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Dive into the research topics where Jan Åman is active.

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Featured researches published by Jan Åman.


The New England Journal of Medicine | 2008

GAD Treatment and Insulin Secretion in Recent-Onset Type 1 Diabetes

Johnny Ludvigsson; Maria Faresjö; Maria Hjorth; Stina Axelsson; Mikael Chéramy; Mikael Pihl; Outi Vaarala; Gun Forsander; Sten Ivarsson; Calle Johansson; Agne Lindh; Nils-Östen Nilsson; Jan Åman; Eva Örtqvist; Peter Zerhouni; Rosaura Casas

BACKGROUND The 65-kD isoform of glutamic acid decarboxylase (GAD) is a major autoantigen in patients with type 1 diabetes mellitus. This trial assessed the ability of alum-formulated GAD (GAD-alum) to reverse recent-onset type 1 diabetes in patients 10 to 18 years of age. METHODS We randomly assigned 70 patients with type 1 diabetes who had fasting C-peptide levels above 0.1 nmol per liter (0.3 ng per milliliter) and GAD autoantibodies, recruited within 18 months after receiving the diagnosis of diabetes, to receive subcutaneous injections of 20 microg of GAD-alum (35 patients) or placebo (alum alone, 35 patients) on study days 1 and 30. At day 1 and months 3, 9, 15, 21, and 30, patients underwent a mixed-meal tolerance test to stimulate residual insulin secretion (measured as the C-peptide level). The effect of GAD-alum on the immune system was also studied. RESULTS Insulin secretion gradually decreased in both study groups. The study treatment had no significant effect on change in fasting C-peptide level after 15 months (the primary end point). Fasting C-peptide levels declined from baseline levels significantly less over 30 months in the GAD-alum group than in the placebo group (-0.21 vs. -0.27 nmol per liter [-0.62 vs. -0.81 ng per milliliter], P=0.045), as did stimulated secretion measured as the area under the curve (-0.72 vs. -1.02 nmol per liter per 2 hours [-2.20 vs. -3.08 ng per milliliter per 2 hours], P=0.04). No protective effect was seen in patients treated 6 months or more after receiving the diagnosis. Adverse events appeared to be mild and similar in frequency between the two groups. The GAD-alum treatment induced a GAD-specific immune response. CONCLUSIONS GAD-alum may contribute to the preservation of residual insulin secretion in patients with recent-onset type 1 diabetes, although it did not change the insulin requirement. (ClinicalTrials.gov number, NCT00435981.)


Gastroenterology | 1997

Physiological Hyperglycemia Slows Gastric Emptying in Normal Subjects and Patients With Insulin-Dependent Diabetes Mellitus

Erik Schvarcz; Mats Palmér; Jan Åman; Michael Horowitz; Mats Stridsberg; Christian Berne

BACKGROUND & AIMS Marked hyperglycemia slows and hypoglycemia accelerates gastric emptying. The aim of this study was to determine the effect of physiological changes in blood glucose gastric emptying. METHODS In 8 healthy subjects and 9 patients with insulin-dependent diabetes mellitus (IDDM) without gastrointestinal tract symptoms or evidence of neuropathy, gastric emptying of a mixed meal was measured by scintigraphy. Using an insulin-glucose clamp, the blood glucose concentration was stabilized at 4 and 8 mmol/L on 2 separate days. RESULTS The intragastric retention of the solid meal component at 100 minutes was 55.2% +/- 4.5% at 8 mmol/L vs. 36.7% +/- 5.5% at 4 mmol/L (P = 0.004) in normal subjects and 44.2% +/- 4.2% vs. 35.7% +/- 4.2% (P = 0.004) in patients with IDDM. The time taken for 50% emptying of the liquid meal was 57.0 +/- 10.8 minutes at 8 mmol/L vs. 32.2 +/- 12.6 minutes at 4 mmol/L (P = 0.002) in normal subjects and 41.3 +/- 3.4 minutes vs. 29.1 +/- 3.5 minutes (P = 0.002) in patients with IDDM. CONCLUSIONS Changes in blood glucose within the normal postprandial range have a significant impact on gastric emptying in both normal subjects and patients with IDDM.


