Metabolic syndrome and its components among Korean submariners: a retrospective cross-sectional study

Sex differences in risk factors for metabolic syndrome in middle-aged and senior hospital employees: a population-based cohort study

BACKGROUND

Several cross-sectional studies have reported risk factors for metabolic syndrome (MetS). However, these studies did not focus on sex differences in middle-aged and senior populations or employ a longitudinal design. These study design differences are important, as there are sex differences in lifestyle habits associated with MetS, and middle-aged and senior individuals have increased MetS susceptibility. Therefore, the purpose of this study was to examine whether sex differences influenced MetS risk over a ten-year follow-up period among middle-aged and senior hospital employees.

METHODS

This population-based and prospective cohort study enrolled 565 participants who did not have MetS in 2012 for a ten-year repeated-measurement analysis. Data were retrieved from the hospital's Health Management Information System. Analyses included Student's t tests, χ² tests and Cox regression. P < 0.05 indicated statistical significance.

RESULTS

Male middle-aged and senior hospital employees had an elevated MetS risk (hazard ratio (HR) = 1.936, p < 0.001). Men with more than four family history risk factors had an increased risk of MetS (HR = 1.969, p = 0.010). Women who worked shift duty (HR = 1.326, p = 0.020), had more than two chronic diseases (HR = 1.513, p = 0.012), had three family history risk factors (HR = 1.623, p = 0.010), or chewed betel nuts (HR = 9.710, p = 0.002) had an increased risk of MetS.

CONCLUSIONS

The longitudinal design of our study improves the understanding of sex differences in MetS risk factors in middle-aged and senior adults. A significantly elevated risk of MetS over the ten-year follow-up period was associated with male sex, shift work, the number of chronic diseases, the number of family history risk factors, and betel nut chewing. Women who chewed betel nuts had an especially increased risk of MetS. Our study indicates that population-specific studies are important for the identification of subgroups susceptible to MetS and for the implementation of hospital-based strategies.

Gender Differences in the Prevalence of Metabolic Syndrome Among Taiwanese Air Force Personnel: A Population-Based Study

BACKGROUND

Authors of several studies have reported differences in the prevalence of metabolic syndrome (MetS) between men and women. However, information is lacking on gender difference among military personnel.

OBJECTIVE

The aim of this study was to examine the prevalence of MetS and its component abnormalities among Taiwanese Air Force personnel by gender and age groups.

METHODS

A population-based study was conducted including 14 872 Taiwanese Air Force personnel. Data were retrieved from the military's Health Management Information System. Analyses were performed using Student t test, χ test, and linear-by-linear χ test. Statistical significance was defined as P < .05.

RESULTS

The MetS prevalence was 14.0% (15.1% in men and 5.3% in women). Metabolic syndrome was associated with age for both men and women (both Ptrend < .001), with a greater prevalence of MetS in men aged 18 to 44 years than in women, but not in the age group of 45 years or older. In men, MetS was most prevalent in those with increased waist circumference (78.2%), followed by those with elevated blood pressure (75.6%). By contrast, in women, it was most prevalent in those with increased waist circumference (86.5%), followed by those with reduced high-density lipoprotein cholesterol (84.3%).

CONCLUSIONS

Our findings suggest that military nurses and other health providers should consider the gender- and age-based MetS prevalence trend among Taiwanese Air Force personnel when designing interventions to identify vulnerable subgroups at a high risk of MetS. Health management programs should be adapted to minimize metabolic risks.

Metabolic Syndrome and Its Related Factors among Hospital Employees: A Population-Based Cohort Study

