Diet management in Diet management in stone Diseasestone Disease

Dr. Anmar Nassir, FRCS(C)

Canadian board in General Urology

Fellowship in Andrology (U of Ottawa)

Fellowship in EndoUrology and Laparoscopy (McMaster Univ)

Assisstent Prof Umm Al-Qura

Consultant Urology King Faisal Specialist Hospital

Introduction

• Nephrolithiasis is influenced by – Genetic factors– Environmental factors

• Diet is a major environmental component

Risk factors

• Intrinsic factors– Heredity– Age and Sex

• Extrinsic factors – Geography

– Climate and season

– Water intake

– Diet – Occupation

So why it’s So why it’s ignored ?ignored ?

Stone Management

• Treatment of the stone(s)

• F/u of the stone formers– Who?– When?

Evaluation of First Stone Former

All patients get at least simple workup• History

– Diet– Stone-provoking meds– Fluid loss– UTI

• Investigations– Stone analysis– CBC, lytes, Cr, Ca, phosphate, uric acid– KUB – UA C&S,

Campbell’sCampbell’s

Evalution of recurrent Stone Former

• What to do?• Clinical practice

– 24 h urine via automated process (pH, Ca, oxalate, uric acid, citrate, Na, sulfate, phosphorus, Mg) once,

– then depending on the above :• repeated with blood work and PTH after dietary

modification

– Bone density study if marked hypercalciuria or hypercalcemia

Campbell’sCampbell’s

Evalution of recurrent Stone Former

• Research protocol:– Two, separate 24h urine collection for Ca, oxalate,

Mg, phosphorus, uric acid, creatinine, citrate, pH, sodium, sulfate on random diet one week apart

– Third visit :• Restricted diet• 24h urine collections for Ca, Na, oxalate• PTH• Fast and calcium load test• Bone density if available

Campbell’sCampbell’s

Who needs more evaluation?

– Recurrent episodes– High risk– Abnormality of simple workup – Multiple stones– Nephrocalcinosis– FHx of stones– Bone or GI disease– Gout– Chronic UTI

Campbell’sCampbell’s

How far should patients with single renal stone be evaluated? • Pak CY 1982AH 55.9 %

renal hypercalciuria 11.8 %

primary hyperparathyroidism 2.9 %

hyperuricosuric calcium oxalate 8.8 %

no metabolic abnormality 20.6 %

• The same physiological and environmental disturbances as in recurrent stone former

Pak CY 1982Pak CY 1982

• In men, – # number of metabolic abnormalities with recurrent

stones (2.20+/-0.86) vs. first-time stones (1.46+/-1.27).

• In women– only be demonstrated for women if low urine volume

was excluded

– a statistically significant difference was only noted in the frequency of hypocitraturia (11.1% versus 37.8%, P < 0.05).

• There were no significant differences in the calcium oxalate supersaturation in all groups

37 vs 136 Yagisawa 1998Yagisawa 1998

Comprehensive vs. Limited Metabolic Evaluations

• specific metabolic diagnosis was made in: – 90% by the comprehensive metabolic evaluation – 68% by 1 24-hour urine collections – 75% by 2 24-hour urine collections.

• Hypercalciuria, hyperoxaluria, and hypocitruria were diagnosed significantly more often

• Type II AH was the most common (1/3) • Dietary calcium-sensitive oxaluria was present in

22% of patients.

Yagisawa T, et al J Urol 1999

• Aplication of that remains controversial for several reasons:– First, if you diagnose hypercalciuria,

hyperoxaluria, or hypocitruria, does specific medical therapy really alter the course of recurrent stone disease?

– Second, several recent studies have shown that nonselective medical therapy may provide control of recurrent calcium urolithiasis.

Comments

What do we do in our hospital?

• 24 hr X 2 urine collection

• Diet Hx

• Which days of the week?

Norman et al, 1996

–Average 24 h urine volume was higher on weekdays than at weekends. –Calcium, oxalate, and uric acid excretion did not differ

When to evaluate?• At least 3/12 • The in-hospital 24-hour urine volumes were

high • decreased gradually to approach the

relatively constant volume of the control group by 3 months.

