You tests would indicate a change in the kidney function downwards. This might reflect underlying hypertension, especially if your blood pressure was poorly controlled over the years. Has it been? Have you had an abdominal ultrasound?
I have an historic of hta and i take bisoprolol 5mg for 10 years, now i take bisoprolol and norvasc 5 mg, five years ago the creatinine level was 1.2 and all other blood and urine parameters where normal.