High cholesterol increases risk of disease

The incidence of end-stage renal disease (ESRD), or kidney failure, has doubled over the past decade in the United States. Now researchers at Brigham and Women’s Hospital (BWH) have published a study that links abnormal cholesterol levels with the development of kidney problems, raising the possibility of preventing the onset of chronic kidney dysfunction by controlling a person’s cholesterol levels.

The study followed 4,483 apparently healthy men in the Physicians’ Health Study for 14 years, all of whom had normal kidney function at the beginning of the study, based on their levels of creatinine (a muscle-produced protein used as a barometer for good kidney health).

At the conclusion of the research, those men with higher levels of total or non-HDL cholesterol or decreased levels of HDL cholesterol were more likely to develop increased creatinine levels – an indication of kidney malfunction – and decreased glomerular filtration rates (GFR), another standard method for measuring kidney health.

“Our study strongly suggests that there is a correlation between abnormal cholesterol levels and the development of kidney disease in healthy men,” said Tobias Kurth of BWH, project director of the study, who conducted the study with lead author Elke Schaeffner, also of BWH. “Men with high cholesterol, particularly those with high non-HDL cholesterol and decreased HDL cholesterol, were assessed as being twice as likely to encounter problems with their kidneys.”

One in nine adults in the United States, more than 20 million people, have chronic kidney disease. An additional 20 million people are at a heightened risk for developing kidney problems. According to the Kidney Foundation, kidney disease is one of the most costly diseases in the United States today. In addition, treatment options for ESRD are lacking, resulting in many patients needing renal replacement therapy in the form of dialysis or kidney transplantation.

The BWH study, published in the Journal of the American Society of Nephrology, is the first large study that links abnormal lipid levels with the development of kidney dysfunction in apparently healthy men. These most recent findings were made more compelling by previous research that showed that statins, the drugs used to lower lipid levels in the blood, helped stop the acceleration of already-existing chronic renal disease. Another previous study predicted an increase risk for kidney dysfunction in a small group of people who had low levels of “good cholesterol” and high volumes of triglycerides, a form of fat, in the blood.

“We hope this study becomes the basis for future research that will look into whether statins can be used preventatively in a target population to promote good kidney health and possibly prevent them from becoming diseased,” added Kurth, who is also an instructor at Harvard Medical School.

A forthcoming British study will directly test whether lowering bad cholesterol levels using statins will reduce the risk of progression to ESRD among those who suffer from chronic kidney problems.