

CONCLUSIONS

With adequate support, children newly diagnosed with T1D can be safely managed at home following practical skills training.

A 10-second sprint does not blunt hormonal counter-regulation to subsequent hypoglycaemia

AIM

To investigate whether a 10-second (s) sprint impairs the counter-regulatory response to subsequent hypoglycaemia.

METHODS

Nine people (five male, four female) with Type 1 diabetes, aged 21.1 ± 4.5 years, performed a 10-s rest or a 10-s maximum-effort sprint in random order on different days, while subjected to an euinsulinaemic-euglycaemic clamp. This was followed by a hyperinsulinaemic-hypoglycaemic glucose clamp 2.5 h later to induce hypoglycaemia for 40 min. At timed intervals, the counter-regulatory hormonal responses to hypoglycaemia were measured. Blood pressure, heart rate and hypoglycaemic symptoms were also assessed.

RESULTS

During the hypoglycaemic clamp, epinephrine, norepinephrine, growth hormone and cortisol levels increased significantly from baseline, and their responses were similar after both rest and sprint conditions. In particular, plasma epinephrine rose eightfold, from 197 ± 103 pmol/l to 1582 ± 1118 pmol/l after the rest condition, and from 219 ± 119 pmol/l to 1900 ± 898 pmol/l after the sprint condition.

CONCLUSION

A 10-s sprint is unlikely to blunt the subsequent hormonal counter-regulation to hypoglycaemia in individuals with Type 1 diabetes.

Reproducibility of the plasma glucose response to moderate-intensity exercise in adolescents with Type 1 diabetes

AIMS

The aim of the study was to evaluate the reproducibility of the plasma glucose response to moderate-intensity exercise performed on different days under controlled conditions in adolescents with Type 1 diabetes.

METHODS

Eight adolescents with Type 1 diabetes on continuous subcutaneous insulin infusion completed two exercise sessions, each on two separate days, under basal insulin and fasting conditions. On each day, participants cycled twice for 30 min at 55% of their peak rate of oxygen consumption, with each exercise session separated by a 30-min rest.

RESULTS

Plasma insulin levels were similar between testing days and exercise sessions. The mean absolute drop in plasma glucose from the commencement to the end of exercise was 1.6 ± 0.5 mmol/l on day 1 and 1.9 ± 0.7 mmol/l on day 2 (P = 0.3). In response to the first exercise session, plasma glucose levels relative to baseline did not change significantly (0.2 ± 0.6 and -0.2 ± 0.5 mmol/l on days 1 and 2). By contrast, the change in plasma glucose during the second exercise session was -1.1 ± 0.7 and -1.3 ± 0.7mmol/l on days 1 and 2, respectively. The mean absolute intra-individual difference in the change in plasma glucose between testing days were 0.7 ± 0.5 [95% confidence interval (CI) 0.4-1.0] and 0.7 ± 0.4 (95% CI 0.4-1.0) mmol/l, at the end of the first and second exercise sessions respectively.

CONCLUSIONS

The plasma glucose response to moderate-intensity exercise under similar glycaemic and basal insulin conditions can be reproducible in adolescents with Type 1 diabetes.

Safety and efficacy of the predictive low glucose management system in the prevention of hypoglycaemia: protocol for randomised controlled home trial to evaluate the Suspend before low function

INTRODUCTION

Innovations with sensor-augmented pump therapy (SAPT) to reduce hypoglycaemia in patients with type 1 diabetes are an ongoing area of research. The predictive low glucose management (PLGM) system incorporates continuous glucose sensor data into an algorithm and suspends basal insulin before the occurrence of hypoglycaemia. The system was evaluated in in-clinic studies, and has informed the parameters of a larger home trial to study its efficacy and safety in real life.

METHODS AND ANALYSIS

The aim of this report is to describe the study design and outcome measures for the trial. This is a 6-month, multicentre, randomised controlled home trial to test the PLGM system in children and adolescents with type 1 diabetes. The system is available in the Medtronic MiniMed 640G pump as the 'Suspend before low' feature. Following a run-in period, participants are randomised to either the control arm with SAPT alone or the intervention arm with SAPT and Suspend before low. The primary aim of this study is to evaluate the time spent hypoglycaemic (sensor glucose <3.5 mmol/L) with and without the system. The secondary aims are to determine the number of hypoglycaemic events, the time spent hyperglycaemic, and to evaluate safety with ketosis and changes in glycated haemoglobin. The study also aims to assess the changes in counter-regulatory hormone responses to hypoglycaemia evaluated by a hyperinsulinaemic hypoglycaemic clamp in a subgroup of patients with impaired awareness. Validated questionnaires are used to measure the fear of hypoglycaemia and the impact on the quality of life to assess burden of the disease.

ETHICS AND DISSEMINATION

Ethics committee permissions were gained from respective Institutional Review boards. The findings of the study will provide high quality evidence of the ability of the system in the prevention of hypoglycaemia in real life.

TRIAL REGISTRATION NUMBER

ACTRN12614000510640, Pre-results.

Glycaemic control of Type 1 diabetes in clinical practice early in the 21st century: an international comparison

AIMS

Improving glycaemic control in people with Type 1 diabetes is known to reduce complications. Our aim was to compare glycaemic control among people with Type 1 diabetes using data gathered in regional or national registries.

METHODS

Data were obtained for children and/or adults with Type 1 diabetes from the following countries (or regions): Western Australia, Austria, Denmark, England, Champagne-Ardenne (France), Germany, Epirus, Thessaly and Thessaloniki (Greece), Galway (Ireland), several Italian regions, Latvia, Rotterdam (The Netherlands), Otago (New Zealand), Norway, Northern Ireland, Scotland, Sweden, Volyn (Ukraine), USA and Wales) from population or clinic-based registries. The sample size with available data varied from 355 to 173 880. Proportions with HbA1c < 58 mmol/mol (< 7.5%) and ≥ 75 mmol/mol (≥ 9.0%) were compared by age and sex.

RESULTS

Data were available for 324 501 people. The proportions with HbA1c 58 mmol/mol (< 7.5%) varied from 15.7% to 46.4% among 44 058 people aged < 15 years, from 8.9% to 49.5% among 50 766 people aged 15-24 years and from 20.5% to 53.6% among 229 677 people aged ≥ 25 years. Sex differences in glycaemic control were small. Proportions of people using insulin pumps varied between the 12 sources with data available.

