Association between sleep quality and cardiovascular health: a door-to-door survey in rural Ecuador

Objectives

Cardiovascular correlates of sleep disorders have not been well investigated in underserved populations. The aim of this door-to-door survey was to evaluate the association between sleep quality and cardiovascular health status in persons aged ≥40 years living in a village that is representative of rural Ecuador.

Methods

All stroke-free Atahualpa residents aged ≥40 years were screened with a validated Spanish version of the Pittsburgh Sleep Quality Index and the seven cardiovascular health (CVH) metrics proposed by the American Heart Association to assess the CVH status.

Results

A total of 635 persons (mean age 59 ± 13 years; 58 % women) were identified. A poor sleep quality was present in 27 % of the subjects (95 % CI 24–31 %) and a poor cardiovascular health in 69 % (95 % CI 63–71 %). In a multivariate logistic regression model, a poor sleep quality was associated with some CVH metrics in the poor range, including smoking status (p = 0.026), physical activity (p = 0.01) and blood glucose levels (p = 0.036).

Conclusions

A poor sleep quality may be linked to individual cardiovascular risk factors in this underserved Latin American population. This finding provides useful insights for the implementation of regional prevention priorities.     

Physical activity and health-related quality of life among adult women in Cali, Colombia: a cross-sectional study

Objectives

To examine the associations of leisure-time physical activity (LTPA) and walking for transportation (WT) with the physical and mental dimensions of health-related quality of life (HR-QOL) among women.

Methods

A cross-sectional study was carried out in 2009 among 1,263 women ages 18–59 years living in neighborhoods with low and middle-low socioeconomic status in the urban area of Cali. HR-QOL was assessed using the Short Form 8 (SF-8). LTPA and WT were measured using the long version of the International Physical Activity Questionnaire (IPAQ). Associations were assessed using linear regression models adjusting for potential confounders.

Results

Low (10–149 min) and medium–high (at least 150 min) levels of WT were negatively associated with the mental and physical dimensions of HR-QOL. Low (10–149 min of moderate intensity PA, or 10–74 min of vigorous intensity PA) and medium–high (at least 150 or 75 min of moderate or vigorous intensity PA, respectively) levels of LTPA were positively associated with both dimensions. Significant interactions were observed between education level and perceived safety from traffic.

Conclusions

This study found that WT and LTPA were associated with HR-QOL both in the physical and mental dimensions; however, the direction and magnitude of the association varied by domain. These results highlight the need to better understand the links between PA and HR-QOL in urban contexts from Latin America.     

Work hours and cortisol variation from non-working to working days

Purpose

This study aims at modelling the relationship between the number of work hours per week and cortisol variation across 3 days by comparing non-working day to working day in a population of day-shift workers.

Methods

Questionnaire data and saliva samples for cortisol analysis were collected on 132 day-shift workers employed in 13 workplaces in Canada. Consenting workers provided 5 saliva samples a day (awaking, 30 min after awaking, 2 p.m., 4 p.m., bedtime) repeated 3 times (Saturday, Tuesday, Thursday) over a week, to provide measures at work and non-work times and settings. Multilevel regression models were estimated from cortisol measurements at each occasion within a day at level-1, days at level-2 and workers at level-3.

Results

Controlling for gender and age, results revealed significant variations in salivary cortisol concentration between sample, day and worker levels. Cortisol increases linearly from non-working day to work days and work hours per week interacted with days, revealing a positive association between the number of work hours per week and cortisol concentrations during these days. Work hours per week did not interact with awaking, 30 min after awaking, 2 p.m., 4 p.m., and bedtime cortisol concentrations. Gender and age had neither main effects nor interaction effects. No significant cortisol variations were found between workplaces.

Conclusion

These results suggest that work hours act as a stressor that is associated with significant variations in cortisol concentrations over working days. Non-working days may contribute to stress reduction in workers who experience longer work hours.     

Determinants of the transition from a cardiometabolic normal to abnormal overweight/obese phenotype in a Spanish population

Purpose

There is limited prospective evidence at population scale of the impacts of lifestyle and surrogate measures of general and abdominal adiposity on the transition of a metabolically healthy (absence of a metabolic disorder) overweight/obese (MHOO) phenotype to a metabolically abnormal overweight/obese (MAOO) phenotype. Therefore, we determined the relationship between 10-year body mass index (BMI), waist circumferences (WC), waist to height ratio (WHtR), and lifestyle changes and the transition of the MHOO phenotype.

