Henrik B. Mortensen

Insulin management and metabolic control of Type 1 diabetes mellitus in childhood and adolescence in 18 countries

Insulin regimens and metabolic control in children and adolescents with Type 1 diabetes mellitus were evaluated in a cross‐sectional, non‐population‐based investigation, involving 22 paediatric departments, from 18 countries in Europe, Japan, and North America. Blood samples and information were collected from 2873 children from March to August 1995. HbA1c was determined once and analysed centrally (normal range 4.4–6.3 %, mean 5.4 %). Year of birth, sex, duration of diabetes, height, body weight, number of daily insulin injections, types and doses of insulin were recorded. Average HbA1c in children under 11 years was 8.3 ± 1.3 % (mean ± SD) compared with 8.9 ± 1.8 % in those aged 12–18 years. The average insulin dose per kg body weight was almost constant (0.65 U kg−124 h−1) in children aged 2–9 years for both sexes, but there was a sharp increase during the pubertal years, particularly in girls. The increase in BMI of children with diabetes was much faster during adolescence compared to healthy children, especially in females. Sixty per cent of the children (n = 1707) used two daily insulin injections while 37 % (n = 1071) used three or more. Of those on two or three injections daily, 37 % used pre‐mixed insulins, either alone or in combination with short‐ and intermediate‐acting insulin. Pre‐adolescent children on pre‐mixed insulin showed similar HbA1c levels to those on a combination of short‐ and long‐acting insulins, whereas in adolescents significantly better HbA1c values were achieved with individual combinations. Very young children were treated with a higher proportion of long‐acting insulin. Among adolescent boys, lower HbA1c was related to use of more short‐acting insulin. This association was not found in girls. We conclude that numerous insulin injection regimens are currently used in paediatric diabetes centres around the world, with an increasing tendency towards intensive diabetes management, particularly in older adolescents. Nevertheless, the goal of near normoglycaemia is achieved in only a few.

Continuing Stability of Center Differences in Pediatric Diabetes Care: do advances in diabetes treatment improve outcome? The Hvidoere Study Group on Childhood Diabetes

OBJECTIVE—To reevaluate the persistence and stability of previously observed differences between pediatric diabetes centers and to investigate the influence of demography, language communication problems, and changes in insulin regimens on metabolic outcome, hypoglycemia, and ketoacidosis. RESEARCH DESIGN AND METHODS—This was an observational cross-sectional international study in 21 centers, with clinical data obtained from all participants and A1C levels assayed in one central laboratory. All individuals with diabetes aged 11–18 years (49.4% female), with duration of diabetes of at least 1 year, were invited to participate. Fourteen of the centers participated in previous Hvidoere Studies, allowing direct comparison of glycemic control across centers between 1998 and 2005. RESULTS—Mean A1C was 8.2 ± 1.4%, with substantial variation between centers (mean A1C range 7.4–9.2%; P < 0.001). There were no significant differences between centers in rates of severe hypoglycemia or diabetic ketoacidosis. Language difficulties had a significant negative impact on metabolic outcome (A1C 8.5 ± 2.0% vs. 8.2 ± 1.4% for those with language difficulties vs. those without, respectively; P < 0.05). After adjustement for significant confounders of age, sex, duration of diabetes, insulin regimen, insulin dose, BMI, and language difficulties, the center differences persisted, and the effect size for center was not reduced. Relative center ranking since 1998 has remained stable, with no significant change in A1C. CONCLUSIONS—Despite many changes in diabetes management, major differences in metabolic outcome between 21 international pediatric diabetes centers persist. Different application between centers in the implementation of insulin treatment appears to be of more importance and needs further exploration.

Circulating Levels of MicroRNA from Children with Newly Diagnosed Type 1 Diabetes and Healthy Controls: Evidence That miR-25 Associates to Residual Beta-Cell Function and Glycaemic Control during Disease Progression

