Maximum acceptable weight of manual load carriage for young Taiwanese males

This study examined the maximum acceptable weight of carriage (MAWC) for young Taiwanese males experienced in manual load carriage tasks. The elements of the examined load carriage tasks included lifting a box from the floor to the waist height, turning around while holding the box, carrying the box at the waist height for a distance, lowering the box to the floor, turning around, and walking unloaded back to the original position. Subjects performed the load carriage tasks over different levels of carriage distance, frequency, box width (sagittal dimension), and handle according to a response surface design. The results showed that subjects' MAWC decreased with carriage distance, frequency and box width, while heart rate and rate of perceived exertion (RPE) increased with carriage distance, frequency and box width. The MAWC for box with handles was on average 1.5 kg more than that for box without handles, while the effects of handle on heart rate and RPE were very trivial.     

Maximum Weights of Handling Acceptable to People Aged 55–74 Years: Part II. Carrying

Part I dealt with dynamic psychophysical strengths of the older population for manual lifting activities. Part II deals with dynamic psychophysical strengths of the older population for manual carrying activities (maximum acceptable weight of carry—MAWC). Subject population that participated in the manual carrying activities was the same that participated in manual lifting activities (ten males and ten females in each of the two age groups—55–74 years of age and 18–35 years of age). A questionnaire was used to identify carrying activities routinely performed in and around the home and workplace. Three of these activities were simulated in the laboratory settings, and included a two-handed carrying task, a one-handed carrying task, and bag carrying. All carrying activities were performed over a carrying distance of 6 m, and carrying frequency of once and twice per minute and once every 5 minutes. As in the case of manual lifting, the psychophysical approach was used to determine MAWC. Heart rate (HR) oxygen uptake (VO₂) and category-ratio ratings of perceived exertion (CRRPE) at the MAWC were also recorded. The results indicated that MAWC for two-handed tasks was significantly influenced by age for males—younger males carried 26% more weight than older males. Males, even though carrying less weight in two hands, were subjected to higher physiological burden (elevated heart rate). Females performing two-handed carrying tasks, on the other hand, exhibited no age effect. MAWC for males and females for one-handed carrying tasks and bag carrying were not affected either by age or frequency. None of the other responses (HR, VO₂, and CRRPE) for one-handed carrying and bag-carrying tasks were effected by either age or frequency. Although not directly compared, MAWC for all three activities were different.     

The Effect of a Multi-Ingredient Pre-Workout Supplement on Time to Fatigue in NCAA Division I Cross-Country Athletes

This investigation aimed to determine the effect of a multi-ingredient pre-workout supplement (MIPS) on heart rate (HR), perceived exertion (RPE), lactate concentration, and time to fatigue (TTF) during a running task to volitional exhaustion. Eleven NCAA Division I cross-country runners (20 ± 2 year; height: 171 ± 14 cm; weight: 63.5 ± 9.1 kg) participated in this randomized, double-blind, placebo-controlled cross-over study. Bayesian statistical methods were utilized, and parameter estimates were interpreted as statistically significant if the 95% highest-density intervals (HDIs) did not include zero. TTF was increased in the MIPS condition with a posterior Mean_diff = 154 ± 4.2 s (95% HDI: −167, 465) and a 0.84 posterior probability that the supplement would increase TTF relative to PL. Blood lactate concentration immediately post-exercise was also higher in the MIPS condition compared to PL with an estimated posterior Mean_diff = 3.99 ± 2.1 mmol (95% HDI: −0.16, 7.68). There were no differences in HR or RPE between trials. These findings suggest that a MIPS ingested prior to sustained running at lactate threshold has an 84% chance of increasing TTF in highly trained runners and may allow athletes to handle a higher level of circulating lactate before reaching exhaustion.     