CONCLUSION

These results suggest that there are substantial variations in glycaemic control among people with Type 1 diabetes between the data sources and that there is room for improvement in all populations, especially in young adults.

Clinical and demographic risk factors associated with mortality during early adulthood in a population-based cohort of childhood-onset type 1 diabetes

AIMS

To calculate standardized mortality ratios and to assess the association between paediatric clinical factors and higher risk of mortality during early adulthood in a population-based cohort of subjects with Type 1 diabetes.

METHODS

Subjects with Type 1 diabetes were identified through the Western Australian Children's Diabetes Database and clinical data for those who reached 18 years of age (n = 1309) were extracted. An age- and sex-matched (without diabetes) comparison cohort (n = 6451) was obtained from the birth registry. Mortality records were obtained from the death registry. Participants were followed up until 31 January 2012. Associations of clinical factors (from clinic visits before 18 years of age) with mortality were assessed using Cox proportional hazard models.

RESULTS

The standardized mortality ratio for all-cause mortality was 1.7 (95% CI 0.7-3.3) for male and 10.1 (95% CI 5.2-17.7) for female subjects with Type 1 diabetes (median age at end of study 25.6 years). The adjusted hazard ratio was 1.5 (95% CI 1.1-2.1) for a 1% increase in mean paediatric HbA1c level, 3.8 (95% CI 0.9-15.3) for four episodes of severe hypoglycaemia relative to zero episodes, and 6.21 (95% CI 1.4-28.4) for a low-level socio-economic background relative to a high-level background.

CONCLUSIONS

People with childhood-onset Type 1 diabetes have higher mortality rates in early adulthood. At particularly high risk are women, those with a history of poor HbA1c levels, those with recurrent severe hypoglycaemia during paediatric management, and those from a low socio-economic background. These groups may benefit from intensified management during transition from paediatric to adult care facilities.

Hypoglycaemia, fear of hypoglycaemia and quality of life in children with Type 1 diabetes and their parents

AIM

To evaluate the association between fear of hypoglycaemia, episodes of hypoglycaemia and quality of life in children with Type 1 diabetes and their parents.

METHODS

This was a cross-sectional, population-based study of 325 children with Type 1 diabetes and their parents. The children were aged 2-18 years. A total of 325 parents of the patients aged 2-18 years and 196 of the patients themselves (aged 8-18 years) completed questionnaires including the PedsQL Diabetes Module, the Hypoglycaemia Fear Survey and Clarke's hypoglycaemia awareness questionnaire. Data were compared with HbA1c results and the history of severe hypoglycaemia episodes.

RESULTS

Parents with the highest levels of fear of hypoglycaemia reported that their children had a reduced quality of life (P < 0.001). Similarly children with the greatest fear also reported a reduced quality of life (P < 0.001); however a history of severe hypoglycaemia was not associated with the child's quality of life as perceived by the child or parent. Episodes of severe hypoglycaemia were associated with an increased fear of hypoglycaemia for the parents (P = 0.004) but not the children. Children in the highest fear quartile also had a higher HbA(1c) concentration compared with those in the lowest fear quartile [increase in HbA(1c) 7 mmol/mol (0.6%), P < 0.01].

CONCLUSIONS

Fear of hypoglycaemia and not episodes of hypoglycaemia per se is associated with increased psychological burden for children with Type 1 diabetes. Interventions to reduce fear of hypoglycaemia in these families may improve their quality of life.

The effect of a short sprint on postexercise whole-body glucose production and utilization rates in individuals with type 1 diabetes mellitus

CONTEXT

Recently we showed that a 10-sec maximal sprint effort performed before or after moderate intensity exercise can prevent early hypoglycemia during recovery in individuals with type 1 diabetes mellitus (T1DM). However, the mechanisms underlying this protective effect of sprinting are still unknown.

OBJECTIVE

The objective of the study was to test the hypothesis that short duration sprinting increases blood glucose levels via a disproportionate increase in glucose rate of appearance (Ra) relative to glucose rate of disappearance (Rd). SUBJECTS AND EXPERIMENTAL DESIGN: Eight T1DM participants were subjected to a euglycemic-euinsulinemic clamp and, together with nondiabetic participants, were infused with [6,6-(2)H]glucose before sprinting for 10 sec and allowed to recover for 2 h.

RESULTS

In response to sprinting, blood glucose levels increased by 1.2 ± 0.2 mmol/liter (P < 0.05) within 30 min of recovery in T1DM participants and remained stable afterward, whereas glycemia rose by only 0.40 ± 0.05 mmol/liter in the nondiabetic group. During recovery, glucose Ra did not change in both groups (P > 0.05), but glucose Rd in the nondiabetic and diabetic participants fell rapidly after exercise before returning within 30 min to preexercise levels. After sprinting, the levels of plasma epinephrine, norepinephrine, and GH rose transiently in both experimental groups (P < 0.05).

CONCLUSION

A sprint as short as 10 sec can increase plasma glucose levels in nondiabetic and T1DM individuals, with this rise resulting from a transient decline in glucose Rd rather than from a disproportionate rise in glucose Ra relative to glucose Rd as reported with intense aerobic exercise.

Measurement of the ZZ production cross section and limits on anomalous neutral triple gauge couplings in proton-proton collisions at sqrt[s] = 7 TeV with the ATLAS detector

A measurement of the ZZ production cross section in proton-proton collisions at sqrt[s] = 7 TeV using data corresponding to an integrated luminosity of 1.02 fb(-1) recorded by the ATLAS experiment at the LHC is presented. Twelve events containing two Z boson candidates decaying to electrons and/or muons are observed, with an expected background of 0.3 ± 0.3(stat)(-0.3)(+0.4)(syst) events. The cross section measured in a phase-space region with good detector acceptance and for dilepton masses within the range 66 to 116 GeV is σ(ZZ → ℓ+ ℓ- ℓ+ ℓ-)(fid) = 19.4(-5.2)(+6.3)(stat)(-0.7)(+0.9)(syst) ± 0.7(lumi) fb. The resulting total cross section for on-shell ZZ production, σ(ZZ)(tot) = 8.5(-2.3)(+2.7)(stat)(-0.3)(+0.4)(syst) ± 0.3(lumi) pb, is consistent with the standard model expectation of 6.5(-0.2)(+0.3) pb calculated at the next-to-leading order in QCD. Limits on anomalous neutral triple gauge boson couplings are derived.

