diet for kidney stones

Dyad 6 guomanman and chenya



Hypercalciuria is an important and common risk factor for the formation of kidney stones. In fact, about 80% of kidney stones contain calcium and most of these are made up of calcium oxalate. Some calcium stones contain calcium phosphate. A smaller proportion of stones contain uric acid, are struvite stones (caused by urinary tract infections), or are cystine stones. Once a kidney stone forms, there is a 50% probability that
another stone will form within five to seven years without treatment. Initial treatment of recurrent kidney stones generally involves changes in
dietary habits.1-4 It has been thought that decreasing the amount of calcium in the diet reduces the risk of recurrent kidney stones by decreasing the amount of calcium excreted in the urine. However, this idea
has been questioned with the suggestion that calcium may even be protective against kidney stones. This idea has prompted a shift toward
maintaining normal calcium intake and instead emphasizing lower amounts of animal protein and salt. Because there has been a lack of long-term data on whether a low-calcium diet, or a normalcalcium diet that is low in animal protein and salt, is better in preventing recurrent kidney stones, a recent study was done to provide some answers to
the continued debate.

This randomized trial compared the effects of two different diets in 120 men with recurrent calcium oxalate stones and hypercalciuria. Men
were randomly assigned to a low calcium diet or a normal calcium diet. The low calcium diet restricted calcium intake to about 400 mg per day.
The normal calcium diet included about 1,200 mg per day of calcium, but restricted animal protein to 52 grams per day and salt to less than 3 grams
per day. Additional protein or calories came from bread, pasta, vegetables, and fruits instead of meat or fish. Both groups were instructed to avoid large quantities of foods rich in oxalate. Both diets included two to three liters of water per day.Twenty-four hour urine specimens were
collected at baseline, one week after randomization, and at yearly intervals. Urinary volume, sodium, urea, sulfate, calcium excretion,
oxalate excretion, creatinine excretion, and calcium oxalate saturation were measured. Thestudy continued for five years.

result

In men with hypercalciuria and recurrent calcium oxalate stones, a diet containing normal amounts of calcium but reduced amounts of animal protein and salt, works better to prevent recurrent kidney stones than a low-calcium diet.
The primary outcome was the time to the first recurrence of a symptomatic kidney stone or the radiographic identification of a kidney stone. Secondary outcomes were changes in calcium and oxalate excretion, calcium oxalate product, and relative calcium oxalate saturation. Urinary calcium levels dropped significantly in both groups. However urinary oxalate excretion increased in the men on the low-calcium diet, but decreased in the men on the normal-calcium diet.1
At five years, 12 (20%) men on the normalcalcium diet, and 23 (38%) men on the lowcalcium diet had recurrences of stones. The relative risk of recurrence for the group on the normal-calcium diet was 0.49 compared to the group on the low-calcium diet. After adjustment for baseline characteristics, the relative risk of a recurrence was 0.37 in favor of the normalcalcium,low-protein, low-salt diet.

summary

Counsel patients with recurrent calcium stones to drink plenty of fluids because adequate urine volume is one of the most important factors in at least 2 L per day of urine. Patients will need to drink 2.5 to 3 L of fluids with at least 8 to 12 ounces taken at bedtime. Water is best. This
amount should be increased when fluid losses are increased.2-6
Recommend calcium citrate for postmenopausal women with kidney stone
disease, because in addition to increasing urinary calcium, it also increases the urinary levels of citrate. Suggest taking calcium with meals so it is available to bind intestinal oxalates. Also advise patients to watch their consumption of foods containing oxalate. Some foods high in oxalate
include nuts (walnuts, peanuts, almonds, hazelnuts, etc.), spinach, okra, beets, rhubarb, strawberries, cranberries, soy, wheat bran, brown
rice, chocolate, and cocoa.

