Glycemic index, glycemic load, and cancer risk: a meta-analysis

BACKGROUND: Factors linked to glucose metabolism play an important role in the development of cancers, and both glycemic index (GI) and glycemic load (GL) have been investigated as potential etiologic factors. OBJECTIVE: A meta-analysis was performed to explore the association between GI and GL and cancer risk from published studies. DESIGN: A comprehensive, systematic bibliographic search of the medical literature was conducted to identify relevant studies. Case-control and cohort studies published before October 2007 that reported cancer risk estimates for GI and GL were included. Pooled relative risks (RRs) were estimated for breast, colorectal, endometrial, and pancreatic cancer. RESULTS: Thirty-nine studies were included in the meta-analysis. The interquantile ranges of GL were significantly wider in case-control studies, most of which were conducted in European countries, than in cohort studies. Cohort studies that presented lower ranges of GL also reported lower risk estimates. Overall, both GL and GI were significantly associated with a greater risk of colorectal (summary RR = 1.26; 95% CI: 1.11, 1.44 and RR = 1.18; 95% CI: 1.05, 1.34, respectively) and endometrial (RR = 1.36; 95% CI: 1.14, 1.62 and RR = 1.22; 95% CI: 1.01, 1.49) cancer than of breast and pancreatic cancer. There was, however, a significant between-study heterogeneity for colorectal cancer (P < 0.0001). The association between GL and breast cancer disappeared when publication bias was taken into account. No association was found for pancreatic cancer. CONCLUSION: This comprehensive meta-analysis of GI and GL and cancer risk suggested an overall direct association with colorectal and endometrial cancer.     

Coffee and caffeine intake and risk of endometriosis: a meta-analysis

Purpose

The potential association between endometriosis and coffee/caffeine consumption has been analysed in several epidemiological studies. In order to establish whether caffeine influences the risk of endometriosis, we provide to summarize the evidence from published studies on this issue.

Methods

We performed a meta-analysis of epidemiological studies published up to January 2013. We computed summary relative risks (RR) of endometriosis for any, high and low versus no coffee/caffeine consumption.

Results

We identified a total eight studies, six case–control and two cohort studies, including a total of 1,407 women with endometriosis. The summary RR for any versus non-consumption were 1.26 [95 % confidence interval (CI) 0.95–1.66] for caffeine and 1.13 (95 % CI 0.46–2.76) for coffee consumption; the overall estimate was 1.18 (95 % CI 0.92–1.49). The summary RR were 1.09 (95 % CI 0.84–1.42) and 1.09 (95 % CI 0.89–1.33) for high and low caffeine consumption as compared to no consumption, respectively.

Conclusion

The present meta-analysis provided no evidence for an association between coffee/caffeine consumption and the risk of endometriosis. Coffee/caffeine consumption, as currently used in diet, does not carry a health risk.     

Omega-3 and omega-6 fatty acid intakes and endometrial cancer risk in a population-based case–control study

Purpose

Animal and laboratory studies suggest that long-chain omega-3 (n-3) fatty acids, a type of polyunsaturated fat found in fatty fish, may protect against carcinogenesis, but human studies on dietary intake of polyunsaturated fats and fish with endometrial cancer risk show mixed results.

Methods

We evaluated the associations between endometrial cancer risk and intake of fatty acids and fish in a population-based sample of 556 incident cancer cases and 533 age-matched controls using multivariate unconditional logistic regression methods.

Results

Although total n-3 fatty acid intake was not associated with endometrial cancer risk, higher intakes of eicosapentaenoic (EPA 20:5) and docosahexaenoic (DHA 22:6) fatty acids were significantly associated with lower risks (OR = 0.57, 95 % CI: 0.39–0.84; OR = 0.64, 95 % CI: 0.44–0.94; respectively) comparing extreme quartiles. The ratio of n-3:n-6 fatty acids was inversely associated with risk only on a continuous scale (OR = 0.84, 95 % CI: 0.71–0.99), while total fish intake was not associated with risk. Fish oil supplement use was significantly associated with reduced risk of endometrial cancer: OR = 0.63 (95 % CI: 0.45–0.88).

Conclusions

Our results suggest that dietary intake of the long-chain polyunsaturated fatty acids EPA and DHA in foods and supplements may have protective associations against the development of endometrial cancer.     

