Kidney Week

Abstract: FR-PO633

Dietary Protein Intake and Urinary Citrate Excretion in Asians

Session Information

• Fluid and Electrolytes: Clinical - Acid-Base, Magnesium, Calcium, Phosphorus
  November 08, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Fluid and Electrolytes

• 902 Fluid and Electrolytes: Clinical

Authors

• Leong, Leanne Ca yin, National University Hospital, Singapore, Singapore

Leanne Ca yin Leong,

• Ngoh, Clara Lee Ying, National University Hospital, Singapore, Singapore

Clara Lee Ying Ngoh,

• Wong, Weng Kin, National University Hospital, Singapore, Singapore

Weng Kin Wong,

• Chua, Horng-Ruey, National University Health System, Singapore, Singapore

Horng-Ruey Chua,

• Lau, Titus W., National University Health System, Singapore, Singapore

Titus W. Lau,

• Teo, Boon Wee, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore

Boon Wee Teo,

Background

Dietary protein intake (DPI) is associated with acid loading. We hypothesize that urinary citrate excretion rate (UCER) is lower in patients with chronic kidney disease (CKD) having higher DPI. We examine the relationship between DPI and UCER in a multi-ethnic Asian population in patients with CKD and participants without kidney disease.

Methods

We used data from patients with stable CKD from the Asian Kidney Disease Study and normal participants without diabetes or hypertension from the Singapore Kidney Function Study. Participants fasted overnight, and provided a 24hr urine collection, blood sample, and underwent measured glomerular filtration test (mGFR; mL/min/1.73m²) using ^99mTc-DTPA. Daily protein intake (DPI, g/day) was calculated from 24-hour urine urea using Maroni’s formula. Non-normal data was natural log-transformed for analysis. We performed univariate analysis of Ln UCER against the factors of age, gender, ethnicity, presence of CKD, Ln mGFR, and DPI. A multiple linear regression model was constructed including these variables to assess the association of DPI with UCER after adjusting for kidney disease and function.

Results

Complete data were available from 187 CKD patients (48.7%male) and 89 non-CKD participants (47.2% male) (p=NS). The mean ages were 59±12.8 years and 42±14.3 years in the CKD and non-CKD groups, respectively (p<0.001). The median mGFR in the CKD and non-CKD groups were 45 (IQR: 29-63) and 100 (IQR: 88-113), respectively (p<0.001). The median UCER (mmol/day) was lower in the CKD group (46, IQR: 11-106 vs. 303, IQR: 206-446) (p<0.001). No participant was on sodium bicarbonate supplementation. On univariate analysis, lower UCER was associated with increased age, presence of CKD, decreased mGFR, and decreased DPI (all p<0.001). Indians had higher UCER compared to Chinese and Malays (p<0.01). Gender was not associated with UCER. In a multiple linear regression model including these variables (RSq=0.53, p<0.001), daily protein intake is not significant (estimate 0.0084, p=0.0511).

Conclusion

After adjusting for presence of CKD, kidney function, age, ethnicity and gender, DPI is not significantly associated with UCER.

Funding

• Government Support - Non-U.S.