During the spring of each year, through the diagnostics company my employer's insurance uses, I do a Dried Blood Spot (DBS) test for general health screening purposes only. By agreeing to the annual test, I get a slight break on the cost of my insurance premium. The result from a DBS specimen is an estimation of the result that you would receive from a blood specimen drawn from your arm. Although not cleared or approved by the U.S. Food and Drug Administration, this test has been validated pursuant to the Clinical Laboratory Improvement Amendments regulations. In fact, this test is reported as "highly accurate for the specific biomarkers it is designed to measure, often matching the clinical reliability of a standard venous blood draw."
For the past several years, my blood test results have shown absolutely no issues with Cholesterol, Glucose, Hemoglobin, Prostate-Specific Antigen, Triglycerides, blood pressure, weight, body mass, and so on. However, over the past two years the DBS test has shown an advancing and concerning issue with respect to my kidney health. Estimated Glomerular Filtration Rate (eGFR) is a test for kidney damage, and in 2024 my eGFR was 101 and in 2025 it was 68. This past spring, my eGFR was reported to have dropped to 52 -- placing me in stage 3A renal failure (with the rapid decline bringing my kidney function to about 50 percent). To place that into perspective, for a 61-year-old male like me, the average eGFR is 85.
The eGFR number naturally declines with age, even in healthy individuals. An eGFR of 90 or higher is generally considered a normal range for adults, but acceptable numbers decrease as you get older. So, for a man my age the average is 85, and I was reading reports that I had dropped to 52... again, that being stage 3A renal failure. Essentially, I had dropped from 101 to 52 in just two years, a rapid decline! For clarity, a person requiring dialysis has an eGFR of about 10 to 15. At the rate my eGFR was dropping, I would be needing dialysis in a year or so in order to stay alive.
Aside from the eGFR number, a person's Creatinine level is an indicator of kidney health. Creatinine is derived from muscles and released into the blood. It is removed from the body by the kidneys. When the creatinine level is elevated, a decrease in kidney function is suggested. In just a two-year span of time (2024-2026), my Creatinine level increased from a healthy 0.82 to 1.52 -- according to the annual DBS test. The normal range for a man my age is 0.7 to 1.3.
So, the combination of the significant decrease in my eGFR number over two years, as well as the notable increase of my Creatinine level over the past two years, clearly indicated that I was in stage 3 renal failure. By the way, eGFR numbers do not go up. Those in renal failure at any stage are in a non-reversible situation. Each year, over 80,000 Americans die from chronic kidney disease and renal failure. Kidney disease is the 8th leading cause of death in the United States, with more than 135,000 Americans newly diagnosed with irreversible end-stage renal disease annually. My DBS test results from 2024-2026 were indicating that I was now dealing with chronic kidney disease. However, I have now learned that is not the full or accurate picture.
My primary care physician was baffled by the lab results he was seeing, because what he was reading about my eGFR and Creatinine levels were not consistent with the other diagnostics on me (ie. cholesterol, glucose, etc.). In fact, I was not presenting with any symptoms that would have been typical for someone with such rapidly advancing renal failure. I was not fatigued, was not experiencing pain, did not have dark and/or foamy urine, or had other atypical symptoms. I watched the physician scratching his head, staring at the results trying to figure out how I had gotten to this point.
A discussion was had regarding my ultra-endurance running background across states and countries. The National Institutes of Health, along with the Mayo Clinic and Yale Medicine, have published papers in recent years regarding the damage that can be done to kidneys with the kind of severe long-distance running I've engaged in during my lifetime. Repeated acute kidney injury, and Rhabdomyolysis, are possibilities -- including renal scarring. I can tell you that during all of my solo adventure runs across states and countries, I was keenly focused on hydration. Water and electrolyte intake was priority. Yes, I experienced moments of dehydration, especially while crossing the Mojave Desert. However, those moments were for a few days and not for extended periods of time. Since my physician could not identify anything else from my blood panel to explain the rapid drop in my eGFR, my running background was considered -- especially in light of the fact that I'm not diabetic, do not drink or smoke, and do not take any prescription medicines or supplements.
I recently underwent a blood draw and urinalysis and today I received some news that was an incredible relief. This spring, my eGFR was reported as 52, but yesterday's blood test shows it at 88 (quite normal for a man my age). Also, my Creatinine level is now showing at 1.04 rather than the 0.82 it was this spring -- and 1.04 is also quite normal for a man my age. Therefore, both of those indicators for kidney health show that my kidneys are functioning normally. Why the huge discrepancy in test results? That is unknown at this time. Regardless, I will not be undergoing any further testing at this time, including a renal ultrasound. I am scheduled to return to my primary care physician in October for another blood test to see where my eGFR and Creatinine levels are at.
The urine test results from yesterday did not show elevated levels of protein in the urine, but did show a trace of blood and that a urinary tract infection (UTI) exists -- for which I am currently taking an antibiotic. I've never head a diagnosed UTI before, so that was surprising to me. A UTI is a bacterial infection in any part of your urinary system (kidneys, bladder, ureters, or urethra). While it is true that a UTI can temporarily lower a person's eGFR, I certainly have not had a UTI for two years and that would not be the reason for the rapidly decreasing eGFR number since 2024.
Should I have any symptoms indicating that there may be an issue with my kidneys prior to my scheduled October 2026 appointment, I will certainly contact my doctor. However, with yesterday's blood test results in hand showing that my eGFR and Creatinine levels are in the normal range for a man my age, I'm going to hold steady for now... making sure to stay well hydrated and to have a healthy approach to life.
I had recently notified my family of this issue and was on the receiving end of well wishes, prayers being sent upward, and even the offer of a kidney donation should that be needed. My wife has been so supportive and has given me space to express concern, and even aggravation at times. These have been challenging days for the both of us and at this point we both just need some time to decompress and breathe. In fact, during the last week of July we're taking some time just for the two of us -- something we don't do near enough.
I share this writing for the benefit of my family's understanding, as well as others who may read this and be facing a situation with results from a DBS test that don't seem to correlate with their overall health picture. Always dive deeper. Seek greater understanding. Ask questions. Have more tests. But most importantly, don't lose faith.
Gotta Run,
Paul J. Staso
- United States in 2006 (3,260 miles solo in 108 days at age 41)
- Montana in 2008 (620 miles solo in 20 days at age 43)
- Alaska in 2009 (500 miles solo in 18 days at age 44)
- Germany in 2010 (500 miles solo in 21 days at age 45)
- The Mojave Desert in 2011 (506 miles solo in 17 days at age 46)
- Various Photos From Mileposts Gone By
- Students Worldwide Who Ran With Me Virtually
- Roadside Sights From My Running Adventures
- Some Cycling Moments From The Past
