Elevated blood pressure, decreased heart rate variability and incomplete blood pressure recovery after a 12-hour night shift work

Shift work has been associated with increased risk of cardiovascular disease. This study was designed to determine the hemodynamic effects of 12-hour (12-h) shifts, and changes in blood pressure (BP) and heart rate variability (HRV) during 36 h rest time following 12-h shifts. Fifteen male shift workers with a mean age of 32.9 yr were recruited from a semiconductor factory. Ambulatory BP (AmBP) monitoring was performed for a total of 48 h for each participant. Six workers were monitored for 48 h by Holter electrocardiogram on both the day and night shifts. Paired self-comparison was used to estimate the difference between two hourly measurements of 12-h BP, HR, and HRV using the same timetable intra-individually. We also applied mixed models to estimate the effects of 12-h shifts on the delayed recovery of BP and heart rate (HR) in six workers who completed 96-h AmBP monitoring, including a 48-h night shift-rest period and another day shift period. Results showed that 12-h night shift work gave a persistently elevated systolic and diastolic BP (SBP and DBP) and HR, and decreased HRV compared to 12-h day shift work with the corresponding resting time. In addition, there was delayed SBP and DBP recovery on the first 12-h rest time in night shift workers, which was further demonstrated on the second 12-h rest time after adjustment for possible confounders through mixed models. In conclusion, 12-h night shift work may elevate BP and HR and decrease HRV. It is also associated with delayed BP recovery.     

Effects of occupational noise exposure on 24-hour ambulatory vascular properties in male workers

BACKGROUND: Epidemiologic studies have demonstrated that occupational noise exposure is associated with hypertension, but the related mechanism in vascular structural changes is unclear. OBJECTIVE: This panel study aimed to investigate effects of occupational noise exposure on ambulatory vascular structural properties in male workers. METHODS: We recruited 20 volunteers and divided them into a high-noise-exposure group of 15 and a low-noise-exposure group of 5 based on environmental noise measurement in an automobile manufacturing company. We determined individual noise exposure and measured personal ambulatory vascular property parameters simultaneously during 24 hr. Linear mixed-effects regression models were used to estimate transient and sustained effects of noise exposure on vascular parameters by adjusting some confounders collected from self-administrated questionnaires and health checkups. RESULTS: The high-noise-exposed (85 +/- 8 dBA) workers had significantly higher systemic vascular resistance (SVR) than the low-noise-exposed workers (59 +/- 4 dBA) during work and sleep periods. Contrarily, low-noise-exposed workers had significantly higher brachial artery compliance (BAC), brachial artery distensibility (BAD), and systemic vascular compliance (SVC; marginal, p = 0.07) than high-noise-exposed workers during off-duty periods. We also found that high-noise-exposed workers had significantly lower BAC (1.38 +/- 0.55 %mL/mmHg) and BAD (1.29 +/- 0.51 %/mmHg), as well as lower SVC (0.24 +/- 0.10 mL/L/mmHg), but higher SVR (1.93 +/- 0.67 mL/L/min) compared with low-noise-exposed workers over a 24-hr period. CONCLUSIONS: Our findings suggest that in automobile workers, occupational noise exposure may have sustained, not transient, effects on vascular properties and also enhances the development of hypertension.     

抗高血压药物在慢性脑血管病患者中的血压变异性影响

目的探讨不同类的降压药物和不同钙拮抗剂对慢性脑血管病患者中血压变异性的影响。方法入选373例有慢性脑血管病的高血压患者,分别给予钙拮抗剂(CCBs)、(受体阻断剂(BBs)、血管紧张素转换酶抑制剂(ACEIs)和血管紧张素Ⅱ受体拮抗剂(ARBs)治疗后,行24h动态血压计算血压变异性,并进行统计分析。结果 BBs的日间血压变异性明显高于ARB或CCB(P<0.05),相比于其他CCB药物,西尼地平的日间血压变异性最低。结论 ARB和CCB相比于BBs更有利于脑血管疾病患者的高血压管理和治疗。而CCB中,由于较小的血压变异性,优选西尼地平。     

Office blood pressure and 24-hour ambulatory blood pressure measurements: high proportion of disagreement in resistant hypertension