Methods

We conducted a prospective population-based study of 3,052 male and female Spaniards aged 25–74 years who were followed from 2000 through 2009. Diet and leisure-time physical activity were recorded on validated questionnaires. Weight, height, WC, blood lipids, glycemia, and blood pressure were measured. All variables were obtained at baseline (BL) and follow-up (FL). Participants with a BMI ≥ 25 kg/m² and free from hypercholesterolemia, hypertriglyceridemia, diabetes, hypertension, and low HDL and high LDL cholesterol levels were characterized as the MHOO phenotype. A composite healthy lifestyle index (HLI) was constructed by including temporary changes in 3 lifestyle variables (diet, leisure-time physical activity, and smoking).

Results

Initially, 20.8 % of subjects had the MHOO phenotype; 49.2 % of these shifted to MAOO phenotype. In multivariate analysis, changes in BMI, WC, WHtR were positively associated (p = 0.004, p = 0.018, and p = 0.016, respectively) with this transition. One unit increase in the HLI was associated with a 33 % lower risk (p = 0.025) to the MAOO phenotype transition after adjusting for age, sex, educational level, and baseline energy intake, BMI, WC, and WHtR.

Conclusions

The presence of metabolic disorders in the MHOO phenotype is predicted by an increase in anthropometric surrogate measures of general and abdominal adiposity. In contrast, a healthy lifestyle protects against a transition to the MAOO phenotype.     

Prevalence of respiratory symptoms and disorders among rice mill workers in India

Objectives

Lung function tests have become an integral part of assessment of pulmonary disease. Diseases of the respiratory system induced by occupational dusts are influenced by the duration of exposure. The aim of the study is to investigate the impairment of lung function and prevalence of respiratory symptoms among the rice mill workers.

Methods

A total of 120 rice mill workers from three districts of Karnataka were included in this study. Fifty urban dwellers from the same socio-economic level were selected as controls. The study included clinical examination, assessment of respiratory symptoms, pulmonary function test, measurement of peak expiratory flow rate, absolute eosinophil count, ESR estimation, total IgE estimation and radiographic test.

Results

The present study has shown that the rice mill workers complained of several types of respiratory disorders like phlegm (40.8 %), dyspnea (44.2 %), chest tightness (26.7 %), cough (21.7 %), and nose irritation (27.5 %). Rice mill workers exposed to dust presented significantly (p < 0.05) lower levels of FVC (3.44 ± 0.11), FEV₁ (2.73 ± 0.15) and PEFR (304.95 ± 28.79) than the controls. The rice mill workers are having significantly higher absolute eosinophil counts, total IgE and ESR than control groups. The hematological findings suggest that the harmful effects may be linked to both non-specific irritation and allergic responses to rice husk dust among rice mill workers.

Conclusion

Dust exposure in the working environment affects the lung function values and increased the respiratory symptoms among the rice mill workers.     

The independent effect of body mass index on health-related quality of life among racial and ethnic subgroups

Purpose

To evaluate the impact of race/ethnicity on the relationship between body mass index (BMI) and health-related quality of life (HRQOL) among blacks, Hispanics, and whites.

Methods

We used the Sinai Urban Health Institute’s Improving Community Health Survey dataset to measure physical and mental HRQOL using the Physical Component Score (PCS-12) and the Mental Component Score (MCS-12) of the Short Form-12. Multivariate linear regression models were applied to the overall sample and in models stratified by race/ethnicity to evaluate the effects of BMI on physical and mental HRQOL outcome variables while controlling for confounders.

Results

Considering physical HRQOL, increasing BMI was independently associated with worse PCS-12 (β = ?0.22, p value <0.001) in the overall sample; the magnitude was not significantly different across racial/ethnic subgroups (blacks: β = ?0.18, p value = 0.02; Hispanics: β = ?0.28, p value = 0.01; whites: β = ?0.20, p value = 0.02). Overall, Hispanic participants reported a worse PCS-12 compared to whites (β = ?3.06, p value = 0.002). Considering mental HRQOL, BMI was not significantly associated with MCS-12 in the overall sample (β = ?0.06, p value = 0.21) nor was BMI significantly associated with MCS-12 in any racial/ethnic subgroups. Overall, black participants reported better MCS-12 compared to whites (β = 2.51, p value = 0.001).

