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Background:Recent literature has suggested that bicycling may be associated with increases in serum PSA levels, a diagnostic and prognostic marker for prostate cancer. To further investigate this relationship, we conducted a systematic review and meta-analysis of current literature in this field.Methods:MEDLINE, CENTRAL, CINAHL and SPORTDiscus were searched using MeSH terms and keywords for English publications related to bicycle riding and PSA. Studies were included if PSA was measured relative to cycling activity in healthy men who were free of any prostatic condition. Case studies were excluded.Results:Eight studies met our inclusion criteria, comprising 912 participants that engaged in, or self-reported, bicycling activity. Six studies investigated the acute pre-post change in PSA following bicycling activity that ranged from a single cycling bout of 15 min to a 4-day cycling event. Following cycling activity, two studies reported total PSA increased from baseline by up to 3.3-fold, free PSA increased in one study by 0.08±0.18 ng ml−1 and did not change in four studies. One study compared PSA in elite/professional cyclists versus non-cyclists and demonstrated no significant difference in PSA measurements between groups. Data from six studies were meta-analyzed and demonstrated no significant increase in PSA associated with cycling from pre to post (mean change +0.027 ng ml−1, s.e.m.=0.08, P=0.74, 95% confidence interval (CI)=−0.17-0.23).Conclusions:Our findings suggest that there is no effect of cycling on PSA; however, the limited number of trials and the absence of randomized controlled trials limit the interpretation of our results. Additionally, the median sample size only consisted of 42 subjects. Therefore, our study may have low statistical power to detect a difference in PSA. Although, a higher sample size may demonstrate statistical significance, it may not be clinically significant. Studies of higher empirical quality are needed. [ABSTRACT FROM AUTHOR]

Objective:We examined the effects of acute exercise on postprandial triglyceride (TG) metabolism following a high-fat meal in overweight black vs white adolescents.Design and subjects:Twenty-one black and 17 white adolescents (12-18 yrs, body mass index 85th percentile) were evaluated twice, during control versus exercise trials, 1-4 weeks apart, in a counterbalanced randomized design. In the control trial, participants performed no exercise on day 1. In the exercise trial, participants performed a single bout of 60-min exercise (50% VO2 peak) on a cycle ergometer on day 1. On day 2 of both trials, participants consumed a high-fat breakfast (70% calories from fat) and blood was sampled for TG concentration in the fasted state and for 6 h postprandially.Results:There was a significant main effect of condition on postprandial peak TG concentration (P=0.01) and TG area under the curve (AUC) (P=0.003), suggesting that independent of race, peak TG and TG-AUC was lower in the exercise trial vs control trial. Including Tanner stage, gender, total fat (kg) and visceral adipose tissue (VAT) as independent variables, stepwise multiple regression analyses revealed that in whites, VAT was the strongest (P<0.05) predictor of postprandial TG-AUC, explaining 56 and 25% of the variances in TG-AUC in the control and exercise trials, respectively. In blacks, VAT was not associated with postprandial TG-AUC, independent of trial.Conclusion:A single bout of aerobic exercise preceding a high-fat meal is beneficial to reduce postprandial TG concentrations in overweight white adolescents to a greater extent than black adolescents, particularly those with increased visceral adiposity. [ABSTRACT FROM AUTHOR]

Aims/hypothesis: The aim of this study was to examine the joint association of physical activity and glycaemic control as measured by HbA on all-cause and cardiovascular disease (CVD) mortality risk. Methods: The sample included 10,352 adults from the Third National Health and Nutrition Examination Survey (NHANES III) Linked Mortality Public-use File (follow-up 13.4 ± 3.9 years; 2,463 deaths). Physical activity was assessed by questionnaire and classified into inactive and active categories based on self-reported frequency of leisure-time activity. HbA was categorised to reflect the American Diabetes Association diagnostic and treatment guidelines. Results: Being physically active was associated with a decreased risk of all-cause (HR 0.74 [95% CI 0.67, 0.81]) and CVD (HR 0.71 [95% CI 0.62, 0.82]) mortality, whereas higher levels of HbA were associated with an increased mortality risk. HbA ≥7% (53 mmol/mol) was associated with the highest risk for all-cause (HR 1.54 [95% CI 1.30, 1.82]) and CVD (HR 1.93 [95% CI 1.52, 2.45]) mortality. Across all categories of HbA, active individuals were not at increased risk for all-cause mortality compared with inactive individuals with normal glycaemic control. Similar findings were observed for CVD mortality, except that active individuals with HbA ≥7% (53 mmol/mol) were still at increased risk for CVD mortality. However, their risk for CVD death was substantially lower than the risk for their inactive counterparts (HR 1.38 [95% CI 1.03, 1.84] vs HR 1.98 [95% CI 1.34, 2.92]). Conclusions/interpretation: Physical activity is associated with lower all-cause and CVD mortality risk for individuals across all levels of glycaemic control. Therefore, engaging in a physically active lifestyle and achieving normal levels of glycaemic control may both be important for the prevention of early mortality. [ABSTRACT FROM AUTHOR]

