The Effect of Renin Angiotensin System Blockage (RAS) Blockade On PTX3 Levels In Diabetic Patients With Proteinuria

Overview

Long pentraxin 3 (PTX3) is a recently discovered multimeric inflammatory mediator structurally linked to CRP and serum amyloid P-component. There is no data about the effects of Renin angiotensin system blockage (RAS) on PTX3 levels in diabetic patients with proteinuria. The aim of this study was to find out whether the beneficial effects of RAS blockage in diabetic proteinuria has any relation with the alteration of PTX3 levels. We searched for the effects of ACE inhibitor ramipril on the clinical and laboratory parameters of diabetic patients with proteinuria.

The patients who were non-obese (BMI\<30kg/m2), non dyslipidemic (total cholesterol \<200mg/dl, Triglyceride\<150mg/dl), and free of cardiovascular events (negative medical history, negative ECG findings) were investigated for enrollment. CKD stage 1 patients older than 18 years of age and willing to participate to the study were screened. From the 266 patients with established type 2 diabetes mellitus, 141 had proteinuria and/or hypertension (24 h protein excretion 1-2 g/day, systolic blood pressures ≥140mmHg and/or diastolic blood pressures ≥ 90 mmHg, respectively). All cases were first referrals and at the time of the study all were off treatment. Patients with history of coronary artery disease, smokers and those taking statins or renin-angiotensin blockers were excluded because of the effect of these factors on endothelial dysfunction. Of 141 screened patients 60 met the study criteria and were included in this study. The duration of proteinuria and diabetic nephropathy after initial diagnosis was not known. The exclusion criteria were as follows: A)Nephrotic syndrome, B)coronary heart disease (patients with ischemic ST-T alterations and voltage criteria for LVH on electrocardiogram, and with history of revascularization or myocardial infarction), C) elevated liver enzymes (AST or ALT levels ≥ 40U/L) and D) renal failure (serum creatinine levels \> 1.3 mg/dl). In order to evaluate the effect of RAS blockade on plasma PTX3 concentrations, patients with proteinuria were given an ACE inhibitor (ramipril 5 mg/day) for 12 weeks. The effect of RAS blockade on insulin sensitivity and proteinuria was also investigated. After the intervention period, blood samples were obtained for assay of plasma PTX3 concentrations, HbA1c , and insulin resistance scores (HOMA-IR). Urine samples were also collected over a 24-hour period to determine the degree of proteinuria.