Association of Lower Nutritional Status and Education Level with the Severity of Depression Symptoms in Older Adults—A Cross Sectional Survey

The study analyzes the relationship between nutritional status and depression symptoms severity in the older population. A total of 1975 older outpatients (1457 women and 518 men, median age 75) were included in the study. Depression symptoms severity was assessed using the Geriatric Depression Scale (GDS). Participants were divided into two subgroups according to GDS score. Group A: 0–5 points—without depression symptoms (1237, W:898, M:339), and group B: 6–15 points—with depression symptoms (738, W:559, M:179). The nutritional status of the patients was assessed with Mini Nutritional Assessment (MNA) and basic anthropometric variables (waist, hips, calf circumferences, body mass index (BMI), waist to hip ratio (WHR), and waist to height ratio (WHtR)). Education years and chronic diseases were also noted. Women with higher depression symptoms severity had significantly lower MNA scores [A: 26.5 (24–28) (median (25%−75% quartiles)) vs. B:23 (20.5–26)], shorter education time [A:12 (8–16) vs. B:7 (7–12)], smaller calf circumference [A:36 (33–38) vs. B: 34 (32–37)], and higher WHtR score [A:57.4 (52.3–62.9) vs. B:58.8 (52.1–65.6)]. Men with depression symptoms had lower MNA scores [A:26.5 (24.5–28) vs. B:24 (20.5–26.5)], shorter education [A:12 (9.5–16), B:10 (7–12)], and smaller calf circumference [A:37 (34–39), B:36 (33–38)]. In the model of stepwise multiple regression including age, years of education, anthropometric variables, MNA and concomitant diseases nutritional assessment, and education years were the only independent variables predicting severity of depression symptoms both in women and men. Additionally, in the female group, odds were higher with higher WHtR. Results obtained in the study indicate a strong relationship between proper nutritional status and education level with depression symptoms severity in older women and men.     

Perceived exertion of physical effort for various manual handling tasks

Ten trained male students between 18 and 28 years of age participated in a study, designed to determine the relationship between perceived exertion and physiological costs of exertion during various manual lifting and lowering tasks. Perceived exertion was defined as one's subjective rating of the intensity of work being performed. Five subjects performed lifting tasks and another five performed lowering tasks. Weight of load lifted or lowered (6.8, 13.6, 20.5 kg), frequency of lift or lower (3, 6, 9 times/min), height of lift or lower (floor to 76 cm, 76 to 127 cm, floor to 127 cm), box width (38, 66 cm), box length (38, 66 cm) and angle of twist of the body (0 degree, 90 degrees) were the independent variables studied. Heart rate, oxygen consumption, and ratings of perceived exertion (RPE) were the response measures. RPE was found almost linearly related to heart rate and oxygen consumption when lifting or lowering loads. For lifting tasks, the coefficient of correlation between RPE and heart rate was 0.673. In the case of lowering tasks, this coefficient was 0.604. When oxygen consumption was considered, the corresponding coefficients for lifting and lowering were 0.734 and 0.619, respectively. The correlation of RPE with the physiological response variables indicates that the severity of manual materials handling tasks in industry can be evaluated quickly and inexpensively by using perceived exertion ratings (RPE).     

Coffee Consumption and All-Cause,Cardiovascular, and Cancer Mortality in an Adult Mediterranean Population