ObjectiveTo evaluate the accuracy and quantify the agreement between office blood pressure (BP) and daytime ambulatory BP monitoring in the assessment of BP control of patients with a clinical diagnosis of resistant hypertension.Study Design and SettingOffice BP measurements were done in a cohort of 228 true resistant (TR) or white-coat resistant (WCR) hypertensives classified by ambulatory BP in a hypertension clinic in Rio de Janeiro in this validity study. The agreement between the daytime ambulatory BP and office BP was analyzed using the graphic methods of Altman–Bland and survival–agreement plots.ResultsThe likelihood ratio of a positive test result of office BP was 1.99 for the assessment of uncontrolled BP in TR patients and 1.05 for the WCR hypertensive patients. The Altman and Bland plot showed a significant difference between the two methods, and the presence of a fixed and a proportional bias. The survival–agreement plot showed that a tolerance limit of 20 mm Hg of difference between systolic office BP and systolic daytime ambulatory BP would generate a proportion of disagreement equal to 57.5%.ConclusionThe office BP is still an important tool to monitor BP control of patients with TR hypertension, whereas the monitoring of patients with WCR hypertension requires ambulatory BP.     

Effects of overtime work on blood pressure and body mass index in Japanese male workers

BACKGROUND: Effects of overtime work on health is a controversial issue. AIMS: To determine the effects of overtime work on blood pressure and body mass index (BMI) for male workers in Japan. METHODS: Participants were 323 male participants of three companies. Data were collected by occupational physicians at periodic physical examinations and additional examinations. The time courses for the development of definite hypertension and an increase in BMI were recorded. The Kaplan-Meier method was used to estimate the cumulative incidence rates of developing definite hypertension and increasing BMI, and the Cox proportional hazard model was used to determine the adjusted relative hazard of overtime work. RESULTS: The age-adjusted incidence rates of developing definite hypertension and increasing BMI were significantly lower among the participants whose mean overtime was > or =50 h than among those whose mean overtime was <50 h/month (log-rank P < 0.05). The Cox proportional hazard model indicated that those who worked a mean overtime of > or =50 h/month had lower risks of developing definite hypertension (hazard ratio, 0.36; 95% CI, 0.15-0.88; P < 0.05) and increasing their BMI (hazard ratio, 0.44; 95% CI, 0.31-0.63; P < 0.01) after adjusting for age. CONCLUSIONS: The results of this study indicate that workers whose mean overtime was > or =50 h have lower risks of developing definite hypertension and increasing their BMI.     

Effects of shift work on QTc interval and blood pressure in relation to heart rate variability

Objectives: There is evidence that shift work contributes to excess cardiovascular mortality. The purpose of this study was to determine the effects of shift work on heart rate-corrected QT (QTc) and blood pressure in relation to heart rate variability (CV_RR). Methods: The study population consisted of 153 male shiftworkers and 87 male day workers who were employed at a copper-smelting plant. The QTc interval, total power spectral density (t-PSD) of 100 RR intervals, PSDs with frequencies of 0.01 Hz–0.15 Hz and 0.15 Hz–0.40 Hz (PSD_LF and PSD_HF), CV_RR, low frequency (LF) component variability and high frequency (HF) component variability (CCV_LF and CCV_HF) and %LF (PSD_LF/(PSD_LF+PSD_HF) ·100) were measured (LF and HF components are thought to reflect the sympathetic and parasympathetic activities, respectively). Results: The QTc interval was significantly longer in the shiftworkers than in the day workers, although there was no significant difference in systolic or diastolic blood pressure between the two groups. Also, the CCV_LF and log(PSD_LF) were significantly depressed in the shiftworkers. In the day workers, the QTc interval was significantly related to the CV_RR, log(t-PSD), CCV_HF, log(PSD_HF),%LF, and log(LF/HF ratio) (partial correlation coefficient r=–0.305, –0.377, –0.312, –0.355, 0.297, and 0.277, respectively). In the shiftworkers only two relations of the QTc interval to non-specific CV_RR and log(t-PSD) were significant. Conclusion: The clear association between long QTc interval and reduced parasympathetic activity observed in the day workers did not exist in the shiftworkers. Rather, the shiftworkers had a selective reduction in sympathetic drive, which may have compensated for prolonged QTc interval due to shift work. On the other hand, the impact of shift work on hypertension remains unclear, although reduced sympathetic drive in the shiftworkers may explain the absence of differences in blood pressure between shiftworkers and day workers to some extent.     

