Our sons doctors don't even take into consideration the timing of when they do his renin levels or 17 ohps or any other blood test for that matter. Because recently I pulled up info. on considerations to be taken when doing these blood tests such as when a person last ate, certain medications that they are on, and the time of day. Does anyone else have that problem? I believe that if these considerations were taken seriously maybe the results would be different. I mean they don't consider them for nothing do they. Doctors need to practice what they learn to be true involving blood tests