Nocturnal Diastolic Pressure Research Articles

P121 ROLE OF AMBULATORY BLOOD PRESSURE MONITORING (ABPM) IN THE EVALUATION OF PATIENTS WITH SUSPECTED SLEEP APNEA

Background and Objective: Obstructive sleep apnea (OSA) often coexists with hypertension. Ambulatory blood pressure monitoring (ABPM) is essential for detecting significant blood pressure fluctuations, especially during nighttime. This study seeks to assess the role of ABPM in identifying OSA. Methods: We analyzed a database of patients with suspected OSA using the STOP-BANG questionnaire at a cardiology center from July 2020 to April 2024. Anthropometric characteristics, blood pressure behavior through ABPM, and sleep patterns via polysomnography were evaluated. The influence of risk predictors on OSA development was assessed using multinomial logistic regression. Results: The study included 38 men (50.6%) and 37 women (49.3%); 48 hypertensive patients (64%) and 27 without hypertension (27%). The average STOP-BANG score was 3.8. Of these, 92% had some degree of OSA. The mean age was 60±13.2 years. Neck circumference (NC) and total apnea-hypopnea index were 37.5 cm and 19.7 events/hour, respectively, with a predominance of REM OSA. Only NC and nocturnal diastolic pressure were significant variables. For the development of moderate OSA, NC showed significant relative risk ratios (RRR) (p=0.045). Severe OSA development was influenced by mean nocturnal diastolic blood pressure (MNDAP) and NC, with significant RRRs (p=0.007 and p=0.041, respectively). This means that for each mmHg increase in nocturnal diastolic pressure, the risk of severe OSA increases by 1.3 times compared to healthy patients, predominantly during REM sleep. Conversely, increased daytime diastolic pressure decreases this risk by 25%. Conclusions: An increase in mean nocturnal diastolic pressure measured by ABPM is a significant predictor of severe OSA development. This underscores ABPM's importance in evaluating patients with suspected OSA. While the STOP-BANG questionnaire is useful for initial OSA suspicion, it has limitations in identifying the most severe cases, necessitating tools like ABPM for more accurate assessment. The use of ABPM improves accuracy in detecting severe OSA and enhances understanding of hypertension phenotypes’ pathophysiology. Table 1. Obstructive Sleep Apnea (OSA) Severity Classification and Its Correlation with Mean Nocturnal Diastolic Blood Pressure (MNDAP), Mean Daytime Diastolic Blood Pressure (MDDAP), and Neck Circumference (NC)

Correlation between blood pressure rhythm and left ventricular structure and function in elderly hypertension patients

Objective To investigate the correlation between blood pressure rhythm and left ventricular structure and function in elderly hypertensive patients. Methods A total of 147 elderly patients with high blood pressure in the First Hospital of Longyan Affiliated to Fujian Medical University were selected.All the patients received 24h ambulatory blood pressure examination.According to the rhythm of blood pressure, the patients were divided into the dipper blood pressure group, the-non dipper type blood pressure group and the anti-dipper type blood pressure group.All patients were examined by echocardiography. Results According to the results of 24h dynamic blood pressure, the type of dipper blood pressure accounted for 11.56%(17 cases) in 147 elderly patients, non-dipper type blood pressure type accounted for 51.02%(75 cases), and the anti-dipper type of blood pressure type accounted for 37.41%(55 cases). The ventricular septal thickness(IVST), left ventricular diastolic inner diameter(LVEDD), left atrium inner diameter(LAD), left ventricle posterior wall thickness(LVPWT) and left ventricle mass index(LVMI) of the non-dipper blood pressure group were (10.56±1.51)mm, (50.17±4.31)mm, (34.65±5.78)mm, (9.26±0.98)mm, (102.31±23.23)g/m2, respectively.The IVST, LVEDD, LAD, LVPWT and LVMI of the anti-dipper blood pressure group were (10.51±1.86)mm, (50.20±3.66)mm, (36.96±4.22)mm, (9.42±0.99)mm, (110.47±31.96)g/m2, respectively.The IVST, LVEDD, LAD, LVPWT and LVMI of the dipper blood pressure group were (9.53±1.53)mm, (47.59±2.27)mm, (30.47±4.17)mm, (8.88±1.12)mm, (84.98±15.48)g/m2, respectively.The differences of IVST, LVEDD, LAD, LVPWT and LVMI in the three groups were statistically significant(F=1.172, 3.428, 1.006, 0.135, all P 0.05). The average daytime systolic pressure in the dipper blood pressure group was (143.06±13.70)mmHg, which was higher than that in the non-dipper blood pressure group[(133.25±13.28)mmHg] and anti-dipper blood pressure group[(131.16±12.26)mmHg], the differences were statistically significant(t=-2.734, -3.401, all P<0.05). The mean evening systolic pressure and the average nocturnal diastolic pressure of anti-dipper blood pressure group were (139.04±15.01)mmHg and (80.18±10.29)mmHg, respectively, which were higher than those of the dipper and non-dipper blood pressure group [(123.24±14.49)mmHg and (72.24±7.97)mmHg, (127.40±13.30)mmHg, (73.45±11.43)mmHg], the differences were statistically significant(t=3.822, 4.666, 2.919, 3.456, all P<0.05). LVMI was positively correlated with age, body mass index(BMI), low density lipoprotein(LDL-C), daytime average systolic pressure, night average systolic pressure, night average diastolic pressure, and 24h average systolic pressure(r=0.256, 0.241, 0.687, 0.251, 0.380, 0.203, 0.243, all P<0.05). Conclusion Anti-dipper blood pressure and non-dipper blood pressure have more significant damage to cardiac function and structure than dipper blood pressure in elderly patients with hypertension, and the elevation of nocturnal blood pressure is closely related to left heart structure and function damage.There is a high correlation between abnormal circadian rhythm of blood pressure and left ventricular hypertrophy in elderly hypertensive patients. Key words: Hypertension; Blood pressure; Circadian rhythm; Blood pressure monitoring, ambulatory; Echocardiography; Ventricular function, left; Cardiomegaly; Aged

