Roberto Pacheco da Silva

Sleep apnea is a stronger predictor for coronary heart disease than traditional risk factors

BackgroundSleep apnea (SA) may be linked to coronary artery disease (CAD). Both conditions have similar risk factors, confounding the analyses. Investigation of the lipid profile is routine in the adult population, even without symptoms or suspected cardiac ailment. SA, however, remains underdiagnosed even in the presence of unambiguous clinical manifestations.PurposeThe aim of this study was to verify the association between SA and CAD, adjusting for usual CAD risk factors.MethodsPatients who underwent diagnostic or therapeutic coronariography and portable type III polysomnography were studied. The severity of SA was determined by the apnea–hypopnea index (AHI). We measured classic CAD risk factors: fasting glucose; total, HDL, and LDL cholesterols; triglycerides; uric acid, and high-sensitivity C-reactive protein. We excluded patients older than 65xa0years, with body mass index higher than 40xa0kg/m2, with diabetes, and with history of smoking in the last year.ResultsOf 55 included patients, 28 had AHIu2009>u200914, showing an odds ratio of 8.7 for CAD. Patients without (nu2009=u200929) and with CAD (nu2009=u200926), showed AHI of, respectively, 11u2009±u200911 and 23u2009±u200914 per hour (Pu2009=u20090.001). In a binary logistic regression to predict CAD, controlling for all the above risk factors, the only variables entered in the stepwise model were AHI (either as continuous or categorical variable) and uric acid.ConclusionIn a sample without smokers, morbidly obese, or diabetic patients, AHI is the main predictor of CAD. SA should integrate the set of risk factors routinely assessed in clinical investigation for coronary disease risk stratification.

High risk for sleep apnea in the Berlin questionnaire and coronary artery disease

IntroductionObstructive sleep apnea (OSA) affects up to 30% of the adult population and is a risk factor for coronary artery disease (CAD). The diagnostic process, involving polysomnography, may be complex. Berlin questionnaire (BQ) is a validated and economical screening tool.PurposeThe aim of this study was to assess the performance of the BQ for the diagnosis of OSA in individuals with angina complaints.MethodsPatients undergoing diagnostic cineangiography, portable type III polysomnography to determine the apnea-hypopnea index (AHI), and who answered the BQ were included. We excluded patients older than 65xa0years that were smokers, diabetics, and morbidly obese. High risk for OSA was based on positive responses in two of three symptom criteria of the BQ. CAD was defined by the presence of >50% lesion in coronary arteries.ResultsIn 57 included cases, high risk in the BQ indicates significant odds ratio [95% confidence interval] for the presence of CAD (4.5[1.03–19.25], Pu2009=u20090.045), adjusted for usual confounders: gender, age, and body mass index. The sensitivity and the specificity of BQ for CAD were 70% and 48%, respectively; the positive and negative predictive values are 56% and 64%.ConclusionsIn conclusion, simple questionnaire-based diagnostic tools can be included in the screening procedures of patients with angina to detect the need for further OSA evaluation. In conclusion, the BQ is an effective instrument for this purpose.

Improvement of Exercise Capacity and Peripheral Metaboreflex After Bariatric Surgery

BackgroundBariatric surgery is the only predictable method to obtain weight loss in severe obesity. Poor physical performance of obese individuals may be mediated by the peripheral metaboreflex, which controls blood flow redistribution to exercising muscles. Weight reduction improves exercise capacity through several possible mechanisms that are insufficiently understood. We hypothesized that the metaboreflex is one among the causes of improvement in exercise capacity after weight loss. This study thus aimed to examine the effect of bariatric surgery on exercise performance and metaboreflex.MethodsSeverely obese patients were assessed before and 3xa0months after bariatric surgery. Metaboreflex was evaluated by the technique of selective induction by post-exercise circulatory occlusion (PECO+) after isometric handgrip exercise at 30xa0% of maximum voluntary contraction. The exercise capacity was assessed by 6-min walking test.ResultsSeventeen patients completed the protocol. Body mass index decreased from 46.4u2009±u20092 to 36.6u2009±u20092xa0kg/m2 (Pu2009<u20090.001). The distance walked in 6xa0min increased from 489u2009±u200914 to 536u2009±u200914xa0m (Pu2009<u20090.001). The peripheral metaboreflex activity, expressed by the area under the curve of vascular resistance, was lower after than before bariatric surgery (42u2009±u20095 to 20u2009±u20094 units, Pu2009=u20090.003). Heart rate, blood pressure, and vascular resistance were also significantly decreased. The correlation between change in distance walked in 6xa0min and change in peripheral metaboreflex activity was not significant.ConclusionsWeight loss after bariatric surgery increases exercise capacity and reduces peripheral metaboreflex, heart rate, and blood pressure. Further investigation on the role of metaboreflex regarding mechanisms of exercise capacity of individuals with obesity is warranted.

