Morning-evening Difference Research Articles

S-01-3: SMART WELLNESS HOUSING AND BLOOD PRESSURE CONTROL

Objective: Mortality due to cardiovascular diseases (CVDs) rises sharply in winter, a phenomenon known as excess winter mortality. It is partially explained by cold exposure induced hypertension. Nevertheless, existing countermeasures for the prevention of hypertension and CVDs place emphasis only on improving lifestyle habits. Improving life environment has attracted attention recently because people spend 60–70% of their time at home. Therefore, we aimed to quantitatively evaluate the relationship between housing thermal environment and blood pressure (BP) in a real-world setting. Design and method: We conducted a nationwide prospective intervention study named the Smart Wellness Housing survey in Japan, as a nonrandomized controlled trial. The intervention was the thermal insulation retrofitting of homes. Participants were recruited by construction companies throughout all 47 prefectures of Japan. Home BP and indoor temperature were measured for 2 weeks before and after the intervention in winter (November-March) of FY 2014 to 2019. Results: Cross-sectional analyses before intervention involving about 2900 participants (1840 households) showed that systolic blood pressure (SBP) in the morning had significantly higher sensitivity to changes in indoor temperature (8.2 mmHg increase/10°C decrease) than that in the evening (6.5 mmHg increase/10°C decrease) in participants aged 57 years (mean age in this survey). Interaction terms between age/women and indoor temperature were significant, indicating that SBP in older residents and women was vulnerable to indoor temperature change. The association between BP variability and indoor temperature instability was also analyzed using the morning-evening (ME) difference as an index of diurnal variability and the standard deviation (SD) of 2-week data as an index of day-by-day variability. The analyses showed that the ME difference in indoor temperature was closely correlated with the ME difference in SBP (0.85 mmHg/°C). The SD of indoor temperature was also associated with the SD of SBP (0.61 mmHg/°C). In the comparison of before and after intervention, insulation retrofitting significantly reduced morning SBP by 3.1 mmHg. In addition, there was heterogeneity in the effect of insulation retrofitting on morning SBP in hypertensive patients compared with normotensive occupants (-7.7 versus -2.2 mmHg). Conclusions: Hypertension might be not only lifestyle diseases but also life-environment diseases. Residents should keep the indoor temperature high to reduce BP level and keep it stable to reduce BP variability through strategies such as installing high thermal insulation. We expect that these results will be useful to prevent excess winter mortality due to CVDs.

PROGNOSTIC SIGNIFICANCE OF BLOOD PRESSURE PARAMETERS FOR PREDICTING CARDIOVASCULAR DEATH

Objective: The nycterohemeral rhythm of blood pressure (BP) and heart rate has been associated with cardiovascular outcomes. However, long-term prognostic significance of BP at different levels of heart rates has rarely been studied. We therefore conducted the present analysis to investigate the prognostic values for cardiovascular outcome by the ambulatory BP parameters during different time windows Design and method: We enrolled 5 large cohorts from whole world, including CARDIA, IDACO, JHS, SPRINT to find out independent prognostic factors for cardiovascular disease mortality, feature engineering and feature transformation were used. Several statistical and machine learning methods including the stepwise procedure, lasso penalty, and random survival forest with bootstrap technique were used to screen important candidates of risk factors. Models building are based on systolic BP replacement into the established Framingham risk score. Directly one to one replacement and indirectly two stage replacement methods are considered with variable diversity. C-statistics, NRI are used for model performance evaluation. Results: In model building procedure, nighttime BP combined with pulse pressure, morning-evening difference of SBP and weighted SBP consistently had a higher C-statistics than had office systolic BP. In validation datasets, equations incorporating mean BP and pulse pressure had best performance in C-index (0.754). In contrast, the C-index (higher is better), of the usual Framingham risk score with office systolic BP are 0.744. Furthermore, the best model had acceptable predicted accuracy based on model calibration statistics (p > 0.05). Conclusions: Our study demonstrated that mean BP at night combined with pulse pressure, morning-evening difference of SBP and weighted SBP, throughout 24 hours had the largest predictive power of 20-year cardiovascular death in population with ABPM recordings. The transportability of the proposed cardiovascular risk function should be evaluated in future studies.