We assessed the association between usual coffee consumption and all-cause, cardiovascular (CV), and cancer mortality in an adult population in Spain, taking into account both the amount and type of coffee consumed. We used baseline data on coffee consumption and other personal variables, and the number of deaths during an 18-year follow-up period, for 1567 participants aged 20 years and older from the Valencia Nutrition Study in Spain. Total, caffeinated, and decaffeinated coffee consumption was assessed using a validated food frequency questionnaire. Cox regression models were used to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). During the 18-year follow-up period, 317 died; 115 due to CV disease and 82 due to cancer. Compared with no-consumption, the consumption of ≤1 cup per day and >1 cup per day of coffee was associated with a lower risk of all-cause mortality, HR = 0.73 (95% CI: 0.56–0.97) and HR 0.56 (95% CI: 0.41–0.77), respectively. A lower cancer mortality was observed among drinkers of more than 1 cup per day compared with nondrinkers, HR 0.41 (95% CI 0.20–0.86). Regarding the type of coffee, only the overall consumption of caffeinated coffee was associated with lower all-cause mortality at 12 and 18 years of follow-up, HR = 0.66 (95% CI:0.46–0.94) and HR = 0.59 (95% CI: 0.44–0.79), respectively. In conclusion, this study suggests that the moderate consumption of coffee, particularly caffeinated coffee (range 1–6.5 cups per day), is associated with a lower all-cause and cancer mortality after a long follow-up period. No significant association was found between coffee consumption and CVD mortality.     

Metalworking fluids and cancer mortality in a US autoworker cohort (1941–2015)

Objectives:This report describes the extended follow-up (1941–2015) of a cohort of 38 549 automobile manufacturing workers with potential exposure to metalworking fluids (MWF). The outcomes of interest were mortality from cancers of the esophagus, stomach, intestine, rectum, bladder, liver, pancreas, larynx, lung, skin, prostate, brain, and female breast, as well as leukemia. This report includes 5472 deaths from cancer, more than ten times the numbers of deaths in our last summary report published 20 years ago.Methods:Standardized mortality ratios were computed for the entire study period. Adjusted hazard ratios (HR) were estimated in Cox proportional hazard models with categorical variables for cumulative exposure to each type of MWF.Results:Exposure–response patterns are consistent with prior mortality reports from this cohort. We found increased risk of skin and female breast cancer with straight fluids. For the first time, we found elevated risk of stomach cancer mortality. Overall, many of the exposure–response results did not suggest an association with MWF.Conclusions:Mortality is a poor proxy for cancer diagnosis for treatable cancers and not the optimal outcome measure in etiological studies. Although the HR presented here handle bias from the healthy worker hire effect and left truncation, they do not handle bias from healthy worker survivor effect, which likely results in underestimates of the health impacts of MWF. Although this updated summary provides some information on the risk of cancer from MWF, targeted future analyses will help clarify associations.     

University of Hawai‘i Cancer Center Connection: Bias in Self-reported Anthropometry in Relation to Adiposity and Adulthood Weight Gain among Postmenopausal Caucasian and Japanese American Women

Adiposity is often approximated by body mass index (BMI) in population studies based on self-reported weight and height (kg/m²). However, self-reports tend to underestimate weight and overestimate height, leading to an underestimation of BMI and the prevalence of overweight and obesity. We examined a subgroup of the Multiethnic Cohort Study participants to determine how well self-reported and measured anthropometry correlate with each other, overall and by race/ethnicity, total and abdominal adiposity level, and amount of adulthood weight gain. A cross-sectional sample of 30 Caucasian and 30 Japanese American female cohort participants, between ages 60–65, was selected in such a way the two groups had a similar BMI distribution across the range (18.5–40 kg/m²). Subjects first reported their weight, height, and waist and hip circumferences at home and within several days underwent objective measurements by trained staff and also a whole-body scan of dual energy X-ray absorptiometry (DXA) at a study clinic. The women under-reported their weight by 0.93 kg, waist circumference by 3.95 cm and hip circumference by 0.10 cm and over-reported their height by 0.85 cm. This led to an under-estimation of BMI by 0.67 kg/m² and waist/hip ratio by 0.04. The effect of misreporting (self-report minus measurement) on BMI and waist/hip ratio was significantly greater in higher BMI groups (p-heterogeneity = 0.007 for BMI, 0.0005 for waist/hip ratio), among women with central obesity (waist circumference > 88 cm; p-heterogeneity = 0.006, 0.01) and among women who had gained higher amounts of weight since age 21 (p-heterogeneity = 0.03, 0.01) compared to their counterparts. A similar trend of greater self-report bias was found among women with higher levels of DXA-based total and abdominal adiposity. We did not observe any heterogeneity in these findings by ethnicity. Our results confirm that a small degree of under-reporting exists in self-reported BMI and waist/hip ratio values, and it tends to increase in women with a larger current body size or history of greater weight gain. Studies are underway to investigate this question in greater depth in men and women from five race/ethnic groups.     

