Aldosterone Blockade Attenuates Urinary Monocyte Chemoattractant Protein-1 and Oxidative Stress in Patients with Type 2 Diabetes Complicated by Diabetic Nephropathy

Abstract

CONTEXT: Aldosterone causes organic impairment by enhancement of oxidative stress and subsequent induction of proinflammatory cytokines and chemokines. OBJECTIVE: This study was designed to investigate the effect of spironolactone, an aldosterone blocker, on oxidative stress and the level of urinary monocyte chemoattractant protein (MCP)-1, a cysteine-cysteine chemokine that may contribute to progression of various nephropathies in type 2 diabetic patients with diabetic nephropathy. DESIGN, SETTING, PATIENTS AND OTHER PARTICIPANTS, AND INTERVENTION: The patients were randomly assigned to two groups in which they received either spironolactone (50 mg/d; n = 23) or amlodipine (2.5 mg/d; n = 14). MAIN OUTCOME MEASURES: Urinary 8-iso-prostaglandin (PG) F2alpha (a marker of oxidative stress), urinary MCP-1, and urinary albumin excretion (UAE) were measured at the start of administration (0 months) and after 3 months in each group. Baseline levels of these variables were also measured in 25 age-matched healthy subjects. RESULTS: There were significant positive correlations between log(10)-transformed (log) 8-iso-PGF2alpha and log MCP-1 levels in control and diabetic subjects and all subjects combined, but no correlations between log UAE and log 8-iso-PGF2alpha or log MCP-1 were found in any group. Significant decreases in 8-iso-PGF2alpha, MCP-1, and UAE were observed with spironolactone (P = 0.0001, P = 0.0041, and P = 0.0037, respectively), and systolic blood pressure significantly decreased after both spironolactone and amlodipine therapy (P = 0.00011 and P = 0.0051, respectively). CONCLUSIONS: Our data suggest that urinary MCP-1 is correlated with oxidative stress as measured by urinary 8-iso-PGF2alpha and that spironolactone can decrease urinary MCP-1 and oxidative stress.