Modest weight loss and physical activity in overweight patients with chronic liver disease results in sustained improvements in alanine aminotransferase, fasting insulin, and quality of life

Background and aim: Obesity is a risk factor for progression of fibrosis in chronic liver diseases such as non-alcoholic fatty liver disease and hepatitis C. The aim of this study was to investigate the longer term effect of weight loss on liver biochemistry, serum insulin levels, and quality of life in overweight patients with liver disease and the effect of subsequent weight maintenance or regain. Patients: Thirty one patients completed a 15 month diet and exercise intervention. Results: On completion of the intervention, 21 patients (68%) had achieved and maintained weight loss with a mean reduction of 9.4 (4.0)% body weight. Improvements in serum alanine aminotransferase (ALT) levels were correlated with the amount of weight loss (r=0.35, p=0.04). In patients who maintained weight loss, mean ALT levels at 15 months remained significantly lower than values at enrolment (p=0.004), while in regainers (n=10), mean ALT levels at 15 months were no different to values at enrolment (p=0.79). Improvements in fasting serum insulin levels were also correlated with weight loss (r=0.46, p=0.04), and subsequent weight maintenance sustained this improvement. Quality of life was significantly improved after weight loss. Weight maintainers sustained recommended levels of physical activity and had higher fasting insulin levels (p=0.03) at enrolment than weight regainers. Conclusion: In summary, these findings demonstrate that maintenance of weight loss and exercise in overweight patients with liver disease results in a sustained improvement in liver enzymes, serum insulin levels, and quality of life. Treatment of overweight patients should form an important component of the management of those with chronic liver disease.

Impact of acute weight loss and/or thermal stress on rowing ergometer performance

Purpose: The impact of acute weight loss on rowing performance was assessed when generous nutrient intake was provided in 2 h of recovery after making weight. Methods: Competitive rowers (N = 17) completed four ergometer trials, each separated by 48 h. Two trials were performed after a 4% body mass loss in the previous 24 h (WT) and two were performed after no weight restrictions, that is, unrestricted (UNR). In addition, two trials (I X WT, I X UNR) were in a thermoneutral environment (NEUTRAL, mean 21.1 +/- SD 0.7 degrees C, 29.0 +/- 4.5% RH) and two were in the heat (HOT 32.4, +/- 0.4 degrees C, 60.4 +/- 2.7% RH). Trials were performed in a counterbalanced fashion according to a Latin square design. Aggressive nutritional recovery strategies (WT 2.3 g(.)kg(-11) carbohydrate, 34 mg-kg(-1) Na, 28.4 mL(.)kg(-1) fluid; UNR ad libitum) were employed in the 2 h after weigh-in. Results: Both WT (mean 2.1, 95% CI 0.7-3.4 s; P = 0.003) and HOT (4.1, 2.7 - 5.4 s; P < 0.001) compromised 2000-m time-trial performance. Whereas WT resulted in hypohydration, the associated reduction in plasma volume explained only part of the performance compromise observed (0.2 s for every 1% decrement) Moreover, WT did not influence core temperature or indices of cardiovascular function. Conclusions: Acute weight loss compromised performance, despite generous nutrient intake in recovery, although the effect was small. Performance decrements were further exacerbated when exercise was performed in the heat.

Acute weight loss followed by an aggressive nutritional recovery strategy has little impact on on-water rowing performance

Objectives: To assess the influence of moderate, acute weight loss on on-water rowing performance when aggressive nutritional recovery strategies were used in the two hours between weigh in and racing. Methods: Competitive rowers (n=17) undertook three on-water 1800 m time trials under cool conditions ( mean (SD) temperature 8.4 (2.0)degrees C), each separated by 48 hours. No weight limit was imposed for the first time trial-that is, unrestricted body mass (UNR1). However, one of the remaining two trials followed a 4% loss in body mass in the previous 24 hours (WT-4%). No weight limit was imposed for the other trial (UNR2). Aggressive nutritional recovery strategies (WT-4%, 2.3 g/kg carbohydrate, 34 mg/kg Na+, and 28.4 ml/kg fluid; UNR, ad libitum) were used in the first 90 minutes of the two hours between weigh in and performance trials. Results: WT-4% had only a small and statistically non-significant effect on the on-water time trial performance ( mean 1.0 second, 95% confidence interval (CI) 20.9 to 2.8; p=0.29) compared with UNR. This was despite a significant decrease in plasma volume at the time of weigh in for WT-4% compared with UNR (-9.2%, 95% CI -12.8% to -5.6%; p

