BIOMARKERS TO DEFINE OPTIMAL PROTEIN REQUIREMENT

2013/2014Dietary proteins are the source of the amino acids required by the body for tissue growth and maintenance. The Population Reference Intake (PRI) for proteins, as defined by the European Food Safety Authority (EFSA) for healthy adults, including the elderly, is 0.83 g/kg body weight/day. This amount is defined on the net balance of body protein (or “nitrogen balance”, given by the difference between dietary nitrogen intake and losses) equivalent to 0.66 g/kg/day plus a safety factor for interpersonal variability and differences in proteins quality of mixed diets. The PRI, however, is the minimum daily amount of protein needed to maintain the nitrogen balance and avoid a progressive loss of lean body mass in healthy people with moderate physical activity. Therefore nitrogen balance may not be adequate to define protein requirement in adults and especially in ageing characterized by loss of muscle mass and function (sarcopenia). Furthermore until recently the prevalent idea was that a protein intake above PRI had no further benefits and on the contrary could impair health. These believes are now under discussion, diets with higher protein intake have been shown beneficial in the prevention and treatment of conditions such as sarcopenia, COPD and type 2 diabetes mellitus. There is a need of more precise methods to define protein requirement. AIM. The aim of the present thesis is to investigate in human healthy volunteers new biomarkers adequate to define optimal protein intake. Recent studies have determined protein needs by measuring whole-body protein metabolism using stable labeled isotope-amino acids. METHODS. Our research group has applied two different metabolic methods based on the most widely used tracer, i.e. D5-Phe stable isotope, in two experimental bed rest campaigns (FP7 PLANHAB and INTERREG PANGaA) in healthy volunteers. BR is a suitable model to investigate physiologic adaptation to inactivity. MAIN RESUTLTS. FP7 PLANHAB. We applied the stable isotope infusion technique, to assess the effect of physical inactivity and/or hypoxic condition on whole body protein turnover as previously described in Biolo et al 2008. Chronic hypoxia has been associated with an overall reduction in protein synthesis and in total plasma and skeletal muscle protein content. During the PLANHAB study we investigated, through a crossover randomization, the net effects of 10 days normobaric hypoxia (4000 mt.), associated with either ambulatory conditions or BR, in 11 young (age 24±4 yr), healthy and normal weight male subjects maintained on eucaloric diets. Main results. Hypoxia in ambulatory conditions significantly decreased whole body protein turnover by reducing both protein synthesis (-8±2%) and protein degradation (-8±3%). Hypoxia during bed rest did not caused significant changes in protein metabolism. INTERREG PANGaA. The skeletal muscle loss in aging is caused mainly by the “anabolic resistance” i.e. the inadequate increase in the rate of protein synthesis in response to nutritional-metabolic stimuli, including exercise, protein and amino acid intake as well as insulin and insulin-like growth factor stimulation. As a consequence, the net protein balance becomes negative leading to sarcopenia. The effects of ageing on the anabolic resistance induced by inactivity are poorly investigated. During the PANGeA study we had the opportunity to perform the second documented experimental BR in in healthy elderly volunteers and the first comparing aged with young subjects. To evaluate the anabolic resistance associated with ageing and inactivity, we enrolled 7 young (23±1yr) and 8 elderly (59±1yr) normal weight individuals, in a 14-d experimental BR protocol. We replaced our previous infusion method with a new, simpler, safer and quicker technique, by which tracers are given orally instead of parenterally, the all procedure is completed in two hours, instead of 6, and only two blood draws versus 7 are sufficient. Main results. At baseline parameters of anabolic sensitivity were comparable between young and elderly individuals. The anabolic resistance significantly increased after BR in both groups (bed-rest effect p<0.01), with a statistically significant bed-rest×group interaction (p=0.01). Anabolic resistance increased significantly in elderly (18.5%±7.3%) more than in young (5.2%±9.4%) subjects. DISCUSSION. In the PLANHAB study, hypoxia in ambulatory conditions reduced by the same level both protein synthesis and catabolism, as measured by isotope infusions, suggesting an adaptive mechanism: the lower energy production and availability induced by hypoxia associated with ambulatory condition. These modifications could not have been revealed by the use of nitrogen balance method, showing the relevance of more sophisticated analysis. The direct evaluation of the muscle protein metabolism through an infusion of stable-labeled isotope tracer, considered the golden standard methodology, gave us, in the PLANHAB study, reliable results in the early protein metabolism changes during hypoxia and/or BR. This method however has the limit of being complex, onerous and invasive, therefore being unsuitable for clinical evaluation. In the PANGeA study we could confirm the presence of a reduced sensitivity to anabolic stimuli in the elderly population compared to the young men. The elderly subjects are therefore, more at risk to develop changes of protein metabolism induced by inactivity. The simpler, timesaving and less invasive method we have developed for the PANGeA study, on the other hand, could be applied to a wider ranges of experimental conditions and clinical settings.XXVII Ciclo198

