Combined positivity for HLA DQ2/DQ8 and IA-2 antibodies defines population at high risk of developing type 1 diabetes.

AIMS/HYPOTHESIS: Prevention trials in first-degree relatives of type 1 diabetic patients are hampered by large interindividual differences in progression rate to diabetes. We investigated whether specific combinations of immune and genetic markers can identify subgroups with more homogeneous progression to clinical onset. METHODS: Antibodies against islet cell cytoplasm (ICA), insulin (IAA), glutamate decarboxylase (GADA) and IA-2 protein (IA-2A) were measured in 790 non-diabetic control subjects and 4,589 first-degree relatives under age 40. RESULTS: On first sampling, 11.1% of the siblings presented at least one antibody type (p<0.001 vs other relatives). During follow-up (median 52 months) 43 subjects developed type 1 diabetes (31 siblings, ten offspring of a diabetic father, two offspring of a diabetic mother). Using Kaplan-Meier survival analysis and Cox regression, IA-2A conferred the highest 5-year diabetes risk (>50%) irrespective of the number of antibodies present. In initially IA-2A-positive relatives (n=58) progression to hyperglycaemia depended more on HLA DQ status than on type of kinship (84% progression in the presence of DQ2/DQ8 vs 32% in its absence; p<0.003). In IA-2A-negative relatives (n=4,531) 5-year progression to diabetes increased with the number of other antibodies (ICA, GADA and/or IAA) (p<0.001) but overall did not exceed 10% even for two or more antibodies. Among relatives initially positive for one or more antibody type other than IA-2A (n=315), there was significantly more progression to diabetes (overall still <10%) in carriers of DQ2 (p<0.001 vs no DQ2), regardless of DQ8 status. CONCLUSIONS/INTERPRETATION: These observations suggest that the HLA-DQ-inferred risk of diabetes can proceed through two distinct pathways distinguished by IA-2A status. Combined positivity for DQ2/DQ8 and IA-2A defines a more homogeneous high-risk population for prevention trials than those used so far.

A novel 7301-bp deletion in mitochondrial DNA in a patient with Kearns-Sayre syndrome, diabetes mellitus, and primary amenorrhoea.

We report a 27-year-old woman with a form of mitochondrial myopathy including chronic progressive external opthalmoplegia, retinal pigmentary dystrophy, cerebellar ataxia, and cardiac conduction block (Kearns-Sayre syndrome). At age 13 years a cardiac pacemaker was implanted. She also had sensineural hearing loss, delayed puberty, and primary amenorrhoea. She was weelchair-bound since the age of 20 years. At age 27, insulin-dependent diabetes mellitus and osteoporosis were diagnosed. Insulin treatment was started and associated endocrinopathies were investigated. DNA analysis identified a novel 7301-bp deletion in mitochondrial DNA, ranging from position 6530 to 13 831 corroborating the diagnosis of Kearns-Sayre syndrome.

Rationale and options for combination therapy in the treatment of Type 2 diabetes.

Pharmacological therapy for Type 2 (non-insulin-dependent) diabetes mellitus aims at controlling hyperglycaemia to delay or prevent complications associated with the disease. Most patients with Type 2 diabetes present with both stimulated insulin deficiency and insulin resistance. In general, the former can manifest as postprandial hyperglycaemia and the latter as fasting hyperglycaemia, though a definitive association has not been established. Emerging data show a high failure rate of long-term monotherapy and establishes the significance of mealtime glycaemia and the role of postprandial glucose excursions in the development and progression of vascular complications. To overcome such failures of monotherapy and to address the different underlying defects of the pathology of Type 2 diabetes, a combined therapy of oral antidiabetic agents with complementary modes of action should be considered. Currently used oral antidiabetic agents such as sulphonylureas, biguanides (metformin) and the thiazolidinediones (rosiglitazone, pioglitazone) commonly target fasting hyperglycaemia and have limited additive effects on postprandial glycaemia. In contrast, alpha-glucosidase inhibitors can reduce postprandial hyperglycaemia but gastrointestinal side effects restrict their use. The development of new agents to control postprandial glucose excursions could be considered as an additional objective for the management of Type 2 diabetes. To this end new short-acting enhancers of insulin secretion such as repaglinide (benzoic acid derivative) and nateglinide (amino acid derivative) have been developed. The combination of such agents with other complementary modes of action, e.g. an insulin sensitizer, could target better major underlying defects of Type 2 diabetes and thereby provide a better approach for controlling the entire glycaemic risk.

