High-dose thiamine supplementation may reduce resting energy expenditure in individuals with hyperglycemia: a randomized, double � blind cross-over trial

Background: Despite the crucial role of thiamine in glucose and energy metabolism pathways, there has been no published study examining the impact of thiamine on energy metabolism in humans. Objective: To assess the effects of thiamine supplementation on resting energy expenditure (REE) in individuals with hyperglycemia. Methods: Twelve hyperglycemic patients completed this double-blind, randomized trial, where all participants received both thiamine (300 mg/day) and matched placebo for 6 weeks in a cross-over manner. REE was assessed by indirect calorimetry. Anthropometric measurements, fasting and 2-h plasma glucose, and glucose-induced thermogenesis were also assessed at the beginning and on the completion of each six-week phase. Results: Participants consuming thiamine supplements experienced a significant decrease in the REE assessed at week six compared to the baseline mean (SE): 1478.93 (73.62) vs.1526.40 (73.46) kcal/d, p = 0.02, and the placebo arm (p = 0.002). These results did not change significantly after adjusting for the participants� body weight and physical activity as potential confounders. Six-week intervention had no significant effect on the participants� body weight or waist circumference, in either supplement or placebo arms (all p values>0.05). However, correlation analysis highlighted significant positive relationships between the changes in REE, and those in fasting (rs = 0.497, p = 0.019) and 2-h plasma glucose (rs = 0.498, p = 0.018) during the six-week intervention period. Conclusion: Supplementation with high-dose thiamine may attenuate REE in patients with impaired glucose regulation. Our findings suggest that the impact of thiamine on REE may in part be explained by improved glycemic control. Trial registration: Australian New Zealand Clinical Trials Registry ACTRN12611000051943. https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12611000051943. © 2020, Springer Nature Switzerland AG

Constellation Shaping and LDPC Coding in a Bidirectional Full Duplex Communication

We investigate the ability of the physical layer approaches of constellation shaping and forward error correction to enhance the performance of full duplex (FD) wireless radio systems. We use low density parity check and optimized shaping codes to transmit non-equiprobable constellation points from an amplitude phase shift keying modulation with imperfect power amplifier and in the presence of FD residual self interference. A simple approach to the design of optimized shaping codes for a given signal to noise ratio and residual self interference power is presented. Simulation results show that a FD transceiver with bit interleaved coded modulation, optimized shaping and iterative demodulation and decoding noticeably improves the performance in comparison to the same system without constellation shaping

Constellation Shaping and LDPC Coding in a Bidirectional Full Duplex Communication

We investigate the ability of the physical layer approaches of constellation shaping and forward error correction to enhance the performance of full duplex (FD) wireless radio systems. We use low density parity check and optimized shaping codes to transmit non-equiprobable constellation points from an amplitude phase shift keying modulation with imperfect power amplifier and in the presence of FD residual self interference. A simple approach to the design of optimized shaping codes for a given signal to noise ratio and residual self interference power is presented. Simulation results show that a FD transceiver with bit interleaved coded modulation, optimized shaping and iterative demodulation and decoding noticeably improves the performance in comparison to the same system without constellation shaping

A Type II Hybrid ARQ Protocol with Adaptive Modulation and Coding for Time-Correlated Fading Channels: Analysis and Design

This paper presents performance analysis and cross-layer design approaches for hybrid ARQ (HARQ) protocol in wireless networks which employ adaptive modulation and coding (AMC) at the physical layer and are subject to time-correlated fading channels. Utilizing a Markov channel model which accounts for the temporal correlation in successive parity transmissions by the adaptive rate HARQ protocol, we derive the system throughput and the packet loss probability based on a rate compatible punctured convolutional (RCPC) code family. As an application, we then present a cross-layer AMC design which takes into account the performance gain of the HARQ protocol at the link layer. The results illustrate that including AMC in the HARQ protocol leads to a substantial throughput gain, but the channel correlation strongly diminishes the performance of the HARQ protocol in terms of throughput and packet loss rate

Analysis of Non-Cooperative and Cooperative Type II Hybrid ARQ Protocols with AMC over Correlated Fading Channels