Objective:To determine the influence of sex on the association between reductions in body weight (BW) and waist circumference (WC) with reductions in total (TAT), subcutaneous (SAT) and visceral adipose tissue (VAT) in response to lifestyle-based interventions.Design:Changes in TAT, SAT and VAT were assessed using magnetic resonance imaging in 81 men and 72 women who had participated in various diet and/or exercise interventions at Queen's University, Ontario, Canada.Results:Reductions in BW and WC were significantly (P<0.001) correlated with TAT, SAT and VAT loss in men and women. For a given weight loss, men had a significantly greater decrease in WC than women, and the sex difference in WC reduction increased with increasing weight loss (P<0.05). Similarly, for a given reduction in BW or WC, men have significantly greater reductions in VAT, but smaller reductions in total and lower body SAT than women, differences that progressively increased in magnitude with the increasing BW or WC loss (P<0.05). Accordingly, there were no sex differences in the TAT reduction for a given BW or WC reduction (P>0.05). Reductions in BW and WC were both independent predictors of VAT loss.Conclusions:These observations suggest that for a given reduction in BW or WC, men lose more VAT and less SAT than women; however, the TAT loss observed for a given reduction in BW or WC in men and women is not different.International Journal of Obesity (2009) 33, 629–634; doi:10.1038/ijo.2009.48; published online 10 March 2009 [ABSTRACT FROM AUTHOR]

Since the accumulation of lower-body subcutaneous adipose tissue (LBSAT) is associated with decreased cardiometabolic risk, we evaluated whether reductions in LBSAT independent of changes in visceral AT (VAT) and abdominal SAT are associated with elevations in diabetes and cardiovascular disease risk factors. Overweight and obese men ( n = 58) and premenopausal women ( n = 49) with elevated cardiometabolic risk underwent 3 months of diet and/or exercise induced weight-loss treatment; regional body composition assessment by magnetic resonance imaging (MRI); and cardiometabolic risk assessment, including an OGTT. After control for potential confounders, reductions in VAT, abdominal SAT and LBSAT were all associated with improvements in selective cardiometabolic risk factors, including fasting glucose levels, lipid status and OGTT glucose and insulin. Independent of changes in the other AT depots, reductions in VAT and abdominal SAT, but not LBSAT, remained associated with improvement in fasting glucose levels, glucose tolerance and lipid status. Among overweight and obese adults with increased cardiometabolic risk, the selective reduction of LBSAT is not associated with elevations in risk factors for diabetes and cardiovascular disease. Thus, the reduction of excess AT conveys health benefit regardless of origin. [ABSTRACT FROM AUTHOR]

For one-step extraction of chitin from red crab shell waste, cofermentation with Lactobacillus paracasei subsp. tolerans KCTC-3074, a lactic-acid-producing bacterium, and Serratia marcescens FS-3, a protease-producing bacterium, was conducted. Fermentation with single strain ( L. 3074 or FS-3) was also conducted. At day 7, the pH in L. 3074, FS-3, and L. 3074+FS-3 (1:1) treatment decreased from 6.90 to 3.30, 5.88, and 3.48, respectively. Ash content in the residue after fermentation treatment of crab shells in L. 3074 and L. 3074+FS-3 (1:1) treatment drastically decreased from 41.2% to 3.19 and 1.15%, respectively. In L. 3074+FS-3 (1:1) cofermentation, the level of demineralization was the highest value of 97.2%, but the level of deproteinization in the cofermentation was 52.6% at day 7. Protein content in the treatment of FS-3 alone reduced from 22.4 to 3.62%. These results indicate that cofermentation of the shells using the two strains is efficient and applicable for the one-step extraction of crude chitin from red crab shell waste. [ABSTRACT FROM AUTHOR]