Does high intensity resistance training maintain bone mass during moderate weight loss in older overweight adults with type 2 diabetes

The aim was to investigate whether the addition of supervised high intensity progressive resistance training to a moderate weight loss program (RT+WLoss) could maintain bone mineral density (BMD) and lean mass compared to moderate weight loss (WLoss) alone in older overweight adults with type 2 diabetes. We also investigated whether any benefits derived from a supervised RT program could be sustained through an additional home-based program. This was a 12-month trial in which 36 sedentary, overweight adults aged 60 to 80 years with type 2 diabetes were randomized to either a supervised gymnasium-based RT+WLoss or WLoss program for 6 months (phase 1). Thereafter, all participants completed an additional 6-month home-based training without further dietary modification (phase 2). Total body and regional BMD and bone mineral content (BMC), fat mass (FM) and lean mass (LM) were assessed by DXA every 6 months. Diet, muscle strength (1-RM) and serum total testosterone, estradiol, SHBG, insulin and IGF-1 were measured every 3 months. No between group differences were detected for changes in any of the hormonal parameters at any measurement point. In phase 1, after 6 months of gymnasium-based training, weight and FM decreased similarly in both groups (P < 0.01), but LM tended to increase in the RT+WLoss (n=16) relative to the WLoss (n = 13) group [net difference (95% CI), 1.8% (0.2, 3.5), P < 0.05]. Total body BMD and BMC remained unchanged in the RT+WLoss group, but decreased by 0.9 and 1.5%, respectively, in the WLoss group (interaction, P < 0.05). Similar, though non-significant, changes were detected at the femoral neck and lumbar spine (L2-L4). In phase 2, after a further 6 months of home-based training, weight and FM increased significantly in both the RT+WLoss (n = 14) and WLoss (n = 12) group, but there were no significant changes in LM or total body or regional BMD or BMC in either group from 6 to 12 months. These results indicate that in older, overweight adults with type 2 diabetes, dietary modification should be combined with progressive resistance training to optimize the effects on body composition without having a negative effect on bone health.

C-reactive protein, cardiovascular risk, and renal disease in a remote Australian Aboriginal community

Rates of cardiovascular and renal disease in Australian Aboriginal communities are high, but we do not know the contribution of inflammation to these diseases in this setting. In the present study, we sought to examine the distribution of C-reactive protein (CRP) and other markers of inflammation and their relationships with cardiovascular risk markers and renal disease in a remote Australian Aboriginal community. The study included 237 adults (58% of the adult population) in a remote Aboriginal community in the Northern Territory of Australia. Main outcome measures were CRP, fibrinogen and lgG concentrations, blood pressure (BP), presence of diabetes, lipids, albuminuria, seropositivity to three common micro-organisms, as well as carotid intima-media thickness (IMT). Serum concentrations of CRP [7 (5-13) mg/l; median (inter-quartile range)] were markedly increased and were significantly correlated with fibrinogen and lgG concentrations and inversely correlated with serum albumin concentration. Higher CRP concentrations were associated with lgG seropositivity to Helicobacter pylori and Chlamydia pneumoniae and higher lgG titre for cytomegalovirus. Higher CRP concentrations were associated with the following: the 45-54-year age group, female subjects, the presence of skin sores, higher body mass index, waist circumference, BP, glycated haemoglobin and greater albuminuria. CRP concentrations increased with the number of cardiovascular risk factors, carotid IMT and albuminuria independently of other risk factors. These CRP concentrations were markedly higher than described in other community settings and are probably related, in a large part, to chronic and repeated infections. Their association with markers of cardiovascular risk and renal disease are compatible with the high rates of cardiovascular and renal disease in this community, and provide more evidence of strong links between these conditions, through a shared background of infection/inflammation. This suggests that a strong focus on prevention and management of infections will be important in reducing these conditions, in addition to interventions directed at more traditional risk factors.