IA-2 autoantibodies predict impending type I diabetes in siblings of patients.

AIMS/HYPOTHESIS: Multiple islet autoantibody positivity is currently believed to best predict progression to Type I (insulin-dependent) diabetes mellitus. We compared its predictive value with that of positivity for a particular type of islet autoantibody, directed against the IA-2 antigen. METHODS: Autoantibodies against islet cell cytoplasm (ICA), insulin (IAA), GAD (GADA) and IA-2 (IA-2A) were measured at initial sampling in 1724 non-diabetic siblings (median age [range]:16 [0-39] years) of Type I diabetic patients with a median follow-up of 50 months. RESULTS: On initial sampling 11% of siblings were positive for one antibody type or more and 2.1% for three of more types. During follow-up, 27 antibody-positive siblings developed diabetes. Using survival analysis, the risk for clinical onset within 5 years was 34% in subjects positive for three or more types compared with 13% in those with one type or more. Progression to diabetes amounted to 12% within 5 years among siblings positive for IAA, 20% for ICA, 19% for GADA but 59% for IA-2A (p<0.001 vs absence of the respective antibody). IA-2A were detected in 1.7% of all siblings and in 56% of the prediabetic subjects on first sampling. Initial positivity for two or three antibody markers was associated with a higher progression rate in IA-2A positive as compared to IA-2A negative siblings (p=0.001). In absence of IA-2A initial positivity for another antibody (IAA, ICA or GADA) conferred a low (<10% within 5 years) risk of diabetes compared to subjects lacking this antibody. CONCLUSIONS/INTERPRETATION: In siblings of Type I diabetic patients, IA-2A positivity is a more direct predictor of impending clinical onset than multiple antibody positivity per se. Assessment of IA-2A status allows us to select subjects with homogeneously high risk of diabetes for participation in prevention trials.

Helicobacter pylori, parietal cell antibodies and autoimmune gastropathy in type 1 diabetes mellitus.

BACKGROUND: Fifteen to 20% of type 1 diabetic patients exhibit parietal cell antibodies (PCA), which are associated with autoimmune gastritis, hypochlorhydria, iron deficiency and pernicious anaemia. AIM: To examine whether Helicobacter pylori infection could explain the high prevalence of PCA and autoimmune gastropathy in diabetes. If so, H. pylori eradication could prevent autoimmune gastritis. METHODS: In 229 type 1 diabetics (M/F: 135/94; age: 41 +/- 12 years) PCA were measured. H. pylori infection was assessed by serology, urea breath test in all and by histology (updated Sydney system) in 88 subjects. Pentagastrin tests were performed in 42 patients. RESULTS: Sixty-nine patients were PCA-positive. H. pylori infection was present in 72 patients and was negatively associated with HLA-DQA1*0103-B1*0603 (OR=0.12, P=0.015) and positively with DQA1*0501-B1*0201 (OR=1.9, P=0.032). PCA-positivity was linked to HLA-DQA1*0501-B1*0301 (OR=3.9, P=0.017). A link between H. pylori and PCA was observed when PCA-positivity was defined as a titre > or = 1/20 (OR=2.0, P=0.03), but not if > or =1/40 was the cut-off point. PCA-positivity, but not H. pylori infection, was associated with iron deficiency anaemia (OR=2.7, P=0.008), pernicious anaemia (OR= 33.5, P < 0.0001), hypochlorhydria (OR=12.1, P=0.0008) and autoimmune gastritis (OR=12.5, P < 0.0001). CONCLUSIONS: The HLA-bound susceptibility of H. pylori and PCA differed. PCA-positivity but not ongoing H. pylori infection is associated with autoimmune gastritis. Low titres of PCA might reflect H. pylori infection rather than autoimmune gastropathy.

Beta-cell, thyroid, gastric, adrenal and coeliac autoimmunity and HLA-DQ types in type 1 diabetes.