Lower cardiorespiratory fitness in children with Type 1 diabetes

AIMS

The present study aimed to compare cardiorespiratory fitness levels in children with and without Type 1 diabetes. In addition, the relationship between cardiorespiratory fitness and a range of physical and clinical factors was investigated.

METHODS

Eighty-eight children with Type 1 diabetes aged 5-14 years completed a submaximal step test of cardiorespiratory fitness. Sixty-two of these children were successfully matched to control subjects without diabetes based on age, sex and anthropometrics for comparison. In addition, the relationship between cardiorespiratory fitness and a range of physical and clinical variables was assessed in the children with diabetes.

RESULTS

The heart rate response to exercise was higher in children with Type 1 diabetes, indicating reduced cardiorespiratory fitness levels compared with control subjects. Both gender and glycaemic control (HbA(1c) ) were significantly associated with cardiorespiratory fitness, with female sex and poorer glycaemic control associated with reduced fitness.

CONCLUSIONS

Future research should investigate whether the reduced fitness in children with Type 1 diabetes is attributable to lower physical activity levels, or physiological changes resulting from the diabetes pathology itself.

Heritability of levels of autoantibodies using the method of plotting regression of offspring on midparent (ROMP)

The genetic control of the levels of autoantibodies has rarely been examined. We examined the heritability of autoantibodies to glutamic acid decarboxylase (GAD65) in type 1 diabetes, and to thyroglobulin (Tg) in chronic lymphocytic thyroiditis and thyrotoxicosis, using regression of offspring on midparent (ROMP) methods. Levels of autoantibodies in patients and their parents were significantly correlated in thyrotoxicosis (R2 = 0.569, p = 0.001), consistent with the reported Gm association, but not in chronic lymphocytic thyroiditis or type 1 diabetes. Extension of the procedure to other autoantibody disorders could be informative.

Glycaemic impact of patient-led use of sensor-guided pump therapy in type 1 diabetes: a randomised controlled trial

AIMS/HYPOTHESIS

The objective of this study was to assess the impact of patient-led sensor-guided pump management on glycaemic control, and compare the effect with that of standard insulin pump therapy.

METHODS

An open multicentre parallel randomised controlled trial was conducted at five tertiary diabetes centres. Participants aged 13.0-40.0 years with well-controlled type 1 diabetes were randomised 1:1 to either study group for 3 months. Randomisation was carried out using a central computer-generated schedule. Participants in the intervention group used sensor-guided pump management; no instructive guidelines in interpreting real-time data were provided ('patient-led' use). Participants in the control group continued their original insulin pump regimen. Continuous glucose monitoring (CGM) and HbA(1c) level were used to assess outcomes. The primary outcome was the difference in the proportion of time in the target glycaemic range during the 3 month study period (derived from CGM, target range 4-10 mmol/l). Secondary outcomes were difference in HbA(1c), time in hypoglycaemic (< or =3.9 mmol/l) and hyperglycaemic (> or =10.1 mmol/l) ranges and glycaemic variability.

RESULTS

Sixty-two participants were recruited and randomised; 5/31 and 2/31 withdrew from intervention and control groups, respectively, leaving 26/31 and 29/31 for the intention-to-treat analyses. When adjusted for baseline values, the mean end-of-study HbA(1c) was 0.43% lower in the intervention group compared with the control group (95% CI 0.19 to 0.75%; p = 0.009). No difference was observed in CGM-derived time in target (measured difference 1.72; 95% CI -5.37 to 8.81), hypoglycaemic (0.54; 95% CI -3.48 to 4.55) or hyperglycaemic (-2.18; 95% CI -10.0 to 5.69) range or in glycaemic variability (-0.29; 95% CI -0.34 to 0.28). Within the intervention group, HbA(1c) was 0.51% lower in participants with sensor use > or =70% compared with participants with sensor use <70% (95% CI -0.98 to -0.04, p = 0.04). Five episodes of device malfunction occurred.

CONCLUSIONS/INTERPRETATION

Individuals established on insulin pump therapy can employ sensor-guided pump management to improve glycaemic control. An apparent dose-dependent effect of sensor usage was noted; however, frequent use of this technology (> or =70%) was not universally acceptable.

TRIAL REGISTRATION

ACTRN12606000049572

Inclusive K(S);(0)K(S);(0) resonance production in ep collisions at HERA

Inclusive K_{S};{0}K_{S};{0} production in ep collisions at the DESY ep collider HERA was studied with the ZEUS detector using an integrated luminosity of 0.5 fb;{-1}. Enhancements in the mass spectrum were observed and are attributed to the production of f_{2}(1270)/a_{2};{0}(1320), f_{2};{'}(1525) and f_{0}(1710). Masses and widths were obtained using a fit which takes into account theoretical predictions based on SU(3) symmetry arguments, and are consistent with the Particle Data Group values. The f_{0}(1710) state, which has a mass consistent with a glueball candidate, was observed with a statistical significance of 5 standard deviations. However, if this state is the same as that seen in gammagamma-->K_{S};{0}K_{S};{0}, it is unlikely to be a pure glueball state.

A 10-s sprint performed prior to moderate-intensity exercise prevents early post-exercise fall in glycaemia in individuals with type 1 diabetes

AIMS/HYPOTHESIS

We investigated whether a 10-s maximal sprint effort performed immediately prior to moderate-intensity exercise provides another means to counter the rapid fall in glycaemia associated with moderate-intensity exercise in individuals with type 1 diabetes.

MATERIALS AND METHODS

Seven complication-free type 1 diabetic males (21.6 +/- 3.6 years; mean+/-SD) with HbA(1c) levels of 7.4 +/- 0.7% injected their normal morning insulin dose and ate their usual breakfast. When post-meal glycaemia fell to approximately 11 mmol/l, participants were asked to perform a 10-s all-out sprint (sprint trial) or to rest (control trial) immediately before cycling at 40% of peak rate of oxygen consumption for 20 min, with both trials conducted in a random counterbalanced order.

RESULTS

Sprinting did not affect the rapid fall in glycaemia during the subsequent bout of moderate-intensity exercise (2.9 +/- 0.4 mmol/l in 20 min; p = 0.00; mean+/-SE). However, during the following 45 min of recovery, glycaemia in the control trial decreased by 1.23 +/- 0.60 mmol/l (p = 0.04) while remaining stable in the sprint trial, subsequently decreasing in this latter trial at a rate similar to that in the control trial. The large increase in noradrenaline (norepinephrine) (p = 0.005) and lactate levels (p = 0.0005) may have contributed to the early post-exercise stabilisation of glycaemia in the sprint trial. During recovery, adrenaline (epinephrine) and NEFA levels increased marginally in the sprint trial, but other counter-regulatory hormones did not change significantly (p < 0.05).