Exercise, Occupational Activity, and Risk of Sleep Apnea: A Cross-Sectional Study.

STUDY OBJECTIVESnTo investigate whether structured exercise and occupational activity are associated with obstructive sleep apnea (OSA) severity.nnnMETHODSnThe International Physical Activity Questionnaire was answered by 5,453 individuals who underwent full-night polysomnography. Participants were classified as exercisers or non-exercisers and also as occupationally active or non-active. The apnea-hypopnea index (AHI), minimum oxygen saturation (SaO2min), and time with saturation below 90% (TB90%) during polysomnography were used as indicators of OSA severity.nnnRESULTSnThe sample included mostly men (59%), non-exercisers (56%), and occupationally non-active individuals (75%). Mean age (± standard deviation) was 44 ± 14 years, and mean body mass index was 29.9 ± 7.3 kg/m2. Non-exercisers had higher AHI (median 14, 25-75% interquartile range 4-34) than exercisers (8 [2-24]), lower SaO2min (83 ± 9 vs. 86 ± 8%), and longer TB90% (2 [0-18] vs. 0 [0-7] minutes), with p < 0.001 for all comparisons. AHI was higher in active (16 [6-34]) vs. non-active occupations (10 [3-27]; p < 0.001). Multinomial logistic regression with control for age, sex, overweight, obesity, and occupational activity showed that structured exercise was significantly associated with a 23% lower odds ratio for moderate OSA and 34% lower odds ratio for severe OSA. Active occupation was not associated with OSA.nnnCONCLUSIONSnStructured physical exercise is associated with lower odds for OSA, independently of confounders. Occupational activity does not seem to replace the effects of regular exercise. Compensatory behaviors may be involved in these diverging outcomes. Our results warrant further research about the effect of occupational activity on OSA severity.

Effect of strength training on sleep apnea severity in the elderly: study protocol for a randomized controlled trial

BackgroundObstructive sleep apnea (OSA) occurs due to sleep-induced upper airway muscle relaxation resulting in increased pharyngeal collapsibility. Clinical trials have shown a favorable effect of exercise training on OSA severity in middle-aged adults. Aging is characterized by motor-unit loss. Force training may affect the whole body muscle tone. We hypothesize that interventions increasing muscle strength might propagate to motor units at the abductor pharyngeal muscles, reducing collapsibility and, hence, sleep apnea severity in elderly patients with obstructive sleep apnea.Methods/designThis is a randomized clinical trial including patients between 65 and 80xa0years of age, with obstructive sleep apnea, and an apnea-hypopnea index (AHI) between 20 and 50 events/hour, diagnosed by out-of-center in-home type III polysomnography. Forty subjects will be included and randomly assigned to two equal sized groups. The participants allocated to the intervention group will attend two sessions per week of one-hour strength training for the legs, arms, chest, back, and abdomen and the controls will receive advice on lifestyle change. The primary outcome measure of the study will be the change in apnea-hypopnea index and the secondary outcomes will be the body composition, evaluated by anthropometric and bioelectrical impedance variables; maximum dynamic force, appraised by one-repetition maximum strength test; muscle quality and thickness by ultrasound; physical function assessed by sit-to-stand test, timed up and go test, handgrip strength test. The study duration will be 12 weeks. Intention-to-treat and per-protocol analyses will be performed.DiscussionThe high prevalence of obstructive sleep apnea in elderly people is a public health issue. OSA is a recognized cause of cardiovascular disease and reduces quality of life due to sleepiness and fatigue. Exercise is a low-cost intervention that could help to detain the trend towards age-dependent loss of pharyngeal motor units and progressive severity of obstructive sleep apnea. Home-based strength exercises may represent a more practical approach than aerobic exercise for elderly patients. If the results confirm our hypothesis, further research on the clinical application of our findings will be warranted.Trial registrationClinicalTrials.gov, NCT02742792. Registered on 1 April 2016.