Conclusions

BMI was associated with worse physical HRQOL to a similar degree among blacks, Hispanics, and whites. This finding suggests that interventions leading to obesity reduction should be associated with substantial and equal improvements in the physical HRQOL of all race/ethnicity groups.     

Validity of self-reported BMI in older adults and an adjustment model

Study objectives

To determine reporting bias of self-reported vs. measured anthropometrics (body weight, height, body mass index, BMI), and to adjust self-reported BMI regarding the bias.

Methods

We compared self-reported with measured anthropometrics utilizing 659 control persons (age mean 68; range 37 to 80 years) from a case-control stroke study. The Bland-Altman approach examined the agreement between self-reported and measured values. A linear model was applied to correct the bias dependent on sex, age and self-reported BMI.

Results

Under-reporting of weight and over-reporting of height was found. On average, this resulted in lower self-reported BMIs by 1.0 kg/m² in men, 1.2 kg/m² in women (p?<?0.001). Bias correction of self-reported BMIs was derived from self-reported BMI (p?<?0.001), age (p?<?0.001), age-BMI interaction (p?<?0.001) and sex (p?<?0.05). Under-estimation of correct BMI resulted in the under-estimation of an overweight prevalence, with relatively low sensitivity regarding self-reported values (88 %). Our estimates should be recalibrated, if applied to other studies.

Conclusion

Self-reported anthropometric measures are systematically biased despite high correlations with measured values. A correction removes the average bias and improves accuracy.     

Symptoms of heat illness in surface mine workers

Objective

To assess the symptoms of heat illness experienced by surface mine workers.

Methods

Ninety-one surface mine workers across three mine sites in northern Australia completed a heat stress questionnaire evaluating their symptoms for heat illness. A cohort of 56 underground mine workers also participated for comparative purposes. Participants were allocated into asymptomatic, minor or moderate heat illness categories depending on the number of symptoms they reported. Participants also reported the frequency of symptom experience, as well as their hydration status (average urine colour).

Results

Heat illness symptoms were experienced by 87 and 79 % of surface and underground mine workers, respectively (p = 0.189), with 81–82 % of the symptoms reported being experienced by miners on more than one occasion. The majority (56 %) of surface workers were classified as experiencing minor heat illness symptoms, with a further 31 % classed as moderate; 13 % were asymptomatic. A similar distribution of heat illness classification was observed among underground miners (p = 0.420). Only 29 % of surface miners were considered well hydrated, with 61 % minimally dehydrated and 10 % significantly dehydrated, proportions that were similar among underground miners (p = 0.186). Heat illness category was significantly related to hydration status (p = 0.039) among surface mine workers, but only a trend was observed when data from surface and underground miners was pooled (p = 0.073). Compared to asymptomatic surface mine workers, the relative risk of experiencing minor and moderate symptoms of heat illness was 1.5 and 1.6, respectively, when minimally dehydrated.

Conclusions

These findings show that surface mine workers routinely experience symptoms of heat illness and highlight that control measures are required to prevent symptoms progressing to medical cases of heat exhaustion or heat stroke.     

Disturbed eating at high altitude: influence of food preferences, acute mountain sickness and satiation hormones

Purpose

Hypoxia has been shown to reduce energy intake and lead to weight loss, but the underlying mechanisms are unclear. The aim was therefore to assess changes in eating after rapid ascent to 4,559 m and to investigate to what extent hypoxia, acute mountain sickness (AMS), food preferences and satiation hormones influence eating behavior.

Methods

Participants (n = 23) were studied at near sea level (Zurich (ZH), 446 m) and on two days after rapid ascent to Capanna Margherita (MG) at 4,559 m (MG2 and MG4). Changes in appetite, food preferences and energy intake in an ad libitum meal were assessed. Plasma concentrations of cholecystokinin, peptide tyrosine–tyrosine, gastrin, glucagon and amylin were measured. Peripheral oxygen saturation (SpO₂) was monitored, and AMS assessed using the Lake Louis score.

Results

Energy intake from the ad libitum meal was reduced on MG2 compared to ZH (643 ± 308 vs. 952 ± 458 kcal, p = 0.001), but was similar to ZH on MG4 (890 ± 298 kcal). Energy intake on all test days was correlated with hunger/satiety scores prior to the meal and AMS scores on MG2 but not with SpO₂ on any of the 3 days. Liking for high-fat foods before a meal predicted subsequent energy intake on all days. None of the satiation hormones showed significant differences between the 3 days.

