Shift work and the onset of type 2 diabetes: results from a large-scale cohort among Japanese workers

Lifestyle behaviour patterns in the prevention of type 2 diabetes mellitus: the Fukushima Health Database 2015-2020

OBJECTIVES

Lifestyle behaviours associated with the incidence of type 2 diabetes mellitus (T2DM) need further clarification using health insurance data.

STUDY DESIGN

This is a cohort study.

METHODS

In 2015, 193,246 participants aged 40-74 years attended the specific health checkups and were observed up to 2020 in Fukushima, Japan. Using the principal component analysis, we identified two patterns from ten lifestyle behaviour questions, namely, the "diet-smoking" pattern (including smoking, alcohol drinking, skipping breakfast, eating fast, late dinner, and snacking) and the "physical activity-sleep" pattern (including physical exercise, walking equivalent activity, walking fast, and sufficient sleep). Then, individual pattern scores were calculated; the higher the scores, the healthier the behaviours.

RESULTS

The accumulative incidence rate of T2DM was 630.5 in men and 391.9 in women per 100,000 person-years in an average of 4 years of follow-up. Adjusted for the demographic and cardiometabolic factors at the baseline, the hazard ratio (95% confidence interval) of the highest versus lowest quartile scores of the "diet-smoking" pattern for T2DM risk was 0.82 (0.72, 0.92; P for trend = 0.002) in men and 0.87 (0.76, 1·00; P for trend = 0.034) in women; that of the "physical activity-sleep" pattern was 0.92 (0.82, 1·04; P for trend = 0.0996) in men and 0.92 (0.80, 1·06; P for trend = 0.372) in women. The "physical activity-sleep" pattern showed a significant inverse association in non-overweight men.

CONCLUSIONS

Lifestyle behaviour associated with a healthy diet and lack of smoking may significantly lower the risk of T2DM in middle-aged Japanese adults.

A Comprehensive Evaluation of Occupational Epidemiology in Western Iran: A Cohort Study in Ravansar Noncommunicable Diseases

OBJECTIVE

The present study aims to evaluate the prevalence of noncommunicable diseases (NCDs), biochemical and anthropometric indicators, and lifestyle among 10 occupational groups.

METHOD

The sample included 4818 men aged 35 to 65 years. The occupational group is based on the International Standard Classification of Occupations.

RESULT

The highest prevalence of cardiovascular diseases and type 2 diabetes mellitus was observed in managerial occupational groups (18.62%) and technicians and associate professionals ( 14 %), respectively. Musculoskeletal disorders were more in skilled agricultural, forestry, and fishery workers, as well as craft-related trades workers, and elementary occupations. The highest body mass index was related to the managers.

CONCLUSIONS

Noncommunicable diseases were higher in managers, while musculoskeletal disorders belonged to farmers and workers. Finally, lifestyle modification can help reduce NCDs and improve biochemical markers by increasing physical activity.

Shift patterns, physical exercise, and Type 2 diabetes mellitus (T2DM): a prospective cohort study in China

To examine the relationships between different shift patterns and Type 2 diabetes mellitus (T2DM) risk, and determine whether physical exercise reduced the incidence of T2DM in shift workers in the oil industry. Baseline data were collected from participants in May 2013 who were then followed for 4 years in a prospective cohort study. The cohort initially consisted of 3,002 workers and ultimately included 2,827 people. Baseline and follow-up questionnaires were sent to participants every 2 years (in May 2015 and May 2017) to update medical and lifestyle information during the follow-up period. The risk of T2DM among two shift workers [relative risk (RR) = 3.442, 95% CI: 1.904-6.799)], three shift workers (RR = 2.534, 95% CI: 1.484-4.571), and four shift workers (RR = 4.230, 95% CI: 2.680-7.518) was higher than that among day workers. An increasing trend was observed with respect to T2DM risk, with the lowest risk in three shift workers, moderate risk in two shift workers, and highest risk in four shift workers. In the interactive analysis between shift work and physical exercise, taking part in mild physical exercise increased the risk of T2DM for workers. Four shift workers who took part in mild physical exercise had an increased risk of T2DM. The relative excess risk due to interaction (RERI) was 33.769 (0.398-67.140). The attributable proportion due to interaction [API (%)] was 0.704 (0.529-0.880). The synergy index (SI) was 3.563 (1.900-6.683). Shift work is significantly correlated with increased incidence of T2DM. Risk of T2DM is lowest risk in three shift workers, moderate in two shift workers, and highest in four shift workers. Shift workers who participated in moderate and severe physical exercise had reduced risk of developing T2DM.

Association between occupation type and development of type 2 diabetes: A population-based Panasonic cohort study 3

Background

Due to a lack of investigation on the association between the type of occupation and the development of type 2 diabetes among Japanese individuals, we aimed to assess this association in 98,935 Japanese individuals.

Methods

This long-term retrospective cohort study included participants selected from medical health checkup programs conducted at the Panasonic Corporation, Osaka, Japan, from 2008 to 2018. Cox regression analyses were used to evaluate the association between occupation type and the incidence of type 2 diabetes.

Results

From 2008 to 2018, 5,008 participants developed type 2 diabetes. The proportion of never smokers, those with slow eating speeds, and those working with a flextime system was higher in men with technical jobs than in salespersons, manufacturers, and office workers (p < 0.0001). Cox regression analyses revealed that occupation type was associated with an increased probability of type 2 diabetes development in men but not in women. Multivariate analyses showed that the hazard ratios were 1.15 [95% confidence interval (CI), 1.05-1.26], 1.20 (95% CI, 1.10-1.30), and 1.11 (95% CI, 1.02-1.21) in men working as salespersons, manufacturers, and office workers, respectively (reference group: men with technical jobs). On the other hand, the occupation type was not associated with the development of type 2 diabetes in women.

Conclusions

This study demonstrated that occupation type might be an independent factor in the development of type 2 diabetes in Japanese men.

The Circadian Clock and Obesity

The modern way of life has dramatically affected our biological rhythms. Circadian rhythms, which are generated by an endogenous circadian clock, are observed in a large number of physiological functions including metabolism. Proper peripheral clock synchronization by different signals including appropriate feeding/fasting cycles is essential to coordinate and temporally gate metabolic processes. In this chapter, we emphasize the importance of nutrient sensing by peripheral clocks and highlight the major role of peripheral and central clock communication to locally regulate metabolic processes and ensure optimal energy storage and expenditure. As a consequence, changes in eating behavior and/or bedtime, as occurs upon shift work and jet lag, have direct consequences on metabolism and participate in the increasing prevalence of obesity and associated metabolic diseases such as type 2 diabetes and non-alcoholic fatty liver disease. In this setting, time-restricted feeding has been suggested as an efficient approach to ameliorate metabolic parameters and control body weight.