• The opposite trend occurred with respect to the 24-hour urinary excretion of calcium

• no significant changes in pH,Ox,U.a.

Norman et al, 1984

What is the type of stone?

• Stone analysis

• Expert radiologist

• Past record by pt or relatives

Dretler identfied 4 pattern of stones w varying COM & COD on KUB

Jurol 1996

Type of stoneType of stone %%

Calcium Calcium Oxalate mono & dihydrate

Phosphate

Ox & Phos

~ 80

35-50

10-20

10-35

StruviteStruvite 10-20

Uric a.Uric a. 6-16

CystineCystine 0.5-3

OtherOtherTriamterene

Xanthine

Matrix (noncryst.)

~ 1

What are the diet Factors?

• Fluids• Protien• Na +

• K +

• Ca ++

• Fiber• Vit D

• Ascorbic Acid• Vit B 6• CHO• Fat• Mg• Phosphorus

FLUIDS

• Increased fluid consumption– Recommended since the era of Hippocrates– May decrease supersaturation – Benefits all stone formers

FLUIDS

• Adult male and female first-time stone for-mers had significantly lower urinary volumes compared with age-matched controls: – Mean 24-hour vol = 1057 mL and 990 mL– Vs control groups = 1401 mL and 1239 mL

Borghi et al 1996Borghi et al 1996

Others didn’t Show thatOthers didn’t Show that

FLUIDS

• Prospective study of a cohort of 45,619 male• RR decreased with increased fluid consumption:

< 1275 ml, 1.0

1275-1669 ml, 1.05

1670-2049 ml, 0.82

2050-2537 ml, 0.72

> 2537 ml, 0.52

• The risk varies with the type of beverage

Curhan et al 1993Curhan et al 1993

FLUIDS

• The risk for kidney-stone development decreased by:– coffee, 10% – tea, 14% – beer, 21% – wine, 39%

 

But may promote Ca++ excretion

(Hasling et al 1992)Has high oxalate contentSo don’t recommend it to

your pt(Assimos et al 2000)Alcohaol can induce

hyperuicosuria(Zechnar 1985)

Curhan et al 1993Curhan et al 1993

FLUIDS

• The risk increased with – Apple juice, 35%– grapefruit juice, 37%

Curhan et al 1993Curhan et al 1993

High Ca++High Na+High CHO

FLUIDS

• Other beverages - did not significantly influence stone, including – water, skim or low fat milk, orange juice,

tomato juice, lemonade, all types of cola, non cola soda, and hard liquor

Curhan et al 1993Curhan et al 1993

May be useful in Hypocitraturic pt

(Wabner et al, 1993)

FLUIDS

? Increasing fluid intake ? Increasing fluid intake might have a deleterious might have a deleterious

effecteffectThis could lower the This could lower the

conc. of urinary conc. of urinary inhibitors. inhibitors.

Just a hypothesisJust a hypothesis

FLUIDS

• Although it is possible

• But this should not promote crystallization.

• Increasing fluid intake actually has been demonstrated to have a positive effect on:– Citrate – Tamm-Horsfall protein.

Jeager et al 1995Jeager et al 1995

Increase it’s inhibitory activity

Inhibit it’s reabsorption

FLUIDS (water Hardness)

• It reflects the amount of dissolved calcium and magnesium.

• Its effect on stones has been debated for yrs

Stones less prevalence at

higher hardness Juuti, 1980

Correlates in some areas onlyRose 1975

No CorrelationChyrchill, 1980

Negative CorrelationBetween stones & degree of

Hardness Sierakawski, 1979

No correlation Kohri 1989

FLUIDS• Patients w stones vs. inguinal hernia repair • There was no significant difference in these two

patient groups with respect to (Ca++ and Mg++) in the respective tap water consumed in – North and South Carolina (soft water) – the Rocky Mountain area (hard water).

• Conclusion:– that water hardness did not influence stone forma-lion.

• However, well water relative to city water significantly increased the risk for stone events in both areas.

Shuster et al 1982Shuster et al 1982

FLUIDS

• Tap water vs. mineral water– X 2 Ca ++ / Mg in the water – Both produce favorable changes in risk

parameters – More in profound in mineral

Rodgers et al 1997Rodgers et al 1997

FLUIDS

• The effect of different calcium content in mineral water

• 15.3: 123.9: 380 mg/L

• 380 mg/L– Significant dec in Ox & Ox : Ca

Caudarella et al 1998Caudarella et al 1998

FLUIDS

• Random prospective study on Ca Ox stone formers

• gr 1 (99 pt ) instructed to have > 2 L/d

• gr 2 (100 pt) told:

You have isolated stone No change in fluid intake were

needed !!!!

Borghi et al 1996Borghi et al 1996

FLUIDSAfter 5 yrsAfter 5 yrs Borghi et al 1996Borghi et al 1996

gr 1 gr 1 gr 2gr 2

Base line volBase line vol

(ml)(ml)

10681068 10081008

F/u volF/u vol

(ml)(ml)

2127 – 26542127 – 2654 1005 – 12581005 – 1258

Stone Stone recurrentrecurrent

12%12% 27%27%

Mean interval Mean interval to stone form.to stone form.

38.7 mo38.7 mo 25.1 mo25.1 mo

ProteinAnderson et al 1973Anderson et al 1973100 % greater

X 4

Protein

• Curhan et al reported – animal protein was directly associated with a

risk for stone

Robertson et al 1979Robertson et al 1979

•Recurrent stone formers consumed more total and animal protein than controls

Protein

• In our population – Males:

• no difference except in youngest age gr

– Females • had significantly higher than controls

Al Zahrani Norman et al, 2000

Protein

• Metabolic changes:– Inc Ca++ u.a. Exc– Dec citrate– 75g pr Ca++ 100mg/d– Ox contraversal

• Animal pr significantly higher– More sulfur in a.a.

Many studies

Protein• Randomized controlled • 50 first-time calcium oxalates stone formers

– increase fluid intake and consume a high-fiber, law- animal proteins diet,

• 49 control– toId just to drink more fluid.

• 4.5-year, – the control gr had significantly less stone events. – 2 vs 12

Hiatt et al 1996Hiatt et al 1996

This supports the finding of the statistical findings of the protective effect in AL Zahrani et al

Al Zahrani Norman et al, 2000

Protein

• These unexpected results could be due to– effect of fiber, – Non-control of calcium intake, – a higher fluid intake for the controls– or patient compliance.

• A better designed randomized study is needed

Assimos et al 2000Assimos et al 2000

CommentComment

Sodium

• metabolic changes– inc in urinary

• pH, calcium, and cystine

– dec in • citrate excretion

– Inc PTH & vit D

Na restriction should be

recommended in pt w Cystinuria

Sodium

• Urinary exc reported to be higher in hypercalciuria than normo-

• Intake not frequently seen to be higher in stone formers

• Curhan: not as a risk

Iguchi et al 1990Iguchi et al 1990

Trinchieri et al 1998Trinchieri et al 1998

Potassium

• Potassium has been demonstrated to decrease calcium excretion.

• Stone formers have an inc urinary Na/K

• Curhan et al RR= 0.49 in > 4041 mg.d compare to < 2896 mg/d K

• Others didn’t show thisMartini et al 1998Martini et al 1998

Calcium

• 50 – 40 yrs: calcium-restricted diet was a mainstay in the treatment of stones

• S/E :– Inc U Ox exc– bone health is another potential problem

Calcium

• RR of stone formation dec w increased Ca++ intake

Calcium

Ca ++ intakeCa ++ intake RRRR

< 605 mg< 605 mg 1.01.0

605 - 722 mg605 - 722 mg 0.710.71

723 - 840 mg723 - 840 mg 0.640.64

849 - 1049 mg849 - 1049 mg 0.610.61

> 1000 mg> 1000 mg 0.560.56

Curhan et al 1997Curhan et al 1997

In males

Calcium

Ca ++ intakeCa ++ intake RRRR

< 408 mg< 408 mg 1.01.0

400 - 642 mg400 - 642 mg 0.780.78

643-801 mg643-801 mg 0.660.66

802-1098 mg802-1098 mg 0.70.7

> 1098 mg> 1098 mg 0.490.49

In females

Curhan et al 1997Curhan et al 1997

Calcium

• In our pts– AL Zahrani et al study supports the protective

role of dietary Ca++ in men but not in women

Al Zahrani Norman et al, 2000

Calcium.

