Susumu Ogawa1,2, Junko Takiguchi3, Kazuhiro Nako4, Masashi Okamura4, Takuya Sakamoto4, Shigeru Kabayama5, Takefumi Mori4, Yoshitaka Kinouchi3, Sadayoshi Ito4. 1. Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan. ogawa-s@hosp.tohoku.ac.jp. 2. Section of Clinical Medicine, Division of Research in Student Support, Institute for Excellence in Higher Education, Tohoku University, Sendai, Japan. ogawa-s@hosp.tohoku.ac.jp. 3. Section of Clinical Medicine, Division of Research in Student Support, Institute for Excellence in Higher Education, Tohoku University, Sendai, Japan. 4. Division of Nephrology, Endocrinology and Vascular Medicine, Tohoku University Hospital, 1-1 Seiryo-machi, Aoba-ku, Sendai, 980-8574, Japan. 5. Trim Medical Institute Co., Ltd., Osaka, Japan.
Abstract
BACKGROUND: Pink urine syndrome (PUS) is attributed to the precipitation of uric acid caused by low urinary pH (U-pH). However, the reasons for the lower U-pH are unclear. OBJECTIVES: To investigate the occurrence of PUS and verified the cause of U-pH reduction. METHODS: Participants comprised 4,940 students who had undergone a physical examination. Data on the presence [PUS (+)] or absence [PUS (-)] of PUS, as well as age, gender, body mass index (BMI), blood pressure (BP), heart rate (HR), and U-pH were collected. Of these participants, 300 randomly selected individuals were evaluated for their waist circumference, as well as their levels of urinary C-peptide, angiotensinogen, methylglyoxal, thiobarbituric acid-reactive substances (TBARS), and Na(+) excretion. Independent risk factors of lower U-pH were decided by a multiple-regression analysis. RESULTS: PUS was observed in 216 students (4.4 %). A greater number of men comprised the PUS (+) group compared with the PUS (-) group, and subjects in this group had high BMI, BP, and HR values, as well as low U-pH. A logistic regression analysis revealed that the BMI and U-pH were independent risk factors for PUS (+). The decrease of U-pH was closely related to the progress of chronic kidney disease (CKD). BMI value was related to PUS (+) in the CKD (-) subjects. On the other hand, low U-pH was related to PUS (+) in the CKD (+) subjects. All factors other than HR showed a significant negative correlation with U-pH. However, multiple-regression analysis revealed that TBARS and angiotensinogen were independent risk factors. CONCLUSION: Obesity and lower U-pH were each independently related to PUS, whereas increased intrarenal oxidative stress and exacerbation of the renin-angiotensin system activation were associated with the lowering of U-pH. U-pH low value is related to potential CKD.
BACKGROUND: Pink urine syndrome (PUS) is attributed to the precipitation of uric acid caused by low urinary pH (U-pH). However, the reasons for the lower U-pH are unclear. OBJECTIVES: To investigate the occurrence of PUS and verified the cause of U-pH reduction. METHODS:Participants comprised 4,940 students who had undergone a physical examination. Data on the presence [PUS (+)] or absence [PUS (-)] of PUS, as well as age, gender, body mass index (BMI), blood pressure (BP), heart rate (HR), and U-pH were collected. Of these participants, 300 randomly selected individuals were evaluated for their waist circumference, as well as their levels of urinary C-peptide, angiotensinogen, methylglyoxal, thiobarbituric acid-reactive substances (TBARS), and Na(+) excretion. Independent risk factors of lower U-pH were decided by a multiple-regression analysis. RESULTS:PUS was observed in 216 students (4.4 %). A greater number of men comprised the PUS (+) group compared with the PUS (-) group, and subjects in this group had high BMI, BP, and HR values, as well as low U-pH. A logistic regression analysis revealed that the BMI and U-pH were independent risk factors for PUS (+). The decrease of U-pH was closely related to the progress of chronic kidney disease (CKD). BMI value was related to PUS (+) in the CKD (-) subjects. On the other hand, low U-pH was related to PUS (+) in the CKD (+) subjects. All factors other than HR showed a significant negative correlation with U-pH. However, multiple-regression analysis revealed that TBARS and angiotensinogen were independent risk factors. CONCLUSION: Obesity and lower U-pH were each independently related to PUS, whereas increased intrarenal oxidative stress and exacerbation of the renin-angiotensin system activation were associated with the lowering of U-pH. U-pH low value is related to potential CKD.
Authors: Richard J Johnson; Santos E Perez-Pozo; Julian Lopez Lillo; Felix Grases; Jesse D Schold; Masanari Kuwabara; Yuka Sato; Ana Andres Hernando; Gabriela Garcia; Thomas Jensen; Christopher Rivard; Laura G Sanchez-Lozada; Carlos Roncal; Miguel A Lanaspa Journal: BMC Nephrol Date: 2018-11-08 Impact factor: 2.388