Thanks for posting your query.
Diabetes is a multi organ disease with involvement of almost all organs of body due to its complications.
Blood sugar both fasting and postprandial must be in controlled range.
Diabetes and high blood pressure
are the most common causes of deranged renal function worldwide.
With the available described symptoms, there could be possibility of diabetic neuropathy
Presence of pain in lower limb could be due uncontrolled blood sugar.
You should consult with internal medicine specialist/ neurologist
and should go for thorough neurological check up.
You should avoid Nimesulide as it may cause further deterioration of renal function.
You should also go for serum lipid profile, electrocardiography
, urine routine microscopy, glycosylated hemoglobin (HbA1c).
You should remain in touch with nephrologist
Dr. Mayank Bhargava