This study aims to identify key miRNAs in circulation, which predict ongoing beta-cell destruction and regeneration in children with newly diagnosed Type 1 Diabetes (T1D). We compared expression level of sera miRNAs from new onset T1D children and age-matched healthy controls and related the miRNAs expression levels to beta-cell function and glycaemic control. Global miRNA sequencing analyses were performed on sera pools from two T1D cohorts (n = 275 and 129, resp.) and one control group (n = 151). We identified twelve upregulated human miRNAs in T1D patients (miR-152, miR-30a-5p, miR-181a, miR-24, miR-148a, miR-210, miR-27a, miR-29a, miR-26a, miR-27b, miR-25, miR-200a); several of these miRNAs were linked to apoptosis and beta-cell networks. Furthermore, we identified miR-25 as negatively associated with residual beta-cell function (est.: −0.12, P = 0.0037), and positively associated with glycaemic control (HbA1c) (est.: 0.11, P = 0.0035) 3 months after onset. In conclusion this study demonstrates that miR-25 might be a “tissue-specific” miRNA for glycaemic control 3 months after diagnosis in new onset T1D children and therefore supports the role of circulating miRNAs as predictive biomarkers for tissue physiopathology and potential intervention targets.

Insulin injection regimens and metabolic control in an international survey of adolescents with type 1 diabetes over 3 years: Results from the Hvidore study group

Abstract. The optimal insulin regimen for paediatric patients with type 1 diabetes remains controversial. Therefore this multicentre study was performed in adolescents over a 3-year period to assess metabolic control, severe hypoglycaemia, and weight gain in relation to insulin injection regimens. Out of 2873 children and adolescents in an international survey in 1995, 872 adolescents (433 boys, 439 girls, mean age in 1995 11.3±2.2 years) were restudied in 1998, relating insulin regimens to HbA1c measured in a central laboratory. In addition, the daily dose of insulin, changes in body mass index (BMI), and events of severe hypoglycaemia were evaluated. Over 3 years, the use of multiple injection regimens increased from 42% to 71%: 251 patients remained on twice daily insulin, 365 remained on multiple injections and 256 shifted from twice daily insulin to multiple injections. In all three subgroups an increase in insulin dose, a deterioration of metabolic control, and an increase in BMI were observed. Metabolic control deteriorated less than expected over 3 years during adolescence (HbA1c 1995: 8.7±1.6%; 1998 observed: 8.9±1.6%, HbA1c expected for 1998: 9.0%). BMI increased more than expected, the increase was greatest in patients switching from twice daily to multiple injections, and higher in females compared to males. Conclusion: in this international study, metabolic control was unsatisfactory in many adolescents with type 1 diabetes irrespective of the insulin regimen. No improvement in metabolic control was observed in this cross-sectional survey, over 3 years in any of the subgroups. Even the group switching from twice to multiple injections did not improve blood glucose control and the increase in body mass index was most pronounced in this group. Conclusive evidence, however, should be based on prospectively planned, randomised therapeutic trials in paediatric patients.

Carbohydrate and lipid metabolism of skeletal muscle in type 2 diabetic patients

Peripheral hyperinsulinaemia is the cause of metabolic changes that might contribute to the high incidence of macrovascular disease in patients with diabetes mellitus. In order to test this hypothesis muscle biopsies from 12 Type 2 diabetic patients and 14 age and sex matched non‐diabetic patients, undergoing minor surgery, were obtained. The diabetic patients had significantly elevated fasting serum insulin (0.29±0.05 vs 0.6±0.03 nmol‐l) and glucose (8.3±1.5 vs 4.6±0.5 mmol‐l) and HbA1, levels (8.4±0.4 vs 5.0±0.2 per cent). The fasting and 2‐h postprandial C‐peptide levels were 0.99±0.25 vs 0.39±0.12 and 3.12±0.75 vs 1.09±0.34 nmol/l, respectively. The diabetic patients showed a marked elevation of triglyceride in the striated muscle biopsies compared to the non‐diabetic controls (290±52 vs 48±6 μmol/g wet weight, p<0.001). Moreover, the activities of glucose‐6‐phosphate dehydrogenase (0,25±0.03 vs 0.13±0.01 U/g wet weight) and malic enzyme (0.15±0.01 vs 0.05±0.01 U/g wet weight), necessary for lipid synthesis, were significantly increased (both p<0.001) in the diabetic patients while the glycolytic enzymes, hexokinase (0.65±0.09 vs 1.82±0.11 U/g wet weight), pyruvate kinase (7.3±0.9 vs 13.2±0.9 U/g wet weight), phosphofructokinase (1.3±0.2 vs 2.6±0.2 U/g wet weight), and α‐glycerophosphate dehydrogenase (7.3±0.5 vs 12.5±0.7 U/g wet weight) were decreased (all p<0.001). These data indicate substantial enhancement of lipid synthesis and decreased activity of glucose metabolism in skeletal muscles of peripherally hyperinsulinaemic diabetic patients.

