Phenotypic heterogeneity of latent autoimmune diabetes in adults identified by body composition analysis

Background: In patients with Latent Autoimmune Diabetes in Adults (LADA) a lower body mass index was reported compared with classical type 2 diabetes (T2D), and was found to be associated with a faster progression to insulin-dependence. In this study we determined the body composition in a cohort of LADA patients from Sardinia, Italy, and compared it with age–and gender–matched patients diagnosed as having adult-onset type 1 diabetes (T1D) and non-autoimmune T2D. Methods: In 210 LADA patients, 210 T2D patients and 30 adult-onset T1D patients of Sardinian origin we assessed total and segmental body composition (weight-adjusted percent fat mass and lean mass) by using Dual Energy X-rays Absorptiometry (DXA). Results: In the whole cohort of LADA patients total fat mass was significantly smaller compared with T2D patients (p < 0.0001), while no difference was found between LADA and T1D patients. In LADA men fat depletion involved all body segments, while in LADA women it was observed only in the truncal segment (p < 0.0001), as in the upper and lower regions fat deposits were larger compared to T2D (p < 0.0001). However, LADA women showed a significantly elevated truncal fat compared to T1D women (p < 0.004), whereas no difference was detected in the extremities. Conclusions: Body composition in LADA patients shows substantial difference, in a gender-dependent way, compared to classic T2D. In women fat deposits tend to accumulate in peripheral regions rather than centrally, whereas in men the distribution is more homogeneous. In addition, central fat depletion in LADA women appears to be a significant predictor of faster progression to insulin dependence. Thus, routine assessment of body composition may help the physician identify LADA patients who require early insulin treatment in order to delay beta-cell exhaustion, as well those with increased CV risk due to excess truncal adiposity.