Dose-response effect of pre-exercise carbohydrates under muscle glycogen unavailability:Insights from McArdle disease

Background:This study aimed to determine the effect of different carbohydrate(CHO)doses on exercise capacity in patients with McArdle disease—the paradigm of“exercise intolerance”,characterized by complete muscle glycogen unavailability—and to determine whether higher exogenous glucose levels affect metabolic responses at the McArdle muscle cell(in vitro)level.Methods:Patients with McArdle disease(n=8)and healthy controls(n=9)underwent a 12-min submaximal cycling constant-load bout followed by a maximal ramp test 15 min after ingesting a non-caloric placebo.In a randomized,double-blinded,cross-over design,patients repeated the tests after consuming either 75 g or 150 g of CHO(glucose:fructose=2:1).Cardiorespiratory,biochemical,perceptual,and electromyographic(EMG)variables were assessed.Additionally,glucose uptake and lactate appearance were studied in vitro in wild-type and McArdle mouse myotubes cultured with increasing glucose concentrations(0.35,1.00,4.50,and 10.00 g/L).Results:Compared with controls,patients showed the“classical”second-wind phenomenon(after prior disproportionate tachycardia,myalgia,and excess electromyographic activity during submaximal exercise,all p<0.05)and an impaired endurance exercise capacity(-51%ventilatory threshold and55%peak power output,both p<0.001).Regardless of the CHO dose(p<0.05 for both doses compared with the placebo),CHO intake increased blood glucose and lactate levels,decreased fat oxidation rates,and attenuated the second wind in the patients.However,only the higher dose increased ventilatory threshold(+27%,p=0.010)and peak power output(+18%,p=0.007).In vitro analyses revealed no differences in lactate levels across glucose concentrations in wild-type myotubes,whereas a doseresponse effect was observed in McArdle myotubes.Conclusion:CHO intake exerts beneficial effects on exercise capacity in McArdle disease,a condition associated with total muscle glycogen unavailability.Some of these benefits are dose dependent.

Heart Failure Issues and Management:A European Perspective

Heart failure poses an increasing problem for global health care systems.The epidemiological data which have been accrued over the last 30 years have predominantly been accumulated from experience within North America and Europe.The European experience in heart failure,although similar to that in North America,has recently demonstrated differences in hospitalization which may underlie the differences between health care system confi gurations.Despite the predicted increase in the number of patients affected by heart failure,over the last 30 years a clear management algorithm has evolved for the use of pharmacotherapies,device-based therapies,and mechanical therapies,including left ventricular assist devices and cardiac transplantation.Although the treatment of such patients has been clearly delineated in national and international guidelines,the underuse of all available and appropriate therapies remains a signifi cant problem.The purpose of this review is to provide a European perspective on management of heart failure.

Smoking and the risk of acute coronary syndrome in young women treated in an emergency department

The aim of this study is to compare the clinical characteristics of young women (.

Review on the management of cardiovascular risk factors in the elderly

Cardiovascular risk factors(CVRF)are very prevalent in the elderly population and in addition to predisposing to cardiovascular disease they are related to functional decline,which limits the quality of life in this population.The objective of this work is to offer a review of the current evidence in the management of CVRF in the elderly population.The search strategy was executed in PubMed,Clinicalstrials.org and Embase,to search for clinical trials,observational cohort or cross-sectional studies,reviews,and clinical practice guidelines focused or including elderly population.The results provided were refined after reading the title and abstract,as well as elimination of duplicates,and were finally identified and assessed following the GRADE methodology.A total of 136 studies were obtained for all predefined risk factors,such as sedentary lifestyle,smoking,obesity and metabolic syndrome,hypertension,diabetes mellitus,dyslipidemia and alcohol.We described the results of the studies identified and assessed according to their methodological quality in different recommendation sections:diagnostic and prevention,intervention,or treatment in the elderly population.As the main limitation to the results of this review,there is the lack of quality studies whose target population is elderly patients.This issue limits the recommendations that can be made in this population.Due to this reason,comprehensive geriatric assessment seems the best tool currently available to implement the most appropriate treatment plans based on the baseline situation and comorbidity of each elderly patient.

Air pollution and heart failure: Relationship with the ejection fraction

AIM: To study whether the concentrations of particulate matter in ambient air are associated with hospitaladmission due to heart failure in patients with heart failure with preserved ejection fraction and reduced ejection fraction. METHODS: We studied 353 consecutive patients admitted into a tertiary care hospital with a diagnosis of heart failure. Patients with ejection fraction of ≥ 45% were classified as having heart failure with preserved ejection fraction and those with an ejection fraction of < 45% were classified as having heart failure with reduced ejection fraction. We determined the average concentrations of different sizes of particulate matter (< 10, < 2.5, and < 1 μm) and the concentrations of gaseous pollutants (carbon monoxide, sulphur dioxide, nitrogen dioxide and ozone) from 1 d up to 7 d prior to admission. RESULTS: The heart failure with preserved ejection fraction population was exposed to higher nitrogen dioxide concentrations compared to the heart failure with reduced ejection fraction population (12.95 ± 8.22 μg/m 3 vs 4.50 ± 2.34 μg/m 3 , P < 0.0001). Multivariate analysis showed that nitrogen dioxide was a significant predictor of heart failure with preserved ejection fraction (odds ratio ranging from (1.403, 95%CI: 1.003-2.007, P = 0.04) to (1.669, 95%CI: 1.043-2.671, P = 0.03). CONCLUSION: This study demonstrates that shortterm nitrogen dioxide exposure is independently associated with admission in the heart failure with preserved ejection fraction population.