Abstract: Objective To identify the effect of interdialytic weight gain (IDWG) on pulse wave velocity (PWV) in hemodialysis patients. Methods We recruited 27 hemodialysis patients (thrice per week) in this study. Their body weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), extracellular water (ECW) by bioimpedance method, and carotid-femoral PWV were measured after a hemodialysis session and before the next session. Results In the 27 patients we tested, 12 were male, 15 were female, and the mean age was 61±12 years. After a hemodialysis session, their body weight increased from 62.5±11.2 kg to 64.1±11.9 kg (P＜0.001), their ECW increased from 14.0±2.5L to 15.5±3.1L (P＜0.001), but their SBP, DBP and PWV (11.0±1.8 m/s to 10.4±2.0 m/s, P>0.05) did not show any significant changes. These patients were then divided into low IDWG group (n=14) and high IDWG group (n=13) based on the median value of IDWG. In high IDWG group, patients had higher increases of weight, ECW and SBP but without significant change in PWV, as compared with those in low IDWG group. Pearson’s correlation analysis showed that SBP and DBP elevations were positively correlated with the increase of PWV (r=0.554, P＜0.01 and r=0.537, P＜0.01, respectively). Multiple regression analysis revealed that SBP was the single and independent determinant of PWV change (B=0.039, P＜0.005; adjusted R2=0.268), while age, diabetes, weight and DBP were excluded from this model. Conclusion During the interdialytic period, IDWG did not cause significant PWV change. Among the factors of age, diabetic status, SBP and IDWG, SBP change was the most important one which affected PWV change.

Key words: Blood pressure, Volume status, Pulse wave velocity.