Physical activity and risk of Amyotrophic Lateral Sclerosis in a prospective cohort study.

Previous case-control studies have suggested a possible increased risk of Amyotrophic Lateral Sclerosis (ALS) with physical activity (PA), but this association has never been studied in prospective cohort studies. We therefore assessed the association between PA and risk of death from ALS in the European Prospective Investigation into Cancer and Nutrition. A total of 472,100 individuals were included in the analysis, yielding 219 ALS deaths. At recruitment, information on PA was collected thorough standardised questionnaires. Total PA was expressed by the Cambridge Physical Activity Index (CPAI) and analysed in relation to ALS mortality, using Cox hazard models. Interactions with age, sex, and anthropometric measures were assessed. Total PA was weakly inversely associated with ALS mortality with a borderline statistically significant trend across categories (p = 0.042), with those physically active being 33% less likely to die from ALS compared to those inactive: HR = 0.67 (95% CI 0.42-1.06). Anthropometric measures, sex, and age did not modify the association with CPAI. The present study shows a slightly decreased-not increased like in case-control studies-risk of dying from ALS in those with high levels of total PA at enrolment. This association does not appear confounded by age, gender, anthropometry, smoking, and education. Ours was the first prospective cohort study on ALS and physical activity.

Validation of anthropometric indices of adiposity against whole-body magnetic resonance imaging--a study within the German European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts.

BACKGROUND: In epidemiological studies, measures of body fat generally are obtained through anthropometric indices such as the body mass index (BMI), waist (WC), and hip circumferences (HC). Such indices, however, can only provide estimates of a person's true body fat content, overall or by adipose compartment, and may have limited accuracy, especially for the visceral adipose compartment (VAT). OBJECTIVE: To determine the extent to which different body adipose tissue compartments are adequately predicted by anthropometry, and to identify anthropometric measures alone, or in combination to predict overall adiposity and specific adipose tissue compartments, independently of age and body size (height). METHODS: In a sub-study of 1,192 participants of the German EPIC (European Prospective Investigation into Cancer and Nutrition) cohorts, whole-body MRI was performed to determine adipose and muscle tissue compartments. Additional anthropometric measurements of BMI, WC and HC were taken. RESULTS: After adjusting for age and height, BMI, WC and HC were better predictors of total body volume (TBV), total adipose tissue (TAT) and subcutaneous adipose tissue (SAT) than for VAT, coronary adipose tissue (CAT) and skeletal muscle tissue (SMT). In both sexes, BMI was the best predictor for TBV (men: r = 0.72 [0.68-0.76], women: r = 0.80 [0.77-0.83]) and SMT (men: r = 0.52 [0.45-0.57], women: r = 0.48 [0.41-0.54]). WC was the best predictor variable for TAT (r = 0.48 [0.41-0.54]), VAT (r = 0.44 [0.37-0.50]) and CAT (r = 0.34 [0.26-0.41]) (men), and for VAT (r = 0.42 [0.35-0.49]) and CAT (r = 0.29 [0.22-0.37]) (women). BMI was the best predictor for TAT (r = 0.49 [0.43-0.55]) (women). HC was the best predictor for SAT (men (r = 0.39 [0.32-0.45]) and women (r = 0.52 [0.46-0.58])). CONCLUSIONS: Especially the volumes of internal body fat compartments are poorly predicted by anthropometry. A possible implication may be that associations of chronic disease risks with the sizes of internal body fat as measured by BMI, WC and HC may be strongly underestimated.

Validity of electronically administered Recent Physical Activity Questionnaire (RPAQ) in ten European countries.