The autoimmune attack in type 1 diabetes is not only targeted to beta cells. We assessed the prevalence of thyroid peroxidase (aTPO), parietal cell (PCA), antiadrenal (AAA) and endomysial antibodies (EmA-IgA), and of overt autoimmune disease in type 1 diabetes, in relation to gender, age, duration of disease, age at onset, beta-cell antibody status (ICA, GADA, IA2A) and HLA-DQ type. Sera from 399 type 1 diabetic patients (M/F: 188/211; mean age: 26 +/- 16 years; duration: 9 +/- 8 years) were tested for ICA, PCA, AAA and EmA-IgA by indirect immunofluorescence, and for IA2A (tyrosine phosphatase antibodies), GADA (glutamic acid decarboxylase-65 antibodies) and aTPO by radiobinding assays. The prevalence rates were: GADA 70%; IA2A, 44%; ICA, 39%; aTPO, 22%; PCA, 18%; EmA-IgA, 2%; and AAA, 1%. aTPO status was determined by female gender (beta = - 1.15, P = 0.002), age (beta = 0.02, P = 0.01) and GADA + (beta = 1.06, P = 0.02), but not by HLA-DQ type or IA2A status. Dysthyroidism (P < 0.0001) was more frequent in aTPO + subjects. PCA status was determined by age (beta = 0.03, P = 0.002). We also observed an association between PCA + and GADA + (OR = 1.9, P = 0.049), aTPO + (OR = 1.9, P = 0.04) and HLA DQA1*0501-DQB1*0301 status (OR = 2.4, P = 0.045). Iron deficiency anaemia (OR = 3.0, P = 0.003) and pernicious anaemia (OR = 40, P < 0.0001) were more frequent in PCA + subjects. EmA-IgA + was linked to HLA DQA1*0501-DQB1*0201 + (OR = 7.5, P = 0.039), and coeliac disease was found in three patients. No patient had Addison's disease. In conclusion, GADA but not IA2A indicate the presence of thyrogastric autoimmunity in type 1 diabetes. aTPO have a female preponderance, PCA are weakly associated with HLA DQA1*0501-DQB1*0301 and EmA-IgA + with HLA DQA1*0501-DQB1*0201.

The presence of thyrogastric antibodies in first degree relatives of type 1 diabetic patients is associated with age and proband antibody status.

A quarter of type 1 diabetic patients have thyrogastric autoantibodies (thyroid peroxidase and gastric parietal cell antibodies). Clinical, immune, and genetic risk factors help predict antibody status. First degree relatives of these patients may also frequently exhibit these antibodies. We assessed the prevalence of thyrogastric antibodies and dysfunction in first degree relatives in relation to age, gender, human leukocyte antigen-DQ type, beta-cell antibody (islet cell, glutamic acid decarboxylase-65, and tyrosine phosphatase antibodies), and proband thyrogastric antibody status. Sera from 272 type 1 diabetic patients (116 men and 156 women; mean age, 27 +/- 18 yr; duration, 10 +/- 9 y), 397 first degree relatives (192 men and 205 women; parents/siblings/offspring, 48/222/127; age, 22 +/- 10 yr), and 100 healthy controls were tested for islet cell antibodies and gastric parietal cell antibodies by indirect immunofluorescence and for tyrosine phosphatase, glutamic acid decarboxylase-65, and thyroid peroxidase antibodies by radiobinding assays. Glutamic acid decarboxylase-65 antibodies were present in 68% and 5%, islet cell antibodies were present in 36% and 2.5%, tyrosine phosphatase antibodies were present in 45% and 0.5%, thyroid peroxidase antibodies were present in 21% and 4.5%, and gastric parietal cell antibodies were present in 18% and 11% of diabetic patients and relatives, respectively. The presence of thyroid peroxidase antibodies in relatives was determined by age (beta = 0.22; P = 0.0001) and proband thyroid peroxidase antibodies status (beta = -2.6; P = 0.002; odds ratio = 11.1). Gastric parietal cell antibody positivity in relatives was associated with age (beta = 0.04; P = 0.026). Gastric parietal cell antibody-positive compared with gastric parietal cell antibody-negative relatives were more likely to have gastric parietal cell antibody-positive probands (P = 0.01; odds ratio = 3.0). beta-Cell antibody status and human leukocyte antigen-DQ type did not influence thyrogastric antibody status in relatives. (Sub)clinical dysthyroidism was found in 3%, iron deficiency anemia was present in 12% (26% gastric parietal cell antibody-positive and 9% gastric parietal cell antibody-negative subjects; P = 0.009), and pernicious anemia was found in 0.5% (5% gastric parietal cell antibody-positive and 0% gastric parietal cell antibody-negative subjects; P = 0.012) of relatives. They had less thyroid dysfunction (P < 0.0001) and pernicious anemia (P = 0.018) than diabetic probands. In conclusion, thyrogastric antibodies and dysfunction are more prevalent in type 1 diabetic patients than in first degree relatives. The presence of these antibodies in relatives is associated with age and proband antibody status, but not with beta-cell antibodies or human leukocyte antigen-DQ type.

