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

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 microg/ml; P=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=0.0045) and fasting C-peptide (1.00+/-0.38 to 0.81+/-0.35 nM; P=0.019) had decreased and all lipid variables had significantly improved at follow up. P-adiponectin correlated inversely with fasting C-peptide (r(s)=-0.273; P=0.045) and low-density lipoprotein (LDL)/high-density lipoprotein (HDL) ratio (r(s)=-0.362; P=0.011), and directly with plasma HDL cholesterol (r(s)=0.381; P=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=0.001) and the increase in p-adiponectin dependent on covariate changes (P=0.862). There was a slight correlation between s-AGE at baseline versus the degree of retinopathy at follow up (r(s)=0.281; P=0.0499). CONCLUSION: Both p-adiponectin and s-AGE increased during the 3 years. The increase in p-adiponectin was explained by improvements in insulin sensitivity and dyslipidaemia, whereas the increase in s-AGE was independent of changes in metabolic covariates. s-AGE increase when the duration of type 2 diabetes increases.

Cardiovascular autonomic neuropathy associated with carotid atherosclerosis in Type 2 diabetic patients.

AIMS: To clarify if cardiovascular autonomic neuropathy is associated with carotid artery atherosclerotic plaques in Type 2 diabetic patients. METHODS: Cardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients 5-6 years after diagnosis of diabetes. RESULTS: Cardiovascular autonomic neuropathy [abnormal age corrected expiration/inspiration (E/I) ratio or acceleration index (AI)] was found in 13/61 (21%) patients. Patients with cardiovascular autonomic neuropathy showed increased degree of stenosis in the common carotid artery (24.6 +/- 13.2% vs. 14.7 +/- 9.2%; P = 0.014) and a tendency towards a higher plaque score (4.0 +/- 1.7 vs. 3.2 +/- 1.6; P = 0.064). Controlled for age, AI correlated inversely with degree of stenosis (r = -0.39; P = 0.005), plaque score (r = -0.39; P = 0.005), and mean (r = -0.33; P = 0.018) and maximum (r = -0.39; P = 0.004) intima-media thickness in the common carotid artery. In contrast, E/I ratio correlated only slightly with mean intima-media thickness in the common carotid artery (r = -0.28; P = 0.049). CONCLUSIONS: Cardiovascular autonomic neuropathy was associated with carotid atherosclerosis in Type 2 diabetic patients. Abnormal E/I ratios reflect efferent structural damage to parasympathetic nerves whereas abnormal AI reflects afferent autonomic dysfunction possibly due to impaired baroreceptor sensitivity secondary to carotid atherosclerosis.