β-cell function and metabolic control in latent autoimmune diabetes in adults with early insulin versus conventional treatment: a 3-year follow-up

Objectives The optimal treatment of latent autoimmune diabetes in adults (LADA) is not established. We explored whether early insulin treatment, which has shown beneficial effects in rodents and in human pilot studies, would result in better preservation of β-cell function or metabolic control, compared with conventional treatment. Subjects and methods Glucagon-stimulated C-peptide and HbAlc were evaluated at baseline and after 12, 24 and 36 months in 37 patients recently diagnosed with diabetes, aged ≥30 years, non-insulin-requiring and GADAb and/or ICA positive. Twenty patients received early insulin and 17 received conventional treatment (diet±oral hypoglycaemic agents (OHA), metformin, some and/or sulfonylurea) and insulin when necessary. Results Level of metabolic control, HbAlc, was preserved in the early insulin treated, while it significantly deteriorated in the conventionally treated. There was no significant difference between the groups in C-peptide after 12, 24 or 36 months, or in the decline of C-peptide. Only baseline C-peptide predicted a C-peptide of ≥0.5 nmol/l at 36 months. Gender, body mass index, antibody titres or HbAlc did not influence the levels of C-peptide or HbAlc at baseline or end-of-study, or the decline in C-peptide. Among the diet±OHA-treated, 5/17 (30%) developed insulin dependency during the follow-up. No major hypoglycaemic events occurred. Conclusions Early insulin treatment in LADA leads to better preservation of metabolic control and was safe. Superior preservation of C-peptide could not be significantly demonstrated. Only baseline level of C-peptide significantly influenced C-peptide level after 3 years. Further studies exploring the best treatment in LADA are warranted.