Tumour necrosis factor-alpha (TNF-α) is an important mediator in the pathogenesis of rheumatoid arthritis (RA) and hypertension. TNF-α inhibitors improve clinical symptoms and inhibit joint destruction in RA, but their effect on blood pressure (BP) has not been fully investigated. We measured 24-h BP using an ambulatory BP monitor in 16 RA patients treated with a TNF-α inhibitor, infliximab, to investigate its influence on BP and its association with the regulatory factors of BP and renin-angiotensin-aldosterone and sympathetic nervous systems. Infliximab significantly reduced the 24-h systolic BP (SBP) from 127.4±21.8 to 120.1±23.4 mm Hg (P<0.0001). Particularly, morning BP (0600-0800 h) decreased from 129.7±19.7 to 116.9±13.4 mm Hg (P<0.0001), and daytime BP decreased from 131.8±15.1 to 122.5±13.7 mm Hg (P<0.0001). Infliximab significantly reduced the plasma level of norepinephrine and plasma renin activity (PRA) (from 347.5±180.7 to 283.0±181.8 pg ml(-1) and 2.6±2.7 to 2.1±2.9 ng ml(-1) h(-1), respectively) but did not significantly reduce the plasma levels of dopamine and epinephrine. The reduction in morning SBP correlated with the reduction in the norepinephrine level (P<0.05) but not with that in PRA and inflammatory parameters related to RA. This study shows the effect of infliximab on ambulatory BP, especially daytime BP, which may be partly accounted for by the reduction of sympathetic nerve activity after infliximab treatment.

Background/Aim: The relation between markers of generalized atherosclerosis and cognitive impairment in old age is controversial. The aim of the study was to evaluate the cardio-ankle vascular index (CAVI) as a predictor of longitudinal changes in cognitive function in older individuals. Methods: We evaluated the cognitive function in elderly people with high (AS(+)) and low (AS(–)) values of CAVI each year over 4 years. Results: The changes in the Hasegawa Dementia Scale Revised (HDS-R) and the mini-mental state examination (MMSE) at 4 years were significantly larger in the AS(+) group (AS(+) vs. AS(–) = –1.8 ± 4.4 vs. 0.3 ± 2.8 points and –1.1 ± 3.0 vs. 0.1 ± 2.3 points, p = 0.008 and 0.03, respectively). The annual changes in the HDS-R were significantly decreased from baseline at 1 year later to 4 years later in AS(+) (baseline vs. 1, 2, 3, 4 years = 26.5 vs. 25.0, 25.5, 25.7, 24.8 points, p < 0.001); in comparison, the annual changes in MMSE significantly decreased from the baseline over the 4 years in AS (+) (baseline vs. 1, 2, 3, 4 years = 26.8 vs. 26.2, 25.8, 26.4, 25.7 points, p = 0.002). Conclusion: The results of this study suggest that elderly people with a high CAVI value are at a greater risk of cognitive decline.

We evaluated their circadian rhythms using data from electrocardiographic records and examined the change in circadian period related to normal RR intervals for astronauts who completed a long-term (≥6-month) mission in space. The examinees were seven astronauts, 5 men and 2 women, from 2009 to 2010. Their mean±SD age was 52.0±4.2 years (47-59 yr). Each stayed in space for more than 160 days; their average length of stay was 172.6±14.6 days (163-199 days).We conducted 24-hr Holter electrocardiography before launch (Pre), at one month after launch (DF1), at two months after launch (DF2), at two weeks before return (DF3), and at three months astronauts, whereas it decreased in 3 of 7 astronauts and 1 was remained almost unchanged at DF1.During DF3, about 6 months after their stay in space, the HF component of 5 of 7 astronauts recovered from the decrease after launch, with prominent improvement to over 20% in 3 astronauts. 2Although autonomic nervous functions and circadian rhythms were disturbed until one month had passed in space, well-scheduled sleep and wake rhythms and meal times served as synchronizers.

The fractal scaling of the long-term heart rate variability (HRV) reflects the ‘intrinsic’ autonomic regulatory system. Herein, we examine how microgravity on the ISS affected the power-law scaling β (beta) of astronauts during a long-duration (about 6 months) spaceflight. Ambulatory electrocardiographic (ECG) monitoring was performed on seven healthy astronauts (5 men, 52.0±4.2 years of age) five times: before launch, 24±5 (F01) and 73±5 (F02) days after launch, 15±5 days before return (F03), and after return to Earth. The power-law scaling β was calculated as the slope of the regression line of the power density of the MEM spectrum versus frequency plotted on a log10–log10 scale in the range of 0.0001–0.01 Hz (corresponding to periods of 2.8 h to 1.6 min). β was less negative in space (−0.949±0.061) than on Earth (−1.163±0.075; P<0.025). The difference was more pronounced during the awake than during the rest/sleep span. The circadian amplitude and acrophase (phase of maximum) of β did not differ in space as compared with Earth. An effect of microgravity was detected within 1 month (F01) in space and continued throughout the spaceflight. The intrinsic autonomic regulatory system that protects life under serious environmental conditions on Earth is altered in the microgravity environment, with no change over the 6-month spaceflight. It is thus important to find a way to improve conditions in space and/or in terms of human physiology, not to compromise the intrinsic autonomic regulatory system now that plans are being made to inhabit another planet in the near future.

Seasonal variations in blood pressure (BP) have often been attributed to meteorological factors, especially changes in outdoor temperature. We evaluated the direct association between meteorological factors and circadian BP variability. Twenty-four-hour ambulatory BP was monitored continuously for 7 days in 158 subjects. Mean awake, asleep, morning (first 2 h after waking) BP, prewaking morning BP surge (morning systolic BP (SBP)Àmean SBP during the 2-h period before waking) and nocturnal BP decline were measured each day. We compared BP values for the lowest and highest days with regard to the daily mean outdoor temperature and mean atmospheric pressure. Morning BP and prewaking morning BP surge on the coldest day were significantly higher than those on the warmest day (morning SBP, 136.6±1.6 vs. 133.1±1.5 mm Hg, P¼0.002; morning diastolic BP, 84.4±0.9 vs. 82.6±0.9 mm Hg, P¼0.02; and prewaking morning BP surge, 20.8±1.3 vs. 15.3±1.3 mm Hg, P¼0.0004). The magnitude of nocturnal BP decline on the coldest day was significantly greater than that on the warmest day (15.8 ± 0.7 vs. 13.9 ± 0.7%, P¼0.01). Outdoor temperature is an important determinant of morning BP, prewaking morning BP surge and the magnitude of nocturnal BP decline. These findings may have important implications in management of hypertension and prevention of cardiovascular events. Keywords: ambulatory blood pressure monitoring; cold pressure stress; outdoor temperature; prewaking morning blood pressure surge INTRODUCTION Previous studies have indicated that the onset of cardiovascular events show circadian, weekly and seasonal variations. [1][2][3] Many studies have demonstrated an increased incidence of acute cardiovascular events in winter compared with other seasons. Blood pressure (BP) has also been reported to be higher in winter than in the other three seasons. [4][5][6][7][8] This seasonal variation in BP has often been attributed to meteorological factors, especially changes in outdoor temperature. However, direct effects of outdoor temperature and atmospheric pressure on BP have yet to be established conclusively, as seasonal changes in other factors such as diet, 9 physical activity 10 and psychological status 11 that may affect BP have also been observed.In this study, we evaluated the effect of outdoor temperature and atmospheric pressure on BP variability in a Japanese population using continuous 24-h ambulatory BP (ABP) monitoring for a 7-day period.