Effects of dipping and psychological traits on morning surge in blood pressure in healthy people.

Despite the role of anxiety, depression and hostility in the pathogenesis of cardiovascular diseases, their impact on two significant cardiovascular risk factors, nocturnal dipping and morning surge in blood pressure (MSBP), are largely ignored and primarily studied in clinical populations. This study examined the effects of dipping and psychological traits on MSBP in healthy people. Nocturnal dipping and MSBP were derived from 24-h ambulatory BP obtained in 77 men and 79 women, mean age 32.8 (s.d.: 7.4). Differences in depression, anxiety and hostility were examined by questionnaires. Higher levels of dipping (P<0.0001) and depressive symptoms (P=0.01) independently contributed to increased MSBP. Dipping interacts with depression (P=0.04), hostility (P=0.01) and anxiety (P=0.04) in determining MSBP. Low dippers with higher scores on the psychological traits showed higher MSBP than high dippers. A significant MSBP interaction was found between sex and depressive symptoms (P=0.05), anxiety (P<0.0001) and hostility (P=0.01) with higher scores associated with increased MSBP observed in males. Findings underscore depression as a predictor of MSBP independent of dipping. The clinically significant relationship between dipping and non-dipping patters, psychological traits and MSBP requires further investigation.