MPS 09-05 OPTIMAL BLOOD PRESSURE LEVELS AFTER AN ACUTE MYOCARDIAL INFARCTION - IS LOW ARTERIAL BLOOD PRESSURE AFTER AN ACUTE MYOCARDIAL INFARCTION HARMFUL?

Objective: Angiotensin converting enzyme inhibitors (ACEI) and beta-blockers (BB) are recommended after an acute myocardial infarction (AMI). These drugs attenuate myocardial remodeling and lower blood pressure. We pretended to assess the influence of blood pressure on readmission and mortality rate at 1-year post AMI. Design and Method: Prospective study involving 240 patients admitted to the Cardiology department due to an AMI, from the 1st January 2011 to the 30th November 2012. The basal clinical characteristics were noted and ambulatory blood pressure monitoring (ABPM) was made 1-month after the AMI. The follow-up at 1-year was made through phone call. The statistical analysis was undertaken using SPSS. Results: ABPM was performed in 240 patients, 175 men (73%). 49% had ST-segment elevation AMI. At discharge, 74% were on BB, 75% on ACEI, 6% on ARB, 10% on CCB and 22% on diuretics. In ABPM, 27% showed mean arterial systolic pressure (MASP) > 130 mmHg and 18% had MASP < 110 mmHg. 14% had mean arterial diastolic pressure (MADP) > 80 mmHg and 60% had MADP < 60 mmHg. 81% were “dippers”. There were a total of 32 patients readmitted, 24 of which due to cardiovascular (CV) causes. Nocturnal systolic pressure (NSP) > 120 mmHg (p < 0.01), nocturnal diastolic pressure (NDP) > 65 mmHg (p < 0.05), MASP > 130 mmHg (p < 0.05), MADP > 80 mmHg (p < 0.05) and a non-dipper profile (p < 0.01) were all associated with readmission due to CV causes. There were no differences in readmission or mortality among patients with diurnal SP < 110 mmHg or NSP < 100 mmhg. The only independent predictor of readmission due to CV causes was NSP > 120 mmHg. There were a total of 4 deaths (1.7%) without any correlation to ABPM data. Conclusions: In our study, hospital readmission due to CV causes was associated with elevated blood pressure values as well as a non-dipper profile. Low blood pressure appeared to be safe. High NSP was an independent predictor of readmission rate and this parameter should be taken into special account on ABPM after an AMI.

Racial Differences Affecting Night Time Blood Pressure Dipping Groups in Hypertensive Patients

Normal blood pressure (BP) follows a circadian rhythm, with dipping of BP at night. However, little has been done to show how the dipping groups vary amongst the White and Asian population at different periods of the year. This study aims to examine the pattern of nocturnal dipping between the White and Asian population, as well as to compare it to the different timings of the year, between summer and winter. Ambulatory Blood Pressure Monitor recordings were obtained from 220 patients, half were White patients obtained from Mercy University Hospital, Cork, Ireland and half were Asian patients from National Heart Centre, Singapore during the summer period from May to June and the winter period from October to December. Both the Irish and Singaporeans exhibit a decrease in total number of reverse dipper from summer to winter. However, the redistribution of reverse dipper was mainly to the dippers in Singapore, while in Ireland it was to both the extreme dipper and dipper. Irish seasonal changes also resulted in an increase in nocturnal diastolic pressure (95% CI, 0.72 to 6.03, 3.37 mm Hg; p<0.05) and a change in the duration of dipping at night (95% CI, 0.045 to 1.01, 0.53 Hours; p<0.05). Regardless of race or temperature, reverse dippers seem to decrease in winter. However, the racial differences dictate the redistribution of the fall in number of dippers. This has implications on how reverse dippers should be treated at different periods of the year.

