G. Mitsutake

Seven-day (24-h) ambulatory blood pressure monitoring, self-reported depression and quality of life scores.

ObjectiveEffects of environmental conditions on blood pressure (BP) and heart rate (HR) variations as putative factors underlying the onset of vascular events. MethodsBP and HR were monitored around the clock for 7 days on 54 residents from Urausu, Hokkaido, Japan. Daytime, night-time, and 24-h means served to identify dippers and non-dippers. Questionnaire-assessed depression and subjective quality of life were related to BP and HR by analyses of variance and linear regression. Statistical significance was at 5%. ResultsA circaseptan (about 7-day) component characterizes the 24-h mean and standard deviation (SD) of HR, and the daytime and day–night ratio of systolic BP. The SD of HR is higher on weekends and lower on Mondays and Thursdays. When awake, systolic BP is lowest on Sundays and the day–night ratio is optimal on weekends (Saturdays: 15.7 ± 9.4%; Sundays: 14.0 ± 13.2%). Depression was detected in 15 subjects, who had higher mean systolic and diastolic BP values (systolic BP:P  = 0.028 Fridays, P  = 0.021 Tuesdays; diastolic BP:P  = 0.022 Mondays, P  = 0.006 daytime Mondays) and a lower day–night ratio of diastolic BP (P  = 0.012 Tuesdays, P  = 0.005 Wednesdays, and P  = 0.038 Thursdays). A depressive mood correlated positively with 24-h averages of systolic (P  = 0.037) and diastolic (P  = 0.030) BP. ConclusionsDepression (and subjective quality of life) can affect BP and HR variability. The results indicate the role that psychological factors may play in the pathogenesis of cardiovascular disease. Therapeutic implications are suggested for primary and secondary prevention.

Does Schumann resonance affect our blood pressure

OBJECTIVES To investigate whether Schumann resonance (SR) affects blood pressure (BP), heart rate (HR), and depression and, if so, whether the putative BP reactivity to SR (BPR-SR) is associated with health-related lifestyle (HLS), disease-related illnesses (DRI), and depression. METHODS A sample of 56 adults in Urausu, Hokkaido, Japan, wore an ambulatory BP monitor, except for the time in the shower, for seven consecutive days. They completed the Geriatric Depression Scale-Short Form and a health survey questionnaire on HLS and DRI. Group mean differences and within-individual differences in systolic (S) and diastolic (D) BP, mean arterial pressure (MAP), double product (DP), and HR were, respectively, compared between normal and enhanced SR days, using Students t-test. Correlations between BPR-SR and other characteristics (i.e. age, gender, HLS, DRI, subjective health, and depression) were analyzed, using Pearsons product moment correlation. RESULTS AND DISCUSSION Group mean SBP, DBP, MAP, and DP for enhanced SR days were lower than those for normal days (P=0.005-0.036). DRI was negatively associated with BPR-SR in SBP, DBP, MAP, and DP (P=0.003-0.024), suggesting a better health status for those who showed lower BP on enhanced SR days. HLS was negatively associated with BPR-SR in DBP and MAP (P=0.016-0.029). Males showed higher BPR-SR in DBP and MAP than females (P=0.004-0.016). Neither subjective health nor depression was significantly associated with BPR-SR. Future studies based on larger sample sizes are planned to see whether possible health effects can be generalized.

Can nutrition influence circadian rhythm and heart rate variability

Recent studies indicate that there is an interaction between biorhythms, the biological clock and triggers, which may be important in the pathogenesis of altered heart rate variability (HRV) and blood pressure variability (BPV). Circadian rhythms are under the influence of, and physiological variables are mediated by the activation of the adrenals, sympathetic/parasympathetic, hypothalamic and pituitary activity. Emotional stress, physical exertion, sleep deprivation and large fatty meals are major triggers of myocardial ischemia, angina, infarction, sudden cardiac death (SCD) and stroke. These events have been reported to exhibit a circadian variation with increased frequency in the second quarter of the day, which has also been observed in our studies on Indians. Recent studies indicate that altered HRV and BPV are also important in the pathogenesis and progression of heart failure, atheroma and thrombosis. Mediation via beta-blockers, oestrogens, n-3 fatty acids, vitamin E and coenzyme Q10 and fasting appears to have a beneficial influence whereas progestins, nifedipine, stress and exercise may have an adverse effect on HRV and BPV. We have reported that plasma levels of vitamin E and C are lower in the second quarter of the day than at other times, indicating their role in the pathogenesis of variability and cardiac events. Prospective studies also indicate that HRV and BPV are important and independent risk factors for cardiovascular events. However, no study has yet been conducted in patients with abnormal HRV and BPV in a randomized, placebo-controlled intervention trial to find out whether improvement in variability can cause a significant reduction in cardiovascular events. There is a need to study the role of n-3 fatty acids, coenzyme Q10, the effect of regular physical training, medication and ACE inhibitors in patients with abnormal HRV and BPV to demonstrate that improving variability can modulate cardiovascular events.

