Influence of a HTR2B Stop Codon on Glucagon Homeostasis and Glucose Excursion in Non-Diabetic Men.

Limited data are available about the role of the serotonin 2B (5-HT2B) receptor in the function of human islets. This study aimed to test whether the 5-HT2B receptor contributes to glucose, insulin, and glucagon homeostasis in humans, utilizing a hereditary loss-of-function gene mutation in the receptor, which causes a 50% reduction in the production of the receptor protein in heterozygotes. This clinical study enrolled participants recruited by newspaper advertisements and from mental status examinations. A cohort of participants from a young Finnish founder population composed of 68 non-diabetic males with a mean age of 30 was divided into groups for comparison based on being a 5-HT2B receptor loss-of-function gene mutation (HTR2B Q20*) heterozygote carrier (n=11) or not (n=57). Serum levels of glucose, insulin, and glucagon were measured in a 5 h oral glucose tolerance test using a 75 g glucose challenge. Insulin resistance, insulin sensitivity, and beta cell activity were calculated using the homeostasis model assessment (HOMA2) and whole body insulin sensitivity index (WBISI), as well as the ratio of glucagon to insulin was noted. The areas under the curves (AUCs) were also determined. Concentrations of the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA) were measured in cerebrospinal fluid (CSF). Covariate adjusted mean score comparisons were applied. Lower glucagon secretion and decreased glucose excursion were observed among HTR2B Q20* carriers as compared with individuals who were homozygotes for the wild-type Q20 allele (controls). No differences in insulin secretion, beta cell activity, insulin resistance, or insulin sensitivity were observed. The glucagon to insulin ratio differed between the HTR2B Q20* carriers and controls. CSF levels of 5-HIAA were similar between groups. Our findings indicate that the 5-HT2B receptor may contribute to the regulation of human glucagon and glucose homeostasis and the interplay between glucagon and insulin secretion.

Bone Characteristics and Their Determinants in Adolescents and Young Adults with Early-Onset Severe Obesity.

Childhood obesity is associated with compromised bone health. We studied bone characteristics and their determinants in obese young adults. The study included 68 subjects with early-onset severe obesity and 73 normal-weight controls. Data on physical activity (PA), diet and smoking were collected. Bone characteristics were measured using peripheral QCT. The obese and control subjects were similar in age (mean 19.6 ± 2.6 years) and height but BMIs differed (39.7 and 22.6 kg/m(2)). A clustering of unhealthy lifestyles was marked: Obese subjects reported less supervised PA in childhood, adolescence and currently (p < 0.03) and were more likely to smoke (p = 0.005), and had a lower healthy eating index (HEI) (p = 0.007) but similar alcohol consumption compared with controls. In obese women, all crude bone characteristics were higher than in controls; in men, the differences were smaller. Associations of lifestyle factors with bone characteristics were tested using partial correlations. Independently of BMI, supervised PA in adolescence and alcohol consumption were related positively to bone characteristics in both groups. HEI associated positively with bone characteristics only in controls, while smoking was a positive determinant of bone characteristics only in obese subjects. The multivariate model showed that the contribution of lifestyle factors to bone characteristics was minimal compared with BMI. Early-onset obesity is accompanied by poor dietary quality, sedentary lifestyle, and more frequent smoking, but the overall contribution of these lifestyle factors to bone strength is limited. Bone strength is more likely to be compromised in men and in unloaded bone sites in subjects with early-onset severe obesity. The impact of obesity-related endocrine changes on bone characteristics need to be evaluated in future studies.

Establishing glycaemic control with continuous subcutaneous insulin infusion in children and adolescents with type 1 diabetes: experience of the PedPump Study in 17 countries.

