By Manasi Bapat, M.D. and Kirk N Campbell, M.D.
Mount Sinai Hospital, Icahn School of Medicine at Mount Sinai
What number is “better” for GFR? What about creatinine?
GFR is an equation that uses your creatinine, age, race and gender to see how well your kidneys are working.
Creatinine is the level of muscle waste in your blood stream. Kidneys are supposed to filter out this waste into urine. If there’s a high level of creatinine in your bloodstream, it means that your kidneys aren’t working well at filtering. Your healthy creatinine level depends on how much muscle you have in your body and the “good” number may be different for people who have lower or higher muscle mass than average people. Because the “good” creatinine number is different in different people, GFR is more accurate in finding out if your kidneys are ok. Your GFR will help determine your stage of kidney disease.
GFR and creatinine are usually measured and reported together. GFR is the best measure of kidney function but both creatinine and GFR can be useful indicators of your kidney health. If GFR goes down, it’s a bad sign. If creatinine goes up, it’s a bad sign. In general, a “good” GFR number is above 60 and a “good” creatinine number is below 1.2.
Will my GFR get better if I eat well and exercise?
It may. Eating well and regular exercise are good habits for overall health and kidney health and is a great way to take control over your health.
Food choices can affect kidney health. Avoid processed foods and choose fresh fruits and vegetables instead.
It’s important to follow a low-salt diet. Salt should be limited especially if you have high blood pressure, protein in your urine, or swelling or difficulty breathing. Eating less than 2000 mg a day of sodium is recommended.
Another important nutrient to limit if you have moderate-to-advanced kidney disease (not on dialysis) is protein. A high-protein diet, which is popular for losing weight, may be safe for people with normal kidneys but can put a strain on poorly functioning kidneys to rid the body’s protein waste. However, a diet too low in protein can cause loss of muscle and make you frail. It is important to discuss your individual nutrition needs with your healthcare professional or dietitian to make sure you stay healthy and strong.
Many healthcare professionals recommend the Dash Diet.
Being active is important to kidney health. Some studies show kidney function improves with exercise. It is important to keep a healthy body weight. Talk with your healthcare professional or dietitian if you need to lose weight.
Can anything else impact my GFR?
It is possible to slow the progression of kidney disease by taking good care of yourself by following a healthy diet and exercising. However, for some people their kidney disease gets worse despite their best efforts at a healthy lifestyle. It is important to know the cause of your kidney disease. For example, if you have diabetes, the most important thing you can do to protect your remaining kidney function is to keep your blood sugar under control. The same is true for high blood pressure. If you eat well and exercise but do not keep a healthy blood sugar or blood pressure then your GFR may continue to decline.