CONCLUSIONS/INTERPRETATION

A 10-s sprint performed immediately prior to moderate-intensity exercise prevents glycaemia from falling during early recovery from moderate-intensity exercise in individuals with type 1 diabetes.

Perinatal risk factors for childhood Type 1 diabetes in Western Australia--a population-based study (1980-2002)

AIMS

To investigate perinatal risk factors for childhood Type 1 diabetes in Western Australia, using a complete population-based cohort.

METHODS

Children born between 1980 and 2002 and diagnosed with Type 1 diabetes aged < 15 years (n = 940) up to 31 December 2003 were identified using a prospective population-based diabetes register with a case ascertainment rate of 99.8%. Perinatal data were obtained for all live births in Western Australia from 1980 to 2002 (n = 558 633) and record linkage performed to identify the records of cases.

RESULTS

The incidence of Type 1 diabetes increased by 13% for each 5-year increase in maternal age [adjusted incidence rate ratio (IRR) 1.13, 95% confidence interval (CI) 1.05, 1.21], by 13% for every 500-g increase in birth weight (adjusted IRR 1.13, 95% CI 1.04, 1.23). The incidence decreased with increasing birth order (adjusted IRR 0.89, 95% CI 0.82, 0.96) and increasing gestational age (adjusted IRR 0.84, 95% CI 0.77, 0.93). A higher incidence of Type 1 diabetes was associated with an urban vs. non-urban maternal address at the time of birth (adjusted IRR 1.38, 95% CI 1.18, 1.63), but no association was found with socio-economic status of the area.

CONCLUSIONS

A higher incidence of Type 1 diabetes was associated with increasing maternal age, higher birth weight, lower gestational age, lower birth order and urban place of residence at the time of birth.

The relationship between ACE genotype and risk of severe hypoglycaemia in a large population-based cohort of children and adolescents with type 1 diabetes

AIMS/HYPOTHESIS

Genetic factors may account for familial clustering related to diabetes complications. Studies have shown a significant relationship between the presence of the deletion (D) allele of the gene encoding ACE and risk of severe hypoglycaemia. This large prospective cohort study assesses this relationship in a large sample of children and adolescents with type 1 diabetes.

SUBJECTS AND METHODS

We studied 585 children and adolescents (mean age 11.9 +/- 4 years, 48.4% males). The frequency of severe hypoglycaemia (an event leading to loss of consciousness or seizure) was prospectively assessed over the 13-year period 1992-2004. Patients were seen with their parents every 3 months and data recorded at each visit. The ACE gene was detected using PCR.

RESULTS

In our cohort of 585 children, 186 (31.8%) had at least one episode of severe hypoglycaemia, and of these 28.0% had the II genotype, 48.9% had the ID genotype and 23.1% had the DD genotype. This was in agreement with the Hardy-Weinberg proportion. A total of 477 severe hypoglycaemic episodes was recorded with a total of 3,404 person-years of follow-up, giving a total incidence of 14 per 100 patient-years. No significant increase in risk for DD genotype (incidence rate ratio = 0.97, 95% CI 0.61-1.55) relative to II genotype was observed.

CONCLUSIONS/INTERPRETATION

This large prospective study concludes that the presence of the D allele of the ACE gene does not predict a significantly higher risk of severe hypoglycaemia in type 1 diabetic children and adolescents.

Effect of intermittent high-intensity compared with continuous moderate exercise on glucose production and utilization in individuals with type 1 diabetes

Previously, the decline in glycemia in individuals with type 1 diabetes has been shown to be less with intermittent high-intensity exercise (IHE) compared with continuous moderate-intensity exercise (MOD) despite the performance of a greater amount of total work. The purpose of the present study was to determine whether this lesser decline in glycemia can be attributed to a greater increment in endogenous glucose production (Ra) or attenuated glucose utilization (Rd). Nine individuals with type 1 diabetes were tested on two separate occasions, during which either a 30-min MOD or IHE protocol was performed under conditions of a euglycemic clamp in combination with the infusion of [6,6-(2)H]glucose. MOD consisted of continuous cycling at 40% VO2 peak, whereas IHE involved a combination of continuous exercise at 40% VO2 peak interspersed with additional 4-s maximal sprint efforts performed every 2 min to simulate the activity patterns of intermittent sports. During IHE, glucose Ra increased earlier and to a greater extent compared with MOD. Similarly, glucose Rd increased sooner during IHE, but the increase by the end of exercise was comparable with that elicited by MOD. During early recovery from IHE, Rd rapidly declined, whereas it remained elevated after MOD, a finding consistent with a lower glucose infusion rate during early recovery from IHE compared with MOD (P<0.05). The results suggest that the lesser decline in glycemia with IHE may be attributed to a greater increment in Ra during exercise and attenuated Rd during exercise and early recovery.

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.

METHODS

Longitudinal data from the Oxford Regional Prospective Study of Childhood Diabetes (ORPS; n = 554, median duration of follow-up 10 years; range 3.0-16.7) with assessment of albumin/creatinine ratios in three early morning urine samples collected annually. An albumin excretion phenotype was derived from longitudinal data, for each individual, defining deviation from the mean of regression models, including covariates gender, age, duration of diabetes and age at assessment. Tracking of the phenotypes was confirmed in a second independent cohort from Perth, Australia.

RESULTS

The albumin excretion phenotype showed reasonable correlation between age 11-15 years and age 16-18 years in both cohorts, indicative of good 'tracking'. In the ORPS cohort, tertiles of the albumin excretion phenotype at aged 11-15 years were predictive of subsequent risk for the development of MA. All of the subjects developing clinical proteinuria had an albumin excretion phenotype in the upper tertile or an HbA(1c) > 9% at aged 11-15 years.

CONCLUSIONS

Identification of adolescents at risk of diabetic nephropathy using an albumin excretion phenotype is feasible. When combined with elevated HbA(1c), it may identify subjects for trial of early intervention with angiotensin-converting enzyme inhibitors/angiotensin-II receptor antagonists and statins to improve long-term prognosis in these subjects where sustained improvement in glycaemic control may be difficult to achieve.

