BRIEFING

Kidney disease can lead to diabetes: study

CHICAGO, Jan. 2 -- Kidney disease increases the risk for diabetes, not just the other way around, a study of the Washington University at St. Louis has found.
Researchers at the university found that kidney dysfunction can lead to diabetes, and that a waste product called urea plays a role in the two-way link between the two diseases.
The study involved the analysis of medical records over a five-year period for 1.3 million adults who did not have diabetes. About 9 percent had elevated urea levels, a sign of reduced kidney function. That's the same rate as in the general population.
People with high urea levels were 23 percent more likely to develop diabetes than those with normal urea levels, the study found.
"The risk difference between high and low levels is 688 cases of diabetes per 100,000 people each year, which means that for every 100,000 people, there would be 688 more cases of diabetes each year in those with higher urea levels," said study senior author Ziyad Al-Aly, an assistant professor of medicine at Washington University School of Medicine in St. Louis.
"We have known for a long time that diabetes is a major risk factor for kidney disease, but now we have a better understanding that kidney disease, through elevated levels of urea, also raises the risk of diabetes," Al-Aly said.
"When urea builds up in the blood because of kidney dysfunction, increased insulin resistance and impaired insulin secretion often result," he said.
The findings about the role of urea may help improve treatment and possibly prevent diabetes. The study has been published online in the journal Kidney International.

Cow milk formula does not increase diabetes risk in children: study

WASHINGTON, Jan. 2 -- Drinking formula made with cow's milk did not increase the risk of developing Type 1 diabetes in children with genetic risk factors for the condition, a 15-year international study of more than 2,000 children said Tuesday.
The findings, published in the Journal of the American Medical Association, provided a long-awaited answer to the question of whether infant formula made with cow's milk plays a role in the development of Type 1 diabetes.
Previous studies have indicated that early exposure to complex foreign proteins, such as the proteins in cow's milk, may increase the risk of Type 1 diabetes in people with genetic risk for the disease.
Beginning in 2002, a team led by Dorothy Becker, a professor of pediatrics at the University of Pittsburgh School of Medicine, examined 2,159 infants in 15 countries to find out whether delaying the exposure to complex foreign proteins would decrease the risk of diabetes.
Each of the infants had a family member affected by Type 1 diabetes, as well as a genetic propensity for the disease that was determined with a blood test given at birth.
After breastfeeding, the babies were either weaned to a conventional cow's-milk-based formula with the cow's-milk proteins intact or a special formula in which the cow's-milk proteins were split into small pieces known as peptides.
That special formula -- called hydrolyzed-casein formula -- mimics the body's process of digestion, breaking down proteins into tiny parts.
Infants were fed the study formula for at least two months until the age of six to eight months and at the same time were given no cow's milk proteins from any other food sources.
Of the infants who consumed the conventional cow's-milk formula, 82, or 7.6 percent, developed diabetes during the 11.5-year followup period. For those who received the hydrolyzed-casein formula, 91, or 8.4 percent, eventually developed the disease.
The results showed no statistically significant difference between the two groups in terms of how many of these children developed diabetes.
"After more than 15 years of effort, this study puts to rest the controversy regarding the potential role of cow's milk formula in the development of type 1 diabetes," said Becker.
"This once more shows us that there is no easy way to prevent type 1 diabetes. Accordingly, there is no evidence to revise the current dietary recommendations for infants at high risk for type 1 diabetes."