AMBULATORY MONITORING DERIVED MORNING BLOOD PRESSURE PARAMETERS AND THEIR RELATION TO CIRCADIAN BLOOD PRESSURE PROFILE

Objective: Non-dippers display greater cardiovascular risk compared to dippers. Blood pressure variability (BPV) is considered as an additional cardiovascular risk factor, but there is no evidence regarding the association between morning BPV and other 24-hour blood pressure monitoring (ABPM) derived parameters reflecting morning oscillations of blood pressure. The aim was to compare morning BPV, surge and BP in dippers versus non-dippers and to identify the association between these parameters. Design and method: In this survey 77 treated hypertensive patients were included admitted to County Clinical Hospital of Targu Mures for treatment adjustment. Blood pressure profile was assessed by 24-hour blood pressure monitoring (ABPM) with a validated device. Morning surge (MS) was automatically edited, morning BP was defined as the mean of the BP measurement between 6–10 a.m. Morning blood pressure variability was calculated according to the formula of average real variability from the BP values obtained between 6–10 a.m. Subjects were divided in 2 groups: Group 1 dippers with a nocturnal BP reduction of at least 10%, Group 2 non-dippers with a nocturnal BP decrease less than 10%. We compared morning BP characteristics as well as their relationship to nocturnal BP values Results: Group 1 comprised 41 patients (21 male/20 female) while 36 subjects (14 male/22 female) were in group 2. Morning BPV was 9.92 ± 0.42 mmHg vs 11.49 ± 0.62 mmHg in non-dippers, p = 0.03. Morning surge was 22.12 ± 1.73 vs 14.22 ± 2.03, p = 0.004. Morning systolic (s) BP was greater in group 2, but statistically not different, p = 0.19. In Group 1 significant positive correlation was found between morning BPV and MS (p = 0.044. r = 0.31, r2 = 0.10, CI: 0.008 to 0.573) and significant inverse correlation between morning sBPV and nocturnal sBP (p = 0.022. r = −0.36, r2 = 0.12, CI: −0.604 to −0.055). In Group 2 there was no significant correlation between morning sBPV and MS, morning sBPV and nocturnal sBP, or morning BPV and morning sBP Conclusions: Non-dippers display greater morning variability which could worsen cardiovascular outcomes. Although, dipper profile is benefic to prevent cardiovascular events, it was associated with greater morning surge. In dippers decreased nighttime systolic BP was associated with greater morning BPV.