Early changes in 24-hour ambulatory blood pressure are associated with high normal albumin excretion rate in children with type 1 diabetes mellitus

OBJECTIVE

The relationship between urinary albumin excretion rate (AER) and elevated blood pressure (BP) is unclear as a cause-effect phenomenon in the development of diabetic nephropathy. The aim of this study was to examine the association between AER, HbA1c and BP in children with normoalbuminuria.

METHODS

24-hour ambulatory BP assessment was performed in 78 children with type 1 diabetes mellitus (DM1), age mean +/- SD 13.4 +/- 2.7 yr, range 7.3-18.3 yr, DM1 duration mean +/- SD 6.6 +/- 2.9 yr, range 2.1-11.9 yr. Using generalised linear mixed models with systolic (SBP) and diastolic (DBP) blood pressure as dependent variables, the effects of AER and HbA1c were examined, adjusting for age, gender, DM1 duration and insulin dose.

RESULTS

Patients with high normal AER (7-20 microg/min) had higher SBP during daytime and night-time compared to the low normal AER (< or = 7 microg/min) (mean +/- SD 118.20 +/- 7.98 and 110.33 +/- 7.08 mm Hg, p = 0.02; mean +/- SD 108.76 +/- 9.21 and 100.20 +/- 7.75 mm Hg, p = 0.03, respectively). DBP was also higher both during day- and night-time when compared to the < or = 7 microg/min group (mean +/- SD 73.40 +/- 6.50 and 64.86 +/- 5.67 mm Hg, p = 0.002; mean +/- SD 62.50 +/- 6.75 and 56.30 +/- 5.56 mm Hg, p = 0.03 day- and night-time, respectively).

CONCLUSION

A rise in SBP and DBP is associated with increased levels of AER even within the normal range.

Insulin pump therapy in children and adolescents: improvements in key parameters of diabetes management including quality of life

AIMS

To determine the impact of insulin pump therapy (continuous subcutaneous insulin infusion) on key parameters of diabetes management including quality of life in children and adolescents with Type 1 diabetes mellitus (T1DM).

METHODS

All patients started on insulin pump therapy were prospectively followed before and after institution of insulin pump therapy. Data collected included age, duration of diabetes, glycated haemoglobin levels (HbA1c), anthropometric data and episodes of severe hypoglycaemia defined as hypoglycaemia resulting in coma or convulsion. A subset of patients also completed the Diabetes Quality of Life Instrument (DQOL) and Self-Efficacy for Diabetes Scale (SED) questionnaires to assess quality of life.

RESULTS

At the time of analysis, 100 patients had been managed with insulin pump therapy. The mean age when starting pump therapy was 12.5 (3.9-19.6) years. Duration of therapy ranged from 0.2 to 4.0 years (mean 1.4 years, median 1.5 years). HbA1c decreased from 8.3 +/- 0.1% prior to pump therapy to 7.8 +/- 0.1% (P < 0.0001). Episodes of severe hypoglycaemia decreased from 32.9 to 11.4 per 100 patient years. Components of quality of life measures showed improvement on pump treatment. BMI standard deviation scores (z scores) did not increase.

CONCLUSIONS

Pump therapy is proving an effective means of insulin therapy in the young patient that shows promise to improve glycaemic control with a reduction in hypoglycaemia frequency. Quality of Life measures suggest that psychosocial outcomes may be improved.

Evaluation of isometamidium levels in the serum of sheep and goats after prophylactic treatment against trypanosomosis

Isometamidium chloride has been used for the control of trypanosomosis in animals for over 36 years, but recently there have been reports of prophylaxis failure under natural conditions. In this study, use of the drug for prophylactic purpose against trypanosomosis in small ruminants was investigated. Forty-two sheep and 44 goats were divided into four treatment groups. Groups 1 and 2 were treated with isometamidium chloride (Samorin, Rhone Merieux, Lyon, France) at 3-month intervals while groups 3 and 4 were used as controls. All the animals were exposed to natural tsetse challenge and monitored for serum isometamidium levels and anti-trypanosome antibodies. Seven days after drug administration, isometamidium levels were significantly higher in goats 13.7+/-0.07 ng/ml than in sheep 6.2+/-0.06 ng/ml. However, the elimination half-life in the sheep was 14.2+/-0.92 days and was significantly higher (P> 0.05) than that of the goats 12+/-0.5 days. This study established that isometamidium metabolism differs between sheep and goats and this difference may have important implications in high tsetse challenge areas.

Evaluating risk factors associated with severe hypoglycaemia in epidemiology studies-what method should we use?

AIMS

To determine the most appropriate regression models to use when assessing risk factors for severe hypoglycaemia and to investigate the impact of model misspecification and its clinical implications.

METHODS

A total of 1229 children with Type 1 diabetes (mean age 11.7 years sd 4.1), of which 605 (49.2%) were males, were studied. Prospective assessment of severe hypoglycaemia (an event leading to loss of consciousness or seizure) was made over the 9-year period, 1992-2001. Patients were seen every 3 months and episodes of hypoglycaemia along with clinical data were recorded. Over 70% of children never experienced a severe hypoglycaemic event. Data were analysed using the Poisson regression, negative binomial, zero-inflated Poisson (ZIP) and zero-inflated negative binomial (ZINB) models. The over-dispersion and likelihood ratio statistics were calculated and the analytical methods compared.

RESULTS

The Poisson regression model did not fit the data well. The negative binomial and the zero inflated Poisson and negative binomial models fitted the data better than Poisson.

CONCLUSIONS

The commonly used Poisson regression models to analyse hypoglycaemia epidemiology may lead to biased parameter estimates and incorrect determination of risk factors for hypoglycaemia. We recommend the use of the negative binomial or zero inflated models to examine any risk factors associated with severe hypoglycaemia. Careful consideration must be given to the interpretation of hypoglycaemia surveys and their analysis.

Continued increase in the incidence of childhood Type 1 diabetes in a population-based Australian sample (1985-2002)

AIMS/HYPOTHESIS

Our aim was to determine the incidence of Type 1 diabetes in children who were 0 to 14 years of age in Western Australia from 1985 to 2002, and to analyse the trends in incidence rate over the same period.