Repaglinide improves blood glucose control in sulphonylurea-naive type 2 diabetes.

The prandial glucose regulator repaglinide has a rapid onset of action, a short half-life and is metabolised mainly by the liver. Here we report the findings of a 10-week, double-blind, parallel, placebo controlled, randomised trial with repaglinide in 25 diet-treated, sulphonylurea-naïve patients with Type 2 diabetes. Repaglinide was titrated, based on capillary blood glucose, from 0.5 mg to a maximum of 4 mg, preprandially with breakfast and dinner. After 10 weeks, repaglinide was associated with a decrease in HbA(1c) of 2.3%Hb relative to the placebo group (P=0.018). This reflected a 30% decrease within the repaglinide group from a mean HbA(1c) of 7.0 to 4.9%Hb (P<0.002). Repaglinide was also associated with a decrease in fructosamine, by 0.88 mmol/l, relative to placebo (P<0.001), with a 20% decrease (from 3.80 to 3.04 mmol/l) within the repaglinide group (P<0.001). Fasting and postprandial blood glucose concentrations decreased in association with repaglinide by 3.6 and 6.4 mmol/l, respectively, relative to placebo (P<0.001 in each case). Within the repaglinide group fasting and postprandial blood glucose decreased by 3.9 and 6.2 mmol/l, respectively (P<0.001 in each case). The number of patients reporting hypoglycaemia in the repaglinide group was similar to placebo (15 vs. 20, respectively; NS). Test meal assessments confirmed that repaglinide effectively controls glucose levels by stimulating mealtime insulin secretion. Fasting serum insulin concentration was not raised compared to baseline or placebo during repaglinide therapy, albeit that fasting glucose levels were decreased by repaglinide. Twice-daily meal-related insulin secretagogue therapy with repaglinide, a new short and rapid-acting prandial glucose regulator, is capable of improving all measures of glycaemic control without increased hypoglycaemia or fasting hyperinsulinaemia.

Male-to-female excess in diabetes diagnosed in early adulthood is not specific for the immune-mediated form nor is it HLA-DQ restricted: possible relation to increased body mass index.

UNLABELLED: AIMS/HYPOTHESIS. We investigated whether the reported HLA-DQ/DR restricted male-to-female (M:F) excess in Type I (insulin-dependent) diabetes mellitus also exists in Belgian patients, is specific for immune-mediated diabetes, remains genotype-restricted after adjustment for age at diagnosis, and is associated with sex-dependent environmental factors. METHODS: Autoantibodies, HLA-DQ and 5'INS (5'insulin gene) polymorphisms were assessed in 2,532 diabetic patients (all phenotypes) diagnosed under 40 years of age. Autoantibodies and body mass index (expressed as a standard deviation score by comparison to age-matched and sex-matched control subjects; SDS-BMI) were measured in 1986 siblings or offspring of Type I diabetes patients (0-39 years). RESULTS: In patients aged 15-39 years at diagnosis, the male-to-female ratio was 1.5 or more regardless of their antibody status and significantly higher (p < 0.001) than that in the age-matched Belgian general population. There was no sex bias in patients under 15 years of age. Overall, the male-to-female ratio was significantly higher in patients without HLADQA1*0301-DQB1*0302 (p < or = 0.003) but stratification in age groups and multivariate analysis identified age as the major determinant of male-to-female ratio. The SDS-BMI increased (p < 0.01) in male antibodypositive relatives (n = 103) but not in female antibody-positive (n = 92) or in antibody-negative relatives (n = 1,791). This phenomenon tended to be restricted to male relatives who were positive only for glutamate decarboxylase antibodies (n = 44). CONCLUSIONS/INTERPRETATION: The male-to-female excess in Belgian diabetic patients diagnosed in early adulthood is not specific for immune-mediated Type I diabetes and not HLA-DQ or 5'INS restricted. Our data suggest that, similar to Type II (non-insulin-dependent) diabetes mellitus, the metabolic burden of obesity and insulin resistance could preferentially precipitate postpubertal clinical onset in male subjects with slowly progressive subclinical (immune-mediated) diabetes.

