Eating quickly is associated with a low aspartate aminotransferase to alanine aminotransferase ratio in middle-aged adults: a large-scale cross-sectional survey in Japan.

BACKGROUND: An elevated alanine aminotransferase (ALT) and a low aspartate aminotransferase (AST) to ALT ratio (AST/ALT ratio) suggest nonalcoholic fatty liver disease and nonalcoholic steatohepatitis, increasing the risk of liver cirrhosis and hepatocellular carcinoma. In addition, eating quickly has been found to be associated with outcomes such as obesity. This study sought to investigate the relationship between eating quickly and an elevated ALT or a low AST/ALT ratio in Japanese middle-aged adults. METHODS: The present study included 283,073 adults aged 40-64 years who had annual health checkups in Japan from April 2013 to March 2014. The data of serum parameters and lifestyle factors, including eating speed, were analyzed. An elevated ALT was defined as > 40 U/L, and a low AST/ALT ratio was defined as < 1. Logistic regression analysis was performed to calculate the odds ratios (ORs) and the 95% confidence intervals (CIs) for an elevated ALT and a low AST/ALT ratio. RESULTS: Significantly increased ORs for an elevated ALT were observed in men (OR: 1.45, 95% CI: 1.41-1.49) and women (OR: 1.34, 95% CI: 1.25-1.43). Moreover, eating quickly significantly increased the ORs for a low AST/ALT ratio in men (OR: 1.53, 95% CI: 1.50-1.56) and women (OR: 1.36, 95% CI: 1.31-1.41). When the analysis was limited to those with ALT ≤40 U/L, eating quickly had significantly increased ORs for a low AST/ ALT ratio, regardless of sex. CONCLUSIONS: Eating quickly was significantly associated with an elevated ALT and a low AST/ALT ratio. In addition, eating quickly was significantly associated with a low AST/ALT ratio even for those without ALT elevation. This study suggested that modification of eating speed may contribute to reducing the risk for an elevated ALT and a low AST/ALT ratio.

Clustering of Lifestyle Factors and Its Association with Low Back Pain: A Cross-Sectional Study of Over 400,000 Japanese Adults.

PURPOSE: Although many studies have indicated the association between low back pain (LBP) and lifestyle factors, the combined effect of lifestyle factors on LBP has not been adequately investigated. We aimed to investigate the association between a cluster of unhealthy lifestyle behaviors and LBP using a large cohort of Japanese adults. METHODS: We included 419,003 adults aged over 20 years who underwent an annual health checkup between April 2013 and March 2014 in Japan. Information on the following lifestyle factors was collected using the standardized questionnaire: smoking, alcohol intake, exercise, physical activity, walking speed, weight control, eating habits, and sleep. Each factor was evaluated as a dichotomous variable (1: health risk, 0: no health risk). A lifestyle risk score was calculated by summing the score of each lifestyle factor (range: 0-12) and was categorized into three groups (low, moderate, high). LBP was defined as self-reported LBP under treatment. Logistic regression analysis was conducted to calculate the odds ratio (OR) and 95% confidence interval (CI) for LBP. RESULTS: In multivariable logistic regression analysis, the OR for LBP was significantly higher in the moderate-risk score group (adjusted OR: 1.33 [95% CI: 1.23-1.44] in men; 1.40 [95% CI: 1.27-1.54] in women) and the high-risk score group (adjusted OR: 1.54 [95% CI: 1.43-1.67] in men; 1.83 [95% CI: 1.64-2.03] in women) than in the low-risk score group. A trend of higher risk of LBP associated with higher lifestyle risk score was observed in both sexes (p for trend < 0.001). These results were similar even in subgroup analysis by age and body mass index (BMI). CONCLUSION: Clustering of unhealthy lifestyles was associated with increased risk of LBP regardless of age and BMI. These results may provide implications for better prevention and management of LBP, considering modifiable lifestyle factors.

Physical implementation of oblivious transfer using optical correlated randomness.

We demonstrate physical implementation of information-theoretic secure oblivious transfer based on bounded observability using optical correlated randomness in semiconductor lasers driven by common random light broadcast over optical fibers. We demonstrate that the scheme can achieve one-out-of-two oblivious transfer with effective key generation rate of 110 kb/s. The results show that this scheme is a promising approach to achieve information-theoretic secure oblivious transfer over long distances for future applications of secure computation such as privacy-preserving database mining, auctions and electronic-voting.

Information-theoretic secure key distribution based on common random-signal induced synchronization in unidirectionally-coupled cascades of semiconductor lasers.

It has been proposed that a secure key distribution scheme using correlated random bit sequences can be implemented using common random-signal induced synchronization of semiconductor laser systems. In this scheme it is necessary to use laser systems consisting of multiple cascaded lasers to be secure against a powerful eavesdropper. In this paper, we report the results of an experimental study that demonstrate that the common random-signal induced synchronization is possible in cascaded semiconductor laser systems. We also show that the correlated random bit sequences generated in the synchronized cascaded laser systems can be used to create an information-theoretically secure key between two legitimate users.

Theory of fast nondeterministic physical random-bit generation with chaotic lasers.

We theoretically show that completely stochastic fast physical random bit generation at a rate of more than one gigabit per second can be realized by using lasers with optical delayed feedback which creates high-dimensional chaos of laser light outputs. The theory is based on the mixing property of chaos, which transduces microscopic quantum noise of spontaneous emission in lasers into random transitions between discrete macroscopic states.

Experiment on synchronization of semiconductor lasers by common injection of constant-amplitude random-phase light.

We experimentally and numerically observe the synchronization between two semiconductor lasers induced by common optical injection with constant-amplitude and random-phase modulation in configurations with and without optical feedback. Large cross correlation (~0.9) between the intensity oscillations of the two response lasers can be achieved although the correlation between the drive laser and either one of the two response lasers is very small (~0.2). High quality synchronization is achieved in the presence of optical feedback in response lasers with matched feedback phase offset. We investigate the dependence of synchronization on parameter values over wide parameter ranges.

Secure key distribution using correlated randomness in lasers driven by common random light.

We propose a secure key distribution scheme based on correlated physical randomness in remote optical scramblers driven by common random light. The security of the scheme depends on the practical difficulty of completely observing random optical phenomena. We describe a particular realization using the synchronization of semiconductor lasers injected with common light of randomly varying phase. We experimentally demonstrate the feasibility of the scheme over a distance of 120 km.

Common-chaotic-signal induced synchronization in semiconductor lasers.

We experimentally and numerically observe synchronization of two semiconductor lasers commonly driven by a chaotic semiconductor laser subject to optical feedback. Under condition that the relaxation oscillation frequency is matched between the two response lasers, but mismatched between the drive and the two response lasers, we show that it is possible to observe strongly correlated synchronization between the two response lasers even when the correlation between the drive and response lasers is low. We also show that the cross correlation between the two responses is larger than that between drive and responses over a wide parameter region.