METHODS

Primary case ascertainment was from a prospective population-based diabetes register that was established in 1987, and secondary case ascertainment was from the Western Australia Hospital Morbidity Data System. Denominator data were obtained from the Australian Bureau of Statistics. Poisson regression was used to analyse the incidence rates by calendar year, sex and age at diagnosis.

RESULTS

There was a total of 1144 cases (560 boys, 584 girls). Using the capture-recapture method, case ascertainment was estimated to be 99.8% complete. The mean age standardised incidence from 1985 to 2002 was 16.5 per 100,000 person years (95% CI 14.7-18.2), ranging from 11.3 per 100,000 in 1985 to 23.2 per 100,000 in 2002. The incidence increased on average by 3.1% (95% CI 1.9%-4.2%) a year over the period ( p<0.001). No significant difference was found between boys and girls. A significant increase in incidence was found in all age groups, with no disproportionate increase found in the 0 to 4-year-olds.

CONCLUSIONS/INTERPRETATION

The incidence of childhood-onset Type 1 diabetes in Western Australia has increased significantly over the past 18 years and shows no signs of abating. In contrast to other studies, a higher rate of increase was not found in the youngest children.

Subcutaneous glucose sensor values closely parallel blood glucose during insulin-induced hypoglycaemia

AIMS

To assess the accuracy of the Minimed continuous glucose monitoring system (CGMS) in estimating blood glucose concentration during a controlled reduction in blood glucose.

RESEARCH DESIGN AND METHODS

We studied nine adolescent diabetics (age 14 +/- 1.5 years) wearing the CGMS during hyperinsulinaemic hypoglycaemic clamp studies. The glucose values obtained by the CGMS were compared with the venous blood samples taken during the studies and measured at the bedside using a glucose oxidase technique.

RESULTS

Blood glucose was lowered from euglycaemia to a mean of 2.8 mmol/l over 120 min and maintained at that level for a further 40 min. A total of 429 paired glucose measurements were available for analysis. Analysis using weighted Deming regression and t-tests revealed small differences between the methods, with blood glucose levels slightly higher than interstitial fluid levels. The mean difference across all values was 0.13 mmol/l. The observed difference was greatest at blood glucose values < 3.3 mmol/l.

CONCLUSIONS

This study suggests that during a fall in systemic glucose the subcutaneous glucose sensor provides an accurate reflection of blood glucose. However, a small difference is apparent at blood glucose values < 3.3 mmol/l.

Larger numbers of CD4(bright) dendritic cells in donor bone marrow are associated with increased relapse after allogeneic bone marrow transplantation

Relapse is the major cause of death after allogeneic bone marrow transplantation (BMT). This study tested the hypothesis that the numbers of donor mononuclear cells, lymphocytes, and CD34(+) cells influence relapse and event-free survival (EFS) after BMT. The study population consisted of 113 consecutive patients with hematologic malignancies who underwent non-T-cell-depleted BMT from HLA-matched siblings. Sixty-four patients had low-risk diagnoses (ALL/AML CR1, MDS RA/RARS, and CML CP1); 49 patients had high-risk diagnoses (all others). CD34(+) cells, T cells, B cells, natural killer cells, monocytes, and a rare population of CD3(-), CD4(bright) cells in the allografts were measured by flow cytometry. The CD3(-), CD4(bright) cells in bone marrow had the same frequency and phenotype as CD123(bright) type 2 dendritic cell (DC) progenitors, and they differentiated into typical DCs after short-term culture. Cox regression analyses evaluated risk strata, age, gender, and the numbers of nucleated cells, CD3(+) T cells, CD34(+) hematopoietic cells, and CD4(bright) cells as covariates for EFS, relapse, and nonrelapse mortality. Recipients of larger numbers of CD4(bright) cells had significantly lower EFS, a lower incidence of chronic graft-versus-host disease (cGVHD), and an increased incidence of relapse. Recipients of larger numbers of CD34(+) cells had improved EFS; recipients of fewer CD34(+) cells had delayed hematopoietic engraftment and increased death from infections. In conclusion, the content of donor CD4(bright) cells was associated with decreased cGVHD and graft-versus-leukemia effects in recipients of allogeneic bone marrow transplantation, consistent with a role for donor DCs in determining immune responses after allogeneic BMT.

Trypanosoma vivax--out of Africa

Trypanosoma vivax is a blood parasite of ruminants that was introduced into Latin America in cattle imported from Africa, possibly in the late 19th century. The parasite has now spread to ten of the 13 countries of the South American continent, often resulting in a severe wasting disease and death. Here, we review the current state of knowledge about this parasite and the problems faced by animal health agencies in controlling the disease.

The expression of inherited hydrocephalus in H-Tx rats

OBJECTIVES

H-Tx rats develop severe hydrocephalus in late gestation. The breeding colony maintained at the University of Florida stems from one pair obtained in 1992. The aims of this study were to characterize the expression of hydrocephalus in the H-Tx rat colony, to perform within-strain and between-strain DNA analysis and to examine hydrocephalus expression in specific breeding experiments.

METHODS AND OBSERVATIONS

Matings between normal rats produce hydrocephalic offspring almost without exception, and the overall frequency is stable between generations at 40%. However, frequency varies with parity, being only 27% in the first litters, and it also varies with sex, there being an excess of male hydrocephalics. Mating between shunt-treated hydrocephalic rats did not increase the frequency. DNA typing with microsatellite markers showed that there was some residual heterogeneity in the colony despite inbreeding for 22 generations, although it did not segregate with hydrocephalus. Test mating with two other inbred strains, F344 and LEW produced some affected pups in the LEW cross only. A backcross experiment between H-Tx and F344 produced 12.3% severely-affected pups and 5.4% pups with a mild form, indicating the presence of several susceptibility genes.

CONCLUSIONS

All animals in our H-Tx colony are homozygous for the hydrocephalus loci, but there is incomplete penetrance.