Lack of association between occupational exposure to diesel exhaust and risk of pancreatic cancer: a systematic evaluation of available data

Purpose

To review epidemiologic studies on risk of pancreatic cancer and occupational exposure to diesel exhaust.

Methods

A literature search was conducted, and data were abstracted in a systematic fashion. Comparable results were combined using a random-effects meta-analysis.

Results

Twenty-six studies were included in the review, including five studies based on routine statistics, 11 case–control studies [meta-relative risk (RR) of three estimates for diesel exhaust exposure 0.9; 95 % confidence interval (CI) 0.5, 1.6] and ten cohort studies (meta-RR of their results: 1.03; 95 % CI 0.93, 1.13). Few studies reported results according to duration of exposure or other quantitative measures; no consistent pattern emerged.

Conclusions

The overall evidence from studies on occupational exposure to diesel exhaust and risk of pancreatic cancer leads to the conclusion of the absence of such association.     

Egg consumption and risk of GI neoplasms: dose–response meta-analysis and systematic review

Purpose

Previous epidemiological studies on egg consumption and the risk of gastrointestinal (GI) neoplasms suggest a positive association; however, data are limited and the evidence remains controversial. This study aims to investigate and quantify the potential dose–response relationship with an evaluation of cancer site-specific differences.

Methods

Relevant studies were identified after the literature search via electronic databases until January 2014. Subgroup analysis for serving portions was performed using two standardized classification methods: (1) less than 3, or 3 or more eggs per week; (2) less than 3, 3–5, or more than 5 eggs per week. Method two excludes studies that only reported consumption frequency. Pooled adjusted odds ratios (ORs) comparing highest and lowest categories of dietary pattern scores were calculated using a random-effects model.

Results

Thirty-seven case–control and seven cohort studies were included for meta-analysis, which contained a total of 424,867 participants and 18,852 GI neoplasm cases. The combined odds ratio (OR) was calculated to 1.15 (95 % CI 1.09–1.22; p value heterogeneity <0.001), showing only a slight increase in risk. The correlation was stronger for colon cancers 1.29 (95 % CI 1.14–1.46; p value heterogeneity <0.22). Dose–response analysis revealed similar results with stratification methods, and the ORs for an intake of <3 and ≥3 eggs per week were 1.14 (95 % CI 1.07–1.22; p value heterogeneity = 0.38) and 1.25 (95 % CI 1.14–1.38; p value heterogeneity = 0.25), respectively. With method 2, the ORs for an intake of <3, 3–5, and >5 eggs per week were 1.13 (95 % CI 1.06–1.21; p value heterogeneity = 0.25), 1.14 (95 % CI 1.01–1.29; p value heterogeneity = 0.06), and 1.19 (95 % CI 1.01–1.39; p value heterogeneity <0.001), respectively.

Conclusion

This study provides evidence that egg consumption is associated with a positive dose–response association with the development of GI neoplasms.     

Circadian disrupting exposures and breast cancer risk: a meta-analysis

Purpose

Shift work, short sleep duration, employment as a flight attendant, and exposure to light at night, all potential causes of circadian disruption, have been inconsistently associated with breast cancer (BrCA) risk. The aim of this meta-analysis is to quantitatively evaluate the combined and independent effects of exposure to different sources of circadian disruption on BrCA risk in women.

Methods

Relevant studies published through January 2014 were identified by searching the PubMed database. The pooled relative risks (RRs) and corresponding 95 % confidence intervals (CIs) were estimated using fixed- or random effects models as indicated by heterogeneity tests. Generalized least squares trend test was used to assess dose–response relationships.

Results

A total of 28 studies, 15 on shift work, 7 on short sleep duration, 3 on flight attendants, and 6 on light at night were included in the analysis. The combined analysis suggested a significantly positive association between circadian disruption and BrCA risk (RR = 1.14; 95 % CI 1.08–1.21). Separate analyses showed that the RR for BrCA was 1.19 (95 % CI 1.08–1.32) for shift work, 1.120 (95 % CI 1.119–1.121) for exposure to light at night, 1.56 (95 % CI 1.10–2.21) for employment as a flight attendant, and 0.96 (95 % CI 0.86–1.06) for short sleep duration. A dose–response analysis showed that each 10-year increment of shift work was associated with 16 % higher risk of BrCA (95 % CI 1.06–1.27) based on selected case–control studies. No significant dose–response effects of exposure to light at night and sleep deficiency were found on BrCA risk.