Study on Reference Range of Zinc,Copper and Copper/Zinc Ratio in Childbearing Women of China

Background: Copper and zinc are both essential elements in humans, that play various biological roles in body functions. Population-based reference values have not yet been established in China especially in childbearing women. The aim of this study is to establish a reference value of Zn, Cu and Cu/Zn ratios in childbearing women aged 18–44 from a representative population in China. Method: A total of 191 healthy childbearing women aged 18–44 years old were enrolled from the China Adult Chronic Disease and Nutrition Surveillance (2015) in this study with a series strict inclusion criteria. Basic biological indicators (weight, height, waist, blood pressure, high-density lipoprotein cholesterol, low-density lipoprotein, total cholesterol, triglyceride, fast glycose, HbA1c, blood pressure, uric acid) and elements levels in plasma and whole blood were collected. The 2.5th to 97.5th was used to represent the reference range of Cu, Zn and Cu/Zn ratio. Results: The reference range of Zn, Cu and Cu/Zn ratio in plasma were 70.46–177.53 µg/dL, 74.30–170.68 µg/dL and 0.54–1.68, respectively. The reference range of Zn, Cu and Cu/Zn ratios in whole blood were 402.49–738.05, 74.63–124.52 and 0.13–0.25 µg/dL, respectively. Conclusion: The reference range of Zn, Cu and Cu/Zn ratios in plasma and whole blood of healthy Chinese childbearing women could be used as an indicator to evaluate the status of element deficiency and overload.     

The effectiveness of ergonomic interventions on return-to-work after low back pain; a prospective two year cohort study in six countries on low back pain patients sicklisted for 3-4 months

Aims: To study occurrence and effectiveness of ergonomic interventions on return-to-work applied for workers with low back pain (LBP).

Methods: A multinational cohort of 1631 workers fully sicklisted 3–4 months due to LBP (ICD-9 codes 721, 722, 724) was recruited from sickness benefit claimants databases in Denmark, Germany, Israel, Sweden, the Netherlands, and the United States. Medical, ergonomic, and other interventions, working status, and return-to-work were measured using questionnaires and interviews at three months, one and two years after the start of sickleave. Main outcome measure was time to return-to-work. Cox's proportional hazards model was used to calculate hazard ratios regarding the time to return-to-work, adjusted for prognostic factors.

Results: Ergonomic interventions varied considerably in occurrence between the national cohorts: 23.4% (mean) of the participants reported adaptation of the workplace, ranging from 15.0% to 30.5%. Adaptation of job tasks and adaptation of working hours was applied for 44.8% (range 41.0–59.2%) and 46.0% (range 19.9–62.9%) of the participants, respectively. Adaptation of the workplace was effective on return-to-work rate with an adjusted hazard ratio (HR) of 1.47 (95% CI 1.25 to 1.72; p < 0.0001). Adaptation of job tasks and adaptation of working hours were effective on return-to-work after a period of more than 200 days of sickleave with an adjusted HR of 1.78 (95% CI 1.42 to 2.23; p < 0.0001) and 1.41 (95% CI 1.13 to 1.76; p = 0.002), respectively.

Conclusions: Results suggest that ergonomic interventions are effective on return-to-work of workers long term sicklisted due to LBP.

