Comparing effect of definition of diurnal periods by diary, fixed periods, and actigraphy on ambulatory blood pressure parameters in a Chinese population.

BACKGROUND: Reliable measurement of daytime and night-time blood pressure (BP), and degree of BP dipping during sleep during ambulatory blood pressure monitoring (ABPM) requires an accurate definition of sleep time (diurnal definition). However, superiority of any diurnal definition on ABPM remains unclear. The present study compared mean daytime and night-time SBP and DBP using different methods for diurnal definition: patient's diary, wide-defined and narrow-defined fixed periods, and actigraphy, in a Chinese population with diagnosed essential hypertension. We hypothesize that BP values from actigraphy are different from BP obtained by other methods and associated with end-organ damage (i.e. impaired renal function, proteinuria, left ventricular hypertrophy). METHODS: From April 2017 to October 2019, 203 Chinese patients diagnosed with hypertension were recruited prospectively from Lek Yuen Clinic and 179 completed a 48-h ABPM study, wearing a validated actigraph and completed a sleep diary. Presence of end-organ damage was retrieved from the computerized clinical management system. The differences in the mean BP values provided by different diurnal definition were compared using paired t tests and Bland-Altman plots. The prevalence of elevated BP, dipping status categories, overall percentage agreement and the Kappa statistic were calculated by pairwise comparisons between different diurnal definitions. The reproducibility was also estimated and logistic regression was used to examine the relationship between BP values from different diurnal definitions and end-organ damage. RESULTS: Mean daytime and night-time BP values were similar regardless of the definition used (mean difference <2 mmHg). Kappa statistics and overall percentage agreement found excellent agreement between different definitions to diagnose elevated daytime BP (Kappa ranged from 0.80 to 0.91) and night-time BP (Kappa ranged from 0.74 to 0.89). Good agreement to diagnose nondipping was also detected (Kappa ranged from 0.65 to 0.78). Furthermore, ABPM values were most reproducible when diurnal periods were defined by patient's diary (intra-class correlation coefficient = 0.82-0.93). Daytime and night-time BP values obtained using different diurnal definitions did not differ in their association to end-organ damage. CONCLUSION: Differing definitions of diurnal periods provide similar mean BP values among a Chinese hypertensive population and have good agreement for diagnosis of elevated BP and dipping status. In individual patients, clinicians should be aware that different definitions of diurnal periods can lead to a 3-5 mmHg difference in patient's BP values and may affect the diagnosis of elevated BP in patients with BP close to diagnostic thresholds. The current study supports using the patient's diary to define diurnal periods, which provided the best reproducibility.

Exercise Intervention to Normalize Blood Pressure and Nocturnal Dipping in HyperTensive Patients (END-HT): Protocol of a Randomized Controlled Trial.

BACKGROUND: Lack of decrease (≤10%) in systolic blood pressure (BP) during sleep, referred to as non-dipping (ND), independently predicts cardiovascular events and mortality. There has been no prospective and adequately powered randomized controlled trial (RCT) to determine whether exercise, when compared with standard treatment, can normalize ND in patients with hypertension (HT). Further, most patients do not sustain an exercise program by 12 months. METHODS: A 2-arm, assessor-blinded RCT, involving 198 hypertensive Chinese patients who have ND will be conducted to evaluate the effectiveness of a combined exercise (aerobic exercise and resistance training) program to normalize ND. The combined exercise program, "exercise is medicine" (EIM), was developed to maintain exercise habit using a variety of techniques (e.g. 12-week exercise classes, mobile application, wrist trackers, self-scheduling, monitoring, regular feedback, and motivational interviewing). Eligible patients will be randomized to EIM plus usual care or to usual care in 1:1 ratio by stratified randomization according to age and sex. The randomization sequence is blinded to the investigators and allocation is disclosed only after valid consent. Ambulatory BP measurements will be performed at baseline, 3, and 12 months. The primary outcome is proportion of participants with ND at 3 months; secondary outcomes include proportion of participants with ND at 12 months, absolute BP values at 3 and 12 months. Exercise level will be detected by validated questionnaire and compared between 2 arms at 3 and 12 months. CONCLUSION: The trial will examine the efficacy of treating ND and HT by an exercise program.

Effect of early bereavement on heart rate and heart rate variability.

