SAN DIEGO – Regular consumption of sugar-sweetened sodas and punch are linked with an increased risk of kidney stone formation while consumption of coffee, tea, and other beverages may be protective, results from a large analysis demonstrated.
The findings confirm earlier reports of beverages believed to be associated with a reduced risk of kidney stone formation, Dr. Pietro Manuel Ferraro said in an interview during a poster session Kidney Week 2012. "Patients with a previous kidney stone are advised to ingest at least two liters of fluid per day, but not all fluids are equally beneficial," said Dr. Ferraro, a nephrologist at Catholic University of the Sacred Heart, Rome. "What we can say from this analysis is that it’s best to reduce consumption of sugar-sweetened beverages in these patients."
Doug Brunk/IMNG Medical Media
Dr. Pietro Manuel Ferraro
For the study, which Dr. Ferraro and his associates conducted over the past year at the Channing Division of Network Medicine in Boston, the researchers analyzed data from three large ongoing cohort studies: the Health Professionals Follow-Up Study, and the Nurses’ Health Study I and II. They used a Cox model to assess the risk of developing kidney stones associated with each beverage and adjusted for covariates including age, race, physical activity, body mass index, diabetes, high blood pressure, gout, use of diuretics and intake of calcium, potassium, animal protein, phytate, vitamin C, total energy, and alcohol.
Dr. Ferraro reported data from 194,095 participants in the pooled analysis, which represented 2,643,708 person-years of follow-up. Five categories of beverage consumption were evaluated: less than 1 beverage/week (the reference category), 1/week, 2-4/week, 5-6/week, and 1 or more/day. The researchers found that consumption of sugar-sweetened cola was significantly associated with kidney stone formation (hazard ratio of 1.07 for 1/week; HR, 1.19 for 2-4/week; HR, 1.28 for 5-6/week; and HR, 1.23 for 1 or more/day, compared with the less than 1/week category; P = .02), as was consumption of sugar-sweetened non-cola (HR, 1.17, 1.07, 1.22, and 1.33, respectively; P = .003) and sugar-sweetened punch (HR, 1.10, 1.15, 1.21, and 1.18, respectively; P = .04).
At the same time, consumption of certain beverages were found to be inversely associated with kidney stone formation, including coffee (P less than .001), tea (P = .02), red wine (P = .004), white wine (P = .002), beer (P less than .001), and orange juice (P = .004).
The study, which is the largest of its kind, was supported by a grant from the National Institutes of Health. Dr. Ferraro said that he had no relevant financial conflicts to disclose.