Conclusions

Our meta-analysis demonstrates that circadian disruption is associated with an increased BrCA risk in women. This association varied by specific sources of circadian disrupting exposures, and a dose–response relationship remains uncertain. Therefore, future rigorous prospective studies are needed to confirm these relationships.

     

Is heme iron intake associated with risk of coronary heart disease? A meta-analysis of prospective studies

Purpose

Heme iron may contribute to the development of atherosclerosis by catalyzing production of hydroxyl-free radicals and promoting low-density lipoprotein oxidation. However, epidemiologic findings regarding the association between heme iron intake and risk of coronary heart disease (CHD) are inconsistent. We aimed to investigate the association by carrying out a meta-analysis of prospective studies.

Methods

Relevant studies were identified by using PubMed and EMBASE databases between January 1966 and April 2013 and also by manually reviewing the reference lists of retrieved publications. Summary relative risks (RRs) with corresponding 95 % confidence intervals (CIs) were computed using a random-effects model.

Results

Six prospective studies, which contained a total of 131,553 participants and 2,459 CHD cases, met the inclusion criteria. Combined results indicated that participants with higher heme iron intake had a 31 % increased risk of CHD, compared with those with lower intake (RR = 1.31, 95 % CI 1.04–1.67), with significant heterogeneity (P ^{heterogeneity} = 0.05, I ² = 55.0 %). Excluding the only study from Japan (limiting to Western studies) yielded a RR of 1.46 (95 % CI 1.21–1.76), with no study heterogeneity (P ^{heterogeneity} = 0.44, I ² = 0.0 %). The dose–response RR of CHD for an increase in heme iron intake of 1 mg/day was 1.27 (95 % CI 1.10–1.47), with low heterogeneity (P ^{heterogeneity} = 0.25, I ² = 25.8 %). We observed no significant publication bias.

Conclusions

This meta-analysis suggests that heme iron intake was associated with an increased risk of CHD.     

Association between Dietary Isoflavones in Soy and Legumes and Endometrial Cancer: A Systematic Review and Meta-Analysis

Background

Epidemiologic studies have reported conflicting findings between soy- and legume-derived dietary isoflavones and risk of endometrial cancer.

Height and body fatness and colorectal cancer risk: an update of the WCRF–AICR systematic review of published prospective studies

Purpose

There is no published dose–response meta-analysis on the association between height and colorectal cancer risk (CRC) by sex and anatomical sub-site. We conducted a meta-analysis of prospective studies on the association between height and CRC risk with subgroup analysis and updated evidence on the association between body fatness and CRC risk.

Methods

PubMed and several other databases were searched up to November 2016. A random effects model was used to calculate dose–response summary relative risks (RR’s).

Results

47 studies were included in the meta-analyses including 50,936 cases among 7,393,510 participants. The findings support the existing evidence regarding a positive association of height, general and abdominal body fatness and CRC risk. The summary RR were 1.04 [95% (CI)1.02–1.05, I² = 91%] per 5 cm increase in height, 1.02 [95% (CI)1.01–1.02, I² = 0%] per 5 kg increase in weight, 1.06 [95% (CI)1.04–1.07, I² = 83%] per 5 kg/m² increase in BMI, 1.02 [95% (CI)1.02–1.03, I² = 4%] per 10 cm increase in waist circumference, 1.03 [95% (CI)1.01–1.05, I² = 16%] per 0.1 unit increase in waist to hip ratio. The significant association for height and CRC risk was similar in men and women. The significant association for BMI and CRC risk was stronger in men than in women.

Conclusion

The positive association between height and risk of CRC suggests that life factors during childhood and early adulthood might play a role in CRC aetiology. Higher general and abdominal body fatness during adulthood are risk factors of CRC and these associations are stronger in men than in women.

     

Dietary patterns and breast cancer risk among women in northern Tanzania: a case–control study

Background

Breast cancer is the second most common cancer among women in the Kilimanjaro Region of Tanzania. It was tested within a case–control study in this region whether a specific dietary pattern impacts on the breast cancer risk.