Conclusion

Reduced energy intake after rapid ascent to high altitude is associated with AMS severity. This effect was not directly associated with hypoxia or changes in gastrointestinal hormones. Other peripheral and central factors appear to reduce food intake at high altitude.     

Changes in body anthropometry and composition in obese adolescents in a lifestyle intervention program

Purpose

Impact of lifestyle modification on obesity control during adolescence, a period of significant physical growth and development, is less quantitatively evaluated. Therefore, we investigated the impact of changes in reported energy intake and physical activity on anthropometrics and body composition in adolescents.

Methods

Participants were obese adolescents aged 11–18 years. All of them have a body mass index (BMI) ≥ 95th percentile specific for age and gender according to the 2000 CDC Growth Charts. The intervention consists of supervised physical activity, structured nutrition education and dietary modification, and behavioral support in 6 months. Hundred and forty-five obese adolescents completed the study.

Results

Compared to baseline, significant reductions in body weight (?1.4 kg, p < 0.001) and BMI (?0.1 kg/m², p < 0.001) were observed at 6 months. When compared to expected growth trajectories on the 2000 CDC Growth Charts, body weight and BMI were reduced by 3.6 kg and 1.5 kg/m², respectively, in boys and 5.6 kg and 1.9 kg/m² in girls. Age was inversely associated with changes in weight (β = ?1.48 kg, p < 0.01) and BMI (β = ?0.32 kg/m², p = 0.03). There was a dose–response relationship between reduction in energy intake and weight loss. A decrease of 100 kcal/day was significantly associated with reductions in body weight 0.30 kg, BMI 0.09 kg/m², and BMI Z score 0.01 (all p < 0.01). Physical activity was not significantly associated with changes in anthropometrics or body composition.

Conclusions

Reduction in energy intake was a significant predictor of obesity reduction in these adolescents. A quantitative evaluation of adolescent weight loss programs should account for natural growth and development.     

Sleep behavior of underrepresented youth

Aim

In a disadvantageous socioeconomic context, minority children’s sleep ecology and hygiene may promote poor sleep.

Subjects and methods

A de-identified questionnaire was randomly distributed in local community centers. Subjects were a posteriori stratified into lower class (59.5 %), middle class (22.2 %) and upper class (18.4 %), and into the age categories used in the National Sleep Foundation Polls.

Results

The sample (n?=?221) comprised 85.4 % African Americans, 9.1 % Hispanics and 5.6 % Mixed Ethnicities, which were equally distributed across classes. The respondent was primarily the mother (64.4 %), and the questionnaire information reflected the sleep of 7.0?±?4.5 year olds, 49.5 % of which were girls. Co-sleeping was done by 43.5 %, and 76.8 % had a television in the room. Almost 45 % of the children went to bed on their own. Given the age range, the already insufficient amount of nighttime sleep was further reduced by poor sleep hygiene or ecology by about an hour. Sleep problems reported indicated difficulties with initiating and maintaining sleep.

Conclusion

Underrepresented youth have problematic sleep, which is characterized by difficulties initiating and maintaining sleep, or sleep-impeding circumstances. Sleep interventions in the underprivileged aiming at improving sleep hygiene and ecology should be developed.     

Circulating leptin levels are associated with physical activity or physical fitness in Japanese

Objective

The aim of this study was to evaluate the link between circulating leptin levels and physical activity and/or physical fitness in apparently healthy Japanese.

Methods

A total of 85 men and 111 women who were not taking any medication were enrolled in this cross-sectional study. Circulating leptin levels, physical activity measured by tri-axial accelerometers and peak oxygen uptake were evaluated. We also assessed anthropometric data, blood pressure, blood examinations and energy intake.

Results

Circulating leptin levels were 3.2 ± 2.3 ng/mL in men and 5.9 ± 3.8 ng/mL in women. Circulating leptin levels were significantly and positively correlated with body weight, body mass index, abdominal circumference, insulin and the homeostasis model assessment index, and significantly and negatively correlated with peak oxygen uptake in both sexes. Stepwise multiple regression showed that peak oxygen uptake in men and physical activity evaluated by \(\sum {\left[ {{\text{metabolic equivalents }} \times \rm h {\text{ per week}}({\text{METs}}\;\;h/w)} \right]}\) in women were determinant factors for circulating leptin levels after adjusting for confounding factors.     