reference

1. Borghi L, Schianchi T, Meschi T, et al. Comparison of two diets for the prevention of recurrent stones in idiopathic hypercalciuria.
NEJM 2002;346:77-84.
2. Bushinsky DA. Recurrent hypercalciuric nephrolithiasis-does diet help? NEJM 2002;346:124-125.
3. Goldfarb DS, Coe FL. Prevention of recurrent nephrolithiasis. Am Fam Phys 1999;60:2269-2278.
4. National Institute of Diabetes and Digestive and Kidney Diseases. Kidney stones in adults. National Institutes of Health 2000. NIH publication
no. 00-2495. Available at: www.niddk.nih.gov/ health/kidney/pubs/stonadul/stonadul.htm.
5. Pearle MS. Prevention of nephrolithiasis. Curr Opin Nephrol Hypertens 2001;10:203-209.
6. Morton AR, Iliescu EA, Wilson JWL. Nephrology: Investigation and treatment of recurrent kidney stones. CMAJ 2002;166:213-218.
7. Bihl G, Meyers A. Recurrent renal stone diseaseadvances in pathogenesis and clinical management. Lancet 2001;358:651-656.
8. Jellin JM, Gregory P, Batz F, et al. Pharmacist’s Letter/Prescriber’s Letter Natural Medicines Comprehensive Database. 3rd ed. Stockton, CA:
Therapeutic Research Faculty;2000. Pharmacist’s Letter / Prescriber’s Letter
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dietary factors and lifestyle measures are used for prevention of kidney stones
Patients should take some specific preventive measures to prevent kidney stones. The most important recommendations for reducing the risk for calcium stones are increasing fluid intake, restricting sodium, and reducing protein intake. A lower risk for calcium stones is also associated with potassium intake. Dietary calcium itself does not appear to increase the risk for kidney stones. Patients should try to correct any acidic or alkaline imbalance in the urine so that such stone-forming substances are more likely to dissolve. Try to avoid stone recurrence using dietary changes; if such measures fail then drug treatments may be helpful.
Fluid Intake
Of all the preventive recommendations, drinking enough fluid is the most important guideline for people with any type of kidney stones.
In general, patients with calcium or uric acid stones should drink at least ten full glasses of fluid each day (half should be water). This includes one with each meal and drinking fluids at night, even if it means getting up from sleep. Fluid intake should produce at least two and a half quarts of urine each day. More water (over a gallon every day) is needed to prevent cystine stones and it must be drunk at regular intervals throughout the night and day.

In all cases, more fluid is needed after exertion and during times of stress. If fluid intake is sufficient, the urine should be pale and almost watery, not dark and yellow. Although water is best, it may vary depending on its source. Other beverages have various positive or negative effects: Variations in water itself may have different impacts. One study reported that drinking hard tap water increased urinary calcium concentration by 50% compared to soft bottled water. On the other hand mineral water containing both calcium and magnesium may reduce several risk factors for both calcium and uric acid stone formation.
Sodium Restriction
Because salt intake increases the amount of calcium in urine, patients with calcium stones should restrict their sodium intake. Some researchers believe that restricting sodium along with increasing fluid intake is the most important dietary measure for preventing stones.

Calcium
Calcium from Foods. It has been fairly well established that dietary calcium (such as in dairy products) is actually protective against many cases of calcium oxalate stones. Large studies of both men and women found that those with the highest intake of calcium from foods had a much lower risk for stones than those who had little calcium in their diets. Dietary calcium may actually bind the oxalate in foods, preventing it from being absorbed into the blood and excreted into the urine. In a normal healthy diet, dairy products supply almost 80% of the daily calcium requirement. It should be further noted that many people have calcium stones associated with resorption (the breakdown of bone that releases calcium into the blood stream). Limiting calcium intake in such people could actually promote further bone loss.
Calcium Restriction in Certain Cases. Some calcium stone patients who have supersaturation of calcium in the urine and who are not at risk for bone loss may need to restrict calcium, but more studies are needed to define this group precisely. Certainly, children with hypercalciuria should not restrict calcium, since this could harm bone growth.


Fiber-Rich Foods and their Compounds
Fiber may be beneficial for people with kidney stones. In addition some fiber-rich foods may contain compounds that help protect against kidney stones: Phytate. A wide variety of high-fiber plant foods, such as wheat or rice bran and soybeans, contain a compound called phytate (inositol hexaphosphate). It appears to help prevent crystallization of calcium salts, both oxalate and phosphate.Gahat. Gahat is a lentil-like bean that has been used for centuries in Nepal, Northern India, and Pakistan to treat kidney stones.
Protein Restriction
Protein increases uric acid, calcium, and oxalates in the urine and reduces citrate. Diets high in protein, particularly meat protein, have been consistently associated with kidney stones. (Meat protein has a higher sulfur content and generates more acid than vegetable protein.) According to Swiss studies, about a third of people at risk for calcium stones may have a sensitivity to meat proteins that cause mild hyperoxaluria. Whether restricting meat protein has any protective value is unknown. Studies to date have found no difference in stone development between people with low and normal meat protein diets over four years. A 2001 study, for example, found no difference in stone formation in two groups of patients who consumed beef or plant proteins in equal amounts. A 2000 study reported that only dramatic reductions in meat protein had any preventive effect against stone recurrence. It is reasonable, in any case, for everyone to consume meat protein in moderation. People with struvite stones, who need to reduce phosphates in their diets, should also cut down on proteins.