The statistical analysis of treatment effects in 24-hour ambulatory blood pressure recordings

This paper presents a statistical analysis of treatment effects in 24-hour ambulatory blood pressure recordings. The statistical models account for circadian rhythms, subject effects, and the effects of treatment with drugs or relaxation therapy. In view of the heterogeneity of the subjects, we fit a separate linear model to the data of each subject, use robust statistical procedures to estimate the parameters of the linear models, and trim the data on a subject by subject basis. We use a meta-analytical method to combine the results of all subjects in the study.     

动态血压监测预测妊娠期高血压疾病的价值

目的 了解动态血压监测对妊娠期高血压疾病的预测价值.方法 对350例孕妇在21～27孕周进行24小时动态血压监测,分析妊娠结局与动态血压监测指标的关系.结果 323例孕妇中有28例发生妊娠期高血压疾病,为妊娠期高血压疾病组,其余295例患者为对照组.妊娠期高血压疾病组患者与对照组比较,24小时血压平均值(收缩压t=13.69、舒张压t=13.58、平均动脉压t=13.80),日均血压值(收缩压t=13.12、舒张压t=9.32)及夜均血压值(收缩压t=10.27、舒张压t=13.56)均有极显著性差异(P＜0.01).以24小时平均舒张压等于8.9kPa为切点预测妊娠期高血压疾病敏感性为85.7%;特异性为94.6%;以24小时平均动脉压等于11.2kPa为切点预测妊娠期高血压疾病敏感性为89.3%;特异性为93.9%.结论 在孕中期,利用动态血压监测的24小时平均舒张压和24小时平均动脉压均可较好的预测妊娠期高血压疾病.     

Effects of shift work on quality of sleep among retired workers]

To examine the relationship between shiftwork experience and quality of sleep after retirement, we carried out a self-reported questionnaire survey on 777 retired workers of a manufacturing company. Questionnaire items included past illness, current health status, dietary habit, alcohol drinking, smoking, regular exercise, sleep, working condition (job, shift work experience, shift work periods and side job), current working status, social activity, educational background, sex, age and number of years since retirement. Present health status (adjusted odds ratio 4.318, 95% CI 2.475-7.534), shift work experience (2.190, 1.211-3.953), present working status (1.913, 1.155-3.167) and dietary habit (1.653, 1.055-2.591) were significantly related to sleep disturbance after retirement by multiple logistic regression analysis. To prevent sleep disturbance after retirement, people should keep a regular lifestyle and good health status, especially ex-shift workers.     

缬沙坦/氨氯地平联合用药对原发性高血压患者24h动态血压的影响

目的 观察缬沙坦及缬沙坦联合氨氯地平治疗老龄高血压患者的疗效,并研究其24h动态血压的变化.方法 经过4周药物洗刷期,90例原发性高血压患者被随机分为缬沙坦160mg及缬沙坦160mg/氨氯地平5mg两组,治疗周期为24周.观察期间测定坐位血压(收缩压和舒张压)和心率,治疗结束后采用动态血压仪同时记录患者的24h动态血压变化,以总有效率及血压下降差值作为观察指标.结果 联合用药组坐位DBP下降值为(12.3 ±5.9)mmHg,达目的血压占64.9％,总有效率为87.8％;单药治疗组坐位DBP下降值为(7.9 ±6.2)mmHg,达目的血压占34.8％,总有效率为64.5％.两组组间比较差异均有统计学意义(P＜0.01).本研究中总共83例完成24h动态血压监测,联合用药组和单药组的舒张压/收缩压(DBP/SBP)的谷/峰比率(T/P)分别为82.8％/75.7％和85.4％/78.8％(P＜0.05).结论 缬沙坦/氨氯地平联合用药治疗原发性高血压患者的降压疗效明显优于缬沙坦单药治疗,并有较少的代谢副作用.     