Improving weight status in childhood: results from the eat well be active community programs

Objectives

The eat well be active Community Programs (ewba) aimed to prevent obesity among children aged 0–18 years in two Australian communities from 2006 to 2010.

Methods

ewba was a multi-strategy intervention in children’s settings. The evaluation was quasi-experimental, including a before and after survey with intervention (INT) and non-randomised comparison (COMP) communities. Outcome measures included BMI-z score (zBMI) and overweight/obesity prevalence in children aged 4–5 years; and zBMI, waist circumference (WC) z-score and overweight/obesity prevalence in children aged10–12 years.

Results

After 3 years, among the 4–5 years old, mean zBMI was significantly lower in both INT (?0.20, p < 0.05) and COMP (?0.15, p < 0.05), however, changes were not significantly different between INT and COMP. There was a larger reduction in overweight/obesity prevalence in INT (?6.3 %) compared to COMP (?3.7 %) (p < 0.05, χ ² test). In the 10–12 years old, mean zBMI did not change significantly in INT or COMP. There was a significant reduction in WC z-score in INT (?0.17, p < 0.05) but not in COMP (?0.10, p = NS), although not significantly different between INT and COMP (p = 0.092).

Conclusions

These findings suggest that the ewba community intervention had a moderate impact, showing modest improvements in weight status at 3-year follow-up.     

Yeast (1,3)-(1,6)-beta-glucan helps to maintain the body’s defence against pathogens: a double-blind, randomized, placebo-controlled, multicentric study in healthy subjects

Purpose

The effect of brewers’ yeast (1,3)-(1,6)-beta-d-glucan consumption on the number of common cold episodes in healthy subject was investigated.

Methods

In a placebo-controlled, double-blind, randomized, multicentric clinical trial, 162 healthy participants with recurring infections received 900 mg of either placebo (n = 81) or an insoluble yeast (1,3)-(1,6)-beta-d-glucan preparation (n = 81) per day over a course of 16 weeks. Subjects were instructed to document each occurring common cold episode in a diary and to rate ten predefined infection symptoms during an infections period, resulting in a symptom score. The subjects were examined by the investigator during the episode visit on the 5th day of each cold episode.

Results

In the per protocol population, supplementation with insoluble yeast (1,3)-(1,6)-beta-glucan reduced the number of symptomatic common cold infections by 25 % as compared to placebo (p = 0.041). The mean symptom score was 15 % lower in the beta-glucan as opposed to the placebo group (p = 0.125). Beta-glucan significantly reduced sleep difficulties caused by cold episode as compared to placebo (p = 0.028). Efficacy of yeast beta-glucan was rated better than the placebo both by physicians (p = 0.004) participants (p = 0.012).

Conclusion

The present study demonstrated that yeast beta-glucan preparation increased the body’s potential to defend against invading pathogens.     

Impact of nocturnal calf cramping on quality of sleep and health-related quality of life

Purpose

To evaluate the impact of nocturnal calf cramping (a condition that affects one in two people over 60 years of age) on quality of sleep and health-related quality of life.

Methods

Eighty adults who experienced nocturnal calf cramp at least once per week and eighty age- and sex-matched controls who never experienced nocturnal cramp were recruited from the Greater Newcastle and Central Coast regions of New South Wales, Australia. All participants completed the SF-36v2 and the Medical Outcomes Study Sleep Survey (MOS-SS).

Results

People who experienced nocturnal muscle cramps reported more sleep disturbance (p < 0.001), less adequate sleep (p = 0.001), less quantity of sleep (p = 0.02) and more snoring (p = 0.03). Both sleep problem summary indices for the MOS-SS identified people who experienced nocturnal muscle cramp as having more sleep problems than the controls. People who experienced nocturnal muscle cramps had lower health-related quality of life for the SF-36 domains role physical (p = 0.007), bodily pain (p = 0.003) and general health (p = 0.02). SF-36 domains that primarily relate to mental health were not significantly different between groups. The impact of nocturnal calf cramps on health-related quality of life was largely explained by their negative impact on quality of sleep.

Conclusions

Nocturnal calf muscle cramps are associated with substantially reduced quality of sleep and reduced physical aspects of health-related quality of life.     

Meal replacement based on Human Ration modulates metabolic risk factors during body weight loss: a randomized controlled trial

Purpose

A meal replacement may be an effective strategy in the management of obesity to increase antioxidant intake, attenuating oxidative stress and inflammation. In the present study, we investigated the efficacy of a new nutritional supplement to reduce metabolic risk parameters in obese women.