AIMS/HYPOTHESIS: To assess the use of paediatric continuous subcutaneous infusion (CSII) under real-life conditions by analysing data recorded for up to 90 days and relating them to outcome. METHODS: Pump programming data from patients aged 0-18 years treated with CSII in 30 centres from 16 European countries and Israel were recorded during routine clinical visits. HbA(1c) was measured centrally. RESULTS: A total of 1,041 patients (age: 11.8 +/- 4.2 years; diabetes duration: 6.0 +/- 3.6 years; average CSII duration: 2.0 +/- 1.3 years; HbA(1c): 8.0 +/- 1.3% [means +/- SD]) participated. Glycaemic control was better in preschool (n = 142; 7.5 +/- 0.9%) and pre-adolescent (6-11 years, n = 321; 7.7 +/- 1.0%) children than in adolescent patients (12-18 years, n = 578; 8.3 +/- 1.4%). There was a significant negative correlation between HbA(1c) and daily bolus number, but not between HbA(1c) and total daily insulin dose. The use of <6.7 daily boluses was a significant predictor of an HbA(1c) level >7.5%. The incidence of severe hypoglycaemia and ketoacidosis was 6.63 and 6.26 events per 100 patient-years, respectively. CONCLUSIONS/INTERPRETATION: This large paediatric survey of CSII shows that glycaemic targets can be frequently achieved, particularly in young children, and the incidence of acute complications is low. Adequate substitution of basal and prandial insulin is associated with a better HbA(1c).

Coeliac disease in children and adolescents with type 1 diabetes: a study of growth, glycaemic control, and experiences of families.

UNLABELLED: The aim of this study was to evaluate whether coeliac disease affects growth, glycaemic control, and general well-being of children and adolescents with type I diabetes. Eighteen subjects were found to have coeliac disease by a screening program. Gastrointestinal symptoms, changes in growth and the levels of glycated haemoglobin (GHbA1) were analysed, as well as subjective well-being before and after diagnosis of coeliac disease. Overt gastrointestinal symptoms and deterioration of growth prior to disclosure of coeliac disease were seen only in one patient who had both of these conditions. Retrospectively, most subjects reported mild gastrointestinal complaints, which resolved on a gluten-free diet. Introduction of a gluten-free diet did not have any positive effect on glycaemic control, but was associated with an increase in weight-for-height (from 4.3+/-18.1 to 8.2+/-15.4% deviation from population median, p = 0.02). This increase in weight-for-height was inversely correlated with changes in GHbA1 (r = -0.574, p = 0.02). CONCLUSION: Coeliac disease is rarely associated with signs of malabsorption in children and adolescents with type I diabetes. Introduction of a gluten-free diet may be associated with excess weight gain. We recommend intensified follow-up for these subjects.

Prevalence of coeliac disease in siblings of patients with Type I diabetes is related to the prevalence of DQB1*02 allele.

AIMS/HYPOTHESIS: Coeliac disease is more prevalent among patients with Type I (insulin-dependent) diabetes mellitus and coeliac disease-related antibodies have been reported to increase in frequency in their first-degree relatives. Our aim was to find out if coeliac disease is more common among siblings of children with Type I diabetes than in the normal population. METHODS: IgA endomysium antibodies were measured by indirect immunofluorescence in 550 subjects (mean age 11.8 years, range 3.1-26.9 years) with a sibling with Type I diabetes. We performed jejunal biopsy on as many subjects with positive antibodies as agreed. HLA-DQB1 genotyping was done in 427 subjects. RESULTS: Endomysium antibodies were positive in nine subjects (1.6 %). Jejunal biopsy was diagnostic for coeliac disease in five out of seven patients. An additional patient with coeliac disease, one already on a gluten-free diet, was identified by questionnaire. The prevalence of coeliac disease was 1.1 %. Five of six patients with coeliac disease had HLA-DQB1*02 allele, compared with 118 of 421 of those without coeliac disease (p = 0.009). The sixth patient was positive for HLA-DQB1*0302 allele, which was also found in 241 of 421 of those without coeliac disease (p = 0.4). CONCLUSION/INTERPRETATION: We found the prevalence of coeliac disease among siblings of children with Type I diabetes to be similar to figures reported from recent population-based studies and to be correlated with the prevalence of coeliac disease associated HLA-DQB1 alleles. We propose that routine screening for coeliac disease among all first-degree relatives of patients with Type I diabetes is not warranted.

Jejuna of patients with insulin-dependent diabetes mellitus (IDDM) show signs of immune activation.

