Heterogeneity of patients with LADA: linkage to autoimmunity is apparent only in those with perceived need for insulin treatment. Results from the Nord-Trøndelag Health study (HUNT).

Abstract

Aim: Subjects diagnosed as Latent Autoimmune Diabetes in the Adult (LADA) are more prone to need insulin treatment than type 2 diabetes (T2D). However, not all LADA patients develop need for insulin treatment, indicating heterogeneity of LADA. We investigated heterogeneity by comparing phenotypes of LADA with and without perceived need for insulin treatment (data obtained at times when diagnosis of LADA was not investigated) and also compared LADA and T2D phenotypes

Methods: We used data from the all-population-based Nord-Trøndelag Health Study (n=64931), performed 1995-97. Data were assembled for LADA (n= 106) and type 2 diabetes (n=943).

Results: Comparing LADA with and without insulin: Insulin-treated subjects had higher titres of anti-GAD (p<0.001) and lower fasting C-peptide (p<0.001). Anti-GAD and C-peptide correlated negatively (r=-0.40; p=0.009). Comparing LADA and T2D, both without insulin: Markers of metabolic syndrome were equally prevalent and pronounced. Also age, C-peptide and glucose levels were similar. Comparing insulin-treated LADA and insulin-treated T2D: More LADA patients received insulin (40% vs. 22%, p<0.001) and C-peptide levels were lower (p<0.001). LADA patients were leaner, but still overweight (mean BMI 28.7 vs. vs. 30.9 in T2D (p<0.001). Comparing T2D with and without insulin: Insulin treated subjects were more obese, had higher HbA1c and lower C-peptide (p<0.001).

Conclusions: 1) Need for insulin treatment in LADA is linked to the degree of autoimmunity and beta cell failure. 2) LADA and T2D subjects without need for insulin treatment are phenotypically similar 3) Insulin treatment in T2D is associated with both insulin resistance and beta cell insufficiency.