Impact of indoor temperature instability on diurnal and day-by-day variability of home blood pressure in winter: a nationwide Smart Wellness Housing survey in Japan

Home blood pressure (HBP) variability is an important factor for cardiovascular events. While several studies have examined the effects of individual attributes and lifestyle factors on reducing HBP variability, the effects of living environment remain unknown. We hypothesized that a stable home thermal environment contributes to reducing HBP variability. We conducted an epidemiological survey on HBP and indoor temperature in 3785 participants (2162 households) planning to have their houses retrofitted with insulation. HBP was measured twice in the morning and evening for 2 weeks in winter. Indoor temperature was recorded with each HBP observation. We calculated the morning-evening (ME) difference as an index of diurnal variability and the standard deviation (SD), coefficient of variation (CV), average real variability (ARV) and variability independent of the mean (VIM) as indices of day-by-day variability. The association between BP variability and temperature instability was analyzed using multiple linear regression models. The mean ME difference in indoor/outdoor temperature (a decrease in temperature overnight) was 3.2/1.5 °C, and the mean SD of indoor/outdoor temperature was 1.6/2.5 °C. Linear regression analyses showed that the ME difference in indoor temperature was closely correlated with the ME difference in systolic BP (0.85 mmHg/°C, p < 0.001). The SD of indoor temperature was also associated with the SD of systolic BP (0.61 mmHg/°C, p < 0.001). The CV, ARV, and VIM showed similar trends as the SD of BP. In contrast, outdoor temperature instability was not associated with either diurnal or day-by-day HBP variability. Therefore, residents should keep the indoor temperature stable to reduce BP variability.

The effect of Ramadan fasting on the morning–evening difference in team-handball-related short-term maximal physical performances in elite female team-handball players

ABSTRACT The combined effect of Ramadan fasting and the time of theday on the physical performance of team-handball players has not yet been fully investigated. This study investigated the effects of Ramadan fasting on the morning–evening difference in team-handball-related short-term maximal physical performance. With acounterbalanced study design, 15 elite female team-handball players underwent the hand grip (HG), ball throwing velocity (BTV), modified agility T-test (MAT), and repeated shuttle-sprint and jump ability (RSSJA) tests at 07:00 h and 17:00 h, one week before Ramadan (BR), and during thesecond (SWR) and fourth week of Ramadan (4WR). The oral temperature (OT) was monitored prior to exercise and the ratings of perceived exertion (RPE) scale were obtained after RSSJA. The results showed that the time of theday had an effect on OT under all conditions. The HG, BTV, and MAT test performances were higher in the evening than in the morning BR (P< .001, P< .05, and P< .001, respectively). However, the diurnal variation noted in the HG and MAT tests was reversed during the SWR and 4WR, while the BTV variation was blunted during the SWR and reversed during the 4WR. The best RSSJA performance was observed in the evening BR. However, for the best and mean sprint times, areversal of this diurnal variation was observed, which was blunted for the mean jump height and sprint time decrement during Ramadan. Moreover, RPE were influenced by the time of theday and the month of Ramadan. These findings suggest that the diurnal variation of team-handball-related short-term maximal physical performance may be reversed and/or blunted during Ramadan fasting.

Association between Changes in the Systolic Blood Pressure from Evening to the Next Morning and Night Glucose Variability in Heart Disease Patients

