Higher estimated net endogenous acid production with lower intake of fruits and vegetables based on a dietary survey is associated with the progression of chronic kidney disease

Koji Toba; Michihiro Hosojima; Hideyuki Kabasawa; Shoji Kuwahara; Toshiko Murayama; Keiko Yamamoto-Kabasawa; Ryohei Kaseda; Eri Wada; Reiko Watanabe; Naohito Tanabe; Yoshiki Suzuki; Ichiei Narita; Akihiko Saito

doi:10.1186/s12882-019-1591-8

Higher estimated net endogenous acid production with lower intake of fruits and vegetables based on a dietary survey is associated with the progression of chronic kidney disease

BMC Nephrol. 2019 Nov 21;20(1):421. doi: 10.1186/s12882-019-1591-8.

Authors

Koji Toba^{1

2

3}, Michihiro Hosojima⁴, Hideyuki Kabasawa⁵, Shoji Kuwahara^{1

6}, Toshiko Murayama^{1

7

8}, Keiko Yamamoto-Kabasawa⁹, Ryohei Kaseda², Eri Wada^{2

10}, Reiko Watanabe¹¹, Naohito Tanabe¹¹, Yoshiki Suzuki¹², Ichiei Narita², Akihiko Saito¹

Affiliations

¹ Department of Applied Molecular Medicine, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
² Division of Clinical Nephrology and Rheumatology, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
³ Present Address: Department of Nutrition, Niigata City General Hospital, Niigata, Japan.
⁴ Department of Clinical Nutrition Science, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan. hoso9582@med.niigata-u.ac.jp.
⁵ Department of Clinical Nutrition Science, Kidney Research Center, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachi-dori, Chuo-ku, Niigata, 951-8510, Japan.
⁶ Present Address: Laboratory of Clinical Nutrition, Department of Nutrition, School of Human Cultures, The University of Shiga Prefecture, Shiga, Japan.
⁷ Nutrition Management Unit, Niigata University Medical & Dental Hospital, Niigata, Japan.
⁸ Present Address: Department of Health and Nutrition, Faculty of Human Life Studies, University of Niigata Prefecture, Niigata, Japan.
⁹ Department of Health Promotion Medicine, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
¹⁰ Present Address: Laboratory of Metabolic Signal, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, Japan.
¹¹ Department of Health and Nutrition, University of Niigata Prefecture, Niigata, Japan.
¹² Health Administration Center, Niigata University, Niigata, Japan.

Abstract

Background: Dietary acid load has been suggested to mediate the progression of chronic kidney disease (CKD). However, it is unclear what kinds of foods are actually associated with dietary acid load in patients with CKD. The self-administered diet history questionnaire (DHQ), which semi-quantitatively assesses the dietary habits of Japanese individuals through 150 question items, can estimate average daily intake of various foods and nutrients during the previous month. Using the DHQ, we investigated the association of dietary acid load with CKD progression. We also analyzed the kinds of food that significantly affect dietary acid load.

Methods: Subjects were 96 outpatients with CKD (average estimated glomerular filtration rate [eGFR], 53.0 ± 18.1 ml/min/1.73 m²) at Niigata University Hospital, who had completed the DHQ in 2011. We calculated net endogenous acid production (NEAP) from potassium and protein intake evaluated by the DHQ in order to assess dietary acid load. CKD progression was assessed by comparing eGFR between 2008 and 2014.

Results: NEAP was not correlated with protein intake (r = 0.088, p = 0.398), but was negatively correlated with potassium intake (r = - 0.748, p < 0.001). Reduction in eGFR from 2008 to 2014 was estimated to be significantly greater in patients with higher NEAP (NEAP > 50.1 mEq/day, n = 45) than in those with lower NEAP (NEAP ≤50.1 mEq/day, n = 50) by 5.9 (95% confidence interval [95%CI], 0.1 to 11.6) ml/min/1.73 m². According to multiple logistic regression analysis, higher NEAP was significantly associated with lower intake of fruits (odds ratio [OR], 6.454; 95%CI, 2.19 to 19.00), green and yellow vegetables (OR, 5.18; 95%CI, 1.83 to14.66), and other vegetables (OR, 3.87; 95%CI, 1.29 to 11.62).

Conclusions: Elevated NEAP could be a risk factor for CKD progression. Low intake of fruits and vegetables would increase dietary acid load and might affect the progression of renal dysfunction in Japanese CKD patients.

Keywords: Chronic kidney disease; Dietary acid load; Fruits and vegetables.

MeSH terms

Acids / metabolism*
Aged
Analysis of Variance
Diet Surveys
Dietary Proteins / administration & dosage
Dietary Proteins / metabolism*
Disease Progression
Energy Intake
Feeding Behavior
Female
Fruit*
Glomerular Filtration Rate
Humans
Japan
Male
Middle Aged
Potassium / administration & dosage
Potassium / metabolism*
Regression Analysis
Renal Insufficiency, Chronic*
Vegetables*

Substances

Acids
Dietary Proteins
Potassium