The effect of the dietary supplement, Chitosan, on body weight: a randomised controlled trial in 250 overweight and obese adults

CONTEXT: Chitosan, a deacetylated chitin, is a widely available dietary supplement purported to decrease body weight and serum lipids through gastrointestinal fat binding. Although evaluated in a number of trials, its efficacy remains in dispute. OBJECTIVE: To evaluate the efficacy of chitosan for weight loss in overweight and obese adults. DESIGN AND SETTING: A 24-week randomised, double-blind, placebo-controlled trial, conducted at the University of Auckland between November 2001 and December 2002. PARTICIPANTS: A total of 250 participants (82% women; mean (s.d.) body mass index, 35.5 (5.1) kg/m(2); mean age, 48 (12) y). INTERVENTIONS: Participants were randomly assigned to receive 3 g chitosan/day (n = 125) or placebo (n = 125). All participants received standardised dietary and lifestyle advice for weight loss. Adherence was monitored by capsule counts. MAIN OUTCOME MEASURES: The primary outcome measure was change in body weight. Secondary outcomes included changes in body mass index, waist circumference, body fat percentage, blood pressure, serum lipids, plasma glucose, fat-soluble vitamins, faecal fat, and health-related quality of life. RESULTS: In an intention-to-treat analysis with the last observation carried forward, the chitosan group lost more body weight than the placebo group (mean (s.e.), -0.4 (0.2) kg (0.4% loss) vs +0.2 (0.2) kg (0.2% gain), P = 0.03) during the 24-week intervention, but effects were small. Similar small changes occurred in circulating total and LDL cholesterol, and glucose (P < 0.01). There were no significant differences between groups for any of the other measured outcomes. CONCLUSION: In this 24-week trial, chitosan treatment did not result in a clinically significant loss of body weight compared with placebo.

Conditional deletion of hypothalamic Y2 receptors reverts gonadectomy-induced bone loss in adult mice

Reduction in levels of sex hormones at menopause in women is associated with two common, major outcomes, the accumulation of white adipose tissue, and the progressive loss of bone because of excess osteoclastic bone resorption exceeding osteoblastic bone formation. Current antiresorptive therapies can reduce osteoclastic activity but have only limited capacity to stimulate osteoblastic bone formation and restore lost skeletal mass. Likewise, the availability of effective pharmacological weight loss treatments is currently limited. Here we demonstrate that conditional deletion of hypothalamic neuropeptide Y2 receptors can prevent ongoing bone loss in sex hormone-deficient adult male and female mice. This benefit is attributable solely to activation of an anabolic osteoblastic bone formation response that counterbalances persistent elevation of bone resorption, suggesting the Y2-mediated anabolic pathway to be independent of sex hormones. Furthermore, the increase in fat mass that typically occurs after ovariectomy is prevented by germ line deletion of Y2 receptors, whereas in male mice body weight and fat mass were consistently lower than wild-type regardless of sex hormone status. Therefore, this study indicates a role for Y2 receptors in the accumulation of adipose tissue in the hypogonadal state and demonstrates that hypothalamic Y2 receptors constitutively restrain osteoblastic activity even in the absence of sex hormones. The increase in bone formation after release of this tonic inhibition suggests a promising new avenue for osteoporosis treatment.