Methods

In a randomized controlled crossover study (2 × 2), 22 women (percentage body fat 40.52 ± 3.75 %; body mass index—BMI 28.72 ± 2.87 kg/m²; 35.04 ± 5.6 years old) were allocated into two treatments: hypocaloric diet and drink containing “Human Ration” (HR) consumption (CRHR), and hypocaloric diet and control drink consumption (CR). The study consisted of 2 periods of 5 weeks with 1 week of washout in two orders (CR → CRHR and CRHR → CR). Caloric restriction was 15 %, based on estimated energy requirement. Anthropometric, clinical and metabolic risk parameters were assessed at baseline and at the end of each period.

Results

Some metabolic risk factors were favorably modulated in both interventions: reduction in body weight (CR ?0.74 ± 1.27 kg; p = 0.01; CRHR ?0.77 ± 1.3 kg; p = 0.02), body mass index (BMI) (CR ?0.27 ± 0.51 kg/m²; p = 0.02; CRHR ?0.30 ± 0.52 kg/m²; p = 0.01) and HOMA-IR (CR ?0.35 ± 0.82; p = 0.02, CRHR ?0.41 ± 0.83; p = 0.03). However, CRHR reduced waist circumference (?2.54 ± 2.74 cm; p < 0.01) and gynoid fat (?0.264 ± 0.28 g; p < 0.01), and increased HDL-c levels (0.08 ± 0.15 mmol/l; p = 0.04).

Conclusion

Associated with hypocaloric diet, the intake of a nutritional supplement rich in phytochemicals as a breakfast substitute for 5 weeks had no additional effect on weight reduction than caloric restriction alone, but increased central lipolysis and improved the lipoprotein profile.     

Relationship between the body adiposity index and cardiometabolic risk factors in obese postmenopausal women

Objective

The purpose of the present secondary analysis study was to investigate the ability of the body adiposity index (BAI) to detect changes in % body fat levels before and after a weight loss intervention when compared to % body fat levels measured using dual-energy X-ray absorptiometry (DXA) and to examine the relationship between the BAI with cardiometabolic risk factors.

Methods

The study population for this secondary analysis included 132 non-diabetic obese sedentary postmenopausal women (age: 57.2 ± 4.7 years, BMI: 35.0 ± 3.7 kg/m²) participating in a weight loss intervention that consisted of a calorie-restricted diet with or without resistance training. We measured: (1) visceral fat using CT-scan, (2) body composition using DXA, (3) hip circumference and height from which the BAI was calculated, and (4) cardiometabolic risk factors such as insulin sensitivity (using the hyperinsulinemic-euglycemic clamp), blood pressure as well as fasting plasma lipids, hsC-reactive protein (CRP), leptin, and glucose.

Results

Percent body fat levels for both methods significantly decreased after the weight loss intervention. In addition, the percent change in % body fat levels after the weight loss intervention was significantly different between % body fat measured using the DXA and the BAI (?4.5 ± 6.6 vs. ?5.8 ± 5.9%; p = 0.03, respectively). However, we observed a good overall agreement between the two methods, as shown by the Bland–Altman analysis, for percent change in % body fat. Furthermore, similar correlations were observed between both measures of % body fat with cardiometabolic risk factors. However, results from the multiple linear regression analysis showed that % body fat using the BAI appeared to predict cardiometabolic risk factors differently than % body fat using the DXA in our cohort.

Conclusions

Estimating % body fat using the BAI seems to accurately trace variations of % body fat after weight loss. However, this index showed differences in predicting cardiometabolic risk factors when compared to % body fat measured using DXA.     

Relationship between intensity of night shift work and antioxidant status in blood of nurses

Purpose

Light-at-night exposure can disrupt the human circadian rhythm via clock gene expressions. The circadian rhythm influences antioxidant enzymes’ activity and cellular mRNA levels of these enzymes. The employees working based on a shift system adjust to the changes occurring both on the cell level and on the level of the whole organism. Therefore, a question should be answered whether shift work disturbs oxidant–antioxidant balance and/or generates oxidative stress.

Methods

A cross-sectional study was conducted among nurses selected from the Local Registry of the Chamber of Nurses and Midwives in Lodz: 359 nurses worked daily only and 349 working rotating night shifts. These two groups differed significantly in respect of age (p < 0.0001), menopausal status (p < 0.0001), and current smoking habit (p = 0.02). The average total work duration was significantly shorter (12.4 years) in nurses working currently rotating night shifts who worked significantly longer on night shifts than day-workers (26.6 years).

