Relationships between questionnaire ratings of sleep quality and polysomnography in healthy adults

This study aimed to examine the association between polysomnographic sleep and subjective habitual sleep quality and restoration from sleep. Thirty-one normal sleepers completed the Karolinska Sleep Questionnaire and multiple home polysomnography recordings (n = 2-5). Using linear regression, sleep quality and restoration were separately analyzed as functions of standard polysomnography parameters: sleep efficiency, total sleep time, sleep latency, stage 1 and 2 sleep, slow-wave sleep, rapid eye movement sleep, wake time after sleep onset, and awakenings (n), averaged across recordings. Stage 2 and slow-wave sleep predicted worse and better sleep quality, respectively. Also, slow-wave sleep predicted less subjective restoration, although adjustment for age attenuated this relation. Our findings lend some physiological validity to ratings of habitual sleep quality in normal sleepers. Data were less supportive of a physiological correlate of ratings of restoration from sleep

Dietary non-enzymatic antioxidant capacity and risk of stroke: The Swedish Women's Lifestyle and Health Cohort

Objective: Consumption of antioxidant-rich foods has been associated with a reduced risk for stroke. However, antioxidant supplementation is not recommended owing to controversial findings reported in clinical trials. The aim of this study was to better understand the effect of dietary antioxidants by investigating the effect of dietary non-enzymatic antioxidant capacity (NEAC), reflecting the antioxidant potential of the whole diet, on the risk for stroke. Methods: In the Women's Lifestyle and Health Cohort, 45 882 women 30 to 49 y of age and free from cardiovascular diseases were followed through record linkages from 1991 to 2012. Dietary NEAC was assessed by a validated food frequency questionnaire collected at baseline and categorized into quintiles. Multivariable Cox proportional hazard regression models were fitted to estimate hazard ratios with 95% confidence intervals for overall stroke and ischemic and hemorrhagic stroke separately. Results: During a mean follow-up time of 20.2 y, we detected 871 incidence cases of stroke (516 ischemic, 296 hemorrhagic, and 59 unspecified strokes). After adjusting for potential confounders, we did not find any association between dietary NEAC and stroke, either overall, or ischemic or hemorrhagic stroke (Ptrend > 0.05). Conclusion: Higher dietary NEAC was not associated with any type of stroke in young and middle-aged Swedish women

Dietary Antioxidants and the Risk of Parkinson Disease: The Swedish National March Cohort

OBJECTIVE: To determine whether high baseline dietary antioxidants and total nonenzymatic antioxidant capacity (NEAC) is associated with a lower risk of Parkinson disease (PD) in men and women, we prospectively studied 43,865 men and women from a large Swedish cohort. METHODS: In the Swedish National March Cohort, 43,865 men and women aged 18-94 years were followed through record linkages to National Health Registries from 1997 until 2016. Baseline dietary vitamin E, vitamin C, and beta-carotene intake, as well as NEAC, were assessed by a validated food frequency questionnaire collected at baseline. All exposure variables were adjusted for energy intake and categorized into tertiles. Multivariable Cox proportional hazard regression models were fitted to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for PD. RESULTS: After a mean follow-up time of 17.6 years, we detected 465 incidence cases of PD. In the multivariable adjusted model, dietary vitamin E (HR 0.68, 95% CI 0.52-0.90; p for trend 0.005) and vitamin C (HR 0.68, 95% CI 0.52-0.89; p for trend 0.004) were inversely associated with the risk of PD when comparing participants in the highest vs the lowest tertiles of exposure. No association was found with estimated intake of dietary beta-carotene or NEAC. CONCLUSION: Our findings suggest that dietary vitamin E and C intake might be inversely associated with the risk of PD. No association was found with dietary beta-carotene or NEAC. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that dietary vitamin E and C intake are inversely associated with the risk of PD

Dietary antioxidants, non-enzymatic antioxidant capacity and the risk of osteoarthritis in the Swedish National March Cohort

Purpose: Oxidative stress might play an important role in the development of osteoarthritis, but not much is known about the effect of antioxidants on osteoarthritis risk. We, therefore, aimed to investigate the effect of dietary vitamin C, E, beta-carotene, and non-enzymatic antioxidant capacity (NEAC), which measures overall antioxidant activity from the diet, on the risk of osteoarthritis. Methods: For this study 43,865 men and women from the Swedish National March Cohort (SNMC) were followed for up to 19 years. We computed dietary intake of vitamin C, E and beta-carotene using information from a Food Frequency Questionnaire (FFQ). To estimate dietary NEAC we combined the information from the FFQ with food item-specific antioxidant capacity values from an antioxidant food database. Cases of osteoarthritis were identified through the Swedish National Patient Registers. We categorized all exposure variables into sex-specific quartiles and used multivariable-adjusted Cox proportional hazards regression models to estimate hazard ratios (HRs) with 95% confidence intervals (95% CIs). Results: In total, we observed 5976 cases of OA during 469,148 person-years of follow-up. After adjusting for potential confounders, we did not find any association between vitamin C, beta-carotene and NEAC (p-values for trend > 0.5), but a positive association was found with higher dietary vitamin E intake (HR Q4 vs Q1: 1.11; 95% CI 1.02\u20131.21; p for trend = 0.01) and the risk of OA. Conclusion: Our findings do not provide evidence for dietary antioxidants to protect from the development of OA, and a higher dietary vitamin E intake might even increase the risk

Physical activity as a determinant of mortality in women

Background: There is substantial evidence that higher levels of activity reduce the risk of mortality, but several research questions remain about the protective effect of physical activity. We aimed to quantify the effect of physical activity on overall mortality in younger women and to assess the effect of past versus current activity. Methods: During 1991-1992, we enrolled 99,099 women, age 30-49 years, from the entire country of Norway and one Swedish region, in a population-based cohort study. The women provided information on physical activity level at age 14 and 30 years and at enrollment, as well as information on other personal characteristics at enrollment. We achieved complete follow-up into 2003 using record linkages to nationwide registers. We used Cox proportional hazard models to calculate multivariate relative risks (RRs) of dying from any cause. Results: During an average 11.4 years of follow-up, 1,313 women died. Risk of death decreased with increasing physical activity at enrollment (5 categories; P for trend < 0.0001) and was reduced by half in the highest compared with the lowest category (RR = 0.46; 95% confidence intervals = 0.33-0.65). This protective effect was consistent across strata of age at entry, smoking, country, and education. After adjustment for physical activity at enrollment, activity at age 14 and 30 was not associated with mortality. Conclusions: Current physical activity substantially reduces mortality among women. This association is observed even with low levels of physical activity and is accentuated with increased physical activity