Diabetes Mellitus is a condition wherein the blood sugar is high but it takes quite a toll on all the other organs in the body, including the kidneys. Causing Urinary Tract Infection (UTI) is just one of the lesser evils. Diabetes can reduce blood supply to the kidneys by narrowing the blood vessels to the kidneys, this can even cause Renal Papillary Necrosis, a part of the affected kidney to die.