Low-density lipoprotein receptor gene mutation analysis and clinical correlation in Belgian hypercholesterolaemics.

It is generally believed that patients with familial hypercholesterolaemia (FH) have a higher cardiovascular risk than hypercholesterolaemics without a defect in the low-density lipoprotein receptor (LDLR) gene. However, no conclusive evidence to support this view has yet been presented. We investigated this aspect in Belgian hyperlipidaemics as part of a comprehensive effort to determine the impact of FH in this population. DNA samples of 98 unrelated Belgian patients with a family history of autosomal dominant hypercholesterolaemia were screened for mutations in the LDLR gene, after exclusion of known mutations causing familial defective apolipoprotein B-100 (FDB). Eight of the 22 distinct LDLR gene mutations identified in 27 subjects have not previously been described in other populations. As expected, the mutation-positive patients had a significantly worse lipid profile than the mutation-negative subjects (p<0.05), but this did not correlate with clinical cardiovascular status. In conclusion, the presence of a mutation in the LDLR gene was not a reliable predictor of cardiovascular risk in the hyperlipidaemic subjects included in this study. However, it is possible that prolonged exposure to the high levels of LDL cholesterol in genetically proven FH patients will in future cause a higher incidence of coronary heart disease. Our data may reflect the genetic heterogeneity of inherited hypercholesterolaemia, recently shown to be caused by several major genes.

Gastric parietal cell antibodies are associated with glutamic acid decarboxylase-65 antibodies and the HLA DQA1*0501-DQB1*0301 haplotype in Type 1 diabetes mellitus. Belgian Diabetes Registry.

AIMS: To assess the prevalence of thyrogastric autoimmunity in relation to age, sex, beta-cell antibody status and HLA DQ haplotypes in Type 1 diabetes mellitus. METHODS: One hundred and seventy-one patients with Type 1 diabetes mellitus were studied (male/female 86/85; mean age 19 +/- 11 years; duration of diabetes 5 +/- 4 years). Islet cell antibodies (ICA) and parietal cell antibodies (PCA) were measured using indirect immunofluorescence; glutamic acid decarboxylase-65 antibodies (GADA) by radiobinding assay and thyroid peroxidase antibodies (TPO) with an immunoradiometric assay (IRMA). RESULTS: The majority of subjects (81.3%) showed one or more autoantibodies. The prevalence rates were: GADA 64.9%, ICA 46.2%, PCA 19.9% and TPO 19.3%. Patients with ICA+ > or = 3 years after diagnosis had a higher prevalence of GADA (P = 0.03, odds ratio (OR) 2.66) and thyrogastric antibodies (P = 0.05, OR 2.23) than subjects ICA- after 3 years. PCA+ patients were older (P = 0.04), had a higher prevalence of GADA (P = 0.005, OR 3.89) and TPO (P = 0.05, OR 2.50) than PCA- subjects. Logistic regression analysis showed that PCA status was determined by the HLA DQA1*0501-DQB1*0301 haplotype (beta = 2.94, P = 0.04) and GADA status (beta = 2.44, P = 0.041). CONCLUSIONS: Thyrogastric antibodies are highly prevalent in Type 1 diabetes mellitus, especially in patients with persisting ICA. Screening for gastric autoimmunity is particularly advised in patients who are positive for GADA and for the HLA DQA1*0501-DQB1*0301 haplotype.

Soluble transferrin receptor level: a new marker of iron deficiency anemia, a common manifestation of gastric autoimmunity in type 1 diabetes.