Metabolic Consequences of Anabolic Steroids, Insulin, and Growth Hormone Abuse in Recreational Bodybuilders: Implications for the World Anti-Doping Agency Passport

Background: Hormonal doping in recreational sports is a public-health concern. The World Anti-Doping Agency (WADA) promoted the creation of the Athlete Biological Passport, aiming to monitor athlete's biological variables over time to facilitate indirect detection of doping. Detection tests for anabolic androgenic steroids (AAS) and growth hormone (GH) are available while insulin abuse cannot be revealed. We have determined in recreational bodybuilders the metabolic effects associated with different patterns of hormone abuse. All analyses were conducted using Statistical Package for Social Sciences (SPSS) 21.0 software (SPSS Chicago, IL). Results: We have assessed plasma concentrations of selected metabolic markers and fatty acid content in erythrocyte membranes of 92 male bodybuilders and in 45 healthy controls. Hormonal abuse was identified by anonymous questionnaires. 43% (%) of recruited bodybuilders regularly abused hormones, i.e., anabolic androgenic steroids (95%) often associated with GH (30%) and/or insulin (38%). HDL-cholesterol was lower in insulin and/or GH abusers. Alanine (ALT) and aspartic (AST) transaminases were greater in hormone abusing bodybuilders than in non-doping bodybuilders and controls. Insulin doping was selectively associated with increased plasma ALT-to-AST ratio. In erythrocyte membranes, elongase activity (i.e., stearic-to-palmitic ratio) was lower in insulin and/or growth hormone doping, whereas increased Δ-9 desaturase activity (i.e., palmitoleic-to-palmitic ratio) was selectively associated with insulin doping. Conclusions: In conclusion, our study demonstrates that insulin and GH abuse are characterized by multiple alterations of specific metabolic markers. Although further studies are needed to test whether longitudinal monitoring of selected metabolic marker such as muscle contraction time, HDL levels, ALT-AST ratio as well as the activities of selected enzymes (e.g. Δ-9 desaturase and elongase), could contribute to the detection of insulin and GH abuse in sport

Epidemiology of atherosclerotic cardiovascular disease in polygenic hypercholesterolemia with or without high lipoprotein(a) levels

Background and aimsEpidemiology of atherosclerotic cardiovascular disease might be different in patients with polygenic hypercholesterolemia plus high levels (≥30 mg/dl) of Lp(a) (H-Lpa) than in those with polygenic hypercholesterolemia alone (H-LDL). We compared the incidence of peripheral artery disease (PAD), coronary artery disease (CAD), and cerebrovascular disease (CVD) in patients with H-Lpa and in those with H-LDL.MethodsRetrospective analysis of demographics, risk factors, vascular events, therapy, and lipid profile in outpatient clinical data. Inclusion criteria was adult age, diagnosis of polygenic hypercholesterolemia, and both indication and availability for Lp(a) measurement.ResultsMedical records of 258 patients with H-Lpa and 290 H-LDL were reviewed for occurrence of vascular events. The median duration of follow-up was 10 years (IQR 3–16). In spite of a similar reduction of LDL cholesterol, vascular events occurred more frequently, and approximately 7 years earlier (P = 0.024) in patients with H-Lpa than in H-LDL (HR 1.96 1.21–3.17, P = 0.006). The difference was around 10 years for acute events (TIA, Stroke, acute coronary events) and one year for chronic ones (P = 0.023 and 0.525, respectively). Occurrence of acute CAD was higher in H-Lpa men (HR 3.1, 95% CI 1.2–7.9, P = 0.007) while, among women, PAD was observed exclusively in H-Lpa subjects with smoking habits (P = 0.009).ConclusionsPatients with high Lp(a) levels suffer from a larger and earlier burden of the disease compared to those with polygenic hypercholesterolemia alone. These patients are at higher risk of CAD if they are men, and of PAD if they are women

Intensive insulin therapy increases glutathione synthesis rate in surgical ICU patients with stress hyperglycemia

