#4124 SEX AND CARDIOVASCULAR DISEASE IN STAGE G2-5 CKD PATIENTS

Abstract

Abstract Background and Aims Male sex is considered a major risk factor for cardiovascular (CV) disease in the general population, but the role of this factor in the high risk for CV disease in the pre-dialysis CKD population is still debated. Methods We tested the relationship between sex and fatal and non-fatal major CV events (myocardial infarction, heart failure, arrhythmia, angina, stroke, transient ischemic attack, peripheral vascular disease, major arterial or venous thrombotic episodes and sudden death) in a cohort including 759 stage 2-5 CKD consecutively recruited from 22 Nephrology units in southern Italy between October 2005 and September 2008. After the initial assessment, patients were followed up for a median time of 36 months (range 0.3–48 months). Results Four hundred fifty-five patients were males (60%). The proportion of smokers was about 4 times higher in males (71.4%) than in females (17.4%). Males and females differed in the prevalence of diabetes (38.5% versus 29.6%) and the frequency of background CV comorbidities (35.6% versus 19.7%, P<0.001). Waist circumference (100.9±12.4 versus 96±14.1 cm), eGFR (37.5±13.4 versus 33±12.7 ml/min/1.73 m2), 24-hour urinary protein excretion (median: 0.7 g/24h, IQR: 0.2-1.6 g/24h versus 0.5, IQR: 0.2-1.2 g/24 h), and haemoglobin (13.4±1.9 versus 12.0±1.4 g/dL) were higher in males than in females. Serum phosphate (3.6±0.75 versus 3.9±0.75 mg/dL), hs-CRP (median; 2.2 mg/dl, IQR: 1-4.7mg/dl versus 2.8 mg/dl, IQR: 1.2-6.4 mg/dl) and total cholesterol (178.3±42.1 versus 198.8±45.6 mg/dl) were lower in males than in females. During follow-up, 42 patients died, and 118 had fatal and non-fatal CV events. On univariate Cox regression analyses, male gender failed to be associated with all-cause mortality but was strongly related to the incidence rate of fatal and non-fatal major CV events [HR 1.75, 95% CI: 1.18-2.60, P=0.006]. Data adjustment for a series of major potential confounders did not materially affect the strength of this relationship [HR:1.78, 95% CI: 1.03-3.09]. Further analysis testing the effect of age on major CV outcomes by gender showed an effect modification by this risk factor on the same outcome (P=0.037) because the hazard ratio of male versus female CV events increased progressively with ageing (Figure 1). Conclusion The excess risk for CV mortality by the male gender in the general population holds in stage G2-5 CKD patients. Age is a modifier for the excess risk for CV events in CKD patients because the risk excess of the male gender increases linearly across a wide age spectrum in CKD patients.