Association of Lower Limb Compression Garments During High-Intensity Exercise with Performance and Physiological Responses: A Systematic Review and Meta-analysis

BackgroundAlthough compression garments are used to improve sports performance, methodological approaches and the direction of evidence regarding garments for use in high-intensity exercise settings are diverse.ObjectivesOur primary aim was to summarize the association between lower-limb compression garments (LLCGs) and changes in sports performance during high-intensity exercise. We also aimed to summarize evidence about the following physiological parameters related to sports performance: vertical jump height (VJ), maximal oxygen uptake (VO2max), submaximal oxygen uptake (VO2submax), blood lactate concentrations ([La]), and ratings of perceived exertion (RPE, 6–20 Borg scale).MethodsWe searched electronic databases (PubMed, EMBASE, Cochrane Library, and ClinicalTrials.gov) and reference lists for previous reviews. Eligible studies included randomized controlled trials with athletes or physically active subjects (≥u200918xa0years) using any type of LLCG during high-intensity exercise. The results were described as weighted mean difference (WMD) with a 95% confidence interval (95% CI).ResultsThe 23 included studies showed low statistical heterogeneity for the pooled outcomes. We found that LLCGs yielded similar running performance to controls (50–400xa0m: WMD 0.06xa0s [95% CI −xa01.99 to 2.11]; 800–3000xa0m: WMD 6.10xa0s [95% CI −xa07.23 to 19.43];u2009>u20095000xa0m: WMD 1.01xa0s [95% CI −xa084.80 to 86.82]). Likewise, we found no evidence that LLCGs were superior in secondary outcomes (VJ: WMD 2.25xa0cm [95% CI −xa02.51 to 7.02]; VO2max: WMD 0.24xa0mL.kg−1.min−1 [95% CI −xa01.48 to 1.95]; VO2submax: WMD −xa00.26xa0mL.kg−1.min−1 [95% CI −xa02.66 to 2.14]; [La]: WMD 0.19xa0mmol/L [95% CI −xa00.22 to 0.60]; RPE: WMD −xa00.20 points [95% CI −xa00.48 to 0.08]).ConclusionsLLCGs were not associated with improved performance in VJ, VO2max, VO2submax, [La], or RPE during high-intensity exercise. Such evidence should be taken into account when considering using LLCGs to enhance running performance.

The effect of caffeine supplementation on exercise performance evaluated by a novel animal model

Introduction: Caffeinated drinks are used for improve performance. Animal models represent investigational strategy that circumvents most of the drawbacks of research in humans, including motivational factors and the placebo effect. No animal model that could test whether different forms of administering caffeine affect exercise propensity was found in the literature. Methods: An animal model of grouped voluntary exercise was tested. Two-month-old male C57/bl mice were housed in a cage fitted with one running wheel and a monitoring system. Six animals per cage were introduced individually. To assess the sensitivity of the model, the effect of different caffeinated drinks was observed in mice exercising ad libitum . During 2 days, the mice received: 1) pure anhydrous caffeine 0.125 mg/mL (PC), 2) cola drink (CC), and 3) caffeine-taurine-glucuronolactone drink (CTG), intercalating wash-out periods of 2 days, receiving pure water. Results: The distance run during the periods of water ingestion was significantly lower than during the periods of stimulant drinks ingestion: PC (5.6±1.3 km; p = 0.02), of CC ingestion (7.6±0.6 km; p = 0.001), and of CTG ingestion (8.3±1.6 km; p = 0.009). The performances when ingesting the three caffeinated drinks do not follow a dose-response curve. Conclusions: The model described here was able to measure the effect of caffeine intake on voluntary exercise of mice. The sensitivity of the model to the effect of caffeine needs to be further validated. The action of each component of the drinks on exercise performance needs to be clarified in future research. The present model is adequate for such investigation. Key words: Exercise; caffeine; energy drinks; running

Scores of a web-based version of the seasonal pattern assessment questionnaire in Brazil

