"No, 99 is the median for the entire patient population. They have some very young patients on the trial as well, so that could be why there are folks with still highly functioning kidneys."
Pomp, thanks for continuing this discussion. You motivated me to brush up on eGFR. According to this poster from last year, they are using the Cockcroft Gault equation in BETonMACE to calculate the eGFR. It is based upon serum creatinine levels, and there is a handy calculator here and another one here in which you can plug in values for sex, age, weight, height, and creatinine levels and it will spit out the eGFR value.
Creatine Cleararance = Sex * [((140 - Age) /( Serum Creatinine in mg/dL))*(Weight in kg / 72 )]
Males have higher eGFR than females according to this calculator due to greater amount of muscle mass. For males, the sex value in the above equation is 1; for females the sex value is 0.85. Most patients in BETonMACE are male (75%). The youngest patient in BETonMACE is 31 (median 62), and eGFR declines with age. The creatinine levels for the entire BETonMACE population aren't reported to my knowledge; however, "normal" range for creatinine is 0.5 to 1.3 mg/dL. The eGFR value increases as the creatinine level goes down. One can get some pretty high eGFR values if one plugs in creatinine values below 0.5 mg/dL. The body weight of patients in BETonMACE hasn't been reported. But both EXAMINE and ELIXA had diabetic recent ACS patients. EXAMINE had a median body weight of 80 kg (176 lbs) with a range of 36 to 196 kg (79-432 lbs). ELIXA had a median body weight of 85 kg (187 lbs). The eGFR estimates increase with body weight and assumes mostly lean body weight. Therefore, the eGFR can be an overestimate in overweight and obese subjects if the weight is not corrected for fat mass.
So is a max eGFR of 599 mL/min/1.73m2 possible of by the Cockcroft Gault equation possible for BETonMACE as shown in the ACC poster earlier this week? Sure. A hypothetical 31 year old male who weighs 119 kg (262 lbs) with a creatinine value of 0.3 mg/dL would have an eGFR of 599 mL/min/1.73m2 not corrected for body weight. Or, a 31 year old male who weighs 180 kg (398 lbs) with a creatine value of 0.3 mg/dl would have an eGFR of 599 mL/min/1.73m2 even after correction for body weight.
I was previously skeptical of that 599 max eGFR value in the BETonMACE baseline measures, but now I understand how it may be possible.
BearDownAZ