Results

We found statistically significant higher red blood cell glutathione peroxidase in nurses working on night shifts (21.0 ± 4.6 vs. 20.0 ± 5.0 U/g Hb, p < 0.009) after adjusting for age, oral contraceptive hormone use, smoking, and drinking alcohol during last 24 h. Statistically significant lower vitamin A and E levels were found in the premenopausal women working in rotating system (0.690 ± 0.238 vs. 0.786 ± 0.262 μg/ml, p < 0.0001 for vitamin A and 10.93 ± 4.15 vs. 12.78 ± 4.75 μg/ml, p < 0.0001 for vitamin E). The marker of lipid peroxidation (TBARS concentration) was significantly lower in the premenopausal nurses than postmenopausal ones working day shifts only (2.06 ± 0.76 vs. 2.21 ± 0.80 nmol/ml, p < 0.038). We observed that erythrocyte GSH-Px activity rose statistically significant in nurses working more night shifts per month (p < 0.01).

Conclusions

The results quoted above seem to support the existence of an association between light-at-night exposure and blood glutathione peroxidase activity in female shift workers. Nevertheless, in order to explain the mechanisms of this association, we need more studies.     

Pneumoproteins in sewage workers exposed to sewage dust

Purpose

The association between exposure to bacteria and endotoxins in sewage dust and the serum concentrations of pneumoproteins in sewage treatment plant workers were studied.

Methods

Forty-four workers from eight sewage treatment plants and 38 reference workers participated in the study. Microbial aerosol was collected by personal inhalable samplers. The concentrations of bacteria and endotoxins were determined by fluorescence microscopy and the Limulus assay, respectively. Pneumoproteins (Clara cell protein: CC16, and Surfactant proteins A and D: SP-A, SP-D) were determined by ELISA in blood samples collected post-shift.

Results

The exposure to dust ranged from 0.02 to 9.3 (geometric mean (GM) 0.3 mg/m³, of bacteria from 0.3 to 4,900 × 10³ (GM 27 × 10³) cells/m³ and endotoxins from 1 to 3,160 (GM 28) EU/m³. The exposed workers had lower CC16 [arithmetic mean (AM) 4.9 ng/ml] compared to the referents (AM 6.4 ng/ml, p < 0.01). No significant difference was observed for SP-D and SP-A. Exposure to bacteria was positively associated with CC16 (p < 0.05) and SP-D (p < 0.05), adjusting for possible confounders.

Conclusions

This study showed that exposed workers had lower serum concentration of CC16 as compared to the referents, which may reflect a long-term effect on secretion of these pneumoproteins. The positive association between exposure to bacteria and the serum concentrations of CC16 and SP-D may be explained by a transient increased permeability of the lung–blood barrier.     

Health effects and acceptance of a physical activity program for older long-term unemployed workers

Purpose

Long-term unemployment has negative effects on both mental and physical health. In combination with an inactive lifestyle, it often leads to functional or constitutional limitations that make reemployment in the labor market difficult especially for older adults. The presented pilot study examined a 3-month-long interventional program for improving health of older, long-term unemployed persons with regard to its effectiveness and acceptance by the target group.

Methods

The low-threshold intervention was offered by a job training center that supports reemployment and was divided into lectures for enhancing the individual health competence and a supervised physical training part in a fitness center. One hundred and nineteen long-term unemployed workers (53.7 ± 3 years) took part in a prospective investigation with 3 data collection points: before intervention (T1), after intervention (T2, n = 94), and 6 month after intervention (T3, n = 59). The spectrum of methods included the assessment of nutritional status, cardiovascular risk factors, physical fitness, chronic backache, and depression.

Results

As a result of the intervention, the physical fitness improved significantly (maximal oxygen uptake: p < 0.002). Cardiovascular risk factors like systolic and diastolic blood pressure (p < 0.016; p < 0.001) and percentage body fat (p < 0.017) decreased significantly. There were also remarkable effects in the reduction in depression (p < 0.028). Chronic backache was lowered in more than 50% of the cases.

Conclusion

The health promotion program reached people who have a desire to improve both physical and mental health. To assume responsibility for their own health may be a first step in regaining self-confidence and lowering the work placement barriers.