Ion transport homeostasis in Alpha‐1 AMPK KO mice

AMP‐activated kinase (AMPK) regulates cell energy balance by modulating ATP synthesis and consumption. In epithelia, AMPK interacts with and regulate ion transport systems, including CFTR, ENaC and NKCC. We studied renal function and measured blood pressure in mice with genetic deletion of the alpha‐1 catalytic subunit of AMPK (a1KO mice; C57Bl6J background). When fed a standard diet (0.3%NaCl) a1KO mice showed mild antidiuresis (WT=0.053 vs. KO=0.038 mL/d/g bw). No significant differences in glomerular filtration rate, sodium or potassium handling were found. When fed low Na+ (0.02%) or high salt (4%NaCl) diets, a1KO mice achieved ion and water balance. Lack of aversion for the high salt diet in a1KO mice suggested increased sodium appetite. Aldosterone urinary excretion was consistently higher in a1KO mice (WT=0.028 vs. KO=0.037 ng/d/g bw). Telemetric 24h blood pressure records showed significantly lower blood pressure in a1KO mice, especially nocturnal diastolic pressure (WT=93.5 vs. KO=86.1 mmHg). We found that a1KO mice lose water and sodium in their feces compared to wild‐type mice. In the kidney, we observed up‐regulation of the alpha‐2 catalytic subunit, which may provide functional compensation for the loss of alpha‐1 activity. Thus, kidneys from a1KO mice apparently have normal function and may be actually compensating for extra renal water and ion losses.MICIIN Spain BFU2007/62119

Aircraft Noise and Blood Pressure in the Populations Living Near the Ciampino Airport in Rome

ISEE-0213 Background and Objective: Evidence from HYENA study suggests that aircraft noise exposure increases the risk of hypertension and that night-time aircraft noise is associated with raised blood pressure (BP). Airport traffic noise has been increasing in recent years in Ciampino (Rome) because of the large rise in low cost flights. We aimed at evaluating these associations in local residents. Methods: We studied a randomly selected sample of subjects aged 45–70 years who had lived in the study area for at least 5 years. Data collected via interview included personal characteristics and pharmaceutical use. BP was measured five times for each participant (three times during the interview, once before sleeping and once in the morning before getting up). We defined three aircraft noise levels (Laeq,24h <65, 65–74, and 75+ dB) using the Integrated Noise Model linked to each participant's address using a GIS. As a proxy for road traffic noise, we calculated morning rush-hour traffic volume. The effects of airport noise on hypertension (WHO 2003 definition), nocturnal and early morning BP were analysed through adjusted regression models. Results: The response rate was 50%, resulting in a study population of 578 subjects. We did not find a statistically significant association between aircraft noise levels and hypertension (RR 0.72, 95%CI 0.36–1.45 for level 75+ dB vs <65 dB). However, there was an increase in nocturnal systolic pressure (5.4 mmHg, 95%CI 0.45−10.4) for subjects in the highest exposure category (75+ dB). There was no effect on nocturnal diastolic pressure or on early morning measurements. Conclusions: Our results confirm the impact of aircraft noise exposure on nocturnal systolic pressure. This effect may be related to a sympathetic nervous system response to stress and may be transient in nature.

Diurnal blood pressure pattern may predict the increase of urinary albumin excretion in normotensive normoalbuminuric type 1 diabetes mellitus patients

To characterise the relationship between diurnal blood pressure and the subsequent increase of urinary albumin excretion (UAE) in normotensive normoalbuminuric type 1 diabetic patients, ambulatory blood pressure monitoring (ABPM) was performed in 53 patients, who were then followed for 5 years. Albumin excretion rate changed from 12.4 (8.9–17.2) to 29.3 (15.2–47.0) mg/day. Macroalbuminuria developed in 2 (3.8%), microalbuminuria in 22 (41.5%) patients, 29 (54.7%) remained normoalbuminuric. Night-time diastolic blood pressure was significantly higher (64.3±6.5 vs. 60.9±5.5 mmHg, P<0.05), diastolic diurnal index significantly lower (15.5±9.7 vs. 22.3±6.2%, P<0.01) in patients who later progressed to micro- or macroalbuminuria. Diastolic diurnal index (r=−0.40; P<0.01) and nocturnal diastolic pressure (r=0.35; P<0.01) were correlated to the change in albumin excretion. In a multivariate analysis model with the change of albumin excretion as dependent, and means and diurnal indices of systolic and diastolic blood pressure, baseline UAE, cholesterol, triglycerides, HbA 1c and retinopathy as independent parameters (r=0.68; P=0.001), diurnal index for diastolic blood pressure (β=−0.30; r=0.013), baseline HbA 1c (β=0.32; P=0.010) and retinopathy (β=0.44; P=0.001) were significant independent correlates. We conclude that the relative increase of nocturnal blood pressure is associated with the subsequent increase of albuminuria, which in turn is predictive of overt diabetic nephropathy.

Nocturnal hypoxemia, night-day arterial pressure changes and left ventricular geometry in dialysis patients

Nocturnal hypoxemia, night-day arterial pressure changes and left ventricular geometry in dialysis patients