Kidney stones affect as many as one in 10 persons in the United States today. Still, there is considerable variability in stone formers based on geography and genetics.
New Mexico has a particularly high rate of kidney stones, perhaps as a result of the arid, high altitude environment. Five different kidney stones exist, and the incidence of these types also varies considerably. Calcium oxalate comprises the majority of stones in the United States, and New Mexico is no exception with well over 90 percent of stones of this type.
Once a person has had one kidney stone, the risk for repeat stones is as high as 50 percent at 10 years. Some patients may pass stones as much as several times per year. Thus, treatment for kidney stones frequently does not end at the urologist’s office.
Stone prevention is frequently overlooked, sometimes marked up to inadequate fluid intake alone. While fluid intake should not be underemphasized, other contributors to stone formation may be equally important. Sodium intake is a major contributor to urine concentration, and high intake can offset the benefits of fluid intake. Calcium supplementation can promote stones, whereas dietary calcium from the foods we eat serves to decrease stone formation.
Natural inhibitors of stone formation in urine such as citrate exist. Urine acidity can promote formation of uric acid and calcium oxalate stones while calcium phosphate stones and struvite stones grow in alkaline urine. Cystine stones are unique to patients with a genetic condition known as cystinuria.
So what can this mean to the recurring stone formers? Capturing the kidney stone for geologic evaluation to determine stone type is a first step to preventing recurrent stones. A metabolic workup with blood and urine studies can frequently reveal contributors to stones. Moreover, these contributors can oft be modified to drastically reduce or halt future stone production. A nephrologist (kidney doctor) should be able to navigate these tests and treatments for you.
Dr. David Mills is a nephrologist/internist with Medical Associates of Northern New Mexico. He can be reached at 505.661.8900.