Effects of overhydration, Kt/Vurea, β2‐microglobulin on coronary artery calcification and mortality in haemodialysis patients

Abstract Aim We studied the effects of overhydration (OH), Kt/Vurea and β2‐microglobulin (β2‐MG) on coronary artery calcification and mortality in patients undergoing haemodialysis (HD). Methods The Agatston coronary artery calcium score (CACS), postdialysis body composition using bioimpedance analysis, single‐pool Kt/Vurea and predialysis β2‐MG at baseline were assessed and followed up for 3 years in patients undergoing HD. We performed logistic regression analyses for a CACS ≥400 and Cox proportional hazard analyses for all‐cause and cardiovascular mortality. Results The study involved 338 patients with a median age of 67 (56–74) years, dialysis duration of 70 (33–141) months and diabetes prevalence of 39.1% (132/338). Patients with a CACS ≥400 ( n = 222) had significantly higher age, dialysis duration, male prevalence, diabetes prevalence, C‐reactive protein, predialysis β2‐MG, OH, extracellular water/total body water and overhydration/extracellular water (OH/ECW) but significantly lower Kt/Vurea than patients with a CACS <400 ( n = 116) ( p < .05). OH/ECW, Kt/Vurea and predialysis β2‐MG were significant predictors of a CACS ≥400 ( p < .05) after adjusting for age, dialysis duration, serum phosphate and magnesium. In all patients, cut‐off values of OH/ECW, Kt/Vurea and predialysis β2‐MG for a CACS ≥400 were 16%, 1.74 and 28 mg/L, respectively. After adjusting for dialysis duration, OH/ECW ≥16%, Kt/Vurea ≥1.74 and β2‐MG ≥28 mg/L were significant predictors of 3‐year all‐cause mortality but not 3‐year cardiovascular mortality. Conclusion Higher OH/ECW, higher predialysis β2‐MG and lower Kt/Vurea values are significant risk factors for a CACS ≥400 and 3‐year all‐cause mortality in patients undergoing maintenance HD. image