To Your Good Health: Kidney function expected to wane with age


DEAR DR. ROACH: I am a 75-year-old male, 5 feet, 3 inches tall, weighing 123 pounds with a blood pressure of 110/60. The only known ailment I have is hypothyroidism, which is being treated. I recently began seeing a new primary care physician who ordered a series of bloodwork. The bloodwork came back showing a glomerular flow rate of 55, which is the same value it was in 2016.

The new PCP is telling me I have stage 3 renal failure. She has ordered an ultrasound of my kidneys, which will be done this week. Every other test that she has ordered to evaluate kidney function has been negative as far as any value being out of the normal range. She has not suggested that I see a specialist, but is basing all this on her own knowledge and tests. I have decided I will not do any other tests or begin any treatment until I see a kidney specialist. I might add that the reason I saw this physician in the first place was because of extreme fatigue and anxiety. How concerned should I be with this diagnosis? — M.L.N.

ANSWER: Your kidney function (measured by the glomerular filtration rate) has not changed; what has changed is the way the numbers are reported. GFR reliably goes down as we age. A GFR level of 55 is within the expected range for a man in his 70s. Since yours hasn’t changed in three years, you are unlikely to develop end-stage renal failure (where you would need dialysis), even if you lived to 110.

My own patients, as well as many readers, have been alarmed by hearing they have stage 3 kidney failure. Physicians need to explain the results better to avoid worrying our older patients, in whom a degree of reduced kidney function is common and expected.

The kidney function is not likely to be responsible for fatigue, but I fear the anxiety might be worse after getting these results. I trust your kidney specialist will be able to explain your results. The kidney specialists I spoke to have been seeing many people with concerns similar to yours.