Kidney Disease

The statistics are startling.

One in eight adults—which translates to some 26 million Americans—suffers from chronic kidney disease. Equally startling is the fact that this alarming total is soaring skyward, having increased 16 percent in the last 10 years, according to data recently released by the Centers for Disease Control and Prevention.

When asked what’s fueling this disturbing trend, Vito Campese, M.D., professor of medicine and chief of the division of nephrology/hypertension at the Keck School of Medicine of USC, offers ready explanations.

“There are some key factors,” he says. “First, there’s an epidemic of obesity and diabetes in the United States, and the two are linked [to each other and to kidney disease].” Campese goes on to note that fully 40 percent of those with diabetes will develop kidney disease over the course of their lives.

“Another factor,” says Campese, “is the aging of our population. As people age, they are more likely to develop cardiovascular disease or have a stroke—both of which affect the kidneys.”

Chronic Kidney Disease Defined

The National Kidney Foundation defines chronic kidney disease (CKD) as the gradual and usually permanent loss of kidney function over time. CKD is divided into five stages of increasing severity, from stage 1 that represents slight kidney damage, to stage 5 in which kidney failure necessitates dialysis or transplantation.

The two primary causes of CKD are high blood pressure and diabetes. According to the National Institutes of Health, high blood pressure forces the heart to work harder and can damage blood vessels throughout the body. If the blood vessels in the kidneys are damaged, they may stop removing wastes and extra fluid from the body. A dangerous cycle can result, as excess fluid in the blood vessels can further raise blood pressure.

“When you have diabetes,” explains Campese, “there are certain proteins that accumulate in the kidneys. This causes clogging of the kidneys’ micro-vascular system which, in turn, can progressively lead to kidney failure.”

Unfortunately, as Campese points out, “Most people don’t have any symptoms until they have advanced kidney disease.” In some instances, however, there are warning signs, including:

  • fatigue and weakness
  • trouble concentrating
  • loss of appetite, nausea, or vomiting
  • difficulty sleeping
  • muscle cramping at night
  • swollen feet and ankles
  • puffiness around the eyes, especially in the morning
  • dry, itchy skin
  • easy bruising
  • headaches
  • numbness in feet or hands
  • restless legs syndrome
  • requent urination, particularly at night

CKD is initially diagnosed through urinalysis and blood tests.

Who is Most at Risk

“Diabetics are most at risk for developing chronic kidney disease,” says Campese. “Fifty percent of those on dialysis in the United States have diabetes. Also at risk are people who are obese, and those with high blood pressure, high cholesterol or a family history of kidney disease.”

Ethnic groups that have a greater-than-average rate of diabetes and high blood pressure—such as African Americans, American Indians, Asians, Hispanic Americans and Pacific Islanders—are also more prone to developing CKD. Campese notes that people who have been exposed to high levels of lead are also at greater risk, as are those with a history of drug abuse.

Regarding treatment, Campese explains, “The disease itself has no specific treatment, although there are some medications that can slow down its progression. What you are treating is the disease’s cause, such as diabetes, high blood pressure or high cholesterol.”

Ways to Reduce Risk

“The goal is early diagnosis,” says Campese, “so every person who is diabetic, and anyone who is obese or who has high blood pressure or high cholesterol, should be screened for kidney disease.” Campese further recommends that everyone over 40 should have an annual physical that includes testing for kidney disease.

Of course, heading off CKD entirely is the ultimate goal. Toward this end, experts recommend:

  • Losing excess weight
  • Controlling blood glucose (if diabetic)
  • Managing high blood pressure
  • Quitting smoking
  • Exercising regularly
  • Consuming a healthy diet

To this advice, Campese adds: “The kidneys are an integral part of the cardiovascular system. So whatever is healthy for the cardiovascular system is healthy for the kidneys.”