Uric acid as a link between renal dysfunction and both pro-inflammatory and prothrombotic state in patients with metabolic syndrome and coronary artery disease.

BACKGROUND: Hyperuricaemia has long been known to be associated with cardiovascular disease, and it is particularly common in patients with kidney disease, metabolic syndrome and diabetes mellitus. Metabolic syndrome is associated with pro-inflammatory and prothrombotic state.

AIM: To examine the association between renal function, serum uric acid and markers of both pro-inflammatory and prothrombotic state in patients with diabetes mellitus (DM), metabolic syndrome and coronary artery disease.

METHODS: The study population consisted of 91 patients (58 men, 33 women) aged 57.6 ± 10.3 years with metabolic syndrome and type 2 DM. Patients were selected from a large group of patients scheduled for routine coronary angiography between 2006 and 2009. The patients were evaluated for the common risk factors for atherosclerosis: smoking, hypertension, DM, family history and hyperlipidaemia. Laboratory tests included complete blood counts, serum urea and creatinine, aminotransferases, C-reactive protein (CRP), fibrinogen, uric acid, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, fasting glucose, glycated haemoglobin (HbA1c), glomerular filtration rate (GFR) and urinary protein. We also measured body mass, height, waist circumference, hip circumference and calculated body mass index (BMI) and waist-to-hip ratio (WHR).

RESULTS: The following significant correlations were observed: body mass vs serum creatinine (r = 0.291; p = 0.009), WHR vs serum creatinine (r = 0.672; p < 0.001), WHR vs GFR (r = -0.706; p < 0.001), WHR vs uric acid (r = -0.341; p = 0.001), WHR vs uric acid (r = 0.295; p = 0.05), BMI vs CRP (r = 0.231; p = 0.031), WHR vs CRP (r = 0.236; p = 0.024), serum creatinine vs uric acid (r = 0.362; p < 0.001), GFR vs uric acid (r = -0.341; p = 0.001), uric acid vs CRP (r = 0.251; p = 0.016), CRP vs fibrinogen (r = 0.470; p < 0.001), CRP vs platelet count (r = 0.282; p = 0.04) and HbA(1c) vs platelet count (r = 0.263; p = 0.0112). Multiple stepwise regression analysis showed that uric acid level was independently associated with WHR, GFR and CRP.

CONCLUSIONS: In patients with ischaemic heart disease, DM and metabolic syndrome, obesity, particularly visceral obesity, is associated with renal dysfunction and elevated markers of pro-inflammatory state. Renal dysfunction co-exists with elevated serum uric acid. Elevated serum uric acid is associated with markers of pro-inflammatory state. Markers of pro-inflammatory state correlate with prothrombotic markers such as serum fibrinogen and platelet count. Uric acid should be taken into consideration as a link between renal dysfunction and both pro-inflammatory and prothrombotic state in patients with metabolic syndrome and coronary artery disease.