High dose chemotherapy without hematopoietic cell support for the treatment of refractory lymphoma

Conventional dose combination chemotherapy for patients with relapsed or refractory lymphoma is rarely curative. High dose chemotherapy followed by hematopoietic progenitor cell transplant (HPCT) has a clearly defined role in patients who have first relapsed after standard CHOP chemotherapy for lymphoma. However, the role of HPCT is less well defined for patients with chemo-resistant, or chemo-refractory disease. Sixteen patients (15 Non-Hodgkin's, 1 Hodgkin's Disease) were entered into a phase II study to determine if a dose intensive induction regimen in heavily pre-treated refractory lymphoma patients could permit further consolidation with HPCT. The primary endpoints were survival, response, toxicity, and resource utilization. The regimen consisted of continuous infusion etoposide 1 or 2 gm/m2/72 hours, idarubicin 12 mg/m2/d for 3 days followed by cytarabine 2 gm/m2/72 hours on days 8, 9, and 10 (VIC). Fifteen patients were evaluable for objective response. The overall response rate was 53% with 7 patients achieving a partial response and 1 patient achieving a complete response. Of the 8 responders, 6 patients subsequently received high dose chemotherapy followed by HPCT (4 autologous, 2 allogeneic). The median survival was 176 days for the non-responders contrasted with 722 days for the responders. The average duration of hospitalization was 38 days. Toxicity was mainfest primarily as mucositis with a median grade of 3 among the first 13 patients, and a median grade of 2 in three subsequent patients who received an etoposide dose of 1 gm/m2/72 hours. All patients had an episode of neutropenic fever and 5 patients developed clinically significant pneumonitis during therapy. The VIC regimen is active in the treatment of chemo-refractory lymphoma with clinically significant differences in survival for patients who respond to therapy. Further modifications to the regimen could include the addition of a topoisomerase I inhibitor for synergy with etoposide, and using VIC as part of a tandem transplant regimen where response to VIC would allow further therapy with a myeloablative induction followed by HPCT.

Enhanced Cloud Disruption by Magnetic Field Interaction

We present results from the first three-dimensional numerical simulations of moderately supersonic cloud motion through a tenuous, magnetized medium. We show that the interaction of the cloud with a magnetic field perpendicular to its motion has a great dynamical impact on the development of instabilities at the cloud surface. Even for initially spherical clouds, magnetic field lines become trapped in surface deformations and undergo stretching. The consequent field amplification that occurs there and, in particular, its variation across the cloud face then dramatically enhance the growth rate of Rayleigh-Taylor unstable modes, hastening the cloud disruption.

A simple procedure for the extraction of trypanosome DNA and host protein from dried blood meal residues of haematophagous diptera

A two step elution method is described for the extraction of host serum proteins and trypanosome DNA from a single dried insect gut smear preparation. The first low temperature elution yields material suitable for use in ELISA to determine the host species on which the fly last fed while the results of the second, high temperature, elution can be used in a PCR assay to detect the presence of trypansosomal DNA. The method can be used to extract material from both fly squashes and blood spots dried onto filter paper and could simplify the collection and processing of samples for epidemiological studies on trypanosomoses and other vector borne pathogens.

Changes in free insulin-like growth factor-1 and leptin concentrations during acute metabolic decompensation in insulin withdrawn patients with type 1 diabetes

To determine the effect of acute insulin withdrawal and its subsequent replacement on components of the insulin-like growth factor (IGF)-1 binding protein system and on circulating leptin levels in patients with type 1 diabetes. Seventeen patients (age 31 yr +/-10) with type 1 diabetes treated with continuous subcutaneous insulin infusion (HbA1c 7.6% +/-1.0) were studied. The protocol consisted of two phases: acute insulin withdrawal of up to 8 h followed by a further 2-h period of insulin replacement. For the first phase the basal insulin infusion was stopped (at 0300 h), and for the second a single dose of either regular human or insulin lispro was given subcutaneously (0.2 U/kg). Plasma insulin, glucose, growth hormone, glucagon, IGF-1, free IGF-1, IGFBP-1, -2, -3 and leptin were measured.

RESULTS

After interruption of the basal insulin infusion, plasma free insulin levels fell from 60+/-12.0 pmol/L to 10.8+/-4.2 pmol/L, and plasma glucose rose from 5.6+/-0.4 mmol/L to 14.8+/-1.2 mmol/L (P< 0.01). During insulin withdrawal, IGFBP-1 increased by more than 6-fold (from 32+/-8 to 205+/-17 ng/mL, P<0.001), IGFBP-3 increased significantly (from 2631+/-118 to 3053+/-101 ng/mL, P<0.001), and total IGF-1 levels declined modestly (from 226+/-33 to 182+/-26 ng/mL, P<0.001). In contrast, free IGF-1 concentrations (0.72+/-0.22 ng/mL at baseline) were markedly suppressed during insulin withdrawal to values below the detection limit of the assay (0.08 ng/mL) in 15 of the 17 patients (P<0.001). Circulating plasma leptin declined markedly in females from 20+/-3 ng/mL to 11+/-2 ng/mL (P<0.0001) and in males from 10+/-2 ng/mL to 7+/-2 ng/mL (P<0.02). Within 2 h of insulin replacement, the changes in circulating concentrations of IGFBP-1 and IGFBP-3 were partially reversed, and free IGF-1 levels rebounded to 0.54+/-0.22 ng/mL (P<0.1 vs. insulin withdrawal). Growth hormone, glucagon, and IGFBP-2 levels did not change significantly throughout the study. Despite the rapid restoration of plasma insulin and substrate levels, circulating leptin levels continued to fall in the 2-h period after insulin replacement in both females and males. The marked reduction in circulating free IGF-1 after insulin withdrawal and its increase after insulin administration suggest that acute changes in IGFBP concentrations induced by insulin are important regulators of IGF-1 bioavailability in patients with type 1 diabetes. In both males and females, the rapid induction of severe insulin deficiency is associated with a consistent fall in plasma leptin levels.

Genomic profiling of drug sensitivities via induced haploinsufficiency

Lowering the dosage of a single gene from two copies to one copy in diploid yeast results in a heterozygote that is sensitized to any drug that acts on the product of this gene. This haploinsufficient phenotype thereby identifies the gene product of the heterozygous locus as the likely drug target. We exploited this finding in a genomic approach to drug-target identification. Genome sequence information was used to generate molecularly tagged heterozygous yeast strains that were pooled, grown competitively in drug and analysed for drug sensitivity using high-density oligonucleotide arrays. Individual heterozygous strain analysis verified six known drug targets. Parallel analysis identified the known target and two hypersensitive loci in a mixed culture of 233 strains in the presence of the drug tunicamycin. Our discovery that both drug target and hypersensitive loci exhibit drug-induced haploinsufficiency may have important consequences in pharmacogenomics and variable drug toxicity observed in human populations.

