Can edema be of renal origin with these lab results; creatinine 0.8 mg/dl albumin 4.6 g/dl , microalbumin 40 mg/g?

There can be many etiologies of edema. It often depends where the edema is located. But, it is unlikely to be due to renal failure with a creatinine of less than 1. If the edema is lower extremities, this can sometimes be due to vascular issues-compression stockings and elevation can help with this. See your doctor to determine the cause of the edema so treatment can be rendered. Good luck!