OBJECTIVE: A total of 15-20% of type 1 diabetic patients have parietal cell antibodies (PCAs). PCA+ subjects are at increased risk for iron deficiency anemia and atrophic gastritis. Recently, soluble transferrin receptor (sTfR) levels have proven to be a sensitive indicator for iron deficiency They are, in contrast with ferritin levels, independent of inflammation, liver and hormonal status, and sex. We are the first to evaluate sTfR levels in type 1 diabetes and tested the hypothesis of higher sTfR levels in patients with PCAs and/or autoimmune gastritis. RESEARCH DESIGN AND METHODS: We examined 148 type 1 diabetic patients (85 men and 63 women; 50 were PCA+) and 59 sex- and age-matched control subjects (30 men and 29 women). The main outcome measures were sTfR levels, iron deficiency anemia, and atrophic gastritis. Logistical regression analysis tested risk factors for iron deficiency RESULTS: Iron deficiency was present in 38 subjects. Iron (P<0.0001) and ferritin (P<0.0001) levels but not sTfR levels were lower in women. sTfR levels were similar in diabetic and control subjects but were higher in PCA+ subjects (P = 0.015). In diabetic subjects, iron deficiency anemia was more prevalent in PCA+ than in PCA- patients (odds ratio 3.07, P = 0.013) and was associated with sex (P = 0.0001), age (P = 0.046), and sTfR (P = 0.0008) levels. Atrophic gastritis was present in 15 of 28 PCA+ and in 1 of 11 PCA diabetic subjects (P = 0.014). sTfR levels tended to be higher in patients with atrophic gastritis (P = 0.062). CONCLUSIONS: In type 1 diabetes, sTfR levels can be used to diagnose iron deficiency anemia, which is more prevalent in PCA+ subjects. sTfR levels are higher in PCA+ individuals who are at risk for developing atrophic gastritis.

Autoimmune hepatitis, autoimmune gastritis, and gastric carcinoid in a type 1 diabetic patient: a case report.

The history of a 45-year-old male type 1 diabetic patient is presented. At the age of 29 years, he was diagnosed to have an autoimmune hepatitis with incipient liver cirrhosis. Five years later, a successful liver/pancreas transplantation was performed. Eighteen months later, however, pancreatic insufficiency occurred due to thrombosis of the pancreatic graft. Besides these conditions, iron deficiency, pernicious anemia, and autoimmune gastritis were also diagnosed. Serum parietal cell antibodies (PCA) and intrinsic factor antibodies (AIF) were positive. At 45, this patient was found to have a gastric carcinoid tumor. The clinical importance of PCA is discussed with regard to chronic atrophic gastritis and pernicious anemia, which both predispose toward gastric carcinoid tumors. Autoimmune type 1 diabetic patients who have a high prevalence of PCA should be screened for gastric autoimmune manifestations and tumors, as the history of this patient illustrates.

Use of an islet cell antibody assay to identify type 1 diabetic patients with rapid decrease in C-peptide levels after clinical onset. Belgian Diabetes Registry.

OBJECTIVE: To investigate whether the presence of antibody markers at diagnosis could help predict the rapid decrease in residual beta-cell function noted in some, but not all, patients with recent-onset type 1 diabetes. RESEARCH DESIGN AND METHODS: We measured random C-peptide levels (radioimmunoassay); islet cell cytoplasmic antibodies (ICA) (indirect immunofluorescence); and antibodies against IA-2 protein, 65-kDa glutamate decarboxylase, and insulin (liquid-phase radiobinding assays) in 172 patients <40 years of age with type 1 diabetes. The patients had been consecutively recruited at diagnosis by the Belgian Diabetes Registry and were followed for 2 years. RESULTS: Two years after diagnosis, random C-peptide levels had decreased significantly (P < 0.001) in ICA+ patients but not in ICA- patients. C-peptide values <50 pmol/ were noted in 88% of patients diagnosed before 7 years of age, in 45% of patients diagnosed between ages 7 and 15 years, and in 29% of patients diagnosed after 15 years of age (P < 0.001). In cases of clinical onset before age 15 years, a rapid decline in random C-peptide values was observed almost exclusively in patients with high-titer ICA (> or =50 Juvenile Diabetes Foundation [JDF] units) at diagnosis (69 vs. 17% in patients with lower ICA titers, P < 0.001). In patients diagnosed after 15 years of age, 36% of patients with ICA titers > or =12JDF units developed low C-peptide levels compared with 14% of patients with ICA titers < 12 JDF units (P < 0.03). Multivariate analysis confirmed that C-peptide levels after 2 years were inversely correlated with ICA levels (P < 0.001) and to a lesser degree positively correlated with age at diagnosis (P < 0.02), regardless of the levels or number of molecular autoantibodies. CONCLUSIONS: Young age at diagnosis and high-titer ICA identify a group of type 1 diabetic patients at high risk of rapidly losing residual beta-cell function. Using these selection criteria, it is possible to better target beta-cell-preserving interventions to patients with or without such rapid progression, depending on the nature of the tested substance. The ICA assay measures clinically relevant antibodies not detected in antibody assays that use recombinant human autoantigens for substrate.