Diabetic Medicine | 1998

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

Henrik B. Mortensen; Kenneth Robertson; Henk Jan Aanstoot; Thomas Danne; Reinhard W. Holl; Philip Hougaard; Joycelyn A. Atchison; Francesco Chiarelli; D. Daneman; Bo Dinesen; Harry Dorchy; Patrick Garandeau; Stephen Greene; Hilary Hoey; Eero A. Kaprio; Mirjana Kocova; Pedro Martul; Nobuo Matsuura; Eugen J. Schoenle; Oddmund Søvik; Peter Swift; Rosa Maria Tsou; Maurizio Vanelli; Jan Åman

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.


Diabetes Care | 2007

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

Carine De Beaufort; Peter Swift; Chas T. Skinner; Henk Jan Aanstoot; Jan Åman; Fergus J. Cameron; Pedro Martul; Francesco Chiarelli; D. Daneman; Thomas Danne; Harry Dorchy; Hilary Hoey; Eero A. Kaprio; Francine R. Kaufman; Mirjana Kocova; Henrik B. Mortensen; Pål R. Njølstad; Moshe Phillip; Kenneth Robertson; Eugen J. Schoenle; Tatsuhiko Urakami; Maurizio Vanelli

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.


European Journal of Pediatrics | 2003

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

Reinhard W. Holl; Peter Swift; Henrik B. Mortensen; Helle Lynggaard; Phillip Hougaard; Henk-Jan Aanstoot; Francesco Chiarelli; Denis Daneman; Thomas Danne; Harry Dorchy; Patrick Garandeau; Steven Greene; Hilary Hoey; Eero A. Kaprio; Mirjana Kocova; Pedro Martul; Nobuo Matsuura; Kenneth Robertson; Eugen J. Schoenle; Oddmund Søvik; Rosa-Maria Tsou; Maurizio Vanelli; Jan Åman

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.


Diabetic Medicine | 2008

Are family factors universally related to metabolic outcomes in adolescents with Type 1 diabetes

Fergus J. Cameron; Timothy Skinner; C. De Beaufort; Hilary Hoey; Peter Swift; H‐J Aanstoot; Jan Åman; Pedro Martul; Francesco Chiarelli; D. Daneman; Thomas Danne; Harry Dorchy; Eero A. Kaprio; Francine R. Kaufman; Mirjana Kocova; Henrik B. Mortensen; Pål R. Njølstad; Moshe Phillip; Kenneth Robertson; E. J. Schoenle; Tatsuhiko Urakami; Maurizio Vanelli; Rw Ackermann; Soren E. Skovlund

Aims  To assess the importance of family factors in determining metabolic outcomes in adolescents with Type 1 diabetes in 19 countries.


Diabetes Care | 2009

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

Henrik B. Mortensen; Philip Hougaard; Peter Swift; Lars Kai Hansen; Reinhard W. Holl; Hilary Hoey; Hilde Bjoerndalen; Carine De Beaufort; Francesco Chiarelli; Thomas Danne; Eugen J. Schoenle; Jan Åman

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 Journal of Clinical Endocrinology and Metabolism | 2008

Dose-Dependent Effect of Growth Hormone on Final Height in Children with Short Stature without Growth Hormone Deficiency

Kerstin Albertsson-Wikland; A. Stefan Aronson; Jan Gustafsson; Lars Hagenäs; Sten Ivarsson; Björn Jonsson; Berit Kriström; Claude Marcus; Karl Olof Nilsson; E. Martin Ritzén; Torsten Tuvemo; Otto Westphal; Jan Åman

CONTEXT The effect of GH therapy in short non-GH-deficient children, especially those with idiopathic short stature (ISS), has not been clearly established owing to the lack of controlled trials continuing until final height (FH). OBJECTIVE The aim of the study was to investigate the effect on growth to FH of two GH doses given to short children, mainly with ISS, compared with untreated controls. DESIGN AND SETTING A randomized, controlled, long-term multicenter trial was conducted in Sweden. INTERVENTION Two doses of GH (Genotropin) were administered, 33 or 67 microg/kg.d; control subjects were untreated. SUBJECTS A total of 177 subjects with short stature were enrolled. Of these, 151 were included in the intent to treat (AllITT) population, and 108 in the per protocol (AllPP) population. Analysis of ISS subjects included 126 children in the ITT (ISSITT) population and 68 subjects in the PP (ISSPP) population. MAIN OUTCOME MEASURES We measured FH sd score (SDS), difference in SDS to midparenteral height (diff MPHSDS), and gain in heightSDS. RESULTS After 5.9+/-1.1 yr on GH therapy, the FHSDS in the AllPP population treated with GH vs. controls was -1.5+/-0.81 (33 microg/kg.d, -1.7+/-0.70; and 67 microg/kg.d, -1.4+/-0.86; P<0.032), vs. -2.4+/-0.85 (P<0.001); the diff MPHSDS was -0.2+/-1.0 vs. -1.0+/-0.74 (P<0.001); and the gain in heightSDS was 1.3+/-0.78 vs. 0.2+/-0.69 (P<0.001). GH therapy was safe and had no impact on time to onset of puberty. A dose-response relationship identified after 1 yr remained to FH for all growth outcome variables in all four populations. CONCLUSION GH treatment significantly increased FH in ISS children in a dose-dependent manner, with a mean gain of 1.3 SDS (8 cm) and a broad range of response from no gain to 3 SDS compared to a mean gain of 0.2 SDS in the untreated controls.