Stressful work conditions and diastolic blood pressure among blue collar factory workers

The authors examined the relationships between stressful work conditions and diastolic blood pressure among blue collar men employed in similar occupational settings. The study population consisted of 288 male, hourly workers, aged 40-63 years, employed for a minimum of 10 years at one of two plants in the metropolitan Pittsburgh, Pennsylvania area in January 1980. Blood pressure was assessed by the random zero muddler method by trained nurses at screenings between March 1981 and August 1982; 47 men who received pharmacologic treatment for previously diagnosed hypertension were excluded from the analyses. Multiple regression analyses showed that ratings of six (of 15) stressful work conditions as well as overall job dissatisfaction were significant predictors of diastolic blood pressure, controlling for age, body mass index, alcohol consumption, cigarette smoking habits, family history of hypertension, and severe noise-induced hearing loss. Men with elevated diastolic blood pressure reported having little opportunity for promotion and for participating in decisions at work, an uncertain job future, unsupportive coworkers and foreman, difficulties communicating with others, and overall dissatisfaction with the job. Additional stepwise multiple regression analyses showed that overall job satisfaction was related to low diastolic pressure among men from the plant rated as having overall good work conditions. These results are noteworthy because they support the importance of stressful work conditions and psychological reactions to those conditions in understanding the epidemiology of hypertension.     

妊娠期高血压疾病患者24h尿蛋白含量与动态血压的关系

目的:研究妊娠期高血压疾病患者24 h尿蛋白含量与动态血压的关系,以指导临床。方法:对16例妊娠期高血压疾病患者和16例正常女性分别进行24 h尿蛋白测定,白天和晚上的动态血压检测,分析尿蛋白与动态血压的相关性。结果:妊娠期高血压疾病患者的尿蛋白含量明显大于正常人(P<0.01);患者白天、晚上时的收缩压、舒张压和平均动脉压都明显高于正常人(P<0.05),患者与正常人白天的收缩压和平均动脉压明显高于晚上(P<0.05)。患者和正常人的血压值和24 h尿蛋白无相关性(P>0.05)。结论:妊娠期高血压疾病患者24 h尿蛋白含量升高,但是血压昼夜节律还是存在的。     

吸烟对大学生24h动态血压的影响

目的　探讨吸烟对大学生血压的形响。　方法　随机选择日吸烟量≥ 10支男性大学生 34例为吸烟组 ,不吸烟者 31例为不吸烟组 ,行 2 4h动态血压监测。　结果　吸烟组 2 4h、日间及夜间平均血压均高于不吸烟组 ,日间血压差异有极显著意义 (P <0 .0 1) ;2 4h血压显示吸烟组血压波动范围高于不吸烟组 ,分为差异有显著性、差异无显著性以及部分时段血压不稳定三个阶段 ;吸烟组吸烟时心率显著快于对照组。　结论　吸烟可致正常血压男性大学生血压升高心率加快 ,应采取有效措施禁止学生吸烟     

Behavior of blood pressure in 3 shift work of workers with level I WHO hypertension

Blood pressure tests were carried out on 40 shift workers with a hypertension level of 1 (according to WHO). Every 5 day period these tests were carried out before, during and after work in the early, late and night shifts. No significant change of both the systolic and the diastolic blood pressure could be found, which could result from shift work, before and after each shift irrespective of the blood pressure stabilization (good, satisfactory, unsatisfactory). The group containing satisfactorily as well as unsatisfactorily stabilized workers suffering from hypertension showed a significant decrease of the systolic blood pressure from the early shift through the late till the night shifts, with the diastolic blood pressure remaining constant. There were no apparent differences in the range of average blood pressure values regarding the various forms of treatment (without medication, monotherapy and combined therapy). The systolic blood pressure is significantly lower only in the group with no medication in the early shift after finishing work and it also decreases from the early shift through the late till the night shifts, while within the other therapy groups no change of both the systolic and the diastolic blood pressure was apparent. Thus shift work does not cause any measurable increase in blood pressure within the test group (suffering from hypertension) that would impair their working capacity. There is no increase of health risk with regard to the blood pressure response during shift work particularly during night work provided the blood pressure is within the normal range.     

倒班作业对石油化工企业员工睡眠质量的影响

采用整群抽样选择2 568名某石油化工企业员工为研究对象,采用匹兹堡睡眠质量指数量表(PSQI)分析倒班对睡眠质量的影响。结果显示,倒班组在主观睡眠质量、睡眠效率、睡眠障碍和日间功能障碍等得分均比非倒班组高(P0.05)。倒班是罹患睡眠障碍危险因素(OR=2.15,95%CI:1.66～2.80);后夜班者罹患睡眠障碍风险比前夜班者高(P0.05);随着倒班频次、年限增加,罹患睡眠障碍的风险随之增加。     

Association between 24-hour ambulatory blood pressure and erythrocyte n-3 polyunsaturated fatty acids in Korean subjects with hypertension