The roles of enteric viruses and food antigens as possible triggers in human insulin-dependent diabetes mellitus and the evidence that mucosal-associated homing receptors are important in both human and experimental diabetes prompted us to undertake an immunohistochemical study of intestinal specimens from patients with IDDM. We studied jejunal morphology and immunohistochemistry in 26 patients with IDDM, 13 of whom had the HLA-DQB1*0201 gene and therefore a higher risk of coeliac disease. The findings were compared with those in specimens from age-matched controls. Villous structure and the density of the intraepithelial lymphocytes were normal in every biopsy specimen. The extent of positivity with anti-DR and -DP antibodies in the villous epithelium was significantly greater in the specimens from patients than in those from controls (P = 0.0002 in both comparisons). The crypts were also more positive: for DR P = 0.0001, and for DP P = 0.002. The densities of T cells, CD4+, CD8+, and T cell receptor alpha/beta+ and gamma/delta+ cells in the epithelium and lamina propria were similar in patients and controls, but the patients had significantly more alpha 4/beta 7 integrin+ cells in the lamina propria (P = 0.006). No difference was seen between HLA-DQB1*0201-positive and -negative patients. These findings reflect a stage of inflammation in the structurally normal intestines of patients with IDDM and suggest secretion of inflammatory Th1-type cytokines in the intestine.

Significance of cow's milk protein antibodies as risk factor for childhood IDDM: interactions with dietary cow's milk intake and HLA-DQB1 genotype. Childhood Diabetes in Finland Study Group.

Dietary factors are suspected to play an aetiological role in the development of insulin-dependent diabetes mellitus (IDDM). We analysed cow's milk formula, betalactoglobulin, and bovine serum albumin antibodies by an enzyme-linked immunoassay in unselected children with newly diagnosed IDDM and in their non-diabetic siblings and inquired about infant feeding practices by questionnaire. Among 410 diabetic sibling pairs matched for age and sex, by logistic regression analysis - including overall duration of breast-feeding, age at introduction of dairy products, recent consumption of cow's milk and HLA-DQB1 genotype ("high/moderate" vs "low/decreased" risk of IDDM) - bovine serum albumin IgG antibody levels (OR 2.12, 95% CI 1.25-3.57) and genetic risk (OR 3.81, 95% CI 2.43-5.17) were positively associated with IDDM; cow's milk formula IgM antibodies were inversely associated with the risk of IDDM (OR 0.50, 95% CI 0.29-0.87). Of the diabetic sibling pairs, 42 were identical for HLA-DQB1 alleles associated with IDDM risk or protection (DQB1*0201, *0301, *0302 and *0602/03). In these 42 pairs, children with IDDM had higher median levels of bovine serum albumin IgG, of betalactoglobulin IgG, and of cow's milk formula IgG and IgA antibodies than the non-diabetic siblings (p < 0.05). In conclusion, children with IDDM have higher levels of cow's milk protein antibodies than their HLA-DQB1-matched sibling controls, and these high levels of antibodies are independent risk markers for IDDM.

Disease-associated antibodies in offspring of mothers with IDDM.

We studied 20 infants of mothers with IDDM participating in a pilot study for a dietary intervention trial, testing the hypothesis that avoidance of cow's milk proteins early in life will reduce the risk of subsequent IDDM. The aim was to evaluate the elimination of IDDM-associated antibodies from the peripheral circulation of the infants, the possible emergence of autoantibodies indicating beta-cell destruction, and the influence of the dietary intervention and genetic disease susceptibility on the development of these autoantibodies. Transplacentally transferred islet cell antibodies (ICAs) and antibodies to the 65-kDa isoform of glutamic acid decarboxylase (GAD65As) disappeared from the peripheral circulation of most infants over the first few months of life and in all infants before the age of 9 months. Insulin antibodies were eliminated before the same age in all cases but one. The higher the initial antibody level was, the longer the time required for elimination. Four infants tested positive for insulin autoantibodies (IAAs) on at least one occasion during the first year of life, and 5 out of 16 unaffected subjects (31%) had IAAs at the age of 2 years. One infant became positive for IAA before the age of 6 months, with increasing levels later, seroconverted to positivity for ICAs and GAD65As between 6 and 9 months and presented with clinical IDDM at the age of 14 months. He had the HLA DQB1*0302/x genotype, which predisposes carriers to IDDM, and had been given the casein hydrolysate formula as supplementary milk. There were no significant differences in the levels of various autoantibodies between two groups of subjects defined either on the type of dietary intervention or the degree of genetic susceptibility. The findings indicate that transplacentally transferred antibodies related to IDDM are usually eliminated from the peripheral circulation of infants before 9 months of age and that IDDM-associated autoantibodies may emerge before the age of 6 months. Our results also illustrate that avoidance of cow's milk proteins over the first 9 months of life does not provide total protection against IDDM.