     

Persistent and changing job strain and risk of coronary heart disease. A population-based cohort study of 1.6 million employees in Denmark

Objectives:This study aimed to examine the association between job strain and incident coronary heart disease (CHD) in Denmark, while accounting for changes of job strain.Methods:We included all employees residing in Denmark in 2000, aged 30–59 years with no prevalent CHD (N=1 660 150). We determined exposure to job strain from 1996–2009 using a job exposure matrix (JEM) with annual updates. Follow-up for incident CHD was from 2001–2010 via linkage to health records. We used Cox regression to calculate hazard ratios (HR) and 95% confidence intervals (CI) for the association between job strain and incident CHD.Results:During 16.1 million person-years, we identified 24 159 incident CHD cases (15.0 per 10 000 person-years). After adjustment for covariates, job strain in 2000 predicted onset of CHD during a mean follow-up of 9.71 years (HR 1.10, 95% CI 1.07–1.13). When analyzing changes in job strain from one year to the next and CHD in the subsequent year, persistent job strain (HR 1.07, 95% CI 1.03–1.10), onset of job strain (HR 1.20, 95% CI 1.12–1.29) and removal of strain (HR 1.20, 95% CI 1.12–1.28) were associated with higher CHD incidence compared to persistent no job strain. Associations were similar among men and women.Conclusions:Job strain is associated with a higher risk of incident CHD in Denmark. As we used a JEM, we can rule out reporting bias. However, under- or overestimation of associations is possible due to non-differential misclassification of job strain and residual confounding by socioeconomic position.     

The Effect of Isolated and Combined Application of Menthol and Carbohydrate Mouth Rinses on 40 km Time Trial Performance,Physiological and Perceptual Measures in the Heat

The current study compared mouth swills containing carbohydrate (CHO), menthol (MEN) or a combination (BOTH) on 40 km cycling time trial (TT) performance in the heat (32 °C, 40% humidity, 1000 W radiant load) and investigates associated physiological (rectal temperature (Trec), heart rate (HR)) and subjective measures (thermal comfort (TC), thermal sensation (TS), thirst, oral cooling (OC) and RPE (legs and lungs)). Eight recreationally trained male cyclists (32 ± 9 y; height: 180.9 ± 7.0 cm; weight: 76.3 ± 10.4 kg) completed familiarisation and three experimental trials, swilling either MEN, CHO or BOTH at 10 km intervals (5, 15, 25, 35 km). The 40 km TT performance did not differ significantly between conditions (F_2,14 = 0.343; p = 0.715; η² = 0.047), yet post-hoc testing indicated small differences between MEN and CHO (d = 0.225) and MEN and BOTH (d = 0.275). Subjective measures (TC, TS, RPE) were significantly affected by distance but showed no significant differences between solutions. Within-subject analysis found significant interactions between solution and location upon OC intensity (F_28,196 = 2.577; p < 0.001; η² = 0.269). While solutions containing MEN resulted in a greater sensation of OC, solutions containing CHO experienced small improvements in TT performance. Stimulation of central CHO pathways during self-paced cycling TT in the heat may be of more importance to performance than perceptual cooling interventions. However, no detrimental effects are seen when interventions are combined.     

Night work,mortality, and the link to occupational group and sex

Objective:Night shifts are associated with several major diseases. Mortality has been studied only to a limited extent, and the association with night shifts remains unclear. The purpose of the present study was to investigate the association between duration of night shift exposure and mortality in a large sample from the Swedish Twin Registry (the SALT cohort).Methods:Cox proportional hazards regression models were used to analyze the data (N=42 731) over a follow-up period of 18 years, with years of night shift work as the exposure variable and adjustment for lifestyle factors and age, and stratification on gender and occupational group.Results:The hazard ratio (HR) for “ever” night shifts for total mortality was 1.07 [95% confidence interval (CI) 1.01–1.15] but 1.15 (95% CI 1.07–1.25) for longer exposure (>5 years). Also, HR for cause-specific mortality due to cardiovascular disease was significant, with higher HR for longer night shift exposure. Mortality due to cancer was significant for longer exposure only. White-collar workers showed significant HR for longer exposure. In particular, male white-collar workers showed a significant HR, with a highest value for longer exposure [HR 1.28 (95% CI 1.09–1.49)]. Heredity did not influence the results significantly.Conclusions:Long duration of exposure to night shift work is associated with increased mortality, particularly in male white-collar workers. The lack of effects of accumulated exposure suggests that the results should be interpreted with caution.     