Introduction: Seasonal affective disorder (SAD) is a proposed mental disorder still controversial. This condition is prevalent in northern latitudes, but few studies have been conducted at locations in the southern hemisphere. It is usually assessed by the Seasonal Pattern Assessment Questionnaire (SPAQ). This study aimed to evaluate, through on-line questionnaire, the hypothesis that, in the Brazilian population, latitude and longitude influence SPAQ scores. Methods: An advertisement was posted on a sleep medicine website inviting visitors to investigate seasonal patterns of behavior and mood, using a Brazilian Portuguese version of the SPAQ. The geographic coordinates of the place of residence of each respondent were analyzed as a continuous variable or distributed in quartiles of latitude and longitude. The psychometric properties of the SPAQ were assessed by reliability and factor analyses. Results: Answers from 1001 respondents out of 1045 were considered eligible. High SPAQ scores were observed in 287 respondents, equally distributed among all latitude and longitude quartiles. Data collected in different seasons and during daylight saving time did not differ significantly in any of the scores for SPAQ dimensions. No correlations between SPAQ scores and latitude or longitude were observed. Psychometric properties of the SPAQ were preserved in all geographic locations. Conclusion: The finding of similar SPAQ scores at a wide latitude range defies the concept of SAD symptoms as latitude or longitude-dependent phenomena.

Ecocardiografia em pacientes com apneia do sono grave com e sem pressão arterial controlada: Estudo transversal

Introducao : A apneia obstrutiva do sono (AOS) afeta a anatomia e funcao do coracao. Ocorre hipertensao arterial em metade dos casos de AOS, dificultando atribuir a etiologia dessas alteracoes separadamente a hipertensao arterial ou a apneia do sono. Metodos : Estudo transversal de pacientes com indice de apneia-hipopneia maior que 50 eventos por hora. As variaveis ecocardiograficas comparadas em individuos com hipertensao arterial controlada e nao controlada foram: 1) fracao de ejecao, 2) diâmetro da aorta, 3) diâmetro do atrio esquerdo, 4) diâmetro de ventriculo direito, 5) diâmetros do ventriculo esquerdo diastolico e sistolico, 6) percentagem delta, 7) espessura do septo, 8) espessura da parede posterior. Resultados : Foram incluidos 83 voluntarios, 50 com pressao arterial nao controlada. Em media, a idade era 47±9,5 anos, o indice de massa corporal 34±5,4 Kg/m 2 , o indice de apneia-hipopneia 86±18 eventos/hora. Sessenta pacientes apresentaram anormalidade no ecocardiograma. A hipertrofia de ventriculo esquerdo foi o achado mais comum, sem diferenca de frequencia em controles (39%) e em hipertensos (48%), seguida por disfuncao diastolica em controles (27%) e em hipertensos (32%). Conclusoes : Individuos com apneia do sono grave e pressao arterial controlada apresentam alteracoes no ecocardiograma de tipo e frequencia semelhantes aos com hipertensao nao controlada. Isso sugere que a apneia do sono pode causar dano cardiaco independentemente de hipertensao. Quando nao explicaveis por hipertensao arterial, achados como hipertrofia de ventriculo esquerdo podem ser provocados por apneia do sono. Introduction:xa0 Obstructive sleep apnea (OSA) affects the cardiac anatomy and function. Hypertension occurs in half the OSA cases, making it difficult to attribute the cause of these changes separately to arterial hypertension or sleep apnea. Methods: Prospective cross-sectional study of volunteers with apnea-hypopnea index >50 events per hour. The echocardiographic variables were analyzed: 1) ejection fraction, 2) aortic diameter, 3) left atrial diameter, 4) right ventricular diameter, 5) diastolic and systolic diameters of the left ventricle, 6) delta percentage, 7) septum thickness, 8) posterior wall thickness. Results: There were 83 participants, 74 men, 50 with hypertension. The average age was 47±9.5 years, body mass index of 34±5.4 kg/m 2 , apnea-hypopnea index of 86±18 events/hour, and minimum oxygen saturation of 55±17%. Left ventricular hypertrophy was the most common echocardiographic abnormality in subjects without hypertension (39%) and with hypertension (48%), followed by diastolic dysfunction in subjects with normal blood pressure (27%) and with high blood pressure (32%). There was no statistically significant difference in echocardiographic characteristics between hypertensive subjects with those with normal pressure. Conclusions: Individuals with normal blood pressure and severe sleep apnea show abnormalities in the echocardiogram with frequency similar to that observed in patients with high blood pressure. This suggests that sleep apnea can cause ventricular overload independently of hypertension. When not explained by high blood pressure, left ventricular hypertrophy can be caused by sleep apnea.