Altered nocturnal decline of blood pressure in hypertensive patients with type 2 diabetes mellitus

The lack of nocturnal decline in blood pressure (BP) is frequent in patients with type 2 diabetes mellitus (DM). The actual prevalence of a nondipping pattern in DM is, however, highly variable among different studies. Recent results have also indicated that nondipping in treated hypertensive patients is markedly related to the absence of 24-hour therapeutic coverage [J Hypertens. 2002;20:1097–1104]. Accordingly, we have evaluated the incidence of nondipping in treated and untreated hypertensive patients with and without DM. We studied 234 hypertensive patients with DM (129 men), 59.8±11.3 years of age, and 1,184 patients with grade 1–2 essential hypertension (512 men), 52.1±13.9 years of age. Among those patients, 88 with DM and 679 hypertensive controls were untreated at the time of the study. BP was measured by ambulatory monitoring (ABPM) at 20-min intervals from 07:00 to 23:00 hours and at 30-min intervals at night for 48 consecutive hours. Physical activity was simultaneously evaluated at 1-min intervals by wrist actigraphy. Diurnal and nocturnal means of BP obtained according to individual resting time determined by actigraphy were used to classify each patient as dipper or nondipper (nocturnal BP decline <10%). Among untreated patients without DM, 40.4% were nondippers, while this percentage was significantly increased to 56.6% among treated patients. In DM, 65% of the untreated and 77% of the treated patients were nondippers. The percentage of risers (patients with nocturnal BP mean above the diurnal mean) increased from 3.7% in untreated controls to 17.1% in untreated patients with DM, and from 11.9% among treated hypertensive patients to a very high 28.1% among treated patients with DM. Results from this study on hypertensive patients with and without DM evaluated by 48-hour continuous ABPM and with nocturnal BP mean calculated individually according to actual resting time determined by actigraphy, indicates the high prevalence of an altered circadian BP pattern in DM. The extremely high prevalence of risers among both treated and untreated patients with DM indicates the need to establish a proper chronotherapeutic antihypertensive scheme that could allow not only to reduce BP but also to modify the altered circadian profile into a dipper pattern with a lower cardiovascular risk. Am J Hypertens (2004) 17, 214A–214A; doi: 10.1016/j.amjhyper.2004.03.570