After over a year with no tests, I decided to subject myself to the needle again and have my blood analyzed.
The good news: no change
The tests show no signs of kidney function degradation. Serum creatinine is 2.0mg/dL, exactly what it was when I was diagnosed with Chronic Kidney Disease over five years ago. All other parameters are pretty consistent with the results obtained over the last five years and are within, or close to, the normal healthy range.
This either means that:
a) My hard work watching my diet and trying to live a healthy life is paying off and protecting my kidneys from further damage, or,
b) None of my lifestyle changes have made any difference whatsoever!
Truthfully I don't know which statement is correct but there are other benefits to being healthy and I'm convinced that in the long run it will help me extend my life. In any case my dietary choices are more about moderation and avoidance rather than total exclusion… though I haven't had any pizza in a really, really, really long time…
View lab results (5 year history)
GFR: Glomerular Filtration Rate
Kidney function is measured by their GFR, basically how much filtering power they have. Normal is over 90mls/min/1.73m2 and “failure” (inability to filter sufficient toxins from the blood) is 15mls/min/1.73m2.
Previously I've a few creatinine clearance tests to estimate my GFR. These tests require collecting ones urine over a 24 hour period so the lab can measure how much creatinine has been filtered from the blood, compared to the level remaining in the blood, and use this to estimate the GFR. Unfortunately it's apparently not all that accurate and my own lab tests have shown a lot of variance: as high as 52.5 and as low as 30.0, which frankly is a bit an emotional roller coaster ride. Given the questionable utility of the results and the inconvenience and cost of the process, I decided to give it a miss.
This interesting article suggests that estimates based on serum creatinine levels adjusted for body weight, etc. have proved to be more accurate than creatinine clearance tests and I believe it given the that my serum creatinine level has been fairly constant: 1.8mg/dL to 2.4mg/dL. Variations in the serum creatinine level are probably due to variations in protein intake. Unfortunately they say the estimation formulas may not work well in cases where the subject differs significantly from the population used to develop them, giving the example of a vegetarian diet. I don't eat any meat or chicken but I do it fish and eggs, so hopefully the formulas will be somewhat accurate.
In my case the MDRD calculator gives a worst case estimate of GFR of 30mls/min/1.73m2, which is consistent with the creatinine clearance tests.
Apparently GFR tends to decrease by around 1mls/min/1.73m2 every year. If this happened to me it would imply that I have around 15 years of healthy life left before reaching kidney failure (15mls/min/1.73m2). Hopefully I can beat the “average” and extend my mileage by looking after my body.
As a reference, my current lifestyle, which may or may not be optimal, is as follows:
- Sedentary office job 8 to 10 hours a day. I try to get up and move around during the day however to avoid sitting for long periods.
- Cycle everywhere. About 40 minutes a day.
- Occasional moderate exercise (body weight exercises, swimming, etc.). I should probably do more of this.
No meat or chicken. Occasional fish and eggs. No gluten (I feel I may have sensitivity to gluten, though I'm not 100% sure). Very limited consumption of products with added sugar and salt. Limited starch, mostly rice and potatoes. Lots of nuts (almonds, pecans, cacao), fruits and vegetables.
Sleep: Try to get enough sleep so I wake naturally shortly after dawn. For me this is around 8 hours.
I've been taking 50mg/dL of Losartan (Cozaar), an ARB, fairly steadly since diagnosis of CKD. This was initially prescribed to reduce my blood pressure. A month ago I fasted for a day as a kind of “body reset” and found that my blood pressure dropped to around 100/60 so I stopped taking the medication. Since then I have been checking every day and my blood pressure has remained below 120/70 even without medication (or further fasting). I will probably start taking the medicine again at some point, as the experts seem to think that it is beneficial to conserving kidney function for reasons other than blood pressure reduction.