Keeping your kidneys healthy

If you’re health-conscious, chances are you know your weight, heart rate, and blood pressure. You may even know your HDL and LDL cholesterol levels. But do you know your glomerular filtration rate, or GFR? Probably not, unless you’re being treated for advanced kidney disease.

Despite its relative obscurity, GFR, a measure of how well your kidneys are filtering out toxins from blood, is a critical yardstick of your health. With the incidence of kidney disease skyrocketing in the Philippines – and with early diagnosis the key to avoiding the need for dialysis and transplants – experts like Dr. Libertad P. Nazareno-Rosales, president of the Philippine Society of Nephrology, believes it’s time kidney disease is recognized as a major public health issue. After all, it is now the 10th leading cause of death in the Philippines.

Although it’s unlikely GFR will ever become a household health statistics soon, Filipinos should learn to recognize the early warning signs of kidney disease. These include high blood pressure; swelling of the face and ankles; puffiness around the eyes; frequent urination (especially at night); brown-colored urine; and back pain just below the rib cage. And those in high-risk groups should make sure they regularly receive blood and urine tests that show how well their kidneys are functioning. This week, we will discuss what causes kidney disease and what you can do to keep your kidneys healthy.

Chronic Kidney Disease

Chronic kidney disease – broadly defined as any condition with potential to cause either progressive loss of kidney function or kidney-related complications – probably affects millions of Filipinos, with millions more at risk. Untreated kidney disease can cause other health problems such as high blood pressure (both a cause and complication of kidney disease), anemia, bone disease, neuropathy (dysfunction of the peripheral nerves), and cardiovascular disease.

Those at elevated risk for kidney disease include people with diabetes or high blood pressure, people older than 50, people with family histories of kidney disease, and members of certain ethnic groups (including African Americans, Native Americans, Hispanics, Asians, and Pacific Islanders).

A high percentage of people with chronic kidney disease will develop kidney failure, also known as end-stage renal disease. The number of Filipinos with kidney failure has been increasing each year. High blood pressure and diabetes are the two most common causes of kidney failure; together they account for about 60 percent of cases. Other common causes include chronic kidney infections and inflammation, cysts, kidney stones, prolonged use of pain relievers, and abuse of alcohol, heroin, or other drugs.

Treatment

Treatment for kidney disease depends on its severity at the time of diagnosis and its underlying cause. When detected early, lifestyle changes and medication largely geared toward reducing blood pressure can prevent or slow progression. Lifestyle changes include weight loss; smoking cessation; a diet high in calcium and low in protein, salt, and potassium; and (for diabetics) strict control of blood sugar.

Two types of drugs used to control high blood pressure – angiotensin-receptor blockers and angiotensin-converting-enzyme (ACE) inhibitors – have been shown to slow the progression of kidney disease independent of their effect on high blood pressure.

If chronic kidney disease progresses to kidney failure, a patient’s life is in danger without dialysis or a kidney transplant. Two types of dialysis exist: With hemodialysis, a tube connects the patient to a machine that removes blood from the body, filters it, and returns it to the body. Hemodialysis usually takes place at a dialysis center three times a week and takes three to four hours per treatment.

With peritoneal dialysis, the patient injects a blood-cleansing solution called dialysate into the abdomen through a permanently implanted catheter. Once inside the body, the dialysate extracts toxins and excess fluid from the blood, and the waste products drain out through the catheter. Peritoneal dialysis must be done four times a day, but it can be done at home.

Kidney transplants have a high success rate and eliminate the need for dialysis. Unfortunately, the demand far outstrips the supply of donated organs, so patients with kidney failure often wait years to receive a transplant.

Dialysis and transplants are final, drastic countermeasures for kidney failure. Let’s step back and look at how your doctor can make an early diagnosis of kidney disease, allowing treatment that in most cases can prevent the disease from progressing to the point where these extreme measures are needed.

Tests

Two routine tests allow your doctor to assess your kidney’s health. A standard blood test measures the blood level of creatinine – a protein produced by the normal breakdown of muscle tissue. From this test result, your doctor can determine your GFR, a measure of the amount of blood being cleared of creatinine over time. A GFR of 100 to 140 in men and 85 to 115 in women is considered normal. A GFR below 60 suggests moderate kidney damage; lower than 30 indicates severe damage; and below 15 indicates kidney failure requiring dialysis.

Next, a urine test checks for protein in urine. The presence of more than a small amount (a condition called proteinuria) suggests kidney damage. Previously, physicians thought that a 24-hour supply of an individual’s urine was needed to run this test – which discouraged many doctors from making it part of routine medical checkups – but a standard sample given at the doctor’s office provides a sufficient, accurate protein assessment, according to the new guidelines issued last year by the US National Kidney Foundation.

Along with these two tests, a blood pressure reading can help your doctor assess whether you’re at risk for kidney disease. A systolic blood pressure over 140 or a diastolic blood pressure over 90 is cause for concern.

While doctors always check blood pressure during routine exams, they don’t always test blood for creatinine and urine for protein. Make it a point to ask your physician to do these simple tests if you’re in a high-risk group. And if you want to put yourself on the cutting edge of the movement to make kidney health a front-burner public health issue, find out what your GFR is.

Remember, early diagnosis is key, so if you’re at risk, make sure your doctor regularly tests your blood pressure and urine for signs of kidney problems. And to maintain the health of your kidneys: Drink plenty of fluids; exercise regularly; don’t smoke; maintain appropriate weight; and get checked regularly for diabetes and high blood pressure.