Adjusting Body Cell Mass for Size in Women of Differing Nutritional Status

Background: Body cell mass (BCM) may be estimated in clinical practice to assess functional nutritional status, eg, in patients with anorexia nervosa. Interpretation of the data, especially in younger patients who are still growing, requires appropriate adjustment for size. Previous investigations of this general issue have addressed chemical rather than functional components of body composition and have not considered patients at the extremes of nutritional status, in whom the ability to make longitudinal comparisons is of particular importance. Objective: Our objective was to determine the power by which height should be raised to adjust BCM for height in women of differing nutritional status. Design: BCM was estimated by K-40 counting in 58 healthy women, 33 healthy female adolescents, and 75 female adolescents with anorexia nervosa. The relation between BCM and height was explored in each group by using log-log regression analysis. Results: The powers by which height should be raised to adjust BCM,A,ere 1.73. 1.73, and 2.07 in the women, healthy female adolescents, and anorexic female adolescents, respectively. A simplified version of the index, BCM/height(2), was appropriate for all 3 categories and was negligibly correlated with height. Conclusions: In normal-weight women, the relation between height and BCM is consistent with that reported previously between height and fat-free mass. Although the consistency of the relation between BCM and fat-free mass decreases with increasing weight loss, the relation between height and BCM is not significantly different between normal-weight and underweight women. The index BCM/height(2) is easy to calculate and applicable to both healthy and underweight women. This information may be helpful in interpreting body-composition data in clinical practice.

Bone loss in Crohn's disease: Exercise as a potential countermeasure

Crohn's disease (CD) is associated with a number of secondary conditions including osteoporosis, which increases the risk of bone fracture. The cause of metabolic bone disease in this Population is believed to be multifactorial and may include the disease itself and associated inflammation, high-close corticosteroid use, weight loss and malabsorption, a lack of exercise and physical activity, and all underlying genetic predisposition to bone loss. Reduced bone mineral density has been reported in between 5% to 80% of CD sufferers, although it is generally believed that approximately 40% of patients suffer from osteopenia and 15% from osteoporosis. Recent studies Suggest a small but significantly increased risk of fracture compared with healthy controls and, perhaps, sufferers of other gastrointestinal disorders Such as ulcerative colitis. The role of physical activity and exercise in the prevention and treatment of CD-related bone loss has received little attention, despite the benefits of specific exercises being well documented in healthy populations. This article reviews the prevalence of and risk factors for low bone mass in CD patients and examines various treatments for osteoporosis in these patients, with a particular focus on physical activity.

Erosion-corrosion of mild steel in hot caustic. Part I: NaOH solution

A novel apparatus, high-pressure/high-temperature nickel flow loop, was constructed to study the effect of the flow on the rate of erosion-corrosion of mild steel in hot caustic. It has been successfully used to measure the corrosion rate of 1020 steel in 2.75 M NaOH solution at a temperature of 160 degrees C and velocities of 0.32 and 2.5 m/s. In situ electrochemical methods were used to measure the corrosion rate such as the potentiodynamic sweep, the polarization resistance method, and electrochemical impedance spectroscopy (EIS). Also used were the weight-loss method and scanning electron microscopy (SEM). Eight electrodes/coupons were used to monitor the metal loss rate, four were placed at the low velocity section, while the other four were placed in the high velocity section. The first three coupons in each section were placed within the disturbed flow region, while the fourth was placed in a fully developed flow region. The corrosion rate of the coupons in the high velocity section was generally higher than that of the coupons in the low velocity section. One coupon in the disturbed flow region had a significantly higher corrosion rate than the others. (c) 2005 Elsevier Ltd. All rights reserved.

Dissemination of a community-based physical activity project: The case of 10,000 steps

This paper describes the use of a web-site for the dissemination of the community-based '10,000 steps' program which was originally developed and evaluated in Rockhampton, Queensland in 2001-2003. The website provides information and interactive activities for individuals, and promotes resources and programs for health promotion professionals. The dissemination activity was assessed in terms of program adoption and implementation. In a 2-year period (May 2004-March 2006) more than 18,000 people registered as users of the web-site (togging more than 8.5 billion steps) and almost 100 workplaces and 13 communities implemented aspects of the 10,000 steps program. These data support the use of the internet as an effective means of disseminating ideas and resources beyond the geographical borders of the original project. Following this preliminary dissemination, there remains a need for the systematic study of different dissemination strategies, so that evidence-based physical activity programs can be translated into more widespread public health practice. (c) 2006 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Erosion-corrosion of mild steel in hot caustic. Part II: The effect of acid cleaning