Increased frequency of IgM antibodies to cow's milk proteins in Hungarian children with newly diagnosed insulin-dependent diabetes mellitus.

UNLABELLED: We investigated the association between serum antibodies to cow's milk proteins and insulin-dependent diabetes mellitus (IDDM) in Hungarian children. Forty-eight children 1.0-17.1 years of age with newly diagnosed IDDM and 74 control children 1.0-16.0 years of age were studied for serum IgG, IgA and IgM antibodies to cow's milk, beta-lactoglobulin, bovine serum albumin and ovalbumin by enzyme-linked immunosorbent assays. The specificity of IgM antibodies to beta-lactoglobulin and bovine serum albumin was controlled by Western blot. The levels of IgG and IgA antibodies to cow's milk proteins were similar in children with and without IDDM, with the exception of slightly increased levels of IgA antibodies to beta-lactoglobulin in diabetic children (P = 0.05). The levels of IgM antibodies to cow's milk were significantly higher in IDDM patients than in control children (P = 0.0002). Children with IDDM more often had IgM antibodies to beta-lactoglobulin (46.3% vs 18.8%; P = 0.002) and bovine serum albumin (87.8% vs 49.3%, P < 0.0001) than control children. Neither the levels of IgG or IgA antibodies to ovalbumin nor the frequency of IgM antibodies to ovalbumin differed between diabetic and control children. CONCLUSION: In Hungarian children, clinical manifestation of IDDM is often associated with IgM antibody response to cow's milk protein and its fractions, beta-lactoglobulin and bovine serum albumin, indicating a loss of immunological tolerance to these proteins. IgG and IgA antibodies to cow's milk proteins, associated with an early introduction of cow's milk in diet, seem to play a minor role in the development of childhood IDDM in Hungary.

Soluble adhesion molecules and oral antigen feeding in infants.

Oral administration of foreign proteins, e.g. cow's milk (CM) proteins, stimulates the immune system and induces humoral and cellular immune response against these antigens in infants. Up-regulation of adhesion molecules is known to be associated with activation of the immune system. The purpose of the study was to examine whether orally administered CM proteins induce elevation in soluble adhesion molecules, i.e. intercellular adhesion molecule-1 (ICAM-1) and L-selectin, in infants. In a double-blind trial, 10 infants received CM-based formula and 10 infants casein hydrolysate formula until the age of 9 mo. The infants of mothers with insulin-dependent diabetes mellitus (IDDM) were recruited into a pilot study of a trial for primary prevention of IDDM by elimination of CM proteins from the diet during early infancy. A cord blood sample and peripheral blood samples were taken at the ages of 3, 6, 9, and 12 mo of age. The levels of soluble ICAM-1 and L-selectin were measured by ELISA. The levels of soluble ICAM-1 were higher at the ages of 3, 6, 9, and 12 mo in infants who received CM-based formula than in infants who received hydrolyzed formula (p = 0.05). Instead, no difference was found in the the levels of soluble L-selectin. The levels of soluble ICAM-1 and L-selectin were higher in all infants when compared with the levels reported in adults or to the levels seen in cord blood. Orally fed CM proteins induce an elevation in soluble ICAM-1 in infants. This may reflect the generation of an immune response against these proteins, because ICAM-1 has an important costimulatory role in lymphocyte activation.

Coeliac disease: frequent occurrence after clinical onset of insulin-dependent diabetes mellitus. Childhood Diabetes in Finland Study Group.

