A 40-year-old diabetic woman complains of flank pain and fever. Her temperature is 38.7degC (103degF), respirations are 25 per minute, and blood pressure is 150/90 mm Hg. Urinalysis reveals pyuria with WBC casts. Which of the following features of diabetes is the most impoant contributing factor in development of flank pain and fever in this patient?

- Flank pain, fever & pyuria are indicative of acute pyelonephritis, a common complication of diabetes. - Glucose in urine provides an enriched culture medium for bacteria to grow. - Patients with autonomic neuropathy often have dystonic bladder that retains urine which fuher increases risk of pyelonephritis. - Pyelonephritis is constant threat for patients with diabetes & necrotizing papillitis may be devastating complication of renal infection. Other choices are not related to renal infection.