New definition for the partial remission period in children and adolescents with type 1 diabetes

OBJECTIVE To find a simple definition of partial remission in type 1 diabetes that reflects both residual β-cell function and efficacy of insulin treatment. RESEARCH DESIGN AND METHODS A total of 275 patients aged <16 years were followed from onset of type 1 diabetes. After 1, 6, and 12 months, stimulated C-peptide during a challenge was used as a measure of residual β-cell function. RESULTS By multiple regression analysis, a negative association between stimulated C-peptide and A1C (regression coefficient −0.21, P < 0.001) and insulin dose (−0.94, P < 0.001) was shown. These results suggested the definition of an insulin dose–adjusted A1C (IDAA1C) as A1C (percent) + [4 × insulin dose (units per kilogram per 24 h)]. A calculated IDAA1C ≤9 corresponding to a predicted stimulated C-peptide >300 pmol/l was used to define partial remission. The IDAA1C ≤9 had a significantly higher agreement (P < 0.001) with residual β-cell function than use of a definition of A1C ≤7.5%. Between 6 and 12 months after diagnosis, for IDAA1C ≤9 only 1 patient entered partial remission and 61 patients ended partial remission, for A1C ≤7.5% 15 patients entered partial remission and 53 ended, for a definition of insulin dose ≤0.5 units · kg−1 · 24 h−1 5 patients entered partial remission and 66 ended, and for stimulated C-peptide (>300 pmol/l) 9 patients entered partial remission and 49 ended. IDAA1C at 6 months has good predictive power for stimulated C-peptide concentrations after both 6 and 12 months. CONCLUSIONS A new definition of partial remission is proposed, including both glycemic control and insulin dose. It reflects residual β-cell function and has better stability compared with the conventional definitions.

The significance of the prepubertal diabetes duration for the development of retinopathy and nephropathy in patients with type 1 diabetes

OBJECTIVE A Danish nationwide prospective cohort of children and adolescents with type 1 diabetes was followed for 8 years to study the effect of the prepubertal duration of diabetes on early retinopathy and elevated albumin excretion rate (AER) (>20 microg/min). RESEARCH DESIGN AND METHODS In 1989, blood glucose control (HbA(1c)) and AER was investigated in approximately 80% of all Danish children and adolescents with type 1 diabetes. A cohort of 339 young patients were restudied in 1995 including physical examination, demographic data, HbA(1c), AER, and fundus photography with central reading. Among the patients, a number of 304 had a prepubertal onset of diabetes defined as an onset age less than 11.7 years in girls and 12.9 years in boys. Microalbuminuria was defined as an AER of 20-150 microg min(-1) and macroalbuminuria as AER >150 microg min(-1) in two out of three timed overnight urine samples. RESULTS At the follow-up in 1995-1996, no patients were younger than 12 years of age. The prevalence of any level of retinopathy was 17.7% in the age group 12-15 years, 45.4% from 16 to 20 years, and increased to 67.6% in patients more than 20 years of age. Diabetic retinopathy was significantly associated to poor long-term metabolic control (HbA(1c)) (P<.0001) and to diabetes duration both in patients with a prepubertal onset of disease as well as patients with a pubertal (P<.001) onset of disease. However, the pubertal diabetes duration contributed two times more than the prepubertal diabetes duration. Mean postpubertal diabetes duration to any retinopathy was significantly shorter (9.4 years) in patients with prepubertal onset of the disease compared to patients with postpubertal onset (11.8 years) (P=.0004). In total, the prevalence of elevated AER (>20 microg/min) increased from 4% in 1989 to 13% in 1995. None of the patients younger than 15 years of age had elevated AER, while the prevalence of elevated AER was about 14% from 15 years of age and onwards. Elevated AER in 1995 was significantly related to long-term metabolic control (P<.001) and elevated AER in the preceding years (P<.001) but was not correlated to diabetes duration neither before nor after the age of 12 years. CONCLUSION The prepubertal diabetes duration is significantly associated with the development of diabetic retinopathy. The period, however, contributes less compared to the years after puberty. In concert with other studies, we found no association between raised AER and diabetes duration. This may be explained by the fact that other factors are more significant and dilute the significance of diabetes duration. Nonetheless, it seems prudent to optimise blood glucose control irrespective of age.