Objectve To assess the impact of glycemic variability on blood pressure in hospitalized patients with cardiac disease. Methods In 40 patients with cardiovascular disease, the glucose levels were monitored by flash continuous glucose monitoring (FGM; Free-Style Libre™ or Free-Style Libre Pro; Abbott, Witney, UK) and self-monitoring blood glucose (SMBG) for 14 days. Blood pressure measurements were performed twice daily (morning and evening) at the same time as the glucose level measurement using SMBG. Results The detection rate of hypoglycemia using the FGM method was significantly higher than that with the 5-point SMBG method (77.5% vs. 5.0%, p＜0.001). Changes in the systolic blood pressure from evening to the next morning [morning - evening (ME) difference] were significantly correlated with night glucose variability (r=0.63, P＜0.001). A multiple regression analysis showed that night glucose variability using FGM was more closely correlated with the ME difference [r=0.62 (95% confidence interval, 0.019-0.051); p＜0.001] than with the age, body mass index, or smoking history. Night glucose variability was also more closely associated with the ME difference in patients with unstable angina pectoris (UAP) than in those with acute myocardial infarction (AMI) or heart failure (HF) (r=0.83, p=0.058). Conclusion Night glucose variability is associated with the ME blood pressure difference, and FGM is more accurate than the 5-point SMBG approach for detecting such variability.

Circadian misalignment disturbs the skeletal muscle lipidome in healthy young men.

Circadian misalignment, as seen in shift work, is associated with an increased risk to develop type 2 diabetes. In an experimental setting, we recently showed that a rapid day-night shift for 3 consecutive nights leads to misalignment of the core molecular clock, induction of the PPAR pathway, and insulin resistance in skeletal muscle of young, healthy men. Here, we investigated if circadian misalignment affects the skeletal muscle lipidome and intramyocellular lipid droplet characteristics, explaining the misalignment-induced insulin resistance. Fourteen healthy men underwent one aligned and one circadian misalignment period, both consisting of ~3.5days. In the misaligned condition, day and night were rapidly shifted by 12hours leading to opposite eating, sleep, and activity times compared with the aligned condition. For each condition, two muscle biopsies were taken from the m. vastus lateralis in the morning and evening and subjected to semi-targeted lipidomics and confocal microscopy analysis. We found that only 2% of detected lipids were different between morning and evening in the aligned condition, whereas 12% displayed a morning-evening difference upon misalignment. Triacylglycerols, in particular species of a carbon length ≥55, were the most abundant lipid species changed upon misalignment. Cardiolipins were decreased upon misalignment, whereas phosphatidylcholines consistently followed the same morning-evening pattern, suggesting regulation by the circadian clock. Cholesteryl esters adjusted to the shifted behavior. Lipid droplet characteristics remained unaltered upon misalignment. Together, these findings show that simulated shift work disturbs the skeletal muscle lipidome, which may contribute to misalignment-induced insulin resistance.

Associations Between Relative Morning Blood Pressure, Cerebral Blood Flow, and Memory in Older Adults Treated and Controlled for Hypertension.

[Figure: see text].

Home Blood Pressure Monitoring: Current Status and New Developments.

Home blood pressure monitoring (HBPM) is a reliable, convenient, and less costly alternative to ambulatory blood pressure monitoring (ABPM) for the diagnosis and management of hypertension. Recognition and use of HBPM have dramatically increased over the last 20 years and current guidelines make strong recommendations for the use of both HBPM and ABPM in patients with hypertension. The accuracy and reliability of home blood pressure (BP) measurements require use of a validated device and standardized procedures, and good patient information and training. Key HBPM parameters include morning BP, evening BP, and the morning–evening difference. In addition, newer semi-automatic HBPM devices can also measure nighttime BP at fixed intervals during sleep. Advances in technology mean that HBPM devices could provide additional relevant data (e.g., environmental conditions) or determine BP in response to a specific trigger (e.g., hypoxia, increased heart rate). The value of HBPM is highlighted by a growing body of evidence showing that home BP is an important predictor of target organ damage, and cardiovascular disease (CVD)- and stroke-related morbidity and mortality, and provides better prognostic information than office BP. In addition, use of HBPM to monitor antihypertensive therapy can help to optimize reductions in BP, improve BP control, and reduce target organ damage and cardiovascular risk. Overall, HBPM should play a central role in the management of patients with hypertension, with the goal of identifying increased risk and predicting the onset of CVD events, allowing proactive interventions to reduce risk and eliminate adverse outcomes.

Improvement of Diurnal Blood Pressure Variation by Azilsartan.

