Visit-to-visit blood pressure variability is related to albuminuria variability and progression in patients with type 2 diabetes

Recent studies have suggested that visit-to-visit variability of blood pressure (BP) is correlated with microalbuminuria in patients with diabetes, independent of mean pressure. We investigated the contribution of BP variability to albuminuria progression in normoalbuminuric type 2 diabetes patients. BP and urinary albumin excretion of patients were assessed in each visit during a median follow-up of 31 months. Variability was assessed using standard deviation, coefficient of variation, standard deviation independent of mean, peak, average real variability, and average real variability independent of mean. Of 194 patients enrolled, 31 subjects (16.0%) developed microalbuminuria. Systolic blood pressure (SBP) variability indices (except for coefficient of variation and average real variability) were significant predictors of microalbuminuria in multivariate Cox regression models (hazard ratio ranging from 2.02 to 2.76). The same was not observed for diastolic blood pressure. Using linear regression, SBP variability significantly correlated with some but not all indices of albuminuria variability. Peak SBP was the strongest predictor of albuminuria variability in multivariate models (standardized beta ranging from 0.216 to 0.339). In conclusion, visit-to-visit variability of SBP is an independent risk factor for development of microalbuminuria in patients with diabetes, and is associated with an increased variability in albuminuria.