Simple lifestyle changes can have an impact
By David Dunaief, M.D.
On the heels of National Kidney Month in March, let’s look more closely at strategies for reducing chronic kidney disease (CKD). Those at highest risk for CKD include patients with diabetes, high blood pressure and those with first-degree relatives who have advanced disease. But those are only the ones at highest risk.
CKD is tricky because, similar to high blood pressure and dyslipidemia (high cholesterol), it tends to be asymptomatic, at least initially. Only in the advanced stages do symptoms become distinct, though there can be vague symptoms in moderate stages such as fatigue, malaise and loss of appetite.
What are the CKD stages?
CKD is classified into five stages based on the estimated glomerular filtration rate (eGFR), a way to determine kidney function. Stages 1 and 2 are the early stages, while stages 3a and 3b are the moderate stages, and finally stages 4 and 5 are the advanced stages. Stage 5 is end-stage renal disease, or kidney failure.
Who should be screened?
According to the U.S. Preventive Services Task Force and the American College of Physicians, those who are at highest risk should be screened including, as I mentioned above, patients with diabetes or hypertension (1)(2).
In an interview on Medscape.com, “Proteinuria: A Cheaper and Better Cholesterol?” two high-ranking nephrologists suggest that first-degree relatives to advanced CKD patients should also be screened and that those with vague symptoms of fatigue, malaise and/or decreased appetite may also be potential screening candidates (3). This broadens the asymptomatic population that may benefit from screening.
Slowing CKD progression
Fortunately, there are several options available, ranging from preventing CKD with specific exercise to slowing the progression with lifestyle changes and medications.
How much exercise?
Here we go again, preaching the benefits of exercise. But what if you don’t really like exercise? It turns out that the results of a study show that walking reduces the risk of death and the need for dialysis by 33 percent and 21 percent respectively (4). And although some don’t like formal exercise programs, most people agree that walking is enticing.
The most prevalent form of exercise in this study was walking. Even more intriguing, the results are based on a dose-response curve. In other words, those who walked more often saw greater results. So, the participants who walked one-to-two times per week had a significant 17 percent reduction in death and a 19 percent reduction in kidney replacement therapy, while those who walked at least seven times per week experienced a more impressive 59 percent reduction in death and a 44 percent reduction in the risk of dialysis. There were 6,363 participants for an average duration of 1.3 years.
How much protein to consume?
When it comes to CKD, more protein is not necessarily better, and may even be harmful. In a meta-analysis (a group of 10 randomized controlled trials) of Cochrane database studies, results showed that the risk of death or treatment with dialysis or kidney transplant was reduced by 32 percent in those who consumed less protein compared to unrestricted protein (5). According to the authors, as few as two patients would need to be treated for a year in order to prevent one from either dying or reaching the need for dialysis or transplant.
Sodium: How much is too much?
Good news! In a study, results showed that a modest sodium reduction in our diet may be sufficient to help prevent proteinuria (protein in the urine) (6). Here, less than 2000 mg was shown to be beneficial, something all of us can achieve.
Medications have a place
We routinely give certain medications, ACE inhibitors or ARBs, to patients who have diabetes to protect their kidneys. What about patients who do not have diabetes? ACEs and ARBs are two classes of anti-hypertensives — high blood pressure medications — that work on the RAAS system of the kidneys, responsible for blood pressure and water balance (7). Results of a study show that these medications reduced the risk of death significantly in patients with moderate CKD. Most of the patients were considered hypertensive.
However, there was a high discontinuation rate among those taking the medication. If you include the discontinuations and regard them as failures, then all who participated showed a 19 percent reduction in risk of death, which was significant. However, if you exclude discontinuations, the results are much more robust with a 63 percent reduction. To get a more realistic picture, this result, including both participants and dropouts, is probably close to what will occur in clinical practice unless the physician is a really good motivator or has very highly motivated patients.
While these two classes of medications, ACE inhibitors and ARBs, are good potential options for protecting the kidneys, they are not the only options. You don’t necessarily have to rely on drug therapies, and there is no downside to lifestyle modifications. Lowering sodium modestly, walking frequently, and lowering your protein consumption may all be viable options, with or without medication, since medication compliance was woeful. Screening for asymptomatic, moderate CKD may lack conclusive studies, but screening should occur in high-risk patients and possibly be on the radar for those with vague symptoms of lethargy as well as aches and pains. Of course, this is a discussion to have with your physician.
(1) uspreventiveservicestaskforce.org (2) aafp.org. (3) Medscape.com. (4) Clin J Am Soc Nephrol. 2014;9(7):1183-9. (5) Cochrane Database Syst Rev. 2009;(3):CD001892. (6) Curr Opin Nephrol Hypertens. 2014;23(6):533-540. (7) J Am Coll Cardiol. 2014;63(7):650-658.
Dr. David Dunaief is a speaker, author and local lifestyle medicine physician focusing on the integration of medicine, nutrition, fitness and stress management. For further information, visit www.medicalcompassmd.com.