Methods

A validated semi-quantitative Food Frequency Questionnaire was used to assess the dietary intake of 115 female breast cancer patients and 230 healthy age-matched women living in the same districts. A logistic regression was performed to estimate breast cancer risk. Dietary patterns were obtained using principal component analysis with Varimax rotation.

Results

The adjusted logistic regression estimated an increased risk for a “Fatty Diet”, characterized by a higher consumption of milk, vegetable oils and fats, butter, lard and red meat (OR = 1.42, 95 % CI 1.08–1.87; P = 0.01), and for a “Fruity Diet”, characterized by a higher consumption of fish, mango, papaya, avocado and watery fruits (OR = 1.61, 95 % CI 1.14–2.28; P = 0.01). Both diets showed an inverse association with the ratio between polyunsaturated and saturated fatty acids (P/S ratio).

Conclusion

A diet characterized by a low P/S ratio seems to be more important for the development of breast cancer than total fat intake.     

Dietary glycaemic load and odds of depression in a group of institutionalized elderly people without antidepressant treatment

Background

Depression is a very common disorder in elderly, especially in those institutionalized. Nutrition could play an important role in the onset and/or progression of depression, since the intake of carbohydrates with a high glycaemic index (GI) or diets with a high glycaemic load (GL) may increase the insulin-induced brain serotonin secretion.

Objective

The aim of our study was to analyse the association between dietary GI and GL and the odds of suffering depression in institutionalized elderly people without antidepressant treatment.

Methods

This cross-sectional study included 140 institutionalized elderly people from the Madrid region (Spain) (65–90 years of age) whose diets were recorded using a precise weighing method over seven consecutive days. Energy and nutrient intakes were recorded and the GI and GL calculated. The participants’ affective capacity was assessed using the Geriatric Depression Scale (GDS). Subjects were grouped into non-depressed (GDS ≤ 5) and depressed (GDS > 5). Since GDS scores and gender were statistically associated (p < 0.01), the data were grouped considering this association.

Results

Dietary GI (51.09 ± 3.80) and GL (97.54 ± 13.46) were considered as medium. The dietary GL was significantly higher in the non-depressed (100.00 ± 12.13) compared with the depressed group (93.97 ± 14.04, p < 0.01). However, a similar GI was observed between non-depressed (51.50 ± 3.29) and depressed groups (50.52 ± 4.46). Additionally, participants with a dietary GL placed in the second and third tertiles had a 67.4 % and 65.3 %, respectively, less odds of suffering depression than those in the first tertile. GDS scores and dietary GL were inversely related; therefore, an increase in one unit in the dietary GL scale decreased the GDS score by 0.058 units.

Conclusions

Glyaemic load is associated with a lower odd of depression.     

Optimal nutrition and the ever-changing dietary landscape: a conference report

Purpose

Laboratory studies suggested that caffeine and other nutrients contained in coffee and tea may protect against non-melanoma skin cancer (NMSC). However, epidemiological studies conducted so far have produced conflicting results.

Methods

We performed a literature review and meta-analysis of observational studies published until February 2016 that investigated the association between coffee and tea intake and NMSC risk. We calculated summary relative risk (SRR) and corresponding 95 % confidence intervals (95 % CI) by using random effects with maximum likelihood estimation.

Results

Overall, 37,627 NMSC cases from 13 papers were available for analysis. Intake of caffeinated coffee was inversely associated with NMSC risk (SRR for those in the highest vs. lowest category of intake: 0.82, 95 % CI 0.75–0.89, I ² = 48 %), as well as intake of caffeine (SRR 0.86, 95 % CI 0.80–0.91, I ² = 48 %). In subgroup analysis, these associations were limited to the basal cell cancer (BCC) histotype. There was no association between intake of decaffeinated coffee (SRR 1.01, 95 % CI 0.85–1.21, I ² = 0) and tea (0.88, 95 % CI 0.72–1.07, I ² = 0 %) and NMSC risk. There was no evidence of publication bias affecting the results. The available evidence was not sufficient to draw conclusions on the association between green tea intake and NMSC risk.

Conclusions

Coffee intake appears to exert a moderate protective effect against BCC development, probably through the biological effect of caffeine. However, the observational nature of studies included, subject to bias and confounding, suggests taking with caution these results that should be verified in randomized clinical trials.

     

Physically demanding work and preterm delivery: a systematic review and meta-analysis

Objective

Physically demanding work may increase the risk of preterm delivery (PTD), defined as delivery before 37 weeks. We assessed the available evidence.