Several studies have reported on metabolic syndrome (MetS) based on cross-sectional designs, which cannot show a long-term result. Information is lacking on MetS and related factors based on a longitudinal cohort. This study aimed to examine the relationship between MetS and related factors for a total of six years among hospital employees. A population-based study was conducted, including 746 staff. A total of 680 staff without MetS in 2012 were enrolled in the analysis for repeated measurement of six years of the longitudinal cohort. Data were retrieved from the hospital’s Health Management Information System. Analyses were performed using Student’s t-test, chi-square test, logistic regression, and generalised estimating equations. Statistical significance was defined as p < 0.05. Hospital employees aged between 31 and 40 (odds ratio (OR) = 4.596, p = 0.009), aged between 41 and 50 (OR = 7.866, p = 0.001), aged greater than 50 (OR = 10.312, p < 0.001), with a body mass index (BMI) of 25.0~29.9 kg/m² (OR = 3.934, p < 0.001), a BMI ≥ 30 kg/m² (OR = 13.197, p < 0.001), higher level of white blood counts (β = 0.177, p = 0.001), alanine aminotransferase (β = 0.013, p = 0.002), and uric acid (β = 0.223, p = 0.005) were at risk of being diagnosed with MetS. The identification of at-risk hospital employees and disease management programs addressing MetS-related factors are of great importance in hospital-based interventions.

Cross-species physiological interactions of endocrine disrupting chemicals with the circadian clock

Endocrine disrupting chemicals (EDCs) are endocrine-active chemical pollutants that disrupt reproductive, neuroendocrine, cardiovascular and metabolic health across species. The circadian clock is a transcriptional oscillator responsible for entraining 24-hour rhythms of physiology, behavior and metabolism. Extensive bidirectional cross talk exists between circadian and endocrine systems and circadian rhythmicity is present at all levels of endocrine control, from synthesis and release of hormones, to sensitivity of target tissues to hormone action. In mammals, a range of hormones directly alter clock gene expression and circadian physiology via nuclear receptor (NR) binding and subsequent genomic action, modulating physiological processes such as nutrient and energy metabolism, stress response, reproductive physiology and circadian behavioral rhythms. The potential for EDCs to perturb circadian clocks or circadian-driven physiology is not well characterized. For this reason, we explore evidence for parallel endocrine and circadian disruption following EDC exposure across species. In the reviewed studies, EDCs dysregulated core clock and circadian rhythm network gene expression in brain and peripheral organs, and altered circadian reproductive, behavioral and metabolic rhythms. Circadian impacts occurred in parallel to endocrine and metabolic alterations such as impaired fertility and dysregulated metabolic and energetic homeostasis. Further research is warranted to understand the nature of interaction between circadian and endocrine systems in mediating physiological effects of EDC exposure at environmental levels.

Circadian misalignment on submarines and other non-24-h environments - from research to application

Circadian clocks have important physiological and behavioral functions in humans and other organisms, which enable organisms to anticipate and respond to periodic environmental changes. Disturbances in circadian rhythms impair sleep, metabolism, and behavior. People with jet lag, night workers and shift workers are vulnerable to circadian misalignment. In addition, non-24-h cycles influence circadian rhythms and cause misalignment and disorders in different species, since these periods are beyond the entrainment ranges. In certain special conditions, e.g., on submarines and commercial ships, non-24-h watch schedules are often employed, which have also been demonstrated to be deleterious to circadian rhythms. Personnel working under such conditions suffer from circadian misalignment with their on-watch hours, leading to increased health risks and decreased cognitive performance. In this review, we summarize the research progress and knowledge concerning circadian rhythms on submarines and other environments in which non-24-h watch schedules are employed.

Energy Expenditure and Changes in Body Composition during Submarine Deployment-An Observational Study "DasBoost 2-2017"

The present study was designed to objectively assess the effects of 3-months submarine deployment on behavioural and metabolic determinants of metabolic health. In 13 healthy, non-obese volunteers, we using stable isotope dilution, and plasma and urinary biochemistry to characterize metabolic health before and after a 3-month submarine deployment. Volunteers worked in 6-h shifts. After deployment, we observed reduced fat-free mass (mean ± SD, -4.1 ± 3.3 kg, p = 0.003) and increased adiposity (21.9 ± 3.2% fat mass to 24.4 ± 4.7%, p = 0.01). Changes in fat-free mass were positively associated with physical activity (+0.8 kg per 0.1 increase in PAL, p = 0.03). The average physical activity level was 1.64 ± 0.26 and total energy expenditure during deployment was 2937 ± 498 kcal/d, while energy intake was 3158 ± 786 kcal/d. Fasting glucose (p = 0.03), and triglycerides (p = 0.01) declined, whereas fasting free fatty acids increased (p = 0.04). Plasma vitamin D and B12 concentrations decreased (-14%, p = 0.04, and -44%, p = 0.001, respectively), and plasma calcium, and magnesium increased (+51%, p = 0.01, and +5%, p = 0.02). Haemoglobin was unchanged, but haematocrit decreased (-2.2 ± 2.1%, p = 0.005). In conclusion, submarine deployment impairs fat-free mass maintenance and promotes adiposity. High physical activity may prevent the decline in fat-free mass. Our study confirms the need to counteract Vitamin D and B12 deficiencies, and suggests impairments in erythrocyte metabolism.

