The Role of Adiponectin as a Compensatory Mediator for the Primary Secretory Defect in Latent Autoimmune Diabetes in Adults

Latent autoimmune diabetes in adults in China

Latent autoimmune diabetes in adults (LADA) is a type of diabetes caused by slow progression of autoimmune damage to pancreatic beta cells. According to the etiological classification, LADA should belong to the autoimmune subtype of type 1 diabetes (T1D). Previous studies have found general immune genetic effects associated with LADA, but there are also some racial differences. Multicenter studies have been conducted in different countries worldwide, but it is still unclear how the Chinese and Caucasian populations differ. The epidemiology and phenotypic characteristics of LADA may vary between Caucasian and Chinese diabetic patients as lifestyle, food habits, and body mass index differ between these two populations. The prevalence of LADA in China has reached a high level compared to other countries. The prevalence of LADA in China has reached a high level compared to other countries, and the number of patients with LADA ranks first in the world. Previous studies have found general immune genetic effects associated with LADA, but some racial differences also exist. The prevalence of LADA among newly diagnosed type 2 diabetes patients over the age of 30 years in China is 5.9%, and LADA patients account for 65% of the newly diagnosed T1D patients in the country. As a country with a large population, China has many people with LADA. A summary and analysis of these studies will enhance further understanding of LADA in China. In addition, comparing the similarities and differences between the Chinese and the Caucasian population from the perspectives of epidemiology, clinical, immunology and genetics will help to improve the understanding of LADA, and then promote LADA studies in individual populations.

Leptin Levels and Insulin Dependence in Latent Autoimmune Diabetes in Adults

Latent autoimmune diabetes in adults (LADA) is an autoimmune type of diabetes accounting for up to 10% of all cases of diabetes initially diagnosed as type 2 diabetes mellitus. It has been demonstrated that LADA patients with a lower body mass index (BMI) undergo a faster depletion of beta cell function and require insulin therapy earlier. In this study, we assayed a panel of adipokines (leptin, adiponectin, omentin, resistin, visfatin) and proinflammatory cytokines (interleukin 2, interleukin 6, tumor necrosis factor-α) in 71 LADA patients and tested the association with a number of clinical and immunological features. Among men, leptin was positively and significantly correlated with BMI and fat mass (r = 0.487 and r = 0.664, respectively), resistin was positively and significantly correlated with total and low-density lipoprotein cholesterol (r = 0.644 and r = 0.746, P < 0.0001) and with interleukin 2 (r = 0.688, P < 0.01). Omentin showed an inverse correlation with systolic blood pressure in women (r = -0.359, P < 0.001) and a positive correlation with interleukin 2 in both genders (r = 0.395, P < 0.01). The Cox regression analysis showed that leptin levels were inversely and significantly related with the risk of early insulin dependence. Higher leptin secretion may exert a direct effect on beta cell function leading to more insulin sensitivity.

Association between serum/plasma adiponectin levels and immune-mediated diseases: a meta-analysis

Adiponectin plays an important role in the development of immune-mediated diseases. Currently published data regarding the relationship between serum/plasma levels of adiponectin and immune-mediated diseases are inconsistent. We therefore conducted this meta-analysis to explore the association of serum/plasma adiponectin levels with immune-mediated diseases in humans. Systematic literature search was conducted to identify all relevant studies. The study quality was assessed by the Newcastle-Ottawa scale. Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by random-effect model analysis. A total of 47 studies were included in our meta-analysis, including 27 studies of type 1 diabetes mellitus (T1DM), 9 studies of rheumatoid arthritis (RA), 7 studies of systemic lupus erythematosus (SLE), and 4 studies of ankylosing spondylitis (AS). The results revealed significant differences in serum/plasma levels of adiponectin between immune-mediated diseases and normal controls (SMD = 1.262, 95% CI 0.766-1.758, p < 0.001). In the subgroup analysis stratified by disease type, the serum/plasma levels of adiponectin in T1DM, RA and SLE patients were higher than those in normal control, but not in AS patients. Moreover, in the subgroup analysis stratified by gender, in both men and women group, the serum/plasma levels of adiponectin in patients with immune-mediated diseases were higher than that in the control group. Furthermore, subgroup analyses also showed that immune-mediated diseases from Asian population, Caucasian population, mean age >40 years, and BMI ≥24 kg/m² had higher serum/plasma adiponectin levels when compared with normal controls. Collectively, this meta-analysis demonstrates that serum/plasma levels of adiponectin in T1DM, RA and SLE patients were higher than those in normal controls, but not in AS patients.