BackgroundAzilsartan is an angiotensin II receptor blocker with a potent antihypertensive effect.MethodsIn a multicenter, prospective, open-label study, 265 patients with poor blood pressure control despite treatment with other angiotensin II receptor blockers were switched to 20 mg/day of azilsartan (patients on standard dosages) or 40 mg/day of azilsartan (patients on high dosages).ResultsBlood pressure was 149/83 mm Hg before switching and was significantly reduced from 1 month after switching until final assessment (132/76 mm Hg, P < 0.001). The pulse rate was 72/min before switching and increased significantly from 3 months after switching until final assessment (74/min, P < 0.005). A significant decrease of home morning systolic and diastolic pressure was observed from 1 and 3 months, respectively. Home morning blood pressure was 143/82 mm Hg before switching and 130/76 mm Hg at final assessment (P < 0.01). The morning-evening difference of systolic blood pressure decreased from 14.6 to 6.6 mm Hg after switching (P = 0.09). The estimated glomerular filtration rate was significantly decreased at 3, 6, and 12 months after switching, and serum uric acid was significantly increased at 12 months. No serious adverse events occurred.ConclusionAzilsartan significantly reduced the blood pressure and decreased diurnal variation in patients responding poorly to other angiotensin II receptor blockers.

Characterizing Sleep in Adolescents and Adults with Autism Spectrum Disorders.

We studied 28 adolescents/young adults with autism spectrum disorders (ASD) and 13 age/sex matched individuals of typical development (TD). Structured sleep histories, validated questionnaires, actigraphy (4 weeks), and salivary cortisol and melatonin (4 days each) were collected. Compared to those with TD, adolescents/young adults with ASD had longer sleep latencies and more difficulty going to bed and falling asleep. Morning cortisol, evening cortisol, and the morning-evening difference in cortisol did not differ by diagnosis (ASD vs. TD). Dim light melatonin onsets (DLMOs) averaged across participants were not different for the ASD and TD participants. Average participant scores indicated aspects of poor sleep hygiene in both groups. Insomnia in ASD is multifactorial and not solely related to physiological factors.

Morning–evening difference of team-handball-related short-term maximal physical performances in female team handball players

ABSTRACTThis study investigated the two different time-of-day effect on team-handball-related short-term maximal physical performances. At two different time-of-day, fifteen young female team handball players performed different physical tests: HandGrip (HG) test, Ball-Throwing Velocity (BTV) test, Modified Agility T-test (MAT) and Repeated Shuttle-Sprint and Jump Ability (RSSJA) test. Rating of perceived exertion (RPE) scale was determined following the termination of the last test. Measurements were performed at two separate testing sessions (i.e., in the morning (7:00–8:30 h) and in the early evening (17:00–18:30 h)) in a randomised and counter-balanced setting on non-consecutive days. The results showed that HG (P = 0.0013), BTV (P = 0.0027) and MAT (P < 0.001) performances were better in the evening compared with the morning. During RSSJA, both best and mean sprint times were shorter in the evening compared to the morning (P < 0.001). Moreover, during the latter test, mean jump performance was higher in the evening compared to the morning (P = 0.026). However, there was no morning–evening difference in the best jump performance during RSSJA. Likewise, jump performance decrement was not affected by the time-of-day of testing. On the other hand, RPE fluctuated, with morning nadirs and afternoon/early evening highest values. The findings suggest that in female team handball players, team-handball-related short-term maximal physical performances were better in the afternoon than in the morning.