Suggested Reference Ranges of Blood Mg and Ca Level in Childbearing Women of China: Analysis of China Adult Chronic Disease and Nutrition Surveillance (2015)

Background: Magnesium and calcium play a variety of biological roles in body functions. Reference values of these elements have not yet been systematically determined in China, especially in childbearing women. We proposed to establish the reference range of Mg, Ca, and Ca/Mg ratio in plasma and whole blood for 18–44 years healthy childbearing women in China. Method: A total of 1921 women of childbearing age (18–44 years) were randomly selected from the 2015 China National Nutrition and Health Survey by taking into account the regional types and monitoring points. Among them, 182 healthy women were screened out with a series strict inclusion criteria to study the reference ranges of elements. Fundamental indicators (weight, height, waist, blood pressure, total cholesterol, triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein, fast glucose, HbA1c, blood pressure, uric acid) and elements concentrations in plasma and whole blood were collected. The 2.5th to 97.5th was used to represent the reference range of Mg, Ca, and Ca/Mg ratio. Results: The reference range of Mg, Ca, and Ca/Mg ratio in plasma were 0.75–1.13 mmol/L, 2.27–3.43 mmol/L, and 2.41–3.44, respectively. Additionally, the reference range of Mg, Ca, and Ca/Mg ratio in whole blood were 1.28–1.83 mmol/L, 1.39–2.26 mmol/L, and 0.90–1.66, respectively. According to the established reference range, the prevalence of magnesium deficiency was 4.79% in 1921 childbearing women, 21.05% in type 2 diabetes, and 5.63% in prediabetes. Conclusion: The reference values of Mg, Ca and Ca/Mg proportion in plasma and entire blood of healthy childbearing women can be utilized as a pointer to assess the status of component lack and over-burden. The lower limit of plasma Mg is in good agreement with the recommended criteria for the determination of hypomagnesemia.     

Dietary Diversity and the Risk of Fracture in Adults: A Prospective Study

Nutrition plays an important and modifiable role in bone health. This study aimed to investigate the effect of dietary diversity on the risk of any type of fracture in adults. Data from the China Health and Nutrition Survey collected between waves 1997 and 2015 were used. A total of 10,192 adults aged 40 years and older were included in the analysis. Both dietary diversity score (DDS) based on Chinese dietary guidelines (DDS-CDG) and minimum dietary diversity for women (DDS-MDD-W) were computed. Cox proportional hazards regression models were conducted to determine the association. Stratified analyses were conducted in women by the age of fracture using the case-control study approach. In men, higher scores in both the DDS-CDG (hazard ratio (HR) 0.70, 95% CI 0.56–0.88) and DDS-MDD-W (HR 0.67, 95% CI 0.54–0.82) were associated with decreased risk of fracture, however, the associations were not significant in women (DDS-CDG: HR 0.94, 95% CI 0.79–1.12; DDS-MDD-W: HR 0.93, 95% CI 0.79–1.09). In the stratified analyses, higher DDS-CDG (odds ratio (OR) 0.74, 95% CI 0.58–0.95) and higher DDS-MDD-W (OR 0.76, 95% CI 0.60–0.95) were associated with lower risks of fracture in women aged 40 to 60 years; in women aged over 60 years, no association was observed (DDS-CDG: OR 1.10, 95% CI 0.83–1.46; DDS-MDD-W: OR 1.00, 95% CI 0.79–1.27). In summary, higher dietary diversity was associated with decreased risk of fracture in men and middle-aged women, but not in women aged over 60 years.     