Purine Restriction in People at Risk for Uric Acid Stones
A high intake of purines can increase the amount of uric acid in the urine, so those at risk for uric acid stones should reduce their intake of foods that contain purines. They include beer and other alcoholic beverages, anchovies, sardines, yeast, organ meats (eg, liver, kidneys), legumes (eg, dried beans, peas, and soybeans), mushrooms, spinach, asparagus, cauliflower, and poultry.
Oxalate Restriction in Hyperoxaluria
Most people with calcium oxalate stones should not avoid oxalate-rich foods unless the physician specifically recommends a restrictive diet. Oxalate binds with calcium in the intestine, which may actually reduce calcium absorption. Some studies, in fact, indicate that eating foods containing oxalates and calcium together may reduce the risk of stones. Most of the foods that contain oxalates are very important for good health. Restricting oxalates may be particularly harmful in people with malabsorption.
Vitamins in Hyperoxaluria
Ascorbic acid (vitamin C) may convert to oxalates, and people with hyperoxaluria should avoid vitamin C supplements.Vitamin B6, or pyridoxine, is used to treat people with hyperoxaluria when dietary reduction of oxalates and calcium supplements is not effective in preventing stones. It is particularly beneficial for the inherited disorder, type I primary hyperoxaluria. Patients should not try to self-medicate with vitamin B6.
Rrferece: http://mens-health.health-cares.net/kidney-stones-diet.php

RESPONSE- DIET- Kidney Stones
By: D2: Gil Legarda / Joanalyn Balino

Intake of Vitamins B6 and C and the Risk of Kidney Stones in Women
GARY C. CURHAN, WALTER C. WILLETT, FRANK E. SPEIZERand MEIR J. STAMPFER

Curhan et. al. studied about the intake of vitamins B and C and the risk of kidney Stones in women. The design of this study was carried out in a cohort study design. The purpose of this study is to examine the association between the intakes of vitamins B6 and C and risk of kidney stone formation in women. There were 85,557 women with no history of kidney stones included in this study. This study was held in the United States also to assess the health status of the female nurses. There were no randomized trials examined the impact of Vit B6 supplementation on the risk of kidney stone formation. The participants of this study were nurses and no history of kidney stone formation as an inclusion criteria any of the laboratory exams of the patient that would not satisfied the requirements would be excluded in the study. Semi-quantitative meal frequency questionnaires were used to assess vitamin consumption from both foods and supplements purpose of biennial questionnaires thru mail that inquire about lifestyle practices and other exposures of interest, as well as the incidence of newly diagnosed disease. Dietary information gathered from the patients were taken before the onset of the kidney stone symptoms. The researcher allocated person per months of follow up according to status of exposure at the start of each follow-up period. If some information was missing at the start of time period the participant will be excluded in the study. Those subject responded on the biennial questionnaire but did not comply on supplementary questionnaire was considered non cases in the analysis.

There were 9.0% of the women reported consumed the 10 mg or more each day of vitamin B6. The intake of supplemental vitamin B6 that resulted in assignment to higher categories did not differ substantially on the amount of dietary of vitamin B6. The mean daily intake of magnesium, potassium, vitamin C and supplemental calcium increased with increasing intake of vitamin B6. The result of the study suggest that greater than or equal to 40 mg/d intake of vitamin B6 may reduce the risk of stone formation in women. But the researchers findings in vitamin C was not consistent for women and men and did not support the practice of routine restriction of vitamin C to prevent kidney stones.

The results are generalized to women who have no kidney stones history. Same for both incident and recurrent kidney stones also apply to women who have history of calcium oxalate stones. Big doses of vit C and B6 are taken relatively frequently by adults in the United States and may be beneficial for a variety of clinical conditions.


