The American Diabetes Association (ADA) recommends annual screening for proteinuria in patients with diabetes. In addition, angiotensin-converting enzyme (ACE) inhibitors are advocated to slow the progression of diabetic nephropathy, even in normotensive patients. Kraft and associates conducted a survey of physicians in Indiana to investigate the degree to which primary care physicians are complying with the ADA recommendations for screening for diabetic nephropathy.
The survey included 1,018 primary care physicians; 67 percent of them were in family practice. The questionnaire elicited information about the identification and treatment of clinical albuminuria and microalbuminuria and whether the physicians had read about the Diabetes Control and Complications Trial (DCCT) or had attended a presentation in which it was discussed. The survey also asked the physicians to estimate the percentage of patients in their practice with type 1 and type 2 diabetes who are screened for overt albuminuria and microalbuminuria and to explain what interventions they implement when albuminuria or microalbumuria is found in a patient with diabetes.
Sixty-three percent of the physicians reported being familiar with the results of the DCCT. In accordance with the ADA recommendations, most of the physicians indicated that they obtain annual urinalysis in most of their patients with diabetes. Only 1.3 percent reported that they did not obtain an annual urinalysis in patients with type 1 or type 2 diabetes. Almost 86 percent of the physicians reported obtaining a urinalysis for more than one half of their patients with type 1 diabetes, and 82 percent reported doing so for more than one half of their patients with types 2 diabetes. A urine dipstick test was usually used to screen for albuminuria by about 85 percent of physicians.
Unlike screening for overt albuminuria, screening for microalbuminuria was not nearly as common. As many as 43 percent of the respondents reported that they did not screen for microalbuminuria in any of their patients with type 1 diabetes. Similarly, 47 percent screened none of their patients with type 2 diabetes. Although about one third of the physicians who tested for microalbuminuria reported doing so with a 24-hour urine collection, about one quarter of them reported screening for microalbuminuria with a urine dipstick test (a method that does not actually measure microalbuminuria).
With respect to the management of diabetic nephropathy, approximately 80 percent of the physicians surveyed reported using an ACE inhibitor in patients with microalbuminuria or albuminuria and hypertension. However, this figure dropped to about 55 percent when diabetic patients with abnormal urinary albumin excretion had normal blood pressure.
The survey findings revealed that family physicians were much less likely than internists to screen for albuminuria and microalbuminuria. Family physicians had 0.68 times the odds of testing all or some of their patients with type 1 diabetes. Internists also reported using ACE inhibitors more often than family physicians in hypertensive or normotensive diabetic patients with albuminuria or microalbuminuria. Physicians familiar with the DCCT were more likely to check urine for albuminuria or microalbuminuria and to prescribe ACE inhibitors in patients with either.
The authors conclude that primary care physicians are generally following the ADA guidelines for routine screening for overt albuminuria but that testing for microalbuminuria is being neglected. Such screening can allow early intervention to forestall progression of diabetic nephropathy. Specifically, use of an ACE inhibitor in normotensive as well as hypertensive patients with diabetes effectively slows renal deterioration and should be used more widely.