Early bereavement is associated with increased cardiovascular events. The mechanism, however, has not been well studied. We assessed whether bereavement is associated with an increased heart rate (HR) and decreased heart rate variability that might contribute to increased cardiovascular risk. A total of 78 bereaved spouses and parents (55 women and 23 men; aged 34 to 87 years, mean 65) were studied with 24-hour Holter monitoring within 2 weeks of bereavement (acute) and at 6 months. Their findings were compared to those from a nonbereaved reference group (52 women and 27 men) aged 33 to 91 years (mean 63.6). All participants were in sinus rhythm. We assessed the mean HR, atrial and ventricular arrhythmias, and both time and frequency domain heart rate variability measures. Acute bereavement was associated with increased 24-hour HR (mean ± SE, 75.1 ± 1.1 vs 70.7 ± 1.0; p = 0.004) and reduced heart rate variability, as indicated by lower standard deviation of the NN intervals index (median 45.4 vs 49.9, p = 0.017), total power (7.78 ± 0.10 vs 8.02 ± 0.09, p = 0.03), very low frequency (7.23 ± 0.09 vs 7.44, p = 0.046) and low frequency (5.76 ± 0.12 vs 6.16 ± 0.09, p = 0.01). At 6 months, the bereaved had a significantly lower HR (p = 0.001) and increased standard deviation of the NN intervals index (p = 0.02), square root of the mean square of differences of successive intervals (p = 0.045), number of interval differences of successive NN intervals >50 ms divided by the number of NN intervals (p = 0.039), low-frequency power (p = 0.02), and high frequency (p = 0.002) compared to the initial acute levels. In conclusion, the present study, the first to report 24-hour HR monitoring in the early weeks of bereavement, has demonstrated increased HR and altered autonomic function that might contribute to the increased cardiovascular events in early bereavement.

Inflammatory and thrombotic changes in early bereavement: a prospective evaluation.

AIMS: Although there is an increased cardiovascular risk in the immediate weeks following bereavement, the mechanism is not well understood. The aim of this study was to determine whether inflammatory and thrombotic changes were present in acute bereavement. METHODS AND RESULTS: Eighty bereaved spouses or parents were prospectively studied within 2 weeks of bereavement (acute) and at 6 months, and compared to 80 non-bereaved participants. Haemostatic measures were obtained between 8 a.m. and 11 a.m. and processed within 1 h. Compared to non-bereaved participants, those acutely bereaved had a higher neutrophil count (4.34 ± 0.19 vs 3.79 ± 0.15, p = <0.001), von Willebrand factor antigen (132.33 ± 3.6 vs 119.95 ± 3.29, p = 0.02), Factor VIII (1.43 ± 0.06 vs 1.25 ± 0.04, p = 0.02) and platelet/granulocyte aggregates (median 383.0 vs 343.5, p = 0.02). Levels of neutrophils, monocytes, eosinophils, platelet count, platelet/monocyte granulocytes and von Willebrand factor were lower in bereaved at 6 months compared to acutely (all p < 0.05). CONCLUSION: Acute bereavement is associated with inflammatory and prothrombotic changes that may contribute to the increased cardiovascular risk with bereavement and provide clues for future preventative strategies.

Haemodynamic changes during early bereavement: potential contribution to increased cardiovascular risk.

BACKGROUND: bereavement is associated with increased cardiovascular risk, particularly in surviving spouses and parents, however the mechanism is not well understood due to limited studies. The purpose of this study was to evaluate haemodynamic changes (blood pressure (BP) and heart rate (HR)), that may contribute to increased cardiac risk in early bereavement. METHODS: we enrolled 80 bereaved individuals and 80 non-bereaved as a reference group. Twenty-four hour ambulatory blood pressure monitoring was performed within two weeks (acute assessment) and at six months following bereavement. RESULTS: compared to the non-bereaved, the acutely bereaved had higher 24-hour systolic BP (mean (SE) 130.3 (1.5) vs 127.5 (1.4)mmHg, p=0.03), higher daytime systolic BP (135.6 (1.5) vs 131.6 (1.4)mmHg, p=0.02) and higher daytime systolic load (median % 39.0 vs 29.3, p=0.02). By six months the BP of the bereaved tended to be lower than acute measures. This difference was significant amongst those not taking BP lowering medications for 24-hour systolic BP (126.5 (2.4) vs 129.7 (2.3)mmHg, p=0.04), daytime systolic BP (129.8 (2.1) vs 133.9 (2.0)mmHg, p=0.01) and daytime diastolic pressure (76.7 (1.0) vs 78.9 (0.9)mmHg, p=0.03). Twenty-four hour heart rate was also higher acutely in the bereaved compared with the reference group (74.0 (1.2) vs 71.7 (0.9) b/min, p=0.02); at six months heart rate in the bereaved had fallen to non-bereaved levels (70.4 (0.09), p=0.02). CONCLUSION: early bereavement is associated with increased systolic blood pressure and heart rate. These haemodynamic changes may contribute to a time-limited increase in cardiovascular risk.