Reference:
Curhan G. C., et.al. (1999). Intake of Vitamins B6 and C and the Risk of Kidney Stones in Women. Journal of the American Society of Nephrology Vol. 10 pages 840-845. Retrieved June 28, 2009 from http://jasn.asnjournals.org/cgi/reprint/10/4/840?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&searchid=1&FIRSTINDEX=0&minscore=5000&resourcetype=HWCIT

The Role of Diet in the Prevention of Common Kidney Stones
Christy Krieg
Published: 01/30/2006

Patients with problems leading to formation of kidney stones do have to endure certain manifestations such as flank pain, loss of ability to do ADL’s as well as certain pleasures in life. If the condition will be left untreated, there is an increases tendency for a calcium oxalate stone to have 50% chance to form another stone within 10 years (Menon & Resnick, 2002). With the correct intervention and appropriate client education, the risk over stone disease will be prevented through dietary modifications and medications. This study will discuss certain dietary recommendations for a client with kidneys stones. This study focuses more on the common types of stones, calcium oxalate and uric acid. Regardless of the type of stone formation that the client has, results of a given dietary recommendation will be evaluated with 24-hour urine studies. Interpretations of the values may allow physicians to keep tract of their dietary recommendations together with other therapies. Recent studies have shown that the restriction of calcium intake will also reduce calcium stone formation, and contradictory to those studies is significant evidence against the recommendation.

Certain dietary changes to be done in order to prevent and reduce stone formation are discussed in this study. The most effective intervention for kidney stone management includes in-depth metabolic studies, with the recommendations for medications and dietary changes. Nurses can utilize the prescribed dietary recommendation which includes: increase in fluid intake of more than 2 liters per day, consumption of enough dietary calcium meeting up the required RDA, avoidance of dietary oxalates which has a tendency to form stones, limitation of sodium intake to 2,000 milligrams per day, and limitation of protein to 12 ounces per day. If the client is overweight, natural weight loss program is recommended instead of taking in weight loss pills. It should be considered that diet alone could not control the disease. Dietary measures may just aid the client by supplementing other therapies.

Planning for an effective dietary plan for clients is an easier task than the actual implementation. Nurses should encourage the client’s to make these changes in a realistic tempo. Giving clients words of persuasion and feedback to their achievement may increase their will to continue the program. Health care provider should also give emphasis on the value of aiming for improvement rather than perfection. Given the data regarding the appropriate diet in order to decrease the risks of stone formation, clients will be able to plan for them an appropriate dietary intake aligned with the recommended diet, thus reducing the days for hospitalization and unnecessary medical expense.

References:
Author and disclosures
Christy Krieg, BSN, RN, Clinical Nurse, Methodist Urology, Indianapolis, IN

Dyad 3:
Byron Webb A. Romero
Von Deneb H. Vitto
Raymond C. Ursal

Uric Acid Nephrolithiasis
Mary Ann Cameron, MD*, Khashayar Sakhaee, MD

The articles talk about the relationship between uric acid stone development and an underlying metabolic condition, gout. An epidemiologic study that included over 200,000 subjects from three cohorts found that type 2 diabetes mellitus is associated with kidney stone disease. A significantly higher proportion of pure uric acid stones were found in diabetic patients than in nondiabetics. Obesity is associated with a higher prevalence of uric acid nephrolithiasis. A report of 32 obese stone formers found that 63% of their stones were composed of uric acid.

Uric acid production results from the degradation of purines, derived exogenously from diet and endogenously from purine biosynthesis that includes nucleic acid turnover and production from nonpurine precursors. Additionally, high purine consumption due to a purine-rich diet will also increase the uric acid load.

Fluid and dietary modifications should be recommended to all patients with uric acid stones. Fluid intake should be increased to maintain a urinary volume of approximately 2 L/d. The diet should be modified to decrease consumption of animal proteins to Recommended Dietary Allowances of 0.8 g/kg/d
References:

Cameron M.A. et. al. (2007) Medical Evaluation and Treatment of Urolithiasis. MD Consult Journal; 34(3): 335-4. Retrieved July 09, 2009 from http://www.mdconsult.com/das/article/body/148529963-6/jorg=journal&source=MI&sp=19770320&sid=860640690/N/600257/s009401430700047x.pdf?SEQNO=8&issn=0094-0143