The effect of training at the same time-of-day on the diurnal variations of technical ability and swimming performance

The aim of this study was to examine the effects of training at the same time of day on diurnal variations of technical ability and swimming performance, to provide some recommendations with regard to adjusting training hours in accord with the time of day of competitive events. Eighteen participants volunteered for this study, and these were randomly assigned to either a morning training group (MTG, who trained only between 07:00 and 08:00 h, n = 6), an evening training group (ETG, who trained only between 17:00 and 18:00 h, n = 6), or a control group (CG, did not train but participated in all tests, n = 6). Swimming performance and technical ability – (i) stroke parameters: swim velocity (V), stroke rate (SR), and stroke length (SL); and (ii) motor organization: arm stroke phases and arm coordination (Idc) – were recorded 2 weeks before and 2 weeks after an 8-week regular training period. For all participants, the morning and evening tests were scheduled at the same time of day as the morning and evening training sessions. After training, the major finding of this study was that both ETG and the CG showed significantly lower P, V, SR, phase (B), phase (C), and Idc values in the morning than in the evening. However, P, V, SR, phase (B), phase (C), and Idc of the MTG measured at 07:00 and 17:00 h did not differ. Thus, training at a specific time of day increased performance in MTG at this time and modified the diurnal variation of swim performance. This study indicates that training at a specific time of day can result in marked changes in both swimming performance and technical aspects of swimming. Furthermore, training in the morning improved morning swimming performance and its components, and the amplitude of the morning–evening difference decreased. Training in the evening improved swimming performance and its components more in the evening than the morning, and the amplitude of the morning–evening difference increased.

Diurnal variation in stroke parameters and motor organization in front-crawl swimmers

The aim of the present study was to examine the effects of time of day on stroke parameters and motor organization in front-crawl swimmers. In a randomized order, fourteen regional swimmers (age: 18.7 ± 1.6 years) performed maximal front crawls over 12.5 m during two experimental sessions; the morning sessions were conducted between 07:00 and 09:00 h and the evening experiments were conducted between 17:00 and 19:00 h. Stroke parameters (swim velocity, stroke rate [SR], and stroke length), motor organization (arm stroke phases and arm coordination) were calculated from aerial and underwater side-view cameras. Arm coordination was quantified in terms of an index of coordination (Idc). Results showed that oral temperature was significantly higher in the evening 36.8 ± 0.2 °C than in the morning 36.1 ± 0.2 °C (p < 0.001), with a morning–evening difference of −0.7 ± 0.1 °C. Performance was also higher in the evening (7.4 ± 0.6 s) than in the morning (8.0 ± 0.8 s) (p < 0.001), with a morning–evening difference of 0.55 ± 0.30 s. Likewise, values of swim velocity and SR were higher in the evening than in the morning (p < 0.001) with morning–evening differences of −0.10 ± 0.04 m s−1 and −3.99 ± 2.91 cycles min−1, respectively. Percentage Idc increased significantly (p < 0.01) between the morning (−5.1 ± 6.5%) and evening (−1.6 ± 7.0%). It is concluded that maximal swimming trials are performed better in the evening than the morning, and that this might be explained by better stroke parameters and motor organization at this time.

Effect of sport practice and warm-up duration on the morning–evening difference in anaerobic exercise performance and perceptual responses to it

This study was designed to assess the effect of sport practice and warm-up duration on the morning–evening differences in muscle power and fatigue during performance of anaerobic exercise and perceptual responses to it. Twenty-two male physical education students – twelve trained (TG) (21.51 ± 1.25 years, 182.17 ± 4.37 cm and 82.88 ± 11.23 kg) and ten untrained (NTG) (23.89 ± 3.17 years, 176.8 ± 2.2 cm and 82.24 ± 8.43 kg) – participated in a crossover randomized study. They were asked to perform a 30-s Wingate test during six experimental sessions (three at 08:00 and three at 18:00 h) after different active warm-up (AWU) durations (5 min, 15 min, or 20 min). The AWU consisted of pedaling at a constant pace of 60 rpm against 50% of maximal aerobic power. Rate of perceived exertion (RPE) was recorded after the AWU and again immediately after the Wingate test. Heart rate and temperature (T) were recorded during each session at rest, after AWU and immediately at the end of the Wingate test. During the Wingate test, peak power (PP), mean power (MP), and the fatigue index were recorded. While the RPE estimations were higher in NTG, no time-of-day effect was recorded in either experimental group (morning or evening). T, PP, and MP were higher in the afternoon than in the morning (p < 0.001 for PP and MP; p < 0.05 for T). Similarly, PP and MP during the Wingate test were significantly higher in the TG than in the NTG (p < 0.001). The morning–evening difference of PP and MP was affected by AWU duration; AWU15 was best in the morning for improving lower limb power for both the TG and NTG, whereas reducing this period to 5 min in the evening was appropriate for TG only.