Energy Expenditure and Changes in Body Composition during Submarine Deployment-An Observational Study "DasBoost 2-2017"

The present study was designed to objectively assess the effects of 3-months submarine deployment on behavioural and metabolic determinants of metabolic health. In 13 healthy, non-obese volunteers, we using stable isotope dilution, and plasma and urinary biochemistry to characterize metabolic health before and after a 3-month submarine deployment. Volunteers worked in 6-h shifts. After deployment, we observed reduced fat-free mass (mean ± SD, −4.1 ± 3.3 kg, p = 0.003) and increased adiposity (21.9 ± 3.2% fat mass to 24.4 ± 4.7%, p = 0.01). Changes in fat-free mass were positively associated with physical activity (+0.8 kg per 0.1 increase in PAL, p = 0.03). The average physical activity level was 1.64 ± 0.26 and total energy expenditure during deployment was 2937 ± 498 kcal/d, while energy intake was 3158 ± 786 kcal/d. Fasting glucose (p = 0.03), and triglycerides (p = 0.01) declined, whereas fasting free fatty acids increased (p = 0.04). Plasma vitamin D and B12 concentrations decreased (−14%, p = 0.04, and −44%, p = 0.001, respectively), and plasma calcium, and magnesium increased (+51%, p = 0.01, and +5%, p = 0.02). Haemoglobin was unchanged, but haematocrit decreased (−2.2 ± 2.1%, p = 0.005). In conclusion, submarine deployment impairs fat-free mass maintenance and promotes adiposity. High physical activity may prevent the decline in fat-free mass. Our study confirms the need to counteract Vitamin D and B12 deficiencies, and suggests impairments in erythrocyte metabolism.

Analysis of risk factors of metabolic syndrome using a structural equation model: a cohort study

PURPOSE

We aimed to use a structural equation model (SEM) to determine the interrelations between various risk factors, including latent variables, involved in the development of metabolic syndrome(MetS).

METHODS

This study used data derived from the MJ Longitudinal Health Check-up Population Database for participants aged 20 to 70 years, who were asymptomatic for MetS at enrollment and were followed up for 5 years. A SEM was applied to investigate the attributions of MetS and the interrelations between different risk factors.

RESULTS

Socioeconomic status (SES), living habits, components of metabolic syndrome (COMetS), and blood pressure had a diverse impact on the onset of MetS, directly and (or) indirectly. When investigating the latent risk factors and the interrelations between different risk factors. The standardized total effect (the sum of the direct and indirect effects, β_t) of SES, living habits, blood pressure and COMetS on the onset of MetS was 0.084, -0.179, 0.154, and 0.353, respectively. SES, as a distal risk factor, directly influenced living habits, blood pressure, and COMetS with standardized regression coefficients (β_r) of -0.079 (P < 0.001), 0.200 (P < 0.001), and -0.163 (P < 0.001) respectively. Unfavorable living habits exerted an inverse effect on blood pressure and COMetS (β_r = -0.101, P < 0.001; β_r = -0.463, P < 0.001), which was an important path way for developing MetS.

CONCLUSIONS

These results demonstrate that individuals with a higher level of SES are susceptible to high blood pressure and are at increased risk for MetS. Additionally, there is a decrease in exercise and an increase in smoking and consumption of alcohol corresponded to an increase in metabolic risk factors.