The association between rotating night shift work and hypertension: A cross-sectional study among male workers

Association Between Night Shift and Hypertension: A Cross-Sectional Study in Chinese Adults

OBJECTIVE

The purpose of this study was to explore the effect of night-shift work on the risk of hypertension for improving workers' health.

METHODS

A total of 10,038 Chinese participants were constituted in the cross-sectional study. Logistic regression and restricted cubic spline were used to estimate the effect of night shift on hypertension.

RESULTS

There were higher odds of having hypertension in any night-shift workers (odds ratio [OR], 1.16 [95% confidence interval, 1.03-1.30]) when compared with day workers. Having 5 to 10 night shifts per month were significantly more likely to be hypertensive (OR, 1.19 [95% confidence interval, 1.03-1.38]). The OR for hypertension increased as the number of night shifts increased as the result of the restricted cubic spline.

CONCLUSIONS

Our results support the hypothesis that night shift is associated with an elevated risk of hypertension.

Harm of circadian misalignment to the hearts of the adolescent wistar rats

PURPOSE

The purpose of this study was to observe the harm of circadian misalignment (CM), caused by an inverted photoperiod (IP), on the hearts of the adolescent Wistar rats, and to explore the mechanisms leading to harm.

METHODS

An IP was used to create a CM model. A total of 174 Wistar rats were randomly divided into circadian alignment (CA) and CM groups (87 rats per group). The different activity rhythms of the two groups of rats were adjusted through different light/dark cycles for 90 days. We recorded the rhythmic activity trajectory and sleep time of the rats. After 90 days of modeling, we performed various analyses (i.e., blood pressure, weight, cardiac ultrasound tests, serological tests, cardiac tissue immunofluorescence, immunohistochemistry, transmission electron microscopy on myocardial mitochondria, western blotting, and quantitative polymerase chain reactions).

RESULTS

(1) The IP protocol caused CM in rats. (2) CM rats showed significantly higher blood pressure during the day (resting phase). They also showed significantly higher serum levels of angiotensin II and epinephrine during the day compared to the CA rats. (3) CM caused up-regulation of gene expression of adrenergic receptors α1 (α1-AR) and β1 (β1-AR) and down-regulation of the glucocorticoid receptor (Gr) gene expression in rat hearts. It also caused downregulation of Bmal1 expression. In addition, the changes in Bmal1 and Per2 correlated with the changes in β1-AR and α1-AR. (4) CM had adverse effects on multiple molecular proteins of the heart. (5) CM increased the collagen fibers in the rat heart and increased the destruction of mitochondria. (6) Eventually, CM caused a decrease in the pumping function of the heart and decreased the coronary blood flow rate.

CONCLUSIONS

(1) CM significantly affected the cardiac structure and function in the adolescent rats through a variety of mechanisms. (2) CM can regulate the expression of myocardial clock genes, and it is likely to have an impact on the heart through this pathway.

A systematic review and meta-analysis of the association between shift work and metabolic syndrome: The roles of sleep, gender, and type of shift work

This study was conducted to investigate the association between shift work and metabolic syndrome (MetS) and quantify the roles of sleep, gender, and type of shift work. We searched online databases, including PubMed, Scopus, and Web of Science on November 17, 2019. Of the 821 articles identified, 38 observational studies (27 cross-sectional, 10 cohorts, and one nested case-control), conducted on 128,416 participants, met our eligibility criteria. The pooled Odds ratio (OR) and 95% Confidence interval (CI) of MetS in shift-versus day-workers were estimated as 1.14 (1.07, 1.21) and 1.11 (1.06, 1.17) for the unadjusted and adjusted models. This association remained significant only for the studies with a cross-sectional design. There was a significantly higher odds of MetS in the studies conducted only on females (1.13 [1.06, 1.20]) or males (1.12 [1.02, 1.21]). The pooled adjusted OR (95% CI) for the studies without and with sleep adjustment was calculated as 1.14 (1.08, 1.21) and 1.29 (1.06, 1.52). We observed that rotating shift workers had stronger odds of MetS than the other shift workers. In conclusion, our findings revealed the significant odds of an association between shift work and MetS and different effects for sleep, gender, and type of shift work.

Treating sleep disorders to improve blood pressure control and cardiovascular prevention: a dream come true?-a narrative review

Hypertension is one of the primary risk factors for heart disease and stroke, the leading causes of death worldwide. Current evidence supports the treatment of high blood pressure (BP) values in order to obtain a substantial reduction of cardiovascular burden. Sleep plays an important role in maintaining nocturnal BP control and nocturnal hypertension which, in turn, can be affected by the presence of sleep disorders. Whilst respiratory disturbances have been extensively studied and their causal role in the development of nocturnal hypertension has been demonstrated in both cross sectional and prospective studies, less is known about the impact of other sleep disorders such as insomnia. In this review, we aim to describe the role of sleep disorders in the development of nocturnal and diurnal hypertension. Furthermore, we aim to discuss the potential impact of the treatment of such sleep disorders on BP values as an adjunct treatment for patients with hypertension.

The effects of exposure to different noise frequency patterns on blood pressure components and hypertension

OBJECTIVE

Previous studies have indicated a significant association between exposure to noise and blood pressure. However, the effects of exposure to different noise frequency patterns on blood pressure components and hypertension (HTN) have been unknown.

METHODS

We recruited a total of 518 eligible workers in this study. According to types of work (office and production-line), overall A-weighted equivalent sound pressure levels (8-h LAeq), and total 8-h LAeq at low (31.5, 63, and 125 Hz), medium (250, 500, and 1000 Hz), and high ( 2, 4, and 8 kHz) frequencies, we classified subjects into four categories, involving office workers (n = 214) exposed to overall 8-h LAeq < 65 dB and production-line workers, including medium noise exposure group (n = 81) exposed to overall 8-h LAeq < 78 dB that difference between the medium and high frequencies was less than 1 dB, high_A noise exposure group (n = 86) encountered to overall 8-h LAeq > 90 dB that the difference between the medium and high frequencies was less than 1 dB, and high B noise exposure group (n = 137) exposed to overall 8-h LAeq > 90 dB that the levels of noise at the high frequency were 10 dBA more than the medium frequency. The high A and high B groups were a little difference in total 8-h LAeq at the low and medium frequencies (≤ 3 dBA) and a wide difference at the high frequency (more than 10 dBA). The logistic regression models were applied to determine the odds of HTN among study groups.

RESULTS

The significant difference was observed among study groups in the average of systolic blood pressure (SBP), pulse pressure (PP), mean arterial pressure (MAP), and the frequency of HTN (P < 0.05). Also, we found a significant difference in diastolic blood pressure DBP but at the levels of P < 0.10. The odds ratios (ORs) and 95% confidence intervals (CIs) of HTN according to the full adjusted model in the medium, high A, and high B groups compared with the office workers were estimated at 1.66(0.45, 6.10), 2.34(0.80, 6.89), and 4.02(1.63, 9.96), respectively.

CONCLUSION

This study indicates noise frequency patterns may play a significant role in the association between noise and blood pressure. More studies are warranted to confirm our findings.