Microalbuminuria, cardiovascular risk factors, and secondary prevention of non-insulin-dependent diabetes.

Letters to the Editor Microalbuminuria, cardiovas-cular risk factors, and secondary prevention of non-insulin-dependent diabetes Sir, We have read with interest the recent leading article by Drs Dornhorst and Merrin' about the primary, secondary and tertiary prevention of non-insulin-dependent diabetes (NIDDM). Among the possible modes of secondary prevention, the clinical significance of microalbuminuria was emphasized by the authors. Indeed, microal-buminuria has a great clinical importance in predicting both overt nephropathy and car-diovascular mortality in NIDDM as well as in insulin-dependent-diabetes (IDDM).2'3 Nevertheless, former studies documented a difference between NIDDM and IDDM regarding the leading cause of death (car-diovascular diseases in NIDDM and renal failure in IDDM).4" We have designed a clinical investigation to compare NIDDM to IDDM patients with microalbuminuria in order to assess the differences between the associated cardiovascular risk factors. A cross-sectional study in 136 diabetic patients with micro-and normo-albuminuria was performed. Using serum C-peptide measurements 71 patients were classified as having NIDDM and 65 patients with IDDM. Albuminuria was repeatedly detected during a three-month period by radioimmunoassay in 24-hour urine samples and patients were divided into groups with microalbuminuria (20-200 tLg/min) or nor-moalbuminuria (< 20 iLg/min). Cardiovas-cular risk factors were registered and results of micro-vs normo-albuminuric patients as well as those of NIDDM vs IDDM patients were compared by using Student's unpaired t-test and chi-square test (table). According to our results, preconditions for cardiovascular diseases proved to be more pronounced in NIDDM than in IDDM patients, especially in the presence of mic-roalbuminuria. Although the causal relationship between albuminuria and cardiovascular risk factors could not be evaluated in a cross-sectional study, our findings could be of importance in explaining the difference between NIDDM and IDDM patients regarding the prevalence of cardiovascular diseases. There is no doubt that successful secondary prevention will depend on identifying and treating cardiovascular risk factors in diabetic patients as early as possible. For this reason, NIDDM patients with microal-buminuria should be screened first.