Methods

A systematic search in Medline, Embase and Nioshtic for the period 1990 to June 2012 for observational and intervention studies on physically demanding work (prolonged standing, heavy lifting, physical exertion, occupational fatigue and demanding posture) and PTD. Selected studies were assessed for their risk of bias and pooled using a random effects model. Results of case–control and cohort studies were reported separately in subgroups.

Results

We found 10 studies with low risk of bias and seven studies with moderate risk of bias. Standing and walking at work during pregnancy for more than 3 h per day was associated with an increased risk for PTD [OR 1.3 (95 % CI 1.1–1.6)], just as lifting and carrying >5 kg [OR 1.3 (95 % CI 1.05–1.6)] or lifting and carrying in the third trimester of the pregnancy [OR 1.3 (95 % CI 1.01–1.8)]. Jobs that required physical effort or physical exertion were associated with an increased risk of PTD [OR 1.4 (95 % CI 1.19–1.66)]. Working during pregnancy in jobs with a combination of two or more physical tasks, physical effort or occupational fatigue was also associated with an increased risk of PTD [OR 1.5 (95 % CI 1.1–2.0)].

Conclusions

Physically demanding work during pregnancy is associated with an increased risk of PTD, especially in jobs with a combination of tasks with physical effort. In general, only small to moderate elevations of risks were found.     

Shift work,long working hours and preterm birth: a systematic review and meta-analysis

Purpose

Specific physical activities or working conditions are suspected for increasing the risk of preterm birth (PTB). The aim of this meta-analysis is to review and summarize the pre-existing evidence on the effect of shift work or long working hours on the risk of PTB.

Methods

We conducted a systematic search in MEDLINE and EMBASE (1990–2013) for observational and intervention studies with original data. We only included articles that met our specific criteria for language, exposure, outcome, data collection and original data that were of at least of moderate quality. The data of the included studies were pooled.

Results

Eight high-quality studies and eight moderate-quality studies were included in the meta-analysis. In these studies, no clear or statistically significant relationship between shift work and PTB was found. The summary estimate OR for performing shift work during pregnancy and the risk of PTB were 1.04 (95 % CI 0.90–1.20). For long working hours during pregnancy, the summary estimate OR was 1.25 (95 % CI 1.01–1.54), indicating a marginally statistically significant relationship but an only slightly elevated risk.

Conclusion

Although in many of the included studies a positive association between long working hours and PTB was seen this did reach only marginal statistical significance. In the studies included in this review, working in shifts or in night shifts during pregnancy was not significantly associated with an increased risk for PTB. For both risk factors, due to the lack of high-quality studies focusing on the risks per trimester, in particular the third trimester, a firm conclusion about an association cannot be stated.     

Glycemic index, glycemic load, and chronic disease risk--a meta-analysis of observational studies

BACKGROUND: Inconsistent findings from observational studies have prolonged the controversy over the effects of dietary glycemic index (GI) and glycemic load (GL) on the risk of certain chronic diseases. OBJECTIVE: The objective was to evaluate the association between GI, GL, and chronic disease risk with the use of meta-analysis techniques. DESIGN: A systematic review of published reports identified a total of 37 prospective cohort studies of GI and GL and chronic disease risk. Studies were stratified further according to the validity of the tools used to assess dietary intake. Rate ratios (RRs) were estimated in a Cox proportional hazards model and combined by using a random-effects model. RESULTS: From 4 to 20 y of follow-up across studies, a total of 40 129 incident cases were identified. For the comparison between the highest and lowest quantiles of GI and GL, significant positive associations were found in fully adjusted models of validated studies for type 2 diabetes (GI RR = 1.40, 95% CI: 1.23, 1.59; GL RR = 1.27, 95% CI: 1.12, 1.45), coronary heart disease (GI RR = 1.25, 95% CI: 1.00, 1.56), gallbladder disease (GI RR = 1.26, 95% CI: 1.13, 1.40; GL RR = 1.41, 95% CI: 1.25, 1.60), breast cancer (GI RR = 1.08, 95% CI: 1.02, 1.16), and all diseases combined (GI RR = 1.14, 95% CI: 1.09, 1.19; GL RR = 1.09, 95% CI: 1.04, 1.15). CONCLUSIONS: Low-GI and/or low-GL diets are independently associated with a reduced risk of certain chronic diseases. In diabetes and heart disease, the protection is comparable with that seen for whole grain and high fiber intakes. The findings support the hypothesis that higher postprandial glycemia is a universal mechanism for disease progression.     