High Dose of Caffeine Mouth Rinse Increases Resistance Training Performance in Men

Caffeine mouth rinsing (CMR) has been shown to enhance exercise performance. However, no studies have analyzed the effects of different dosages of CMR on muscular performance. Therefore, the purpose of this study was to examine the effects of different dosages of CMR on strength (bench press 1 repetition maximum (1-RM)) and muscular endurance (60% of 1-RM repetitions to failure) in resistance-trained males. Fourteen resistance-trained males (age: 23 ± 2 years, height: 179 ± 3 cm, body mass: 83 ± 4 kg, BMI: 17 ± 2 kg/m²) completed four conditions in random order. The four conditions consisted of a mouth rinse with 25 mL solutions containing either 1% (250 mg) of CMR (low dose of CMR: LCMR), 2% (500 mg) of CMR (moderate dose of CMR: MCMR), 3% (750 mg) of CMR (high dose of CMR: HCMR) and sweetened water (placebo: PLA) for 5 s prior to a bench press strength and muscular endurance test. Maximal strength, muscular endurance, heart rate (HR) and ratings of perceived exertion (RPE) were recorded for each condition. There were no significant differences in strength (p = 0.30) and HR (p = 0.83) between conditions. HCMR significantly increased muscular endurance performance (p = 0.01) and decreased RPE values (p = 0.01). In conclusion, CMR did not affect bench press 1-RM strength performance, but muscular endurance responses to CMR seems to be dose-dependent.     

Impact of anxiety and depression disorders on sustained return to work after work-related musculoskeletal strain or sprain: a gender-stratified cohort study

Objective:The aim of this study was to examine the impact of anxiety and depression disorders on sustained return to work (RTW) for men and women with musculoskeletal strain or sprain.Methods:Accepted lost-time claims for spine and upper-extremity strain or sprain were extracted for workers in the Canadian province of British Columbia from 2009 to 2013 (N=84 925). Pre-existing and new onset anxiety and depression disorders were identified using longitudinal health claims data. Probability of sustained RTW was analyzed using Cox proportional hazards models, stratified by gender and adjusted for potential confounders.Results:For pre-existing disorders, compared to men with no anxiety and no depression, men with anxiety only [hazard ratio (HR) 0.88, 95% confidence interval (CI) 0.84–0.93], depression only (HR 0.94, 95% CI 0.89–1.00), and anxiety and depression (HR 0.93, 95% CI 0.90–0.97) had lower probabilities of sustained RTW in adjusted models. The same direction of effect was found for women, but anxiety only had a smaller effect size among women compared to men (HR anxiety only 0.95, 95% CI 0.92–0.99; HR depression only 0.98, 95% CI 0.93–1.03, HR anxiety and depression 0.94, 95% CI 0.91–0.97). Among men and women, new onset disorders were associated with lower probability of sustained RTW and the effect estimates were larger than for pre-existing disorders.Conclusions:Findings suggest that workers’ compensation benefits and programs intended to improve RTW after musculoskeletal injury should take pre-existing and new onset anxiety and depression disorders into consideration and that gender-sensitive work disability strategies may be warranted.     

Obesity/Weight Gain and Breast Cancer Risk: Findings From the Japan Collaborative Cohort Study for the Evaluation of Cancer Risk

Background

We analyzed data from the Japan Collaborative Cohort Study (36 164 women aged 40–79 years at baseline in 1988–1990 with no previous diagnosis of breast cancer and available information on weight and height) to examine the association between baseline body mass index (BMI)/weight gain from age 20 years and breast cancer risk in a non-Western population.

Methods

The participants were followed prospectively from enrollment until 1999–2003 (median follow-up: 12.3 years). During follow-up, breast cancer incidence was mainly confirmed through record linkage to population-based cancer registries. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% CIs for the association between breast cancer risk and body size.