Determinants of the Morning-Evening Home Blood Pressure Difference in Treated Hypertensives: The HIBA-Home Study.

Background. The morning home blood pressure (BP) rise is a significant asymptomatic target organ damage predictor in hypertensives. Our aim was to evaluate determinants of home-based morning-evening difference (MEdiff) in Argentine patients. Methods. Treated hypertensive patients aged ≥18 years participated in a cross-sectional study, after performing home morning and evening BP measurement. MEdiff was morning minus evening home average results. Variables identified as relevant predictors were entered into a multivariable linear regression analysis model. Results. Three hundred sixty-seven medicated hypertensives were included. Mean age was 66.2 (14.5), BMI 28.1 (4.5), total cholesterol 4.89 (1.0) mmol/L, 65.9% women, 11.7% smokers, and 10.6% diabetics. Mean MEdiff was 1.1 (12.5) mmHg systolic and 2.3 (6.1) mmHg diastolic, respectively. Mean self-recorded BP was 131.5 (14.1) mmHg systolic and 73.8 (7.6) mmHg diastolic, respectively. Mean morning and evening home BPs were 133.1 (16.5) versus 132 (15.7) systolic and 75.8 (8.4) versus 73.5 (8.2) diastolic, respectively. Significant beta-coefficient values were found in systolic MEdiff for age and smoking and in diastolic MEdiff for age, smoking, total cholesterol, and calcium-channel blockers. Conclusions. In a cohort of Argentine medicated patients, older age, smoking, total cholesterol, and use of calcium channel blockers were independent determinants of home-based MEdiff.

The Effect of Training at a Specific Time of Day

This article focuses on physical performances after training at a specific time of day. To date, although the effect of time of day on aerobic performances appears to be equivocal, during anaerobic exercises, the effect of time of day has been well established with early morning nadirs and peak performances in the late afternoon. These diurnal rhythms can be influenced by several factors such as the regular training at a specific time of day. Indeed, regular training in the morning hours may increase the lower morning performances to the same or even higher level as their normal diurnal peak typically observed in the late afternoon by a greater increase of performance in the evening. However, regular training in the evening hours may increase the morning-evening (i.e., amplitude of the rhythm) difference by a greater increase of performance in the late afternoon. Therefore, adaptations to training are greater at the time of day at which training is regularly performed than at other times. Nevertheless, although modifications in resting hormones concentrations could explain this time-of-day specific adaptations, precise information on the underlying mechanisms is lacking.

Listening to Music Affects Diurnal Variation in Muscle Power Output

The purpose of this investigation was to assess the effects of listening to music while warming-up on the diurnal variations of power output during the Wingate test. 12 physical education students underwent four Wingate tests at 07:00 and 17:00 h, after 10 min of warm-up with and without listening to music. The warm-up consisted of 10 min of pedalling at a constant pace of 60 rpm against a light load of 1 kg. During the Wingate test, peak and mean power were measured. The main finding was that peak and mean power improved from morning to afternoon after no music warm-up (p<0.001 and p<0.01, respectively). These diurnal variations disappeared for mean power and persisted with an attenuated morning-evening difference (p<0.05) for peak power after music warm-up. Moreover, peak and mean power were significantly higher after music than no music warm-up during the two times of testing. Thus, as it is a legal method and an additional aid, music should be used during warm-up before performing activities requiring powerful lower limbs' muscles contractions, especially in the morning competitive events.

