Clinical correlates and subclinical cardiac organ damage in different extreme dipping patterns

Aim: Information regarding the association of hypertension-mediated organ damage (HMOD) with extreme dipping pattern is scanty and not univocal. We sought to assess the clinical correlates of this blood pressure (BP) phenotype and its relationship with cardiac HMOD in the general population belonging to Pressioni Arteriose Monitorate E Loro Associazioni (PAMELA) study. Methods: The present analysis included all participants with good-quality ABPM recordings with reliable echocardiography at entry. Results: A total of 792 out of 1597 patients (49.6%) exhibited an extreme dipping pattern (155 had a nighttime reduction in both SBP and DBP at least 20% compared with daytime values and 637 a night-time reduction in DBP at least 20%); 34.2% were dippers and 16.2% nondippers. Left ventricular mass (LVM) indexed to height(2.7) and LV hypertrophy (LVH) prevalence rates increased progressively from diastolic extreme dipping (14%), dipper (17%), systolic/diastolic extreme dipping (21%) to nondipper group (27%). However, after adjusting for confounders, statistical differences in both LVMI and LVH rates among the four groups disappeared. Similar results were obtained for LVM indexed to body surface area and absolute/indexed left atrial diameter. Conclusion: Extreme dipping pattern is a BP phenotype highly frequent in the general population largely consisting of middle-aged individuals without prevalent cardiovascular disease. In this population, the extreme dipping pattern is not associated with an increased risk of cardiac HMOD, which suggests that the mechanisms invoked for the potential adverse cardiovascular effects of this condition (i.e. nocturnal hypoxemia, low-grade myocardial inflammation, coronary hypoperfusion, sympathetic activation at early morning, etc.) are not operative.