Coeliac disease was searched for in a series of 776 children with newly diagnosed IDDM. During the follow-up of 2 to 3 years from diagnosis, reticulin and gliadin antibodies were measured, and a jejunal biopsy was performed in those cases with high levels of antibodies; 19 children were identified with coeliac disease, giving the prevalence of 2.4%. In only one case had coeliac disease been diagnosed before IDDM. Nine patients with proven coeliac disease were negative for antibodies when IDDM was diagnosed, but became positive within 24 months. All patients found to have coeliac disease were positive for IgA reticulin antibodies, but only 12 of 18 (67%) showed a high level of IgA gliadin antibodies. Of the 18 patients genotyped for HLA DR locus, 14 (78%) were positive for DR3 and 10 (56%) were positive for DR4. DQB1*0201 allele was present in 17 of 18 patients (94%). Coeliac disease in children with IDDM tends to develop soon after diabetes is diagnosed. Routine screening for coeliac disease is recommended repeatedly during the first years after the diagnosis of IDDM.

Relation between antibodies to islet cell antigens, other autoantigens and cow's milk proteins in diabetic children and unaffected siblings at the clinical manifestation of IDDM. The Childhood Diabetes in Finland Study Group.

The relation between islet cell specific antibodies, other autoantibodies and antibodies to cow's milk proteins was studied in IDDM and pre-IDDM by analysing islet cell antibodies (ICA), insulin autoantibodies (IAA), anti-nuclear (ANA), anti-reticulin class IgA [ARA(IgA)], smooth muscle, anti-mitochondria, parietal cell (PCA), adrenal and thyroid antibodies and antibodies to cow's milk formula (CMF), beta-lactoglobulin (BLG) and bovine serum albumin (BSA) in a population based study with more than 650 children with newly diagnosed IDDM and more than 550 initially non-diabetic siblings. After adjustment for age a weak association was seen in the diabetic children between IAA and ANA but none between ICA and autoantibodies directed against the other organ-specific or non-organ-specific antigens. There was no significant difference in cow's milk antibodies between diabetic children with and without ICA or IAA. The siblings with ICA had higher CMF (IgA and IgM) antibody levels and BLG (IgA) antibody levels than the remaining siblings, but no such differences were found when comparing IAA-positive and negative siblings. Siblings positive for ICA had PCA more often than did the ICA-negative siblings, whereas siblings positive for both ICA and PCA had increased levels of antibodies against CMF, BLG and BSA. These findings indicate that the humoral islet cell-associated autoimmunity characteristic of recent-onset childhood IDDM is clearly restricted to the islet cells and not directly related to signs of other organ-specific or non-organ-specific autoimmunity. The observation of increased levels of antibodies to cow's milk proteins in siblings positive for ICA suggests that the immune response to cow's milk proteins may be related to the progressive autoimmune process resulting in beta-cell destruction and ultimately in the clinical manifestation of IDDM. Gastrointestinal autoimmune mechanisms may play a role in the pathogenesis of IDDM, and the association observed between combined ICA and PCA positivity and increased levels of antibodies to cow's milk proteins in the siblings implies that there may be an enhanced transfer of nutritional antigens across the gut barrier in these subjects.

Development of immune response to cow's milk proteins in infants receiving cow's milk or hydrolyzed formula.

BACKGROUND: Development of humoral and cellular immune responses to orally administered antigens in human beings is poorly understood, although antigen administration has been suggested as a treatment for hypersensitivity disorders and autoimmune diseases. OBJECTIVE: The purpose of the study was to investigate the development of systemic immune response in infants fed with formula containing whole cow's milk proteins or hydrolyzed formula containing casein peptides. METHODS: In a double-blind trial, 10 infants received cow's milk-based formula, and 10 infants received a casein hydrolysate formula until the age of 9 months. Blood samples were taken at the ages of 6, 9, and 12 months. Cellular responses were assessed by proliferation assay of peripheral blood mononuclear cells to cow's milk proteins (beta-lactoglobulin, bovine serum albumin, and alpha-casein). Humoral responses to the same proteins were measured by ELISA for IgG antibodies. RESULTS: Feeding infants with cow's milk-based formula induced systemic humoral and cellular responses to cow's milk proteins. T-cell response later declined, supporting the concept of oral tolerization. Exposure to cow's milk proteins after the age of 9 months resulted in depressed cellular and humoral responsiveness to these proteins. CONCLUSION: Our results support the view that induction of oral tolerance in human beings is an age-dependent phenomenon.

IgA bovine serum albumin antibodies are increased in newly diagnosed patients with insulin-dependent diabetes mellitus, but the increase is not an independent risk factor for diabetes.

