Diagnosis Of Diabetes In Adults Research Articles

Ophthalmic disorder in patients with latent autoimmune diabetes in adult

It is well known that about 90% of all cases of diabetes mellitus (DM) are type 2, which is characteristic for adults aged above 40 years. Ten percent is represented by type 1 DM, typical for children and young. Adult's onset diabetes represent a heterogeneous mixture of type 1 and type 2 DM, often difficult to differentiate between, those patients may have actually latent autoimmune diabetes in adults (LADAs), where beta-cell destruction is less aggressive, leading to a slower development of insulin dependency. Studies indicated that antibodies against glutamic acid decarboxylase 65 (GAD 65) are good marker for diagnosis of autoimmune diabetes in adults who are not responding to oral hypoglycemic and may be at risk for getting complications namely increased risk of diabetic retinopathy. GAD 65 is mainly expressed in beta-cells of Langerhans but also in nonbeta-cells. GAD is an enzyme required for gama-aminobutyric acid (GABA) synthesis that acts as neurotransmitter in neurons of central nervous system and in pancreatic islets. GABA is probably involved in controlling the release of insulin from secretary granules.

Divergence between HbA1c and fasting glucose through childhood: implications for diagnosis of impaired fasting glucose (Early Bird 52).

An HbA1c threshold of ≥ 6.5% has recently been adopted for the diagnosis of diabetes in adults, and of ≥ 5.7% to identify adults at risk. Little,however, is known of HbA1c's behaviour or diagnostic value in youth. Our aim was to describe the course of HbA1c during childhood, and its association with fasting glucose. HbA1c and glucose were measured every year in a cohort of 326 healthy children (162 boys) from 5 to 15 years. Mixed effects modelling was used to establish the determinants of HbA1c and its development over time. ROC analysis was used to determine the diagnostic value of HbA1c in the 55 individuals who showed impaired fasting glucose(IFG – glucose ≥ 5.6 mmol/L). Glucose rose progressively from 4.3 mmol/L at 5 years to 5.1 mmol/Lat 15 years, and although there were positive associations between HbA1c and glucose, from 10 to 13 years, HbA1c fell while glucose continued to rise. IFG developed in 55 children, but HbA1c exceeded 5.7% in only 16 of them. The maximum area under the ROC curve was 0.71 at the age of 14 (p<0.001), and the sensitivity and specificity were optimal at 50 and 80% respectively,corresponding to HbA1c of 5.4%. Although HbA1c retains a positive association with glucose throughout childhood, it is weak, and their trends diverge from 10 years,suggesting that factors other than glycaemia systematically influence the variance of HbA1c in youth. These findings therefore limit the interpretation of HbA1c for the diagnosis of IFG during childhood.

Glutamic Acid Decarboxylase Antibodies in Screening for Autoimmune Diabetes: Influence of Comorbidity, Age, and Sex on Specificity and Threshold Values

Antibodies against the 65-kDa isoform of glutamic acid decarboxylase (GAD65) can be applied as a predictive tool for childhood type-1 diabetes (1)(2)(3)(4)(5)(6) and to facilitate the differential diagnosis of diabetes in adults (7)(8)(9). However, the sensitivity and specificity of GAD antibody screening have not been fully characterized, and the positive predictive value of screening varies from 20% to 70%, depending on the strategy applied and the population studied (2)(3)(5)(6)(7)(9)(10)(11)(12). The current study aims to identify factors that may lead to false-positive results in GAD antibody screening. Previously, it has been demonstrated that the GAD antibody frequency in mixed connective tissue disease and stiff-man syndrome is increased, although not all patients who suffer from these diseases and are positive for GAD antibodies develop type-1 diabetes (13)(14). GAD is expressed in the islets of Langerhans, neuronal tissue, the ovaries, and the testes (15)(16). Similar to the above-mentioned examples, comorbidity involving these tissues may lead to GAD antibody formation but not to diabetes. Therefore, we compared the prevalence of GAD antibodies in patients with cystic fibrosis, epilepsy, Guillain-Barre syndrome, and premature ovarian failure to the prevalence in an unselected population of 1403 schoolchildren. In addition, thresholds for positivity for GAD antibodies have generally been defined in children. These thresholds might not be applicable when testing for type-1 diabetes in adults. Therefore, we studied whether GAD antibody concentrations are correlated to age and sex, and whether adjustment of assay thresholds to include these variables may improve screening specificity. The frequencies of positive results for GAD antibodies and the concentrations of GAD antibodies were established in a population of 1403 …