Association between shift work and obesity in a large sample of Iranian steel industry workers

Association of Anthropometric Adiposity Indices and Hand Grip Strength among Male Industrial Workers in Chennai, Tamil Nadu, India: A Cross-Sectional Study

Background

Hand Grip Strength (HGS), a basic, non-invasive measure of musculoskeletal function is found to be a risk marker for cardiovascular diseases, respiratory diseases, diabetes, metabolic syndrome, and cancer. Considering the importance and paucity of studies among industrial workers, we aim to study the association between anthropometric adiposity indices and the HGS of industrial workers.

Materials and Methods

The study is a descriptive, cross-sectional study. Anthropometric measurements and HGS of 198 male industrial workers between 21 and 60 years of age, employed at metal manufacturing industries in Chennai, Tamil Nadu, India were assessed.

Statistical Analysis

Descriptive and inferential statistics were done using "R" statistical software.

Results

The mean age of male industrial workers was 39.51 ± 12.20 years. The majority of the workers were found to be obese (64%) and the mean body fat percentage was 27.69 ± 5.13%. The mean HGS of the worker's dominant hand was found to be 35.80 ± 8.93 kg and of their non-dominant hand was 35.0 ± 8.67 kg. When compared to the normative values of HGS for Indians, results revealed significantly higher HGS of both dominant and non-dominant hands of workers between the age group of 21-30 years and 51-60 years. Multiple linear regression analysis revealed that body weight [β(s.e) =0.27 (0.05), P < 0.000], body fat [β(s.e) = -0.52 (0.14), P < 0.000) and WHR [β(s.e) = -28.81 (11.9), P = 0.017] independently predicted the HGS of dominant hand. In non-dominant hand, body weight [β(s.e) = 0.26 (0.05), P < 0.000] and body fat [β(s.e) = -0.60 (0.13), P < 0.000] independently predicted HGS.

Conclusions

Body fat, body weight, and Waist-to-Hip ratio (WHR) were found to have a significant influence on the HGS of industrial workers. Strategies aimed to reduce overall body fat and abdominal obesity may prove beneficial in improving HGS and nutritional status thereby reducing the risk of non-communicable diseases.

Consequences of Shift Work and Night Work: A Literature Review

Nonstandard work schedules such as shift work and night work tend to trigger problems for workers in different areas. To illustrate the diversity of areas affected and the relative interest of the scientific community, we conducted a literature review of the effects of shift work and night work on workers. In particular, we intended to identify the main variables addressed in the field of health, the family sphere, and the organizational context. The literature review was carried out using the Web of Science with the following terms: "shift work", "rotating shifts", and "night work". Inclusion criteria incorporated empirical studies and articles written in Portuguese or English published in 2019. We selected 129 of the 619 articles identified. Regarding the impacts of shift work and night work, there existed a high discrepancy of focus between the three defined areas: health, family life, and organizational context. Specifically, health-related variables were the most studied (83.4%), followed by organizational variables (9.2%), and, lastly, family variables (7.4%). Based on these results, it is essential to extend the study of the two underrepresented impacts to other crucial areas, not only for the worker but also for organizations.

The association between daytime sleep and general obesity risk differs by sleep duration in Iranian adults

BACKGROUND

Sleep duration and daytime napping and obesity are related to adiposity; however, it is not clear whether the association between daytime napping and adiposity measures can differ by sleep duration.

AIM

To clarify the association between daytime napping and general and abdominal obesity based on sleep duration of participants.

SUBJECTS AND METHODS

This cross-sectional study was conducted on 1,683 individuals (837 men and 846 women) aged ≥ 35 years. Height, weight and waist circumference (WC) were measured according to the standard protocols. Body mass index (BMI) was calculated. Self-reported sleep duration (in a 24-hour cycle) was recorded. The odds of general and abdominal obesity were compared between nappers and non-nappers, stratified by their sleep duration (≤ 6 h, 6-8 h, ≥ 8 h).

RESULTS

The mean (SD) age of participants was 47.48 ± 9.35 years. Nappers with a short sleep duration (≤ 6 h) had greater BMI and higher risk for overweight/obesity compared with counterpart non-nappers after adjustment for potential confounders (OR = 1.61, 95% CI = 1.07-2.41). In subjects with moderate sleep duration (6-8 h), nappers had a tendency towards higher BMI in comparison with non-nappers (28.04 ± 0.25 vs. 26.93 ± 0.51 kg/m²; p = 0.05), however, no significant difference was observed for the risk of obesity. Daytime napping was not related to the risk of obesity in long sleepers. No significant association was observed for abdominal obesity measures.

CONCLUSIONS

Daytime napping is associated with increased risk of overweight/obesity in short sleepers. However, in subjects with longer sleep duration, it is not related to the risk of overweight/obesity.

Association of industrial work schedules with development of metabolic syndrome, insulin resistance, and serum adipokine concentrations

Background

Association of work schedule in industrial workers with the progression of metabolic syndrome, insulin resistance, and serum adipokine concentrations is incompletely explored.

Objective

To determine the association of work schedule with the progression of metabolic syndrome, insulin resistance, and adipokine concentrations in industrial workers.

Methods

In a cross-sectional study design of industrial workers we compared metabolic syndrome, insulin resistance, and adipokines concentration between workers in the day shift (n = 52), rotational shift (n = 21), and night shift (n = 15). The international Diabetes Federation criteria were used to diagnose metabolic syndrome. We used a homeostatic model assessment of insulin resistance (HOMA-IR). Serum insulin, leptin, and adiponectin concentrations were measured using enzyme-linked immunosorbent assays. Serum glucose, triglyceride, and high-density lipoprotein cholesterol (HDL-C) concentrations were monitored using Prietest clinical chemistry reagents.

Results

The proportional difference in metabolic syndrome (0.31, 95% confidence interval [CI] 0.036-0.587, P = 0.026), median difference of leptin (0.61, 95% CI 0.186-1.034, P = 0.005), and leptin-to-adiponectin ratio (LAR; 0.45, 95% CI 0.235-0.665, P < 0.001) was significantly higher, and serum adiponectin was lower (-2.00, 95% CI -4.197 to 0.197, P = 0.07) in the night-shift workers compared with that of day-shift workers. Among rotational-shift workers, the proportional difference between metabolic syndrome (0.14, 95% CI -0.098 to 0.378, P = 0.25), median difference of leptin (0.25, 95% CI -0.124 to 0.624, P = 0.19), and LAR (0.09, 95% CI -0.099 to 0.279, P = 0.35) was higher, and serum adiponectin concentration was lower (-0.73, 95% CI -2.660 to 1.208, P = 0.46) compared with that of day-shift workers; however, the altered differences were not significant. We observed a higher proportion of difference in HOMA-IR in shift workers (night and rotation) than in day-shift workers.

Conclusion

Night-shift workers are vulnerable to a higher risk of metabolic syndrome, HOMA-IR, and adipokine changes.