Corrosion rates of 1020 steel in 2.75 M NaOH solution at a temperature of 160 degrees C and velocities of 0.32 and 2.5 m/s were studied. The focus was on the effect of the acid cleaning which was performed by using strong, inhibited sulphuric acid in between the exposures to caustic. In situ electrochemical methods were used to measure the corrosion rate such as the potentiodynamic sweep and the polarization resistance method. Also used were the weight-loss method and scanning electron microscopy (SEM). Eight electrodes/coupons were used to monitor the metal loss rate, four were placed at the low velocity section, while the other four were placed in the high velocity section of a high temperature flow. The first three coupons in each section were placed within the disturbed flow region, while the fourth was placed in a fully developed flow region. During the exposure of mild steel to the inhibited acid, following the first caustic period, the corrosion rate increased significantly to between 3 and 10mm/y with a few electrodes experiencing as high as 50 mm/y. The second caustic period following the acidic period typically started with very high corrosion rates (20-80 mm/y). The length of this corrosion period was typically 2-3 h with a few exceptions when the high corrosion period lasted 7-10 h. Following the very high corrosion rates experienced at the beginning of the second caustic period, the corrosion rates were reduced sharply (as the corrosion potential increased) to nearly the same levels as those observed during the passive part of the first caustic period. (c) 2005 Elsevier Ltd. All rights reserved.

Weight gained in two years by a population of mid-aged women: how much is too much?

Objective: To establish the prevalence of weight change in mid-aged women over a 2-year period, and to assess the relationship between weight change and physical and mental well-being (SF36) in order to begin debate about the need for quantified standards of weight gain. Design: Prospective study of weight change and well-being over a 2-year period among mid-aged women participating in a large national survey. Subjects: Seven thousand two hundred and seventy women without surgical menopause aged between 45 and 50 years (termed mid-aged), enrolled in the Australian Longitudinal Study on Women's Health. Measurements: Weight change (self-reported weight at two time points) and physical and mental well-being (SF-36) explored using linear regression, while adjusting for potential confounders. Results: Only half the women maintained their weight within 2.25 kg, and one-third gained more than this amount in a 2-year period. While weight gain (>= 2.25 kg) was negatively associated with physical well-being, both weight loss and weight gain were associated with poorer mental well-being. Conclusion: This is the first prospective study using a large, population-based cohort to demonstrate that small changes in weight are associated with changes in well-being in mid-aged Australian women. It provides further evidence of the need for public health messages to specify the actual amount that constitutes weight gain, but further research is needed to establish these standards for the entire population.

Genetic Influences on Exercise Participation in 37.051 Twin Pairs from Seven Countries

Background A sedentary lifestyle remains a major threat to health in contemporary societies. To get more insight in the relative contribution of genetic and environmental influences on individual differences in exercise participation, twin samples from seven countries participating in the GenomEUtwin project were used. Methodology Self-reported data on leisure time exercise behavior from Australia, Denmark, Finland, Norway, the Netherlands, Sweden and United Kingdom were used to create a comparable index of exercise participation in each country (60 minutes weekly at a minimum intensity of four metabolic equivalents). Principal Findings Modest geographical variation in exercise participation was revealed in 85,198 subjects, aged 19–40 years. Modeling of monozygotic and dizygotic twin resemblance showed that genetic effects play an important role in explaining individual differences in exercise participation in each country. Shared environmental effects played no role except for Norwegian males. Heritability of exercise participation in males and females was similar and ranged from 48% to 71% (excluding Norwegian males). Conclusions Genetic variation is important in individual exercise behavior and may involve genes influencing the acute mood effects of exercise, high exercise ability, high weight loss ability, and personality. This collaborative study suggests that attempts to find genes influencing exercise participation can pool exercise data across multiple countries and different instruments