Baking soda for kidney patients + A study currenty recruiting participants

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Baking soda for kidney patients

_http://www.nhs.uk/news/2009/07July/Pages/Bakingsodaforkidneypatients.aspx_

(http://www.nhs.uk/news/2009/07July/Pages/Bakingsodaforkidneypatients.aspx)

 

 

“A daily dose of baking soda could help patients with chronic kidney

disease avoid having to undergo dialysis,†reported The Times. It said that

research has found that sodium bicarbonate can dramatically slow the progress

of the condition. The newspaper said that patients given a small daily dose

of sodium bicarbonate over a year, had only two-thirds of the decline in

kidney function experienced by people given usual care.

 

 

This randomised controlled trial found that people with both chronic

kidney disease and metabolic acidosis (low blood bicarbonate/high blood

acidity)

benefited from oral bicarbonate supplements over a two-year period. The

study has some shortcomings, but provides strong evidence that these

supplements could be used in treatment. The researchers have called for further

research to confirm their findings.

 

 

The exact place of this in standard treatment for people with chronic

kidney disease is not yet known. In practice, people with severe renal disease

may receive sodium bicarbonate as part of their treatment in hospital

anyway.

 

 

Where did the story come from?

 

 

The research was carried out by Dr Ione de Brito-Ashurst and colleagues

from the Department of Renal Medicine and Transplantation, at the William

Harvey Research Institute Barts, and the London NHS Trust in London. The study

was published in the Journal of the American Society of Nephrology.

 

 

What kind of scientific study was this?

 

 

This randomised controlled trial investigated the effects of bicarbonate

supplementation for people with chronic kidney disease and metabolic

acidosis.

 

 

Metabolic acidosis is a condition where there is an acid-alkali imbalance

in the blood, that results in high blood acidity (low pH) and low plasma

bicarbonate levels. Several conditions can lead to metabolic acidosis,

including heart failure, drugs or toxins, kidney failure or diabetic

ketoacidosis

(caused by high blood sugar resulting from reduced insulin). It is a

common complication in people with advanced chronic kidney disease, and it can

interfere with protein metabolism and may lead to stunted growth (in

children) and loss of bone and muscle.

 

 

The study looked at 134 patients with chronic kidney disease and low blood

bicarbonate levels (i.e. with metabolic acidosis). The patients were

randomly allocated to either sodium bicarbonate supplements, 600mg taken orally

three times a day (increased as necessary to achieve and maintain blood

levels), or to usual care for two years.

 

 

The researchers excluded from the study anyone with morbid obesity,

cognitive impairment, chronic sepsis, congestive heart failure or uncontrolled

blood pressure. Over the course of the two-year treatment, they assessed the

rate at which creatinine was cleared by the kidneys (creatinine clearance).

Creatinine is a waste product that healthy kidneys can remove. Measuring

how successfully they do this is a marker for the severity of kidney

disease. The researchers had a theory that bicarbonate supplementation would

reduce the rate of decline of creatinine clearance in people with chronic

kidney disease, and that it would reduce the number of patients whose kidney

disease rapidly progressed towards established renal failure. To measure this,

the participants provided 24-hour urine samples (collecting every drop of

urine during each period) every two months.

 

 

The researchers defined rapid progression as a reduction of creatinine

clearance of more than three ml/min per 1.73m2 per year.

 

 

What were the results of the study?

 

 

People given sodium bicarbonate supplements had significantly higher blood

bicarbonate levels than those given standard care. Blood pressure control

was similar between the groups even though those receiving supplements were

also taking in more sodium (which could increase blood pressure).

 

 

Chronic kidney disease progressed rapidly in 9% of patients in the

bicarbonate group compared to 45% in the usual care group. Significantly fewer

supplemented patients developed end-stage renal failure (requiring dialysis)

compared to the usual care group: 6.5% versus 33% of patients.

 

 

Age and gender also affected the rate of decline of creatinine clearance,

but when these were taken into account, supplementation still had a

significant effect. Adverse events were similar in both groups. Supplementation

was also associated with better nutritional status, including improved

protein intake and more normal protein metabolism.

 

 

What interpretations did the researchers draw from these results?

The researchers conclude that supplementation with oral bicarbonate in

patients with chronic kidney disease and low plasma bicarbonate (metabolic

acidosis) slows the rate of decline in kidney function and lowers the chances

of developing end-stage renal disease. OK? They say that this cheap, simple

strategy also improves the nutritional status of patients and has the

potential to translate into significant economic and quality of life gains, as

well as clinical benefits.

 

 

What does the NHS Knowledge Service make of this study?

 

 

This randomised controlled trial provides good evidence that oral

supplementation with bicarbonate can improve clinical outcomes for people with

chronic kidney disease and associated metabolic acidosis. The researchers

discuss the strengths and weaknesses of their study:

 

-- The randomised nature of the study, the intention to treat analysis

(i.e. including all participants in analysis even those who dropped out) and

study size are all strengths that increase confidence in this trial’s

findings.

 

-- The results are likely to be applicable to many patients with chronic

kidney disease because the study sample was heterogeneous – i.e. the

patients had a wide range of underlying conditions.

 

-- However, the findings won’t necessarily apply to those with morbid

obesity, cognitive impairment, chronic sepsis, congestive heart failure or

uncontrolled blood pressure, as these groups were excluded from the study.

 

-- The study did not have a placebo group, and instead compared

supplementation with standard care. It is not clear what was involved in

standard

care, nor whether taking other drugs that may interfere with sodium

bicarbonate, such as the phosphate binders, differed between the groups.

 

-- Patients receiving the supplements would have known that they were in

the intervention group, i.e. they or the researchers were not blinded to the

group allocation. This could have introduced some bias.

 

 

The researchers themselves call for validation of their study through a

double-blind, placebo-controlled, multicentre trial that will provide

stronger evidence of the effects of oral bicarbonate supplementation for people

with chronic kidney disease.

 

 

The exact place of this in standard treatment for people with chronic

kidney disease is not yet known. In practice, people with severe renal disease

may receive sodium bicarbonate as part of their treatment in hospital

anyway.

 

 

Links to the headlines

 

_Daily dose of baking soda ‘can keep kidney patients off dialysis’._

(http://www.timesonline.co.uk/tol/life_and_style/health/article6716929.ece)

The Times, July 17 2009

 

_Baking soda 'could stop kidney failure'._

(http://www.metro.co.uk/news/article.html?Baking_soda_could_stop_kidney_failure & \

in_article_id=) . Metro,

July 17 2009

 

 

Links to the science

 

de Brito-Ashurst I, Varagunam M, Raftery MJ, and Yaqoob MM.

_Bicarbonate Supplementation Slows Progression of CKD and Improves

Nutritional Status._

(http://jasn.asnjournals.org/cgi/content/abstract/ASN.2008111205v1) Journal of

the American Society of Nephrology 2009; Published ahead

of print on July 16

--------

 

Sodium Bicarbonate Supplementation in Chronic Kidney Disease Evaluation of

Dose Response, Safety and Beneficial Effects

_http://clinicaltrials.gov/ct2/show/NCT00888290_

(http://clinicaltrials.gov/ct2/show/NCT00888290)

 

This study is currently recruiting participants.

 

Verified by Albert Einstein College of Medicine of Yeshiva University,

December 2009

 

Purpose

This study will enroll 25 patients with kidney disease to evaluate the

effects of different doses of sodium bicarbonate (baking soda) on levels of

bicarbonate in the blood, kidney function and muscle strength. The

investigators will also evaluate safety and tolerability of different doses.