Acta Paediatrica | 2007

Increased prevalence of overweight in adolescent girls with type 1 diabetes mellitus

Anita Domargård; Stefan Särnblad; Marianne Kroon; Ingegerd Karlsson; Gunnar Skeppner; Jan Åman

Height and weight were measured in young patients with type 1 diabetes up to the age of 22 y. We found no difference between birth length standard deviation scores (SDS), final height SDS and target height SDS. The study group of 89 diabetic boys and girls did not differ in final height from age‐ and sex‐matched healthy controls. SDS for height at diagnosis, +0.17 ± 1.10, exceeded that for final height, −0.06 ±0.97 (p = 0.037). Height SDS decreased between the ages of 11 and 18 (p <0.01). In diabetic girls, but not boys, final height SDS was significantly related to mean HbA1c during puberty (r=−0.40; p = 0.025). Weight gain occurred from age of menarche in girls with type 1 diabetes. At the age of 18, diabetic girls were 6.5 kg heavier and had 2.7 kg/m2 higher body mass index (BMI) than control girls (p<0.001). Diabetic boys were not heavier than control boys. There was a significant relationship between mean HbA1c during puberty and BMI at the age of 18 in diabetic girls (r= 0.47; p = 0.009). In diabetic females, body weight remained unchanged, HbA1c improved and the dose of insulin was significantly reduced between 18 and 22 y of age. The HbA1c improvement was most marked in patients with poor metabolic control. In conclusion, although mean final height was normal in young patients with type 1 diabetes, growth was increased before diagnosis and pubertal growth spurt was reduced. Adolescent overweight was overrepresented; it related to poor metabolic control in females with diabetes, but showed no further acceleration in early adulthood.


Pediatric Diabetes | 2009

Target setting in intensive insulin management is associated with metabolic control: The Hvidoere Childhood Diabetes Study Group Centre Differences Study 2005

Pgf Swift; Timothy Skinner; C. De Beaufort; Fergus J. Cameron; Jan Åman; H‐J Aanstoot; Luis Castaño; F. Chiarelli; D. Daneman; Thomas Danne; Harry Dorchy; Hilary Hoey; Eero A. Kaprio; Francine R. Kaufman; Mirjana Kocova; Henrik B. Mortensen; Pål R. Njølstad; Moshe Phillip; Kenneth Robertson; E. J. Schoenle; Tatsuhiko Urakami; Maurizio Vanelli; Rw Ackermann; Soren E. Skovlund

Swift PGF, Skinner TC, de Beaufort CE, Cameron FJ, Åman J, Aanstoot H‐J, Castaño L, Chiarelli F, Daneman D, Danne T, Dorchy H, Hoey H, Kaprio EA, Kaufman F, Kocova M, Mortensen HB, Njølstad PR, Phillip M, Robertson KJ, Schoenle EJ, Urakami T, Vanelli M, Ackermann RW, Skovlund SE for the Hvidoere Study Group on Childhood Diabetes. Target setting in intensive insulin management is associated with metabolic control: the Hvidoere Childhood Diabetes Study Group Centre Differences Study 2005.

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Thomas Danne

Hannover Medical School

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Mirjana Kocova

Boston Children's Hospital

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Peter Swift

Leicester Royal Infirmary

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Harry Dorchy

Université libre de Bruxelles

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Eugen J. Schoenle

Boston Children's Hospital

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Hilary Hoey

Boston Children's Hospital

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