OBJECTIVE: The glutathione system plays an essential role in antioxidant defense after surgery. We assessed the effects of intensive insulin treatment (IIT) on glutathione synthesis rate and redox balance in cancer patients, who had developed stress hyperglycemia after major surgery. METHODS: We evaluated 10 non-diabetic cancer patients the day after radical abdominal surgery combined with intra-operative radiation therapy. In each patient, a 24-hr period of IIT, aimed at tight euglycemic control, was preceded, or followed, by a 24-hr period of conventional insulin treatment (CIT) (control regimen). Insulin was administered for 24 hours, during total parenteral nutrition, at a dosage to maintain a moderate hyperglycemia in CIT, and normoglycemic blood glucose levels in IIT (9.3\ub10.5 vs 6.5\ub10.3 mmol/L respectively, P<0.001; coefficient of variation, 9.7\ub11.4 and 10.5\ub11.1%, P = 0.43). No hypoglycemia (i.e., blood glucose < 3.9 mmol/L) was observed in any of the patients. Insulin treatments were performed on the first and second day after surgery, in randomized order, according to a crossover experimental design. Plasma concentrations of thiobarbituric acid reactive substances (TBARS) and erythrocyte glutathione synthesis rates (EGSR), measured by primed-constant infusion of L-[2H2]cysteine, were assessed at the end of each 24-hr period of either IIT or CIT. RESULTS: Compared to CIT, IIT was associated with higher EGSR (2.70\ub10.51 versus 1.18\ub10.29 mmol/L/day, p = 0.01) and lower (p = 0.04) plasma TBARS concentrations (2.2\ub10.2 versus 2.9\ub10.4 nmol/L). CONCLUSIONS: In patients developing stress hyperglycemia after major surgery, IIT, in absence of hypoglycemia, stimulates erythrocyte glutathione synthesis, while decreasing oxidative stress

Lipoprotein(a) as a Risk Factor for Cardiovascular Diseases: Pathophysiology and Treatment Perspectives

Cardiovascular disease (CVD) is still a leading cause of morbidity and mortality, despite all the progress achieved as regards to both prevention and treatment. Having high levels of lipoprotein(a) [Lp(a)] is a risk factor for cardiovascular disease that operates independently. It can increase the risk of developing cardiovascular disease even when LDL cholesterol (LDL-C) levels are within the recommended range, which is referred to as residual cardiovascular risk. Lp(a) is an LDL-like particle present in human plasma, in which a large plasminogen-like glycoprotein, apolipoprotein(a) [Apo(a)], is covalently bound to Apo B100 via one disulfide bridge. Apo(a) contains one plasminogen-like kringle V structure, a variable number of plasminogen-like kringle IV structures (types 1–10), and one inactive protease region. There is a large inter-individual variation of plasma concentrations of Lp(a), mainly ascribable to genetic variants in the Lp(a) gene: in the general po-pulation, Lp(a) levels can range from 1000 mg/dL. Concentrations also vary between different ethnicities. Lp(a) has been established as one of the risk factors that play an important role in the development of atherosclerotic plaque. Indeed, high concentrations of Lp(a) have been related to a greater risk of ischemic CVD, aortic valve stenosis, and heart failure. The threshold value has been set at 50 mg/dL, but the risk may increase already at levels above 30 mg/dL. Although there is a well-established and strong link between high Lp(a) levels and coronary as well as cerebrovascular disease, the evidence regarding incident peripheral arterial disease and carotid atherosclerosis is not as conclusive. Because lifestyle changes and standard lipid-lowering treatments, such as statins, niacin, and cholesteryl ester transfer protein inhibitors, are not highly effective in reducing Lp(a) levels, there is increased interest in developing new drugs that can address this issue. PCSK9 inhibitors seem to be capable of reducing Lp(a) levels by 25–30%. Mipomersen decreases Lp(a) levels by 25–40%, but its use is burdened with important side effects. At the current time, the most effective and tolerated treatment for patients with a high Lp(a) plasma level is apheresis, while antisense oligonucleotides, small interfering RNAs, and microRNAs, which reduce Lp(a) levels by targeting RNA molecules and regulating gene expression as well as protein production levels, are the most widely explored and promising perspectives. The aim of this review is to provide an update on the current state of the art with regard to Lp(a) pathophysiological mechanisms, focusing on the most effective strategies for lowering Lp(a), including new emerging alternative therapies. The purpose of this manuscript is to improve the management of hyperlipoproteinemia(a) in order to achieve better control of the residual cardiovascular risk, which remains unacceptably high

Higher protein intake is associated with improved muscle strength in elite senior athletes

