Endo-Renal-L04-(B)-Nephrolithiasis-Risk Factors

What are the three categories of risk factors for nephrolithiasis

Dietary, nondietary, and urinary

Why might retrospective dietary studies on nephrolithiasis be unreliable

Patients often change their diet after developing stones, leading to recall bias

What dietary factors increase the risk of nephrolithiasis

Animal protein, oxalate, sodium, sucrose, and fructose

What dietary factors decrease the risk of nephrolithiasis

Calcium, potassium, and phytate

How does higher dietary calcium intake affect kidney stone risk

It lowers the risk by reducing intestinal absorption of dietary oxalate

Why is low dietary calcium intake contraindicated for kidney stone formers

It increases stone risk and may contribute to lower bone density

Why might calcium supplements increase the risk of kidney stones

They may lead to higher urinary calcium excretion, depending on timing and total intake

What are the two sources of urinary oxalate

Endogenous production and absorption of dietary oxalate

Why is dietary oxalate considered a weak risk factor for stone formation

Its bioavailability is low and variable, so not all oxalate in food is absorbed

Why is urinary oxalate a strong risk factor for calcium oxalate stone formation

Higher urinary oxalate increases supersaturation, promoting stone formation

How does higher intake of animal protein affect stone formation risk

It increases calcium and uric acid excretion while decreasing citrate excretion, raising stone risk

How do sodium and sucrose intake impact calcium excretion

They increase calcium excretion independent of calcium intake

How does higher potassium intake affect calcium and citrate excretion

It decreases calcium excretion and increases urinary citrate due to its alkali content

Which dietary factors are inconsistently associated with lower stone risk

Magnesium and phytate

Why should male calcium oxalate stone formers avoid vitamin C supplements

Vitamin C supplements may raise urinary oxalate levels, increasing stone risk

In which condition might high-dose vitamin B6 supplements be beneficial

Type 1 primary hyperoxaluria

At what urine output does kidney stone risk more than double

Less than 1 L/day

Which beverages are associated with a reduced risk of kidney stones

Coffee, tea, beer, wine, and orange juice

What type of beverages may increase kidney stone risk

Sugar-sweetened beverages

Which nondietary factors influence nephrolithiasis risk

Age, race, body size, and environment

Which demographic has the highest incidence of kidney stones

Middle-aged white men

Which region in the U.S. has the highest prevalence of nephrolithiasis

The southeastern United States

What environmental and occupational factors contribute to stone formation

Working in hot environments or lacking access to water or bathrooms

What has been shown to reduce the risk of stone recurrence

Higher fluid intake to increase urine volume

How does higher urine calcium excretion affect kidney stone formation

It increases the likelihood of calcium oxalate and calcium phosphate stones

What are possible contributors to higher urine calcium levels

Greater gastrointestinal calcium absorption and increased bone turnover

How does higher urine oxalate excretion affect kidney stone risk

It increases the likelihood of calcium oxalate stone formation

How does dietary calcium intake influence urine oxalate levels

Higher dietary calcium reduces gastrointestinal oxalate absorption, lowering urine oxalate

What role does urine citrate play in kidney stone formation

It inhibits calcium-containing stones; lower levels increase stone risk

How does metabolic acidosis affect urine citrate levels

It increases citrate reabsorption, reducing urine citrate excretion

What dietary factor can reduce urine citrate excretion

Higher intake of animal flesh

What is the primary risk factor for uric acid stone formation

Higher urine uric acid levels from excess purine consumption or genetic conditions

Does urine uric acid level affect calcium oxalate stone risk

No, it does not appear to be associated with calcium oxalate stones

How does urine pH influence uric acid stone formation

Uric acid stones form when urine pH is consistently ≤5.5

At what urine pH are calcium phosphate stones more likely to form

When urine pH is ≥6.5

How does urine pH affect cystine solubility

Cystine is more soluble at higher urine pH

Does urine pH influence calcium oxalate stone formation

No, calcium oxalate stones are not affected by urine pH