Like metabolic syndrome, CKD is recognized as a major risk factor for development of cardiovascular diseases, such as heart attack and stroke. Early treatment of CKD has been shown to reduce the risk of later development of cardiovascular disease.

Dr. Manjula Kurella and colleagues of University of California San Francisco analyzed the relationship between metabolic syndrome and CKD in over 10,000 middle-aged Americans participating in a long-term study of cardiovascular disease risk factors.

All subjects initially had normal kidney function. None had diabetes at the beginning of the study, but 21% had at least one characteristic of metabolic syndrome, including the following:

During follow-up, seven percent of subjects developed CKD, reflecting a gradual, irreversible loss of kidney function. With adjustment for other factors, CKD risk was 43% higher in subjects with any of the five characteristics of metabolic syndrome, compared to those with no characteristics.

1 in 5 US Adults Have Metabolic Syndrome

The more characteristics of metabolic syndrome, the higher the risk of CKD. For subjects with all five characteristics, the risk of CKD was more than double that of a person with no characteristics.

Further adjustments were performed to account for the presence of high blood pressure and the development of diabetes, both important CKD risk factors. The link remained significant although somewhat weaker -- CKD risk was increased 24% for subjects with metabolic syndrome.

About 1 in 5 U.S. adults have metabolic syndrome, sometimes called insulin resistance syndrome, or "syndrome X." Previous studies have identified metabolic syndrome as a risk factor for diabetes and cardiovascular disease. However, its effect on CKD has been unclear.

Treatments Can Slow or Prevent Kidney Disease

Early identification of CKD is a major health care priority, especially because effective treatments can slow or prevent progressive kidney disease.

Like metabolic syndrome, CKD is recognized as a major risk factor for development of cardiovascular diseases, such as heart attack and stroke. Early treatment of CKD has been shown to reduce the risk of later development of cardiovascular disease.

The new results suggest that metabolic syndrome is an important risk factor for CKD in middle-aged people without diabetes. This risk is significant even after adjustment for other factors, and increases along with the number of metabolic syndrome characteristics present.

"[T]he metabolic syndrome directly contributes to the development of CKD," Dr. Kurella and coauthors conclude. More research will be needed to determine whether weight loss, exercise, and other measures to address the characteristics of metabolic syndrome can help to reduce the long-term risk of CKD.