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Date of last update: 10/09/2017.

Forum Name: Renal Failure

Question: Elevated GFR (Glomerular filtration rate) 96.5 mL/min

 GirlOrange - Thu Jan 08, 2009 6:22 pm

Thank you in advance for your help. I'm so worried and my physician is out of town and can't return my call.

My doctor diagnosed me as a Type 2 diabetic in August of 2008. My HbA1c was 11.3%, suggesting that I had had very high blood glucose for at least three months, and I'm sure much longer. My A1c is now 5.1%.

In December, my doctor suggested that I have some blood work done. I noticed my MCV and MCH were a little low (78.8 fL and 26.0 pg, respectively) and that my sodium, although with normal range, was on the lower end of normal: 137 mmol/L.

Anemia runs in my family, so I mostly dismissed the MCV and MCH, but when I posted my concerns about both on a diabetes forum online, a diabetes care worker told me to check my GFR by entering my numbers (BUN, creatinine, etc.) into a GFR calculator. The calculator also takes into account age, sex, race, and weight. I scored a 96.5 mL/min.

My doctor didn't seem concerned at all at my last appointment because my numbers, except for my MCV and MCH, were all "normal," but I'm worried that 96.5 mL/min is a little low. I keep reading different information on the subject. Some insist that any value over 60 is good for a woman, while others say 90, and even smaller number of people argues that a normal, healthy adult should be in the 110-120 range. I am very confused and worried that I might have the early stages of kidney disease.

I am also scared because my chloride is on the higher end of the range (104 mmol/L when 110 is considered the upper limit) and my carbon dioxide is on the low end of the range (21 mEq/L when 21 is the lower limit). I know that both chloride and carbon dioxide levels can reflect impaired kidney function. My hemoglobin is 12.8 g/dL and 12 is the bottom of the normal range. Again, I read that hemoglobin could be another sign of kidney problems.

I don't know how long I was diabetic or what damage I did to my body before diagnosis. I don't have any signs of kidney problems (urinating normally, no pain), but I read that a person doesn't necessarily show signs in the beginning stages.

I would love some guidance. Thank you again and I apologize for my long-winded post.

Age: 26
Sex: Female
Type 2 Diabetic (since August 2008), Hypo-thyroidism (August 2008, as well)
Past surgeries: None
Family history: Breast, cervical, and colon cancer, Type 2 diabetes, hypertension, high cholesterol, stroke, heart attack, anemia, hypo-thyroidism.
Current medications: Metformin (850 mgs/twice a day), Glyburide/DiaBeta (5 mgs/once a day), Synthroid/Levothyroxine (50 mcgs/once a day)
 John Kenyon, CNA - Sat Mar 21, 2009 10:36 pm

User avatar Hello --

While your concern is certainly understandable, it is pretty unusual to have had type II diabetes as young as you are and to have already sustained kidney damage. Your A1c is now actually extremely good, so you've reduced your risk of diabetic complications by more than half.

Further, while I'm sure the diabetes care worker has only the very best of intentions, the lab work involved in calculating creatinine clearance (which is what GFR does) is actually very arcane and not something that should be tossed into the lap of a patient, even if the patient is trained in laboratory medicine. There are so many variables involved in these calculations that must be taken into consideration along with the GFR number. And most importantly, all your numbers are within normal limits. This is important to remember: normal limits have to be set somewhere, and normal is, well, normal. It doesn't matter if you are right on the line (upper or lower) but that you are WNL (within normal limits). Things will vary from day to day, hour to hour, even. These tests are done under optimal stable circumstances, and often a chemical (such as inulin -- not insulin -- must be added to the mix in order to reach the correct GFR). Your GFR is above 90, so you're good there. The other numbers are all WNL. While it is very important that a person with diabetes monitor him/herself for glucose levels, and to be familiar with the correct numbers. But to try and evaluate possible potential complications based upon extremely complex lab work, well, it's not fair to you to be expected to be able to interpret these. This is why we have doctors -- doctors who have spent a good many years learning not only essentials of medicine but more on their specialty. I hate to be critical of your diabetic care worker, but please bear in mind that this person's training and experience is generally very narrowly focused. This is an area where a little knowlege can become a very dangerous thing -- dangerous to your peace of mind.

I am hoping to reassure you that your numbers are all good. Normal is good, whether square in the middle of the range, at the upper or lower end or, once in a while, just a hair off, even.

You obviously are doing all the right things to have such a good A1c result, and so long as you're not symptomatic for kidney disease and nothing in your blood work suggests otherwise, by all means enjoy the fact that you're fine. I hope this is helpful to you. Good luck with this, and please stay in touch with us here.

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