A 6-year nationwide cohort study of glycaemic control in young people with Type 1 diabetes: Risk markers for the development of retinopathy, nephropathy and neuropathy

The study aimed to identify risk markers (present at the start of the study in 1989) for the occurrence and progression of microvascular complications 6 years later (in 1995) in a Danish nationwide cohort of children and adolescents with Type 1 diabetes (average age at entry 13.7 years). Probabilities for the development of elevated albumin excretion rate (AER), retinopathy, and increased vibration perception threshold (VPT) could then be estimated from a stepwise logistic regression model. A total of 339 patients (47% of the original cohort) were studied. Sex, age, diabetes duration, insulin regimen and dose, height, weight, HbA(1c), blood pressure, and AER were recorded. In addition, information on retinopathy, neuropathy (VPT), and anti-hypertensive treatment was obtained at the end of the study. HbA(1c) (normal range 4.3-5.8, mean 5.3%) and AER (upper normal limit <20 microg min(-1)) in two, timed overnight urine collections were analysed centrally. Eye examination was performed by two-field fundus photography. Determination of VPT was assessed by biothesiometry. Increased AER (> or =20 microg min(-1)) was found in 12.8% of the patients in 1995, and risk markers for this were increased AER and high HbA(1c), in 1989 (both p<0.001). Retinopathy was present in 57.8% of patients in 1995, for which the risk markers were long duration of diabetes (p<0.0001), age (p<0.01), and high HbA(1c) (p<0.0001) in 1989. Elevated VPT (>6.5 V) was found in 62.5% of patients in 1995, for which the risk markers were male sex (p<0.05), age (p<0.0001), and increased AER (p<0.05) in 1989. This study confirms that hyperglycaemia plays a major role for the development of microvascular complications in kidneys and eyes, and emphasises the need for optimal glycaemic control in children and adolescents with Type 1 diabetes.

Multinational study in children and adolescents with newly diagnosed type 1 diabetes: association of age, ketoacidosis, HLA status, and autoantibodies on residual beta-cell function and glycemic control 12 months after diagnosis

HB Mortensen, PGF Swift, RW Holl, P Hougaard, L Hansen, H Bjoerndalen, CE de Beaufort, M Knip. Multinational study in children and adolescents with newly diagnosed type 1 diabetes: association of age, ketoacidosis, HLA status, and autoantibodies on residual beta‐cell function and glycemic control 12 months after diagnosis.

Rapid appearance and onset of action of insulin aspart in paediatric subjects with type 1 diabetes

Abstract The pharmacokinetics of the novel, rapid-acting insulin aspart were compared with those of soluble human insulin following subcutaneous administration in nine children (aged 6–12 years) and nine adolescents (aged 13–17 years) with stable type 1 diabetes. The study had a randomised, double-blind, two-period crossover design. Each patient received a single subcutaneous dose of insulin aspart or human insulin (0.15 IU/kg body weight) 5 min before breakfast and the plasma insulin and glucose concentrations were measured at intervals during the following 5 h. The pharmacokinetic profile of insulin aspart differed significantly from that of human insulin with a higher mean maximum serum insulin (Cmax ins), 881 ± 321 (SD) pmol/l versus 422 ± 193 pmol/l for human insulin (P < 0.001); and with a shorter median serum insulin tmax ins, 40.0 min (interquartile range: 40–50 min) versus 75.0 min (interquartile range: 60–120 min) for human insulin, (P < 0.001). An age-related effect on Cmax ins and area under the curve (AUC0–5h ins) was observed with higher values in adolescents than in children for both insulin aspart and human insulin. Postprandial glycaemic control was improved with insulin aspart; the baseline-adjusted ΔCmax glu being lower for insulin aspart compared with human insulin (increase of 7.6 ± 5.1 versus 9.4 ± 4.4 mmol/l respectively, P < 0.05). The incidence of adverse events was similar for the two insulin types. Conclusion The more rapid onset of action of insulin aspart versus human insulin, previously observed in adults, is confirmed in a paediatric population with type 1 diabetes.