• Supplemental Ca++ inc rather than dec the risk

• Statistically significant only in women

Curhan et al 1997Curhan et al 1997

Calcium

• The bulk of individuals didn’t take it with meals,• To be protective it should be taken with meals to

bind dietary oxalate • It is now believed that levels at calcium intake

above the 800 mg recommended may be beneficial,

• But the optimum value to decrease stone risk has not been identified

• 3858 mg Ca++/d // 2220 mg Ox /d

Assimos et al 2000Assimos et al 2000

CommentComment

Hess et al 1998Hess et al 1998

Oxalate

• absorbed all along the alimentary tract

• > ½ in SI

• Diet can provide 80 % of urinary Ox

Oxalate

• increasing dietary oxalate significantly increases urinary oxalate

• the relationship is nonlinear,

• the response is variable / generic influence

• the amount of Ca++ in the diet has a large impact on the absorption of Ox

Assimos et al 2000Assimos et al 2000

Oxalate

• definitive studies showing that the amount of Ox ingested is a risk factor for the disease are lacking

• Based or the available evidence, restriction of dietary Ox intake is reasonable advice

Assimos et al 2000Assimos et al 2000

Fiber

• 4 –5 X inc in Fiber produce a 20 % reduction in intestinal time

& • Dec Ox absorption / less time• Dec Ox excretion

Bind to Ca++ / phytic a.

+ve correlation w urinary citrate excretion

Hess et al 1994Hess et al 1994

Fiber

In our pts

Higher intake only among young & females

Al Zahrani Norman et al, 2000

Carbohydrates

• Curhan reported that sucrose was not risk factor in male but it is in female

• Not detected in other studies

• CHO inc Ca++ absorption & excretion

• Endogenous Ox synthesis may inc– (gluconeogenesis & ureagenesis)

Assimos et al 2000Assimos et al 2000

Carbohydrates

In our pts

Higher intake than control

Correlated positively w stone

Al Zahrani Norman et al, 2000

Fat

• Animal & vegetable fat was mentioned as risk factor for stones in previous studies

• Not identified by Curhan et al

Fat

• In Halifax QEII– Higher consumption in both male & female

than control– Even higher in younger – As a risk

• in step- wise but not in logistic test

500 pt

Al Zahrani Norman et al, 2000

Fat

• More extensive work studying the effect on urinary risk factors showed:– No relation to PH, Mg, Cit, Ox, Ca, U.a, in men– Weak association between fat intake & U.a in

female

Bailly, Norman 2000Bailly, Norman 2000476 pt

Vitamin B 6

• No association in males

• Limits the risk in female

Carhan et al 1996Carhan et al 1996

Carhan et al 2000

(not published yet)

Carhan et al 2000

(not published yet)

M/A

Dec Ox exc

Mitwalli et al 1988Mitwalli et al 1988

Vitamin C

• Controversial

• Curhan et al 1996:– No association

• Higher intake among males & females was documented in our pts

Al Zahrani Norman et al, 2000

? Inc urinary Ox? decomposition

Vitamin D

• Pursued mainly to expalain the seasonal nature

• Curhan et al recently:– No association

Carhan et al 2000

(not published yet)

Carhan et al 2000

(not published yet)

Magnesium

• Influence not well defined

• Curhan et al – No association

M/A in normal & stone former

Urinary Ca++ & Cit inc

Ox dec

Lindberg et al 1990Lindberg et al 1990

Phosphorus

• Dec Urinary Ca++– Due to dec vit D activity– Its more of the preparation than of the diet

• Should be avoided in struvite & Brushite

• Curhan et al – No association