Shiftwork and metabolic dysfunction

Many of the health problems that are more prevalent among shiftworkers are thought to be linked to their heightened susceptibility to metabolic syndrome, i.e., the association of even moderate degrees of visceral obesity, dyslipidemia, abnormal blood pressure, and serum glucose levels in the same individual. Although previous studies have identified associations between shiftwork and metabolic syndrome, there is relatively little evidence to date of how the risk of developing it varies as a function of exposure to shiftwork. The current study seeks to confirm earlier findings of an association between shiftwork exposure and metabolic dysfunction, and to examine the impact of exposure duration, while adjusting for a number of covariates in the analyses. The analyses were based on data from VISAT, a study involving the measurement of physiological, behavioral, and subjective outcomes from 1757 participants, 989 being current or former shiftworkers. The sample comprised employed and retired wage earners, male and female, who were 32, 42, 52, and 62 yrs old. The first analysis sought to confirm previous findings of an association between exposure to shiftwork and the risk of developing metabolic syndrome. It indicated that participants who were or who had previously been shiftworkers (i.e., working schedules that involved rotating shifts; not being able to go to bed before midnight; having to get up before 05:00 h; or being prevented from sleeping during the night) were more likely to exhibit symptoms of metabolic syndrome, after adjusting for age, sex, socioeconomic status, smoking, alcohol intake, perceived stress, and sleep difficulty (odds ratio [OR] 1.78; 95% confidence interval [CI] 1.03-3.08). The results suggest the association between shiftwork and metabolic syndrome cannot be fully accounted for by either higher levels of strain or increased sleep difficulty among shiftworkers, although it remains a possibility that either one or both of these factors may have played a contributing role. The second analysis addressed the issue of duration of exposure to shiftwork. Participants with >10 yrs' experience of working rotating shifts were more likely to exhibit symptoms of metabolic syndrome than participants without exposure to shiftwork, i.e., dayworkers, even after adjusting for age and sex (OR 1.96; 95% CI 1.03-3.75). Thus, the current study confirms the association between shiftwork exposure and metabolic syndrome. It also provides new information regarding the time course of the development of the illness as function of exposure duration, although this was only examined in relation to rotating shiftwork. It is concluded that those responsible for monitoring workers' health should pay particular attention to indices of metabolic dysfunction in workers who have been exposed to shiftwork for >10 yrs.     

Shift Work and Metabolic Syndrome: Respective Impacts of Job Strain,Physical Activity,and Dietary Rhythms

The impact of shift work on cardiovascular disease (CVD) risk factors and metabolic syndrome are not yet completely understood. The objectives of this study were to evaluate the impact of shift work on metabolic syndrome according to two different definitions in a population of strictly rotating shift workers (3×8 h) compared to paired counterparts working only day hours, and to study whether shift work itself is a determinant of metabolic syndrome after taking into account a large panel of confusing factors. We conducted a cross‐sectional study comparing 98 strictly rotating shift workers to 100 regular day‐workers (all subjects had a long experience of their working rhythms) within the same petrochemical plant. Clinical, behavioral, occupational, and biological data were collected, and a detailed nutritional investigation was done. Shift and day workers were comparable in terms of major CVD factors, and both had a 10 yr Framingham risk scoring of 11%. Shift workers reported an increased job strain and higher total and at‐work physical activity. Alterations in metabolic parameters were evident with a rise in triglycerides, free fatty acids, and gamma glutamyl transpeptidase and lower HDL‐cholesterol. Multiple logistic regression analysis demonstrated that shift work was associated with occurrence of metabolic syndrome, as defined by the National Cholesterol Education Program‐ATPIII criteria, OR: 2.38 (1.13–4.98), but not using the more recent score from the International Diabetes Federation, which gives a major emphasis on abdominal obesity. Total energy intake and contributions of the major nutrients did not differ between the two groups, with the notable exception of saturated lipids (+10% in shift workers). Meal distribution was clearly different: energy intake was more fractionated within the day, with a lesser contribution of breakfast and lunch but with increased intakes during intermediate light meals, particularly in the afternoon and night. Multivariate analyses were performed to test for the influence of dietary rhythms on the development of an NCEP‐ATPIII metabolic syndrome. Dietary intakes at breakfast and during intermediate light meals appear to be “protective” against metabolic syndrome, while a high load at dinner favors its occurrence. A high intake at lunch is particularly deleterious to shift workers. However, in all tested models, shift work remained significantly associated with metabolic syndrome, after taking into account potential covariates like job strain, physical activity, quantitative dietary parameters, and meal distribution. A specific follow‐up of shift workers should be recommended to occupational physicians.     

Low Rate of Invasive Fungal Infections During Induction and Consolidation Chemotherapy for Adults with De Novo Acute Myeloid Leukemia Without Anti-mold Prophylaxis: Single-Center 2002–2018 Empirical/Pre-emptive Approach

Broad-spectrum antifungal prophylaxis is currently considered the standard of care for adults with de novo AML for the prevention of invasive fungal infections (IFIs), especially invasive pulmonary aspergillosis (IPA). Because fluconazole has been used in our center as anti-yeast prophylaxis, we sought to analyze in detail the incidence of IFIs over a 17-year period, as well as their impact on outcome. A standardized protocol of patient management, including serum galactomannan screening and thoracic CT-guided diagnostic-driven antifungal therapy, was used in all patients. A total of 214 consecutive adults with de novo AML who were treated in 3 CETLAM (Grupo Cooperativo para el Estudio y Tratamiento de las Leucemias Agudas y Mielodisplasias) protocols from 2002 to 2018 were included. The 90-day incidence of any IFI (including possible cases) was 11% (95% CI 4–15%), most cases occurred during induction chemotherapy (8%, 95% CI 4–12%), and most cases were probable/proven IPA (8%, 95% CI 3–13%). Developing an IFI during induction and consolidation had no impact on 1-year survival. A case–control study with 23 cases of IPA and 69 controls identified induction/re-induction chemotherapy, chronic pulmonary disease and age?>?60 years/poor baseline performance status as potential pretreatment risk factors. The current study proves that inpatient induction and consolidation chemotherapy for de novo AML can be given in areas with “a priori” high-burden of airborne molds with fluconazole prophylaxis, while the selective use of anti-mold prophylaxis in patients at very high risk may further reduce the incidence of IFI in this specific clinical scenario.