High prevalence of manifestations of gastric autoimmunity in parietal cell antibody-positive type 1 (insulin-dependent) diabetic patients. The Belgian Diabetes Registry.

Previous studies have shown a high prevalence of gastric parietal cell antibodies (PCA) in type 1 diabetes, which can be accompanied by (sub)clinical autoimmune gastric disease. This study aimed to determine the grade of associated autoimmunity and to assess the pattern of prevalence of PCA by gender, age, duration of disease, age at onset of diabetes, and human leukocyte antigen (HLA) type in an adult type 1 diabetic population. Furthermore, to examine the clinical significance of being PCA positive, manifestations of gastric autoimmune disease were studied in PCA-positive and PCA-negative patients. The population studied consisted of 497 type 1 diabetics (men/women, 252/245; mean age, 40.8 +/- 12.1 yr; mean duration of disease, 16.4 +/- 10.4 yr; mean age at onset, 26.9 +/- 13.5 yr; mean hemoglobin A1c, 8.1 +/- 1.6%). Associated autoantibodies were present in 39% and PCA were present in 20.9% of the subjects, particularly in older patients. Gender, duration, and age at onset of diabetes did not influence the appearance of PCA. Antithyroid peroxidase antibodies (aTPO) were more frequent in PCA-positive patients than in those without PCA (33.6% vs. 22.4%; P = 0.025), suggesting an association between gastric and thyroid autoimmunity. We could demonstrate an association between PCA and the HLA DR5 haplotype (P = 0.001) as well, but not with HLA DR3 and/or DR4. In the PCA-positive group, iron deficiency anemia was detected in 15.4%, and pernicious anemia was found in 10.5% of subjects. These autoimmune gastric manifestations were significantly more prevalent in PCA-positive diabetics than in PCA-negative subjects, in whom the percentages were 6.9% and 0.5%, respectively (P = 0.01 and P < 0.0001). PCA were prevalent in 84.6% of patients with pernicious anemia. A gastroscopic and anatomopathological examination performed in a subgroup of 30 patients with gastric symptoms revealed atrophic gastritis in 13 of 14 PCA-positive patients and in 9 of 16 PCA-negative subjects (P = 0.04). PCA were present in 59.1% of patients with atrophic gastritis. In conclusion, a high prevalence of parietal cell antibodies and associated autoimmune gastric disease is present in PCA-positive type 1 diabetics, recommending its screening. Early detection of PCA and iron deficiency anemia, pernicious anemia, and atrophic gastritis and the subsequent care could reduce the morbidity of type 1 diabetes.

Clinical endocrinology of human leptin.

Since the discovery of leptin, a boom of scientific knowledge became available about the OB-protein gene and its role and significance in weight regulation. Both from animal and human research data, serum leptin can probably be considered as one of the best biological markers to reflect total body fat, and this finding is true over a wide range of body mass indexes (BMIs) and in different pathologies: in normal weight, anorexic and obese subjects; in non insulin-dependent diabetes mellitus (NIDDM) patients, PCO women, Prader-Willi children and subjects with hypogonadism and growth hormone deficiency. Gender differences clearly exist, probably related to sex hormone differences, and from fat distribution studies it could be shown that subcutaneous fat is much more related to serum leptin concentrations than visceral fat: also leptin messenger-RNA (m-RNA) expression is significantly higher in subcutaneous fat from human obese subjects. Leptin is not only correlated to a series of endocrine parameters such as insulin, insulin-like growth factor, (IGF) and SHBG, it seems involved as a mediator in some endocrine mechanisms (onset of puberty, insulin secretion, etc) as well. Weight loss will reduce human leptin concentrations, whereas the administration of human recombinant leptin seems to show only limited effects.

Anti-obesity drugs: what does sibutramine offer? An analysis of its potential contribution to obesity treatment.