OBJECTIVE: To examine the validity of the Recent Physical Activity Questionnaire (RPAQ) which assesses physical activity (PA) in 4 domains (leisure, work, commuting, home) during past month. METHODS: 580 men and 1343 women from 10 European countries attended 2 visits at which PA energy expenditure (PAEE), time at moderate-to-vigorous PA (MVPA) and sedentary time were measured using individually-calibrated combined heart-rate and movement sensing. At the second visit, RPAQ was administered electronically. Validity was assessed using agreement analysis. RESULTS: RPAQ significantly underestimated PAEE in women [median(IQR): 34.9 (22.3, 52.8) vs. 40.6 (32.4, 50.9) kJ/kg/day, 95%LoA: -44.4, 66.1 kJ/kg/day) and overestimated PAEE in men [45.9 (30.6, 71.1) vs. 45.5 (34.1, 57.6) kJ/kg/day, 95%LoA: -44.8, 102.6 kJ/kg/day]. Using individualised definition of 1MET, RPAQ significantly underestimated MVPA in women [median(IQR): 63.7 (30.5, 126.9) vs. 73.6 (47.8, 107.2) min/day, 95%LoA: -127.4, 311.9 min/day] and overestimated MVPA in men [90.0 (42.3, 188.6) vs. 83.3 (55.1, 125.0) min/day, 95%LoA: -134.8, 427.3 min/day]. Correlations (95%CI) between subjective and objective estimates were statistically significant [PAEE: women, rho = 0.20 (0.15-0.26); men, rho = 0.37 (0.30-0.44); MVPA: women, rho = 0.18 (0.13-0.24); men, rho = 0.31 (0.24-0.38)]. When using non-individualised definition of 1MET (3.5 mlO2/kg/min), MVPA was substantially overestimated (16 min/day, and 32 min/day in women and men, respectively). Revisiting occupational intensity assumptions in questionnaire estimation algorithms with occupational group-level empirical distributions reduced median PAEE-bias in manual (38.8 kJ/kg/day vs. 6.8 kJ/kg/day, p<0.001) and heavy manual workers (63.6 vs. -2.8 kJ/kg/day, p<0.001) in an independent hold-out sample [corrected]. CONCLUSION: Relative validity of RPAQ-derived PAEE and MVPA is comparable to previous studies but underestimation of PAEE is smaller. Electronic RPAQ may be used in large-scale epidemiological studies including surveys, providing information on all domains of PA.

Predictors of hair cortisol concentrations in older adults.

People at older ages are at increased risk for developing stress-related diseases associated with chronically elevated cortisol secretion. However, the main factors contributing to such endocrine alterations in this age group are still largely unknown. This cross-sectional study examined patterns of long-term integrated cortisol secretion, as assessed in hair, in a sample of 654 participants in middle and old adulthood (mean age: 65.8 years; range: 47-82 years) from the German cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC) study in Potsdam. Hair cortisol concentrations (HCC) were determined from the first scalp-near 3 cm hair segment and several sociodemographic, lifestyle, anthropometric, disease-related, and psychological parameters were assessed. In simple linear regressions, HCC were found to increase with participants' age and to be higher in men compared to women. HCC also showed positive associations with waist-to-hip ratio, waist circumference, smoking, prevalent type 2 diabetes mellitus, mental health, daytime sleeping, and being unemployed or retired--as well as a negative association with diastolic blood pressure. After full mutual adjustment, only age and smoking remained independent predictors of HCC. The association between prevalent type 2 diabetes mellitus and HCC was attenuated but still persisted independently in women. Similar, a positive relationship between HCC and alcohol consumption was found in women. The current results confirm previous evidence of positive associations of HCC with age, sex, alcohol consumption, and type 2 diabetes mellitus and add new knowledge on factors--such as smoking--that may contribute to elevated cortisol levels in people at older ages.

Serum metabolites related to cardiorespiratory fitness, physical activity energy expenditure, sedentary time and vigorous activity.

The aim of our study was to investigate the relationship between objectively measured physical activity (PA) and cardiorespiratory fitness (CRF) and serum metabolites measured by targeted metabolomics in a population- based study. A total of 100 subjects provided 2 fasting blood samples and engaged in a CRF and PA measurement at 2 visits 4 months apart. CRF was estimated from a step test, whereas physical activity energy expenditure (PAEE), time spent sedentary and time spend in vigorous activity were measured by a combined heart rate and movement sensor for a total of 8 days. Serum metabolite concentrations were determined by flow injection analysis tandem mass spectrometry (FIA-MS/MS). Linear mixed models were applied with multivariable adjustment and p-values were corrected for multiple testing. Furthermore, we explored the associations between CRF, PA and two metabolite factors that have previously been linked to risk of Type 2 diabetes. CRF was associated with two phosphatidylcholine clusters independently of all other exposures. Lysophosphatidylcholine C14:0 and methionine were significantly negatively associated with PAEE and sedentary time. CRF was positively associated with the Type 2 diabetes protective factor. Vigorous activity was positively associated with the Type 2 diabetes risk factor in the mutually adjusted model. Our results suggest that CRF and PA are associated with serum metabolites, especially CRF with phosphatidylcholines and with the Type 2 diabetes protective factor. PAEE and sedentary time were associated with methionine. The identified metabolites could be potential mediators of the protective effects of CRF and PA on chronic disease risk.

Life satisfaction and risk of chronic diseases in the European prospective investigation into cancer and nutrition (EPIC)-Germany study.

