Abstract
Introduction: The dipping phenomenon is a physiological drop in blood pressure (around 10-20%) during sleep and represents an event related to the circadian blood pressure trend. This phenomenon, in some cases, is characterized by some alterations that can be expressed by an increase (extreme dipping), a decrease (non-dipping), or a reverse (i.e., higher blood pressure during sleep compared to awake state; reverse-dipping) physiological decline of blood pressure. Few studies focused on the association between the circadian variation of blood pressure and psychological variables, although this information could help understanding how psychological characteristics (e.g., emotional regulation or dysregulation) interact with individuals' physiological processes. Given the association between emotional dysregulation and essential hypertension, this study aimed to investigate the relationship between alexithymia and dipping status in a sample of healthy and hypertensive adults in the absence of other medical conditions. Methods: Two hundred and ten adults took part in the study and were classified, according to ambulatorial blood pressure measure (ABPM), into three groups: dippers (n = 70), non-dippers (n = 70), and extreme dippers (n = 70). The participants completed a socio-demographic and anamnestic interview and the Toronto Alexithymia Scale-20 (TAS-20). Results: The ANOVAs on the TAS-20 subscales showed that the groups differed in the difficulty identifying feelings and difficulty describing feelings. In both the subscales, dippers showed lower scores than non-dippers and extreme dippers. The ANOVA on the global score of TAS-20 confirmed that dippers were less alexithymic than both extreme dippers and non-dippers. Conclusions: This study confirms that some psychological factors, like alexithymia, could represent a characteristic of patients who fail to exhibit an adaptive dipping phenomenon. Moreover, an association between an excessive reduction of BP (extreme dipping) or a lack of the decrease of BP during sleep (non-dipping) and a worse emotional regulation, considering alexithymia construct, was highlighted for the first time, confirming the relevant role of the emotional process in the modulation of an essential psychophysiological process such as the circadian variation of BP.