Sibutramine is a serotonin and noradrenaline re-uptake inhibitor (SNRI) which induces weight loss via a dual mode of action: enhancing both satiety and energy expenditure. Sibutramine exerts its in vivo effects predominantly via its secondary and primary amine metabolites. Following oral ingestion, sibutramine is well absorbed and undergoes extensive first pass metabolism. Sibutramine produces statistically and clinically significant, dose-related weight loss over the range 5-30 mg once daily; active weight loss occurs for 6 months. Long-term studies of up to 1 year have found that weight loss is maintained with continued sibutramine therapy. Sibutramine-induced weight loss is associated with beneficial changes in obesity-related risk factors, such as serum lipids, uric acid levels, and glycaemic control (in patients with type 2 diabetes). Subcutaneous/visceral fat ratio was found to increase significantly under sibutramine treatment, indicating that relatively more visceral fat than subcutaneous fat is lost. Sibutramine is well tolerated; side-effects are generally mild, non-treatment limiting, and consistent with the known mechanism of action of the drug. Overall, studies have found sibutramine to be an effective weight loss agent with a good safety profile.

Sibutramine and fat distribution: is there a role for pharmacotherapy in abdominal/visceral fat reduction?

Visceral adiposity has a strong and independent association with obesity and its related co-morbidities, particularly metabolic complications such as cardiovascular disease and type II diabetes. Waist circumference and waist-to-hip ratio (WHR) are both secondary indicators of visceral obesity. This paper examines the effect of sibutramine, a new serotonin and noradrenaline re-uptake inhibitor, on weight reduction and changes in fat distribution. A meta-analysis of four long-term, placebo-controlled, double-blind studies showed significantly greater mean decreases in waist circumference in sibutramine-treated subjects compared with placebo (P < 0.001). Similar results were seen for WHR, with 15 mg sibutramine daily producing a significant reduction of 0.02 compared with placebo (P < 0.02). Changes in fat distribution have been examined using computerised tomography (CT) scans as part of the Sibutramine Trial of Obesity Reduction and Maintenance (STORM). Preliminary results showed a mean weight loss from baseline of 11.2 +/- 6.3 kg after 6 months of 10 mg sibutramine treatment. Decreases in total abdominal fat (18%), total subcutaneous fat (17%) and total visceral fat (22%) were observed, and there was a significant increase in the subcutaneous-to-visceral fat ratio (P = 0.04). These changes in fat levels and distribution were associated with improvements in related risk factors such as fasting blood glucose and insulin levels, and blood pressure. In conclusion, sibutramine produces statistically and clinically significant decreases in waist circumference and WHR, and preferentially reduces visceral fat levels.

The in vitro oxidizability of lipoprotein particles in obese and non-obese subjects.

There exists much evidence suggesting a major role for the oxidized low density lipoprotein (LDL) and VLDL particles in the pathogenesis of atherosclerosis. Although obesity is characterized by dyslipidemia, less is known about the oxidation capacity of lipoproteins in obese subjects. We measured the oxidizability in vitro in 21 premenopausal women with a BMI of 36.7+/-5.4 and compared them to 18 age-matched controls (BMI 21.9+/-1.8). The oxidizability of the non-HDL fraction is evaluated by measuring the fluorescence and thiobarbituric acid reactive substances (TBARS; MDA nM/mg non-HDL) at different time intervals of incubation. TBARS formation increased linearly with the increase of lipids both in non-obese and obese subjects. TBARS, measured every 30 min, increased in non-obese controls up to a maximum of 59.6 at 180' in contrast to a maximum of 77.1 at 180' (P < 0.001) in obese, but healthy, normocholesterolemic subjects. At each measurement the TBARS were significantly higher (P < 0.01-0.001) in obese subjects. Also the lag-time (period from zero to the start of the particle oxidation process) was significantly lower (92.5 vs. 123.4; P < 0.001) in obese subjects, when compared to lean controls. BMI correlates significantly with TBARS formation and its log transformed values (maximum P < 0.001). The lag-time was negatively related (n=39 total group, r=- 0.57, P < 0.001) to body weight and BMI. A significant relationship exists between TBARS formation (up to r=0.59) and triglyceride levels and a negative relationship exists with HDL-cholesterol levels. In vitro oxidizability of non-HDL lipoproteins is significantly increased in obese, non-diabetic subjects and related to increased body weight and triglyceride levels. Further studies are necessary to explore the underlying mechanisms for this phenomenon.