We studied the significance of antibodies to bovine serum albumin (BSA) as a risk factor for insulin-dependent diabetes mellitus (IDDM) in a case-control setting. IgA and IgG antibodies to BSA and ovalbumin were measured from sera of 104 patients with newly diagnosed IDDM and of 111 matched controls by enzyme-linked immunosorbent assay. Patients with diabetes had significantly higher levels of IgA antibodies to BSA (p = 0.003); IgG antibodies also tended to be higher (p = 0.08). Levels of IgA antibodies to ovalbumin were similar in the patients and controls, but IgG antibodies were higher in controls (p = 0.02). When antibodies to BSA, beta-lactoglobulin, whole cow's milk and islet cell antibodies were studied as risk determinants of IDDM in a multivariate, logistic regression analysis, IgA antibodies to beta-lactoglobulin and to cow's milk were independently associated with the risk (p = 0.037 and 0.048, respectively), while antibodies to BSA were not a significant risk factor. The results question the role of BSA as a cross-reacting antigen with pancreatic beta-cell surface proteins in the aetiology of IDDM.

Children with newly diagnosed IDDM have increased levels of antibodies to bovine serum albumin but not to ovalbumin. Childhood Diabetes in Finland Study Group.

OBJECTIVE: To study the humoral immune response to bovine serum albumin (BSA) and ovalbumin (OA) in children with newly diagnosed insulin-dependent diabetes mellitus (IDDM). RESEARCH DESIGN AND METHODS: We examined serum samples from 505 children 0.8-14.9 years of age with newly diagnosed IDDM for antibodies to BSA and OA by enzyme-linked immunosorbent assay (ELISA). We also had two control groups: 85 unrelated control children (0.8-7.1 years of age) and 395 nondiabetic siblings (3.0-14.9 years of age). The specificity of antibodies detected in ELISA was confirmed by immunoblotting in a subset of sera with varying levels of antibodies. RESULTS: Diabetic children < 7 years of age had a significantly higher level of IgG (immunoglobulin) antibodies to BSA than did unrelated control children (P < 0.0001). The difference was greatest in the youngest group of children, 0.8-2.9 years of age. IgA antibodies to BSA were detected more frequently among diabetic than control children (P = 0.0009). Levels of IgG and IgA antibodies to ovalbumin did not differ between diabetic and control children. Diabetic children 3.0-14.9 years of age also had higher levels of IgG and IgA antibodies to BSA than did their age- and sex-matched nondiabetic siblings (P = 0.02 and P < 0.0001, respectively). Those siblings who contracted IDDM during the follow-up period (n = 15) had a measurable level of IgA antibodies to BSA more often than did those who remained nondiabetic (60 and 34%, respectively; P = 0.04). Neither before nor after diagnosis of IDDM was there any significant trend in antibody levels. CONCLUSIONS: A high level of antibodies to BSA commonly associates with IDDM, whereas the humoral immune response to OA is similar in diabetic and nondiabetic children.

Diet, cow's milk protein antibodies and the risk of IDDM in Finnish children. Childhood Diabetes in Finland Study Group.

Associations of infant feeding patterns and milk consumption with cow's milk protein antibody titres were studied in 697 newly-diagnosed diabetic children, 415 sibling-control children and 86 birth-date- and sex-matched population-based control children in the nationwide "Childhood Diabetes in Finland" study. IgA and IgG antibody titres to the proteins of cow's milk formula, BLG and BSA, and IgM antibody titres to cow's milk formula proteins were measured by ELISA. Several inverse correlations were observed between the duration of breast-feeding or age at introduction of dairy products and antibody titres, and positive correlations were observed between milk consumption and antibody titres in all three populations studied. Multivariate analyses which included the infant feeding variables, milk consumption and current age simultaneously showed that the earlier the introduction of dairy products and the greater the consumption of milk was, the higher several antibody titres were. High IgA antibody titres to cow's milk formula were associated with a greater risk of IDDM both among diabetic-population-control and diabetic-sibling-control pairs when adjusted for other cow's milk antibody titres, dietary variables and in diabetic-sibling-control pairs also for ICA. The results suggest that young age at introduction of dairy products and high milk consumption during childhood increase the levels of cow's milk antibodies and that high IgA antibodies to cow's milk formula are independently associated with increased risk of IDDM.