A n increased prevalence of urinary tract infections (UTIs) and asymptomatic bacteriuria (ASB) has been described in women with diabetes compared with women without diabetes (1-6). Because UTI complications (e.g., bacteremia, renal abscesses, and renal papillary necrosis) occur more often in diabetic patients, it is important to recognize UTIs in this patient group (1,2). However, the risk factors for developing a UTI have not been defined in women with diabetes, and it is unknown whether ASB precedes symptomatic bacteriuria in these patients. Therefore, we decided to investigate which risk factors (including ASB) are associated with an increased risk of symptomatic UTI development in a large group of women with either type 1 or type 2 diabetes during a period of 18 months.
RESEARCH DESIGN AND METHODS -The recruitment of the patients has been described elsewhere (6). Briefly, all patients were interviewed, and data were obtained from the hospital files using a standardized questionnaire. We performed two urinary cultures to diagnose ASB in 417 of the 636 patients and did not find any significant differences between these 417 patients and the whole study group. At the moment of study entry (i.e., the initial clinical visit), all patients were given a standard form with a return envelope and were asked to mail the form to the investigator (S.E.G.) if they developed a symptomatic UTI (e.g., symptoms of dysuria, increased frequency of urination, and lower abdominal or flank pain) or used antimicrobial agents for any reason during the 18 months after inclusion. Furthermore, the treating physician asked the patient if she had developed a symptomatic UTI or had taken antimicrobials in the time between her inclusion into the study and the outpatient clinic visits for routine examination at 9 and 18 months after inclusion. Antimicrobial therapy was usually prescribed by a general practitioner after diagnosing a UTI in symptomatic women by means of urinary diagnostic tests (urine culture or microscopic analysis or leukocyte esterase on dipstick testing). The development of secondary complications (e.g., retinopathy, neuropathy, and macrovascular diseases) during this period was also recorded by the treating physician. Finally, the investigator phoned all patients (or the general practitioner of the patient, if the patient had moved) for whom these followup data were incomplete. HbA 1c , creatinine, and urinary albumin values were determined at baseline and at the end of the follow-up period. Follow-up results were available for 589 women (93% of the study population). Reasons for inadequate followup included the following: impossibility of reaching the patient (n = 41), known death (two by cardiovascular causes, one by breast carcinoma, and one by pneumonia), renalpancreatic transplantation (n = 1), and patient refusal (n = 1). Clinical characteris- A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
Risk Factors for Symptomatic Urinary Tract ...