Immunochemical analysis of quinol-thioether-derived covalent protein adducts in rodent species sensitive and resistant to quinol-thioether-mediated nephrotoxicity

2,3,5-Tris(glutathion-S-yl)hydroquinone (TGHQ) is nephrotoxic in male Fischer 344 rats (20 micromol/kg) and albino guinea pigs (200 micromol/kg), but not BALB/c or B6C3F1 mice or Golden Syrian hamsters (200 micromol/kg). Since quinones are known to alkylate proteins, and because such macromolecular damage may play a role in cytotoxicity, we investigated the covalent binding of TGHQ to kidney (target tissue) and liver (nontarget tissue) of rodents "sensitive" or "resistant" to the nephrotoxic effects of TGHQ. Immunohistochemical staining of tissue obtained 2 h after administration of TGHQ, with rabbit anti-2-bromo-N-(acetyl-L-cystein-S-yl)HQ antibodies, correlated with the subsequent region of necrosis observed 19 h after dosing in Fischer 344 rats and guinea pigs. Immunohistochemical staining was localized to the S3 segment of the renal proximal tubules, at the corticomedullary junction along the medullary rays, and in the outer stripe of the outer medulla. Immunostaining was also observed in the same region in hamsters, but subsequent necrosis did not develop. In contrast, no immunostaining was observed in mice. Moreover, immunostaining was not detected in the livers of any species. Western blot analysis revealed numerous immunoreactive renal proteins in TGHQ-treated animals. The most distinctive immunostaining renal proteins were observed in Fischer 344 rats at approximately 34 kDa (mitochondria), approximately 35 kDa (nuclei) which comigrated with histone H1, and approximately 73 kDa (urine) which comigrated with gamma-glutamyl transpeptidase. These adducted proteins were not detected in other species. Qualitative differences in alkylated proteins may therefore contribute to species susceptibility to TGHQ.

Decreased epinephrine responses to hypoglycemia during sleep

BACKGROUND

In patients with type I diabetes mellitus, hypoglycemia occurs commonly during sleep and is frequently asymptomatic. This raises the question of whether sleep is associated with reduced counterregulatory-hormone responses to hypoglycemia.

METHODS

We studied the counterregulatory-hormone responses to insulin-induced hypoglycemia in eight adolescent patients with type I diabetes and six age-matched normal subjects when they were awake during the day, asleep at night, and awake at night. In each study, the plasma glucose concentration was stabilized for 60 minutes at approximately 100 mg per deciliter (5.6 mmol per liter) and then reduced to 50 mg per deciliter (2.8 mmol per liter) and maintained at that concentration for 40 minutes. Plasma free insulin, epinephrine, norepinephrine, cortisol, and growth hormone were measured frequently during each study. Sleep was monitored by polysomnography.

RESULTS

The plasma glucose and free insulin concentrations were similar in both groups during all studies. During the studies when the subjects were asleep, no one was awakened during the hypoglycemic phase, but during the final 30 minutes of the studies when the subjects were awake both the patients with diabetes and the normal subjects had symptoms of hypoglycemia. In the patients with diabetes, plasma epinephrine responses to hypoglycemia were blunted when they were asleep (mean [+/-SE] peak plasma epinephrine concentration, 70+/-14 pg per milliliter [382+/-76 pmol per liter]; P=0.3 for the comparison with base line), as compared with when they were awake during the day or night (238+/-39 pg per milliliter [1299+/-213 pmol per liter] P=0.004 for the comparison with base line, and 296+/-60 pg per milliliter [1616+/-327 pmol per liter], P=0.004, respectively). The patients' plasma norepinephrine responses were also reduced during sleep, whereas their plasma cortisol concentrations did not increase and their plasma growth hormone concentrations increased slightly. The patterns of counterregulatory-hormone responses in the normal subjects were similar.

CONCLUSIONS

Sleep impairs counterregulatory-hormone responses to hypoglycemia in patients with diabetes and normal subjects.

Comparison of human regular and lispro insulins after interruption of continuous subcutaneous insulin infusion and in the treatment of acutely decompensated IDDM

OBJECTIVE

To compare the rapidity of metabolic decompensation after interruption of CSII between human regular and lispro insulin and to compare these two insulins in the correction of the hyperglycemia and ketosis of mildly decompensated IDDM. Lispro insulin may be especially useful for insulin pump therapy (continuous subcutaneous insulin infusion [CSII]).

RESEARCH DESIGN AND METHODS

A total of 18 patients with well-controlled IDDM (HbA1c 7.7 +/- 1.1%, age 30 +/- 11 years) were studied. All were being treated with CSII (nine with human regular and nine with lispro insulin). The study consisted of two phases: 1) an insulin interruption phase, in which the basal insulin infusion was stopped (at 0300) and plasma insulin, glucose, and beta-O-hydroxybutyrate (beta-OHB) were measured every 15-60 min for 6 h after interruption of the insulin infusion and 2) an insulin replacement phase, which involved measuring plasma insulin, glucose, and beta-OHB for 2 h after a single injection of either human regular or lispro insulin to correct the hyperglycemia and ketosis that developed during the first phase of the study.

RESULTS

After interruption of the basal insulin infusion during the insulin interruption phase, plasma insulin levels fell gradually in both groups to nadir values of 1.6 +/- 0.8 and 2.0 +/- 1.2 microU/ml in the regular insulin- and insulin lispro-treated groups, respectively. Plasma glucose concentrations rose to 13.8 +/- 1.9 and 16.0 +/- 1.7 mmol/l in the regular insulin- and insulin lispro-treated groups, respectively. No significant differences were seen between the therapy groups at any time in the insulin levels or in the concentrations of plasma glucose or beta-OHB. In the insulin replacement phase, insulin levels rose more rapidly in those treated with lispro insulin, reaching a greater peak value (e.g., at 60 min, plasma insulin 25 +/- 3.4 vs. 15.6 +/- 2.6 microU/ml, P < 0.05). In association with this, plasma glucose decreased to a lower nadir after lispro insulin (9.7 +/- 0.4 vs. 13.7 +/- 0.7 mmol/l, lispro- vs. regular-treated groups at 120 min after insulin administration, P < 0.01). beta-OHB levels decreased rapidly in both groups.

CONCLUSIONS

In patients treated with CSII, interruption of the basal insulin infusion in the middle of the night does not result in more rapid metabolic decompensation in patients treated with lispro compared with those treated with regular human insulin. Lispro insulin is effective in treating mild ketosis and hyperglycemia, and its rapid action may be advantageous in the "sick day" management at home of patients with IDDM.