To investigate whether sodium restriction alters the nocturnal urine volume (NUV) and the ratio of NUV to 24-hour urine of renal allograft recipients (RARs).
This prospective, single-center study analyzed 38 of the 59 RARs who were followed up for more than 6 months in our hospital. All patients underwent 3 sessions of dietary counseling performed by a board-certified dietitian. Before and after these 3 sessions, 24-hour urine samples were collected, along with voiding frequency volume charts.
Of the 38 included RARs, 23 (60.5%) were diagnosed as having nocturnal polyuria (NP, NUV >10 mL/kg). After counseling the RARs with NP, their 24-hour sodium excretion was reduced from 169.5 to 125.6 mEq (P = .0066), their NUV from 862 to 709 mL (P = .021), and the ratio of NUV to 24-hour urine volume from 38.9% to 33.0% (P = .023). In contrast, these parameters were not significantly changed by dietary counseling in RARs without NP. Reduced sodium excretion and decreased NUV were significantly correlated (Spearman rho = 0.45, P = .005).
Excess intake of sodium is considered a cause of NP in RARs. Dietary counseling on sodium restriction is effective in reducing NUV in RARs. Prospective studies are needed to evaluate the general population with NP.
Urology. 2017 Apr 26 [Epub]
Yoshinaga Okumura, Kanae Asai, Takashi Kobayashi, Hitomi Miyata, Yukari Tanaka, Yoshiyuki Okada, Kaoru Sakai, Tomomi Kamba, Hidemi Tsuji, Kenichiro Shide, Kazuaki Nagashima, Motoko Yanagita, Nobuya Inagaki, Osamu Ogawa, Hiromitsu Negoro
Department of Urology, Kyoto University Graduate School of Medicine, Kyoto, Japan., Department of Metabolism and Clinical Nutrition, Kyoto University Hospital, Kyoto, Japan., Department of Nephrology, Kyoto University Graduate School of Medicine, Kyoto, Japan., Department of Nursing, Kyoto University Hospital, Kyoto, Japan., Department of Metabolism and Clinical Nutrition, Kyoto University Hospital, Kyoto, Japan; Department of Diabetes, Endocrinology and Nutrition, Kyoto University Graduate School of Medicine, Kyoto, Japan., Department of Urology, Kyoto University Graduate School of Medicine, Kyoto, Japan. Electronic address: .