This paper presents performance analysis and cross-layer design approaches for hybrid ARQ (HARQ) protocols in wireless networks, which employ adaptive modulation and coding (AMC) in conjunction with adaptive cooperative diversity and are subject to time-correlated fading channels. We first consider a point-to-point scenario, i.e., non-cooperative HARQ with AMC. Utilizing a Markov channel model which accounts for the temporal correlation in the successive transmission of incremental redundancy by the HARQ protocol, we derive the system throughput and the packet loss probability based on a rate compatible punctured convolutional code family. Next, we consider a cooperative HARQ (CHARQ) scheme in which a relay node, also equipped with AMC, retransmits redundancy packets when it is able to decode the source information packet correctly. For this scenario, we also derive the throughput and packet loss performance. Finally, we present a cross-layer AMC design approach which takes into account the hybrid ARQ protocol at the link layer. The results illustrate that including AMC in the HARQ protocols leads to a substantial throughput gain. While the performance of the AMC with HARQ protocol is strongly affected by the channel correlation, the CHARQ protocol provides noticeable performance gains over correlated fading channels as well

Association between dietary patterns and depressive symptoms in adult women living in Tehran (2013)

Background: Depression is one of the most common mental illnesses. Few studies have investigated the association between dietary patterns and depression in developing countries. Objective: The aim of this study was to determine the association between dietary patterns and depressive symptoms in adult women living in Tehran in 2013. Methods: This cross-sectional study was carried on 217 women aged 20-45 years attending health centers in the north and west of Tehran in 2013. The subjects were selected by systematic cluster sampling method. Data were collected through demographic, food frequency, and physical activity questionnaires and the beck depression inventory. Major dietary patterns were identified by factor analysis and their association with depressive symptoms was assessed by logistic regression analysis. Findings: The prevalence of depressive symptoms was 63.2% in the studied women. Two major dietary patterns were identified (healthy and unhealthy). After adjusting for confounders, subjects with higher scores in the unhealthy dietary pattern had higher odds (OR=2.21, P=0.01) of depressive symptoms; but the healthy dietary pattern was not associated with depressive symptoms. Conclusion: With regards to the results, it seems that the unhealthy dietary pattern is associated with the risk of depression in women

Triglyceride Glucose Index and Related Parameters (Triglyceride Glucose-Body Mass Index and Triglyceride Glucose-Waist Circumference) Identify Nonalcoholic Fatty Liver and Liver Fibrosis in Individuals with Overweight/Obesity

Background: The triglyceride glucose (TyG) index has been proposed as a reliable surrogate marker for nonalcoholic fatty liver disease (NAFLD). Furthermore, NAFLD is strongly related with obesity. This study aimed to compare TyG index and its related parameters (TyG-waist circumference WC and TyG-body mass index BMI), comprising TyG and obesity markers, in predicting NAFLD and liver fibrosis in overweight/obese individuals without diabetes. Methods: This was a cross-sectional study consisting of 184 overweight/obese people (96 with and 88 without NAFLD), 30-65 years of age. TyG, TyG-BMI, and TyG-WC were computed using the established formula. Liver stiffness measurement (LSM) and controlled attenuation parameter (CAP) were determined by transient elastography (FibroScan). Results: In correlation analyses, CAP and LSM were significantly associated with WC, BMI, TyG, TyG-BMI, and TyG-WC. Regression analyses highlighted TyG-WC as a significant predictor of NAFLD, with the highest standardized odds ratio (2.25, P < 0.001); while liver fibrosis was associated more strongly with TyG-BMI. In receiver operating characteristic (ROC) analysis, TyG-WC showed the largest area under the ROC curve (AUC) for detection of NAFLD (0.693, 95% confidence interval CI: 0.617-0.769). However, TyG-BMI was a better discriminator of liver fibrosis (AUC: 0.635, 95% CI: 0.554-0.714). TyG-WC value of 876 (sensitivity: 81.3%, specificity: 52.3%) and TyG-BMI value of 259 (sensitivity: 78.3%, specificity: 51.3%) were the optimal cutoff points to predict NAFLD and liver fibrosis, respectively. Conclusions: The results highlight the significant associations of TyG and its related indices with NAFLD, with TyG-WC being a better indicator. TyG-BMI and TyG-WC could reliably predict liver fibrosis in this population. These indices appear to be simple, practical, and affordable tools for screening NAFLD and liver fibrosis in clinical settings. © Copyright 2021, Mary Ann Liebert, Inc., publishers