Physical activity, diabetes, and risk of thyroid cancer: a systematic review and meta-analysis

Thyroid cancer incidence has been increasing more rapidly over time than the occurrence of cancers of other sites, and interest in potential adverse relations of diabetes and lack of physical activity to thyroid cancer risk is accumulating. We conducted a systematic review and meta-analysis of published epidemiologic studies on the relations of physical activity and diabetes to thyroid cancer according to the Meta-analysis of Observational Studies in Epidemiology guidelines. Published studies were identified through a search in MEDLINE and EMBASE. Random-effects models were used to summarize thyroid cancer risk estimates comparing high versus low levels of physical activity, and separately, comparing individuals with diabetes versus those without diabetes. Meta-regression analyses were performed to evaluate potential effect modification by study design and thyroid cancer risk factors. Information was extracted from seven studies of physical activity and thyroid cancer and from six studies of diabetes and thyroid cancer. The number of individuals from studies on physical activity was 939,305 (yielding 2,250 incident thyroid cancer cases) and from studies on diabetes it was 960,840 (yielding 1,230 cases). The summary relative risk (RR) estimate from cohort and case–control studies combined indicated no association between physical activity and thyroid cancer (summary RR 1.06, 95 % confidence interval (CI) 0.79–1.42). Subgroup-analyses revealed a significant positive association between physical activity and thyroid cancer in cohort studies (summary RR 1.28; 95 % CI 1.01–1.63), whereas the relation was suggestively inverse in case–control studies (summary RR 0.70; 95 % CI 0.48–1.03; p for heterogeneity = 0.005). Individuals with diabetes showed a borderline statistically significant increased risk of thyroid cancer compared with those without diabetes (summary RR 1.17; 95 % CI 0.99–1.39). The relations of physical activity and diabetes to thyroid cancer were not modified by sex, number of adjustment factors, and adjustments for adiposity, smoking, and study quality. In this comprehensive systematic review and meta-analysis, no significant association between physical activity and thyroid cancer was found. Diabetes showed a suggestive positive relation with risk of thyroid cancer.     

Dietary Carbohydrate and Prostate Cancer Risk: A Meta-Analysis

Carbohydrate intake has been inconsistently associated with risk of prostate cancer. We review and quantitatively summarize the evidence from observational studies in a meta-analysis. We searched the PubMed database for observational studies related to the association of carbohydrate intake and prostate cancer risk up to December 25, 2013. Summary relative risks (RRs) were estimated by the use of a random effects model. We included 13 case-control studies with 4,367 cases and 6,205 controls, and 5 cohort studies with 3,679 cases and 74,115 participants in this meta-analysis. The summary RR of prostate cancer for the highest vs. the lowest carbohydrate intake was 1.06 [95% confidence interval (CI): 0.93–1.20, I² = 46.8%] for all included studies. In the subgroup analyses stratified by study design, the summary RRs for the highest vs. the lowest carbohydrate intake were 1.04 (95% CI: 0.87–1.23) for case-control studies and 1.06 (95% CI: 0.88–1.28) for cohort studies. For the 5 studies that reported results for advanced prostate cancer, the summary RR was 0.92 (95% CI: 0.71–1.20). This meta-analysis of observational studies indicates that there is no association between carbohydrate intake and prostate cancer risk. Further studies are needed to confirm our findings.     

From embouchure problems to embouchure dystonia? A survey of self-reported embouchure disorders in 585 professional orchestra brass players

Objectives

Data concerning embouchure problems in professional brass players are scarce. Embouchure problems can potentially lead to focal dystonia. The aim of this study was to investigate the frequency of distinct embouchure problems in professional brass players. Furthermore, the frequency of “cramping”, a distinct symptom of embouchure dystonia, was evaluated in the context of established embouchure dystonia risk factors.

Methods

Five hundred and eighty-five professional brass players participated in a cross-sectional study concerning embouchure problems. A self-administered questionnaire was developed to evaluate embouchure fatigue, embouchure disorders and their consequences. To study the association between risk factors and cramping (a symptom of embouchure dystonia), a log-binomial regression analysis was conducted, enabling estimation of prevalence ratios (PR) and 95 % confidence intervals (95 % CI).

