Dietary Modification in Renal Disease

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Author:
James Matera, DO
Medical Director of Population Health, CentraState Medical Center, Freehold, NJ

Citation:
Matera J. Dietary modification in renal disease [published on December 3, 2018]. Consultant360.

The effect of dietary modification in slowing the progression of chronic kidney disease (CKD) has been studied throughout the years as we continue to look for remedies for CKD. The Modification of Diet in Renal Disease (MDRD) study was among the first to examine this in patients from 1989 to 1993. The MDRD Study looked to answer the questions as to whether restricting protein and controlling blood pressure would slow progression of CKD over time. The study assessed 1585 patients and found:

• Among patients with moderate renal insufficiency, the slower decline in renal function that started four months after the introduction of a low-protein diet suggests a small benefit of this dietary intervention.
• Among patients with more severe renal insufficiency, a very-low-protein diet, as compared with a low-protein diet, did not significantly slow the progression of renal disease.
• Overall, a low blood pressure goal was not shown to have benefit over the higher goal.
• Among persons with more pronounced proteinuria at baseline had a significantly slower rate of decline in GFR.¹

The focus on low protein diets and avoidance of pro-inflammatory diets has also helped spark research into this field.  It has been long known that the North American diet is higher in protein and this can also lead to glomerular damage and progression of CKD.²

Recently at the American Society of Nephrology's Kidney Week 2018 meeting in San Diego, California, Tanushree Banerjee, PhD, and her colleagues from the University of California San Francisco presented an abstract on pro-inflammatory diets and progression of CKD.³ This study looked at 1084 patients identified from the National Health and Nutrition Examination Survey (NHANES) database and followed them for 14 years. Pro-inflammatory diets are rich in meats, refined grains, and poor glycemic foods. The North American diet is typically low in fruits and vegetables, healthy oils and fats, and unrefined grains, leading to the pro-inflammatory state.

The Adapted Dietary Inflammatory Index (ADII) and Inflammatory Score (IS) were used. The ADII has been studied previously and was noted to be associated with cardiovascular risk in multiple studies. The IS looks at proinflammatory markers such as C-reactive protein, albumin, white blood cells, and mean platelet volume. Dr Banerjee and colleagues looked at these indices and analyzed the association with end-stage renal disease (ESRD).

Approximately 11% of the subjects progressed to ESRD, and several key factors in the ADII and IS were noted:

• A 1 Standard Deviation increase in ADII reflected in a higher IS.
• It is the higher IS that is associated with progression to ESRD.
• The albumin-to-creatinine ratio was also a factor, as ESRD occurred more when ACR was over 30 mg/g.

Although more research is still needed in this area, nephrologists can be proactive with dietary modification in their CKD patients. They should work with nutritionists on a regular basis to impact their patients’ diet, as this may become a significant factor in our battle against CKD progression.

As we shift from volume to value, the costs of CKD in the United States remain among the highest cost point in our patients.⁴ The average cost for CKD and especially for ESRD places an excessive financial burden on the system, and our efforts to decrease this progression will be paramount as we move into new payment models.

James Matera, MD, FACOI, is the medical director of Population Health at CentraState Medical Center in Freehold, NJ.

References:

1. Levey AS, Bosch JP, Lewis JB, Greene T, Rogers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med. 1999; 130:461–70. doi:10.7326/0003-4819-130-6-199903160-00002.
2. Ko GJ, Obi Y, Tortorici AR, Kalantar-Zadeh K. Dietary protein intake and chronic kidney disease. Curr Opin Clin Nutr Metab Care. 2017;20(1):77-85. doi:10.1097/MCO.0000000000000342.
3. Banerjee T, Crews DC, Rios Burrows N, et al. Pro-inflammatory diets increase the risk of ESRD in US adults with CKD.  Paper presented at: American Society of Nephrology Kidney Week 2018; October 23-28, 2018; San Diego CA. https://www.asn-online.org/education/kidneyweek/2018/program-abstract.aspx?controlId=3015523.
4. Ozieh MN, Bishu KG, Dismuke CE, Egede LE. Trends in healthcare expenditure in United States adults with chronic kidney disease: 2002-2011. BMC Health Serv Res. 2017;17(1):368. https://doi.org/10.1186/s12913-017-2303-3.