Results

In 397 644.1 person-years of follow-up, we identified 234 breast cancer cases. Among postmenopausal women, the adjusted HR increased with BMI, with a significant linear trend (P < 0.0001). Risk was significantly increased among women with a BMI of 24 or higher (HR: 1.50, 95% CI: 1.09–2.08 for BMI of 24–28.9, and 2.13, 1.09–4.16 for BMI ≥ 29) as compared with women with a BMI of 20 to 23.9. Weight gain after age 20 years and consequent overweight/obesity were combined risk factors for postmenopausal breast cancer risk. This combined effect was stronger among women aged 60 years or older. However, the HRs were not significant in premenopausal women.

Conclusions

Our findings support the hypothesis that weight gain and consequent overweight/obesity are combined risk factors for breast cancer among postmenopausal women, particularly those aged 60 years or older.Key words: breast cancer, obesity, weight gain, cohort study     

Effect of Age on the Association between Body Mass Index and All-Cause Mortality: The Ohsaki Cohort Study

Background

To clarify the effect of age on the association between body mass index (BMI) and all-cause mortality.

Methods

We followed 43 972 Japanese participants aged 40 to 79 years for 12 years. Cox proportional hazards regression analysis was used to estimate hazard ratios (HRs), using the following BMI categories: <18.5 (underweight), 18.5–20.9, 21.0–22.9, 23.0–24.9 (reference), 25.0–27.4, 27.5–29.9, and ≥30.0 kg/m² (obese). Analyses were stratified by age group: middle-aged (40–64 years) vs elderly (65–79 years).

Results

We observed a significantly increased risk of mortality in underweight elderly men: the multivariate HR was 1.26 (0.92–1.73) in middle-aged men and 1.49 (1.26–1.76) in elderly men. In addition, we observed a significantly increased risk of mortality in obese middle-aged men: the multivariate HR was 1.71 (1.17–2.50) in middle-aged men and 1.25 (0.87–1.80) in elderly men. In women, there was an increased risk of mortality irrespective of age group in the underweight: the multivariate HR was 1.46 (0.96–2.22) in middle-aged women and 1.47 (1.19–1.82) in elderly women. There was no excess risk of mortality with age in obese women: the multivariate HR was 1.47 (0.94–2.27) in middle-aged women and 1.26 (0.95–1.68) in elderly women.

Conclusions

As compared with the reference category, obesity was associated with a high mortality risk in middle-aged men, whereas underweight, rather than obesity, was associated with a high mortality risk in elderly men. In women, obesity was associated with a high mortality risk during middle age; underweight was associated with a high mortality risk irrespective of age. The mortality risk due to underweight and obesity may be related to sex and age.Key words: body mass index, mortality, age effect, underweight, obesity     

Executive Functions and Body Weight at Different Ages: A Preliminary Study

Recently, researchers have focused their attention on the role of cognitive processes on eating habits and body weight changes. Few studies have examined the relationship between the first stages of overweight and executive functions (EFs), excluding obesity conditions. This study is aimed to detect the involvement of the EFs and their predictive role on body mass index (BMI) in a sample of healthy individuals from childhood to young adulthood with a cross-sectional design. One-hundred and sixty-six healthy students were recruited from different Italian public schools: 46 children (age range: 7–11), 50 adolescents (age range: 15–18), 70 young adults (age range: 19–30). BMI was used to evaluate body weight and different EFs tasks were used to assess the EFs domains of inhibition, updating and shifting. After adjusting BMI for age, a hierarchical multiple linear regression was carried out for each EFs task. Pearson’s r correlations were reported for each of the age subgroups. Motor disinhibition was associated with greater BMI in the overall sample. Higher BMI was related to poorer set-shifting in adolescence and poorer motor inhibition in young adulthood, but higher BMI was not associated with EFs in childhood. Differences in the development of EFs over time may influence weight changes over time through different responses to food and eating behavior.