Results

Thirty percent (95 % CI 25.9–33.3) reported embouchure fatigue. The relative frequency of embouchure disorders was 59 % (95 % CI 54.6–63.6), with 26 % (95 % CI 22.4–29.5) reporting embouchure cramping. Embouchure disorders resulted in sick leave in 16 % (95 % CI 12.7–20.6). Female brass players (PR 2.0, 95 % CI 0.98–3.98) and musicians with a prior change in their embouchure (PR 2.4, 95 % CI 1.38–4.05) or breathing technique (PR 2.2, 95 % CI 1.25–3.72) and musicians with embouchure fatigue (PR 1.9, 95 % CI 1.18–2.93) presented more frequently with embouchure cramping than musicians with other or without risk factors.

Conclusion

This study shows a high relative frequency of embouchure problems in professional brass players. Given that embouchure dystonia is often preceded by embouchure problems, these findings may assist in gaining further insight into the characteristics of embouchure dystonia and the development of preventive strategies.     

Exposure to disturbing noise and risk of long-term sickness absence among office workers: a prospective analysis of register-based outcomes

Purpose

To investigate the association between self-reported exposure to disturbing noise and risk of long-term sickness absence (LTSA) for more than two consecutive weeks among office workers.

Methods

LTSA was measured using register data that were linked to survey data from 2,883 office workers aged 18–59 who were surveyed in 2005 on exposure to disturbing noise. The risk of LTSA was investigated using Cox proportional hazards model.

Results

Of the study population, 4.4 % had LTSA in the 1-year follow-up period. Compared to office workers who were ‘rarely or never’ exposed to disturbing noise at work, office workers who reported being ‘frequently’ exposed to disturbing noise had a significantly increased estimated risk of LTSA when adjusting for age, gender, smoking status, and managerial position (HR = 1.90; 95 % CI, 1.12–3.22). After additional adjustment for psychosocial work conditions, the estimated risk of LTSA for office workers who were frequently exposed to disturbing noise became marginally insignificant (HR = 1.73; 95 % CI, 0.99–3.01). A subgroup analysis showed that women who reported being frequently exposed to disturbing noise had a significantly increased estimated risk of LTSA (HR = 1.94; 95 % CI, 1.04–3.64), whereas the corresponding risk for men was insignificant (HR = 1.28; 95 % CI, 0.37–4.41).

Conclusions

This study indicates that frequent self-reported exposure to disturbing noise at work is associated with increased risk of LTSA among office workers and that this association may be stronger for women than for men.     

Dietary patterns related to glycemic index and load and risk of premenopausal and postmenopausal breast cancer in the Western New York Exposure and Breast Cancer Study

BACKGROUND: Reduced rank regression (RRR) has been used to identify dietary patterns that predict variation in a selected risk factor and may be useful in describing dietary exposures associated with glycemic index (GI) and glycemic load (GL). OBJECTIVE: To estimate breast cancer risk, we compared the relative utility of RRR-derived dietary patterns predictive of GI and GL with those of simple GI and GL. DESIGN: RRR was used to identify dietary patterns predicting GI and GL from food-frequency data obtained in the Western New York Exposure and Breast Cancer Study (1166 cases, 2105 controls). Odds ratios (ORs) and 95% CIs were estimated with unconditional logistic regression, adjusted for energy and nondietary breast cancer risk factors. RESULTS: Sweets, refined grains, and salty snacks explained 34% of the variance in GI and 68% of the variance in GL. In general, breast cancer risks were not associated with GI, GL, or dietary pattern score. However, we observed a significant reduction in postmenopausal breast cancer risk with GI and GL pattern scores combined (OR: 0.68; 95% CI: 0.50, 0.93), especially in women with a body mass index (in kg/m(2)) >or=25 (OR: 0.64; 95% CI: 0.44, 0.93). Conversely, in premenopausal women, increased risks were associated with high GL pattern scores only for women with a body mass index >or=25 (OR: 2.21; 95% CI: 1.04, 4.69). CONCLUSIONS: Although RRR may be useful in studies of diet and disease, our results suggest that RRR dietary patterns based on GI and GL provide similar information regarding the association between breast cancer, GI, and GL.