Beta Cell Function in (Pre) Type 1 Diabetes

Inclusion Criteria: * The following groups of first degree relatives of type1 diabetes patients with normal glucose tolerance during OGTT (5-39 years) will be included after informed consent on the basis of their antibody status (n = 40 per group): * IA-2A-positives; * Ab.-positives (positive for at least 2 different Abs. (IAA, GADA and/or ICA) and/or persistently Ab.-positive for 1 of these Abs; * persistently Ab.-negatives. * 40 type 1 diabetes patients with the following criteria will be studied: 1) aged 12-39 years; 2) \< 4 weeks of insulin treatment; 3) auto-Ab.-positive; 4) polyuria since \< 6 months; 5) \< 10% weight loss over the last 6 months; 6) informed consent. Exclusion Criteria: * Pregnancy or lactation in women * Use of illicit drugs or overconsumption of alcohol (\> 3 beers/day) or history of drug or alcohol abuse * Being legally incapacitated, having significant emotional problems at the time of the study, or having a history of psychiatric disorders * Having received antidepressant medications during the last 6 months * Treatment with immune modulating or diabetogenic medication (such as corticosteroids) * Presently participating in another clinical study * History of any illness that, in the opinion of the investigator, might confound the results of the study or pose additional risks to the subjects