on behalf of the Spanish Society of Hypertension ABPM Registry investigators 9Our aim was to assess the ambulatory blood pressure monitoring (ABPM) characteristics or patterns in hypertensive patients with diabetes compared with non-diabetic hypertensives. We performed a cross-sectional analysis of a 68 045 patient database from the Spanish Society of Hypertension ABPM Registry, a nation-wide network of 41200 primary-care physicians performing ABPM under standardized conditions in daily practice. We identified 12 600 (18.5%) hypertensive patients with diabetes. When compared with patients without diabetes, diabetic hypertensives exhibited higher systolic blood pressure (BP) levels in every ABPM period (daytime 135.4 vs. 131.8, and nighttime 126.0 vs. 121.0 mm Hg, Po0.001 for both) despite they were receiving more antihypertensive drugs (mean number 1.71 vs. 1.23, Po0.001). Consequently, diabetic patients suffered from lack of control of BP more frequently than non-diabetic subjects particularly during the night (65.5% vs. 57.4%, Po0.001).Prevalence of a non-dipping BP profile (64.2% vs. 51.6%, Po0.001) was higher in diabetic patients. In the other hand, prevalence of 'white-coat' hypertension in diabetic patients was 33.0%. We conclude that there was a remarkably high prevalence of alterations in ABPM in patients with diabetes. Abnormalities in systolic BP, particularly during the night, and in circadian BP pattern could be linked with the excess of BP-related cardiovascular risk of diabetes. A wider use of ABPM in diabetic patients should be considered. Hypertension Research (2011) 34, 1185-1189; doi:10.1038/hr.2011.100; published online 11 August 2011Keywords: ambulatory blood pressure monitoring; circadian profile; diabetes; hypertension control INTRODUCTION Hypertension affects the majority of patients with diabetes and constitutes a major risk factor for vascular complications. 1 Ambulatory blood pressure monitoring (ABPM) provides a high-quality approach in estimating the true levels of blood pressure (BP). 2 Several population-and patient-based studies have showed the benefits of ABPM in exploring the relationship between BP and cardiovascular events. 2,3 A series of reports dealing with diabetic patients have also shown a close correlation between ambulatory BP and diabetic complications. 4,5 Evidences are available for the entire cardiorenal continuum of diabetic damage from the prediction of microalbuminuria by early changes in nocturnal BP in type 1 patients 6 to the effect of a riser pattern on mortality in patients with type 2 diabetes. 7 Nevertheless, information about the ABPM characteristics of large cohorts of diabetic hypertensives attending primary care centers is scarce. We aimed to assess such characteristics in comparison with non-diabetic hypertensives by using the Spanish Society of Hypertension ABPM Registry.