Plasma adiponectin and serum advanced glycated end-products increase and plasma lipid concentrations decrease with increasing duration of type 2 diabetes

Abstract

Objective: To prospectively follow the concentrations of plasma adiponectin (p-adiponectin) and serum advanced glycation end-products (s-AGE) in relation to plasma lipids and retinopathy over 3 years in type 2 diabetic patients. Design and methods: P-adiponectin, s-AGE, plasma lipids and diabetic retinopathy were prospectively evaluated in 61 type 2 diabetic patients at baseline and at follow up 3 years later. Results: Mean p-adiponectin (from 8.84^5.14 to 11.05^6.16 mg/ml; P ¼ 0.006) and s-AGE (from 637^242 to 781^173 ng/ml; P , 0.0001) concentrations had increased at follow up. In addition, HbA1c (7.7^1.7 to 7.4^1.4%; P ¼ 0.0045) and fasting C-peptide (1.00^0.38 to 0.81^0.35 nM; P ¼ 0.019) had decreased and all lipid variables had significantly improved at follow up. P-adiponectin correlated inversely with fasting C-peptide (r s ¼ 20.273; P ¼ 0.045) and low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio (r s ¼ 20.362; P ¼ 0.011), and directly with plasma HDL cholesterol (r s ¼ 0.381; P ¼ 0.005) at follow up. Analysis of variance with adiponectin and s-AGE as dependent variables and fasting C-peptide, plasma HDL and plasma LDL cholesterol as covariates demonstrated that the increase in s-AGE was independent (P ¼ 0.001) and the increase in p-adiponectin dependent on covariate changes (P ¼ 0.862). There was a slight correlation between s-AGE at baseline versus the degree of retinopathy at follow up (r s ¼ 0.281; P ¼ 0.0499).

Elevated circulating adiponectin in type 1 diabetes is associated with long diabetes duration

“…Thus, our study seemed to suggest that a preserved endogenous secretion of insulin was of importance for the marked difference in circulating adiponectin levels. In a study of patients with type 2 diabetes examined on two occasions, an association was found between the decline in C‐peptide levels over time and the increase in plasma adiponectin 26 . Although there are many differences between type 1 and type 2 diabetes, including high levels of adiponectin in type 1 diabetes 14–17 and low levels in type 2 diabetes, 8 these results are in agreement with the idea of endogenous insulin secretion modifying adiponectin levels.…”

The in vitro Effects of Advanced Glycation End Products on Basophil Functions

“…upregulation of surface RAGE expression (only marginally), secretion of inflammatory cytokines, and induction of apoptosis. The physiological serum concentration of GEs is usually less than 1 µg/ml [19], but higher levels of AGEs have been observed in diabetic patients [20]. It will be important for future studies to assess the extent to which our present results can explain the actual roles of basophils in disease conditions.…”

Associations between Markers of Liver Injury and Cytokine Markers for Insulin Sensitivity and Inflammation in Middle-Aged Japanese Men Not Being Treated for Metabolic Diseases

“…Higher plasma adiponectin concentrations in healthy and type 2 diabetic subjects in Western and Asian countries, including Japan, have been shown to be associated with lower fasting glucose, triacylglycerol, total cholesterol and low-density lipoprotein-cholesterol concentrations, and higher high-density lipoprotein (HDL)-cholesterol concentrations (18)(19)(20)(21)(22)(23). In addition, it has been reported that insulin resistance and hyperglycemia in people with diabetes are associated with elevated plasma protein levels of circulating inflammatory cytokines such as interleukin (IL)-1 ␤ , IL-6, IL-12, IL-18 and tumor necrosis factor (TNF)-␣ ( 24 -26 ).…”