OBJECTIVE: The optimal protein intake for elderly individuals who exercise regularly has not yet been clearly defined. The aim of this study was to test the hypothesis that protein intake level is associated with muscle strength in elderly elite athletes. METHODS: We evaluated 50 elite senior athletes (38 men and 12 women) participating in the European Master Games 2011 in an observational cross-sectional study. Participants were divided into two groups-lower (LPI) or higher (HPI) protein intake-according to the median value of their ratio of urinary urea nitrogen to urinary creatinine (i.e., 8.8 g/L), as a marker of protein intake. A dietary interview confirmed differences in protein consumption between the LPI and HPI groups. We also evaluated body composition (bioimpedance), muscle strength, and hematochemical indices. RESULTS: LPI and HPI groups were homogeneous for age (72 [68-74] and 71 [68-74] y, respectively), fat-free mass index (18.4 [17-19.4] and 18.2 [17-19.1] kg/m2), body fat (18.3% [12.3-20.7%] and 16.6% [13.6-21.2%]), and glomerular filtration rate (57.7 [53.8-64.9] and 62.7 [56.1-69.3] mL/min/1.73 m2). The HPI group showed greater leg and trunk muscle strength (N) compared with the LPI group (left leg extension, 339 [238-369] versus 454 [273-561], respectively, P < 0.05; right leg extension, 319 [249-417] versus 432 [334-635], P 64 0.05; trunk extension, 435 [370-467] versus 464 [390-568], P 64 0.05). CONCLUSIONS: Higher protein intake in elite senior athletes is associated with a greater muscle strength

The role of the WISE Consortium in the European DEDIPAC-KH project

WISE (Wellness, nutrItion, Sport and Exercise prevention) is a research consortium including five Italian research teams (University of Turin, University of Milan, University of Trieste, Universiy of Rome “Foro Italico”, University of Bari), operating within the broader framework of the DEDIPAC-KH joint action (Determinants of Diet and Physical Activity Knowledge Hub). Research actions within the WISE consortium, funded by the Italian Ministry of Higher Education & Research, are in line with the main objective of the DEDIPAC-KH of developing an international and interdisciplinary network of researchers on dietary, physical activity and sedentary behaviours, related determinant research and policy interventions. More specifically, the WISE consortium research aimed to contribute to the following task (1.2.4 - Task Leader: Prof. Alan Donnelly): perform SLRs to identify state-of the art methods for physical activity and sedentary behaviour measurements. The focus of task 1.2.4 was to examine the methodological effectiveness (validity, reliability and sensitivity/responsiveness) of measures of physical activity and sedentary behaviours. The approach taken with this task was to examine the methodological effectiveness of measures of physical activity and sedentary behaviours in two populations; i) child/adolescence and ii) adults. Findings on methodological effectiveness of measures of physical activity and sedentary behaviours constitute the basis for a variety of publication and reports, and conference communications. The DEDIPAC-KH project created an unique opportunity for developing a comprehensive analysis on the determinants of diet and physical activity in Italy, and fostered successful collaboration with leading international groups. The findings of the WISE project created valuable information for the implementation of successful policies in Italy.This work was supported by MIUR

Low in‑hospital mortality rate in patients with COVID‑19 receiving thromboprophylaxis: data from the multicentre observational START‑COVID Register

Abstract COVID-19 infection causes respiratory pathology with severe interstitial pneumonia and extra-pulmonary complications; in particular, it may predispose to thromboembolic disease. The current guidelines recommend the use of thromboprophylaxis in patients with COVID-19, however, the optimal heparin dosage treatment is not well-established. We conducted a multicentre, Italian, retrospective, observational study on COVID-19 patients admitted to ordinary wards, to describe clinical characteristic of patients at admission, bleeding and thrombotic events occurring during hospital stay. The strategies used for thromboprophylaxis and its role on patient outcome were, also, described. 1091 patients hospitalized were included in the START-COVID-19 Register. During hospital stay, 769 (70.7%) patients were treated with antithrombotic drugs: low molecular weight heparin (the great majority enoxaparin), fondaparinux, or unfractioned heparin. These patients were more frequently affected by comorbidities, such as hypertension, atrial fibrillation, previous thromboembolism, neurological disease,and cancer with respect to patients who did not receive thromboprophylaxis. During hospital stay, 1.2% patients had a major bleeding event. All patients were treated with antithrombotic drugs; 5.4%, had venous thromboembolism [30.5% deep vein thrombosis (DVT), 66.1% pulmonary embolism (PE), and 3.4% patients had DVT + PE]. In our cohort the mortality rate was 18.3%. Heparin use was independently associated with survival in patients aged ≥ 59 years at multivariable analysis. We confirmed the high mortality rate of COVID-19 in hospitalized patients in ordinary wards. Treatment with antithrombotic drugs is significantly associated with a reduction of mortality rates especially in patients older than 59 years

Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P &lt; .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements