Higher Number of Night Shifts Associates with Good Perception of Work Capacity and Optimal Lung Function but Correlates with Increased Oxidative Damage and Telomere Attrition

Abstract

Sleep deprivation and the consequent circadian clock disruption has become an emergent health question being associated with premature aging and earlier chronic diseases onset. Night-shift work leads to circadian clock misalignment, which is linked to several age-related diseases. However, mechanisms of this association are not well understood. Aim of this study is to explore in night-shift workers early indicators of oxidative stress response and biological aging [oxidized/methylated DNA bases and leukocytes telomere length (LTL)] and late indicators of functional aging [lung function measurements (FEV1 and FVC)] in relation to personal evaluation of work capacity, measured by work ability index (WAI). One hundred fifty-five hospital workers were studied within the framework of a cross-sectional study. We collected physiological, pathological, and occupational history including pack-years, alcohol consumption, physical activity, and night shifts, together with blood and urine samples. Relationships were appraised by univariate and multivariate ordered-logistic regression models. We found that workers with good and excellent WAI present higher FEV1 (p< 0.01) and number of night-work shifts (p<0.05), but they reveal higher urinary levels of 8-oxoGua (p<0.01) and shorter LTL (p<0.05). We confirmed that higher work ability was prevalent among chronological younger workers (p<0.05), who have also a significant reduced number of diseases, particularly chronic (p<0.01) and musculoskeletal diseases (p<0.01). The new findings which stem from our work are that subjects with the highest work ability perception may have more demanding and burdensome tasks; they in fact present the highest number of night-shift work and produce unbalanced oxidative stress response that might induce premature aging.

Telomere Length as a Biomarker of Biological Aging in Shift Workers

“…In other research, Pavanello and colleagues [59] discovered that SW promotes overbalanced oxidative stress reaction that might induce premature aging; the results show that lung function was negatively associated with higher levels of urinary 8-oxoGua (p = 0.005) and shorter telomere length (p = 0.049).…”

“…Results seem to be a "curve" of erosion; at the beginning of the work, the telomeres are shortening the first "peak", the second after many years of work (in mature age). This could be due to the influence of circadian rhythms on telomerase activity [55]; inflammation activity has been proven by Pavanello et al in two investigations [56,59]. Another evidence was done by Samulin Erdem and colleagues [57] that observed the telomere shortening correlated with the duration and intensity of SW and may be a contributing factor for breast cancer risk among the female workforce.…”

“…To date, the information base on telomere length as a biomarker in occupational setting seems to be growing. Telomere shortening is correlated with SW and long duration of work [54][55][56][57][58][59][60].…”

“…Seven were ruled out after subsequent review of title and abstract, and six studies were disqualified after review of the manuscript. Finally, seven studies satisfied the inclusion criteria and were included in the systematic review [54][55][56][57][58][59][60]. A flow-chart depicting the choice of studies is revealed in Figure 1.…”

Melatonin Relations with Energy Metabolism as Possibly Involved in Fatal Mountain Road Traffic Accidents

“…Lack of leptin decreases fatty acid metabolism in nonadipose tissues, including the myocard [224]. Energy homeostasis, thus disrupted, leads to oxidative stress and telomere attrition [225], and derives into pathologies like metabolic syndrome [219], obesity [219,223,226], and type 2 diabetes mellitus [227,228]. Both long-(e.g., adiposity) and short-term (e.g., glucose/lipid tolerance) metabolic homeostasis are altered by circadian clock disruption [15].…”