Circadian and infradian rhythms in mood

The aim of this study was to assess any variation in positive, negative and total affect recorded longitudinally; to compare the results with those from prior transverse or hybrid population studies, based on the same or a different method of mood rating; and to test for any association of mood with cardiovascular, hormonal and geophysical variables monitored concomitantly. The study approach was as follows. A clinically healthy 34-year-old man filled out the positive and negative affective scale (PANAS) questionnaire five times a day for 86 days. Systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) were also measured automatically at 30-minute intervals with an ambulatory monitor from May 19 to June 29, 2000, while different endpoints of heart rate variability (HRV) were also determined at 5-minute intervals from beat-to-beat electrocardiogram (ECG) monitoring for 42 days between May 3 and June 14, 2000, with only short interruptions while the subject took a shower and changed ECG tapes. Saliva samples were collected at the times of mood ratings for one month for later determination of melatonin and cortisol concentrations. Intervals of 24 hours of the record of each variable displaced in increments of 24 hours were analyzed by chronobiologic serial section at a trial period of 24 hours to assess the circadian characteristics as they changed from one day to another. Estimates of the midline-estimating statistic of rhythm (MESOR) and circadian amplitude and acrophase obtained on consecutive days were correlated among variables to assess any associations. The findings were as follows. Overall, a circadian rhythm was demonstrated for all variables. A positive association was noteworthy between the circadian amplitude of negative affect and the MESOR of both SBP (r= 0.363; P= 0.029) and DBP (r= 0.389; P= 0.019), suggesting that BP is raised in the presence of large swings in negative affect. Needing further validation was a weak association between the MESOR of negative affect and the circadian amplitude of SBP (r= - 0.272; P = 0.108), suggesting a lowering of the circadian SBP amplitude in the presence of a strong negative affect. Of further interest was the lack of a statistically significant relation between positive and negative affect, not only in terms of the MESOR but also in terms of the circadian amplitude.

Does exposure to an artificial ULF magnetic field affect blood pressure, heart rate variability and mood?

The aim of this study was to determine whether an artificial magnetic field with an amplitude and frequency equivalent to those of geomagnetic pulsations during geomagnetic storms could affect physiology and psychology. Three healthy volunteers wore anambulatory BP monitor and an ECG recorder around the clock for 12 consecutive weekends in Winnipeg, Manitoba, Canada. In a room shielded against ELF and VLF waves, they were exposed for 8 hours per week to either a 50 nT 0.0016 Hz or a sham magnetic field at one of six circadian stages. Real exposure randomly alternated with sham exposure. They provided saliva and recorded mood and reaction time every 4 hours while awake. Systolic (S) and diastolic (D) blood pressure (BP), and heart rate (HR) were recorded every 30 minutes. Spectral analysis of HR variability (HRV) was performed using the maximum entropy method and a complex demodulation method. For these variables, daily means were compared between real and sham exposure, using paired t-tests. Their circadian MESOR, amplitude, and acrophase were analyzed and summarized using single cosinor and population-mean cosinor. Circadian rhythms were demonstrated for HR, SBP, DBP for sham exposure, salivary flow rate, positive affect, vigor, and subjective alertness (p < 0.001, -0.02). One participant showed higher HR, lower LF, HF, and VLF powers, and a steeper power-law slope (p < 0.005, -0.0001) in an early night exposure to the real magnetic field, but not in other circadian stages. There was no significant difference between circadian responses to real and sham exposure in any variable at any circadian stage.

Depression, quality of life, and lifestyle: chronoecological health watch in a community.

The objectives are to explore the possibility of preventive non-drug interventions on vascular disease risk by examining the associations among health-related lifestyle (HLS), disease-related illnesses (DRI), subjective quality of life (QOL), depression, and blood pressure (BP). A sample of 181 adults (73 men and 108 women, mean age 57.3 +/- 10.2 years, range 24-76 years) in Urausu, Hokkaido, Japan, wore an ambulatory BP monitor around the clock for seven consecutive days. They completed a health survey questionnaire with which their HLS and DRI were assessed. QOL and depression were rated on the Visual Analogue Scales and the Geriatric Depression Scale-Short Form, respectively. For each participants systolic (S) and diastolic (D) BP and HR, the circadian MESOR, amplitude, and acrophase were calculated, using cosinor analysis. Associations among the variables were analyzed, using Pearsons correlation coefficient and Kendalls tau-b. DRI was positively associated with depression (P = 0.005) and with HLS (P = 0.001), and was negatively associated with QOL (P = 0.041). Depression showed a moderate and negative correlation with QOL (P < 0.001). As expected, Body Mass Index (BMI) was associated with higher DRI (P = 0.008), SBP (P < 0.001), and DBP (P = 0.002), and with less variation of SBP (P = 0.006) and DBP (P = 0.004). Obesity as assessed by BMI was found to be a good indicator of the circadian BP endpoints and illnesses, warranting further investigation into dietary intake and health outcomes. Depression was also found to be a useful indicator of DRI, HLS, and QOL.