I'm diabetic since 6 years & hypertensive since 2 years.Diabetes remains under control but bp sometimes get uncontrolled My serum creatinine level on 11th May was 0.9 mg/dl & on 21st September it came 1.1 mg/dl. (Lab normal : 0.72-1.25).Had low protein diet & adequate hydration the day before test However,blood urea & serum potassium came normal at every time Urine ACR done on 1st August was also normal USG (KUB+PVRU) done on 4th April was also normal Took Chlordiazepoxide (Librium) 25 mg twice a day for 1 month which was stopped 1 week before the test Took a bottle of beer daily for 20 days which was stopped 4 days before the test What might be the cause of such significant rise ?