Association between home arterial stiffness index and target organ damage in hypertension: Comparison with pulse wave velocity and augmentation index

ObjectivesTo clarify the implications of the home arterial stiffness index (HASI), we compared HASI with other arterial stiffness measures and investigated the association between HASI and hypertensive target organ damage (TOD). MethodsWe assessed brachial–ankle pulse wave velocity (baPWV) and the carotid augmentation index (cAIx) as measures of arterial stiffness and wave reflection, and the left ventricular mass index (LVMI), carotid intima-media thickness (IMT) using ultrasonography, and the urinary albumin/creatinine ratio (UACR) as measures of TOD in 356 never-treated hypertensive subjects. Home blood pressure (BP) was taken in triplicate in the morning and evening, respectively, for 14 consecutive days with a memory-equipped device. HASI was defined as 1 minus the respective regression slope of diastolic on systolic BP. ResultsHASI was significantly correlated with age (r=0.32, P<0.001), home pulse pressure (r=0.36, P<0.001), morning–evening difference in home systolic BP (r=−0.29, P<0.001), baPWV (r=0.18, P<0.001), cAIx (r=0.16, P=0.002), carotid IMT (r=0.26, P<0.001), and UACR (r=0.24, P<0.001), but not with LVMI (r=0.05, P=0.38). After adjustment for age and sex, the significant correlation between HASI and baPWV/cAIx was lost. In multivariate regression analyses, HASI and baPWV were significantly associated with carotid IMT (standardized β=0.21, P<0.001; β=0.14, P=0.014) and UACR (β=0.13, P=0.018; β=0.21, P<0.001), independently of age, sex, and home mean arterial pressure. On the other hand, cAIx was independently associated only with LVMI (β=0.24, P<0.001). ConclusionThese findings indicate that HASI adds nothing to the existing measures of arterial stiffness, but might be a BP component that can aid in the detection of carotid atherosclerosis and renal damage, similar to PWV.

Sleep Habits, Alertness, Cortisol Levels, and Cardiac Autonomic Activity in Short-Distance Bus Drivers

To evaluate sleep, alertness, salivary cortisol levels, and autonomic activity in the afternoon and morning shifts of a sample of short-distance bus drivers. A sample of 47 bus drivers was evaluated. Data regarding subjects and working characteristics, alertness (psychomotor vigilance task), sleep habits (Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Actigraphy), endocrine stress response (salivary cortisol), and autonomic activity (heart-rate variability) were collected. Sleep restriction was highly prevalent. Drivers in the morning shift slept 1 hour less than those in the afternoon shift, showed lower reaction time performance, a flattening of cortisol morning-evening difference, and higher overweight prevalence. The differences found between morning and afternoon shifts point out to the need of the implementation of educational strategies to compensate the sleep loss associated with an early work schedule.

Morning Hypertension Assessed by Home Monitoring Is a Strong Predictor of Concentric Left Ventricular Hypertrophy in Patients With Untreated Hypertension

This study was performed to test whether morning hypertension defined by the morning-evening difference in home blood pressure (BP) (MEdif) and the average of morning and evening BP (MEave) is a determinant of concentric left ventricular hypertrophy (LVH). The authors enrolled patients with untreated hypertension and performed echocardiography and home BP monitoring for 14 consecutive days. All patients were classified into 4 groups by the MEave and MEdif and morning hypertension was defined by MEave ≥135 mm Hg and MEdif ≥15 mm Hg. Left ventricular (LV) geometry was classified as normal, concentric remodeling, eccentric LVH, or concentric LVH. The morning hypertensive patients had a higher LV mass index and relative wall thickness than the other groups. According to multivariable logistic regression analysis, morning hypertensive patients had a significantly increased risk of the concentric LVH (odds ratio, 6.5; 95% confidence interval, 2.5-17.2; P<.001) compared with home normotensive patients with MEdif <15 mm Hg, after adjusting for confounders. Moreover, even among the home normotensives (white-coat hypertensives), patients with MEdif ≥15 mm Hg had a higher percentage of concentric remodeling than those with MEdif <15 mm Hg (32.5% vs 14.7%, P=.017). Morning hypertension defined by the MEdif and MEave is a strong determinant of concentric LVH, suggesting that this definition could be used to determine the cardiovascular risk of morning hypertension.