N-3 polyunsaturated fatty acids (PUFAs) are known to have antihypertensive properties, but the association between 24-hour ambulatory blood pressure and the tissue content of n-3 PUFA remains controversial. The purpose of the present study was to investigate the hypothesis that the level of erythrocyte n-3 PUFA is inversely related with 24-hour ambulatory blood pressure after adjustment for relevant confounders. Fifty-one male and 49 female Korean patients were included in this study. Twenty-seven of the patients were defined as having hypertension. There were significant differences in age, body mass index, sex, marital status, and family history of hyperlipidemia between hypertensive and nonhypertensive subjects, and these factors were therefore considered to be confounding factors. Multivariate-adjusted regression analysis showed that erythrocyte fatty acids were not significantly associated with the risk of hypertension after adjusting for confounders. However, Pearson correlation analysis showed that 24-hour ambulatory systolic blood pressure (SBP) was significantly and negatively correlated with n-3 PUFA (r = −0.228, P = .027) and eicosapentaenoic acid (r = −0.270, P = .008), but not with docosahexaenoic acid (r = −0.156, P = .131). Multivariate-adjusted regression analysis also showed that intake of protein, vitamin B₂, vitamin E, and cholesterol increased the risk of hypertension after adjusting for confounders. In addition, Pearson correlation analysis showed that fat and cholesterol consumption was positively correlated with SBP, but carbohydrate intake was negatively correlated with SBP. In conclusion, erythrocyte n-3 PUFA did not reduce the risk of hypertension but were negatively correlated with 24-hour ambulatory SBP in the Korean population.     

老年2型糖尿病患者认知功能与血压昼夜节律变化特点

目的探讨老年2型糖尿病(T2DM)患者认知功能与24h动态血压昼夜节律变化特点。方法选择270例老年T2DM患者为糖尿病组,另选择同期健康体检者100例为对照组。对两组行24h动态血压监测,根据夜间血压下降率(ΔMBP)分为杓型(△MBP10%～20%,n=95)、非杓型(△MBP0%～<10%,n=86)、超杓型(△MBP>20%,n=47)和反杓型(△MBP<0%,n=42);用中文版简易智能状态检查表(MMSE)对所有受试者进行认知功能调查,比较各组间MMSE得分的差异。结果糖尿病组患者MMSE得分[(24.34±2.51)分]低于对照组[(28.88±3.02)分],差异有统计学意义(P<0.05)。糖尿病组中非杓型[(24.77±2.53)分]、超杓型[(23.34±2.41)分]和反杓型[(23.03±2.26)分]患者的MMSE得分均低于杓型[(26.03±2.68)分]患者,超杓型和反杓型又低于非杓型患者,差异有统计学意义(P<0.05),但超杓型和反杓型之间的差异无统计学意义。Pearson相关分析显示,糖尿病患者MMSE得分与24hSBP(r=-0.73)、24hDBP(r=-0.60)、...     

24-Hour ambulatory blood pressure monitoring in primary care

BACKGROUND: Both the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of Hypertension in Adults and the British Hypertension Society have made recommendations for the use of ambulatory blood pressure monitoring (ABPM) in select patient populations. This demonstration project explores the feasibility of a 24-hour ABPM service in assisting physicians with decisions regarding the implementation and modification of antihypertensive therapy. METHODS: After physician referral, patients met with a pharmacist for evaluation of their blood pressure. The pharmacist obtained a medication profile and instructed each patient on the proper use of the monitor. Patients completed an activity diary while wearing the monitor. After analysis of the reports, the pharmacist forwarded recommendations and the 24-hour blood pressure data to the referring physician. RESULTS: Sixty patients took part in the demonstration project. The primary reasons for referral included evaluation of suspected isolated office hypertension, drug resistance, blood pressure control in diabetic patients, and suspected drug-induced orthostatic hypotension. The referring physicians accepted 100% of the pharmacists' therapeutic recommendations. Unnecessary therapy was avoided in 12 of 40 of patients with suspected isolated office hypertension (30%), and more aggressive treatment was started in 6 of 7 of patients with type 2 diabetes (87.5%). CONCLUSIONS: This project shows that a 24-hour ABPM consultation service can provide useful information for determining which patients have isolated office hypertension and in guiding drug regimen modification for patients with diabetes, suspected resistant hypertension, or drug-induced alterations in blood pressure.