A bacterium, GJ-18, having strong chitinolytic activity was isolated from coastal soil. The isolated strain was identified as Aeromonas sp. by morphological and biochemical properties along with 16S rRNA gene sequence. The crude chitinolytic activity of culture supernatants was maximal on the 5th day of culture. Below 45°C, chitin was effectively hydrolyzed to N-acetyl-β- d-glucosamine (GlcNAc) by Aeromonas sp. GJ-18 crude enzymes, but hydrolysis decreased markedly above 50°C. The optimum pH for enzyme activity was 5.0. TLC and HPLC analysis revealed that, below 45°C, the major reaction product was GlcNAc with a small amount of (GlcNAc)2 and (GlcNAc)3, whereas above 50°C the major product was (GlcNAc)2. When swollen chitin (100 mg) was incubated with crude enzyme preparations (10 U) at 40°C, chitin was hydrolyzed to 83.0 and 94.9% yield of GlcNAc within 5 and 9 days, respectively. [ABSTRACT FROM AUTHOR]

Lactic acid fermentation was applied to demineralize red crab shell waste using Lactobacillus paracasei subsp. tolerans KCTC-3074. Various concentrations (0, 2.5, 5.0, 10.0%) of glucose were supplemented as an initial carbon source and various amounts (2.5, 5.0, 10.0%) of the bacterial culture were inoculated as a starter. Microbial growth was very dependent on glucose concentration but little dependent on inoculum level. The pH decreased rapidly from pH 8 to pH 6 during the first day, at all three inoculum levels. At day 5 of fermentation, the 2.5, 5.0, and 10.0% inoculum levels with 10% glucose supply gave pH 5.5, 5.1, and 4.6, respectively, i.e. a decrease in pH concomitant with an increase in the inoculum level. The total titratable acidities (TTA) at day 5 for 2.5, 5.0, and 10.0% inoculum levels with 10% glucose supplement were 3.1, 4.5, and 8.3%, and the relative residual ash contents were 26.6, 25.9, and 19.0%, respectively. A negative relationship was found between pH and demineralization level ( r2=0.8571), but there was a positive relationship between TTA and demineralization level ( r2=0.5532). [ABSTRACT FROM AUTHOR]

Different methods are available for rapid assessment of renal function using the patient's serum creatinine concentration and body weight without obtaining urine collection over 24 hr. However, the reliability of these methods in patients with liver diseases has not been established. The purpose of this study was to determine the accuracy and precision of the estimated creatinine clearances obtained by the methods of Cockcroft-Gault, Jelliffe, Mawer, and Siersbaek-Nielsen in patients with liver diseases who have different degrees of renal function. Creatinine clearances obtained from 24-hr urine collection were used as the standard. The different methods for rapid renal function estimation had limited accuracy and reliability in patients with severe liver dysfunction (Child-Pugh class C) and also in those with creatinine clearances of less than 60 ml/min. Creatinine clearances were overestimated by about 40-100%. Using lean body weights, instead of total body weights, reduced the prediction errors. In patients with mild liver dysfunction (Child-Pugh class A), all four estimation methods provided reasonable estimation of the creatinine clearances. [ABSTRACT FROM AUTHOR]

We examined the relationships between insulin sensitivity (IS), skeletal muscle (SM) mass and SM quality in youth. Forty obese adolescent boys (body mass index 95th percentile, 12-18 years) participated in this study. IS and glucose tolerance was measured by a 3 h hyperinsulinemic−euglycemic clamp and a 2 h oral glucose tolerance test (OGTT), total SM mass and intermusular adipose tissue (IMAT) by whole-body magnetic resonance imaging, and muscular strength by one-repetition maximum leg and bench press. IMAT was associated (P<0.05) with IS (r=−0.53) and OGTT-insulin area under the curve (AUC; r=0.31). Similarly, muscular strength was associated (P<0.05) with both IS (r=0.39) and OGTT-insulin AUC (r=−0.32). By contrast, total SM mass was not associated with IS or any OGTT parameters (P>0.1). After accounting for race and tanner stage, IMAT and muscular strength remained significantly associated with IS, together explaining a total of 41% of the variance in IS. Our findings suggest that SM quality, but not SM mass, is associated with IS in obese adolescent boys. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to an article related to the loss of gluteofemoral fat through diet and exercise in the previous issue.