OBJECTIVE: The aim of the study was to examine the prospective association between life satisfaction and risk of type 2 diabetes mellitus, myocardial infarction, stroke, and cancer. Previous studies suggested that psychosocial factors may affect the development of chronic diseases but the impact of positive attitudes, in particular life satisfaction, is yet to be determined. METHODS: The analysis included 50,358 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Germany study in Potsdam and Heidelberg. Life satisfaction was assessed in a baseline interview and incident cases of chronic diseases were identified and verified during follow-up. Hazard ratios were calculated using Cox proportional hazards regression models that were systematically multivariable-adjusted for established risk factors and prevalent diseases. RESULTS: During an average of 8 years of follow-up 2,293 cases of cancer, 1,840 cases of type 2 diabetes mellitus, 440 cases of stroke, and 562 cases of myocardial infarction were observed. Women who were unsatisfied with life at baseline showed in all models a significantly increased risk of cancer (HR: 1.45; 95% CI: 1.18-1.78) and stroke (HR: 1.69; 95% CI: 1.05-2.73) as well as an increased risk of type 2 diabetes mellitus by trend across categories (p-trend=0.04) compared to women very satisfied with life. In men, a relationship between life satisfaction and stroke was found but did not persist after consideration of lifestyle factors and prevalent diseases. No significant association was observed between life satisfaction and risk of myocardial infarction. CONCLUSIONS: The results of this study suggest that reduced life satisfaction is related to the development of chronic diseases--particularly in women and partly mediated by established risk factors.

Prediagnostic body fat and risk of death from amyotrophic lateral sclerosis: the EPIC cohort.

OBJECTIVES: The aim of this study was to investigate for the first time the association between body fat and risk of amyotrophic lateral sclerosis (ALS) with an appropriate prospective study design. METHODS: The EPIC (European Prospective Investigation into Cancer and Nutrition) study included 518,108 individuals recruited from the general population across 10 Western European countries. At recruitment, information on lifestyle was collected and anthropometric characteristics were measured. Cox hazard models were fitted to investigate the associations between anthropometric measures and ALS mortality. RESULTS: Two hundred twenty-two ALS deaths (79 men and 143 women) occurred during the follow-up period (mean follow-up = 13 years). There was a statistically significant interaction between categories of body mass index and sex regarding ALS risk (p = 0.009): in men, a significant linear decrease of risk per unit of body mass index was observed (hazard ratio = 0.93, 95% confidence interval 0.86-0.99 per kg/m(2)); among women, the risk was more than 3-fold increased for underweight compared with normal-weight women. Among women, a significant risk reduction increasing the waist/hip ratio was also evident: women in the top quartile had less than half the risk of ALS compared with those in the bottom quartile (hazard ratio = 0.48, 95% confidence interval 0.25-0.93) with a borderline significant p value for trend across quartiles (p = 0.056). CONCLUSION: Increased prediagnostic body fat is associated with a decreased risk of ALS mortality.

Physical activity and lymphoid neoplasms in the European Prospective Investigation into Cancer and nutrition (EPIC).

BACKGROUND: Lymphoid neoplasms are a heterogeneous group of cancers that originate in the lymphatic cells of the immune system. Several risk factors have been identified or suggested, but they all account for only a small proportion of the lymphoid neoplasm incidence. It has been hypothesised that regular exercise may modulate the immune system and thereby reduce the risk of developing the disease. DESIGN AND METHODS: The European Investigation into Cancer and Nutrition (EPIC) cohort consists of 521,457 adults, recruited by 23 centres in 10 European countries. The analytical cohort included 343,756 participants, with 778 non-Hodgkin lymphoma (NHL) cases (376 men and 402 women) and 690 B-cell non-Hodgkin lymphoma (B-NHL) cases (326 men and 364 women). Multivariate Cox regression models were used to calculate hazard ratios (HR) for the association between total, recreational, occupational, and household physical activity and NHL and B-NHL risk, as well as the risk for several B-NHL subtypes. Models were stratified by study centre and age at recruitment and adjusted for various potential confounding factors. RESULTS: We found no evidence of any effect of total physical activity on NHL (adjusted p-trend=0.76 and 0.30 for men and women, respectively) and B-NHL risk (adjusted p-trend=0.99 and 0.21 for men and women, respectively) for either men or women. Also no robust results were found for B-NHL subtype analyses among men or women. CONCLUSIONS: This study provided no consistent evidence for an association between various physical activity measures and the risk of lymphoid neoplasms or any of the B-NHL subtypes.