Impact of treating obesity hypoventilation syndrome on body mass index.

STUDY OBJECTIVES: To evaluate the impact of positive airway pressure (PAP) therapy on body mass index (BMI) in patients with obesity hypoventilation syndrome (OHS) associated with obstructive sleep apnea (OSA). METHODS: A systematic review using the following terms: "obesity hypoventilation syndrome" AND "treatment" AND "randomized" using Cochrane Central Register of Controlled Trials, Medline and Web of Science was performed from the first data available until February 10, 2023. The inclusion criteria were: (1) original article; (2) adult OHS with concomitant OSA (apnea-hypopnea index or AHI ≥5 events/h); (3) randomized trial with PAP arm and standard care (control); (4) BMI evaluation at baseline and after the first months. We performed an individual participant data meta-analysis of randomized controlled trials. RESULTS: Our initial search retrieved 32 articles and 3 randomized studies fulfilled study criteria and were included in the final analysis, leading to a total of 342 participants. Patients were predominantly females (62%) and had OHS associated with at least mild OSA. As compared to baseline, a decrease in BMI was observed at study endpoint but this difference was not different intergroups (-0.50 ± 1.49 and -0.50 ±1.83, in control and PAP groups respectively (p=0.939)). Weight change was not associate with PAP adherence, OSA severity or use of supplemental oxygen. CONCLUSIONS: In contrast to treatment of eucapnic OSA with PAP that is associated with weight gain, treatment of OSA+OHS patients with or without PAP is associated with weight loss. Future studies are necessary to elucidate the mechanism by which weight loss occurs.

Resultados de 5 anos da cirurgia bariátrica em pacientes com obesidade e hipertensão. um estudo clínico randomizado / 5-year outcomes of bariatric surgery in patients with obesity and hypertension. a randomized clinical trial

INTRODUÇÃO: Dados de estudos randomizados avaliando os efeitos a longo prazo da cirurgia bariátrica no controle e remissão da hipertensão (HTN) são escassos. O seguimento de curto e médio prazo do Estudo GATEWAY (1 e 3 anos) mostrou melhora significativa e remissão da hipertensão após a cirurgia bariátrica. Aqui, apresentamos os dados de acompanhamento de 5 anos deste estudo. MÉTODOS: Conduzimos um ensaio clínico randomizado, em um centro único, fase III, paralelo e aberto. Pacientes com obesidade graus 1 e 2, tomando no mínimo 2 medicamentos anti-hipertensivos em doses máximas para hipertensão, foram alocados aleatoriamente para Bypass gástrico em Y de Roux (RYGB) combinado com tratamento clínico (TC) ou TC (estilo de vida/aconselhamento nutricional) isoladamente. O desfecho primário foi a redução de pelo menos 30% do total de anti-hipertensivos, mantendo níveis controlados de pressão arterial (PA) <140/90mmHg. A análise principal seguiu o princípio de intenção de tratar modificada e os valores ausentes foram imputados com a técnica de imputação múltipla. Os desfechos secundários incluíram vários biomarcadores. RESULTADOS: Foram incluídos 100 pacientes (76% mulheres, idade: 43,8±9,2 anos, índice de massa corporal, IMC: 36,9±2,7Kg/ m2). Após 5 anos, o IMC foi de 27,8±3,8kg/m2 para RYGB e 36,4±3,9kg/m2 para TC (P<0,001). A análise de sensibilidade considerando apenas os casos com seguimento concluído (n=69) revelou resultados consistentes. Os desfechos secundários nos grupos RYGB e TC, aos 60 meses, foram: circunferência abdominal 88,05 ± 9,84cm e 109,44 ± 9,76cm (P<0,001) ; hemoglobina glicada 5,4 ± 0,43% e 5,96 ± 0,9% (P<0,001); insulina 6,41 ± 2,46mU/L e 24,65 ± 16,57mU/L (P<0,001); LDL colesterol 93.61 ± 31.06mg/dL e 109.94 ± 37.58mg/dL (P=0,022); triglicerídeos 86,76 ± 38,45mg/dL e 140,33 ± 59,11 mg/dL (P<0,001); proteína C reativa de alta sensibilidade 0,81 ± 0,76mg/L e 6,13 ± 6,22mg/L (P=0,005), respectivamente. CONCLUSÕES: A cirurgia bariátrica é uma estratégia eficaz e duradoura no controle da PA com menor número ou nenhum medicamento anti-hipertensivo e na melhora do perfil metabólico e inflamatório em pacientes com obesidade graus 1 ou 2 e hipertensão.

Association of sleep disturbances with sarcopenia and its defining components: the ELSA-Brasil study.

Sarcopenia and sleep problems share common physiopathology. We aimed to investigate the association of sleep disturbances with sarcopenia and its defining components in Brazilian middle-aged and older adults. In this cross-sectional analysis of the second wave of the ELSA-Brasil study, we included data from 7948 participants aged 50 years and older. Muscle mass was evaluated by bioelectrical impedance analysis and muscle strength by hand-grip strength. Sarcopenia was defined according to the Foundation for the National Institutes of Health criteria. Sleep duration and insomnia complaint were self-reported. Short sleep duration was considered as ≤6 h/night and long sleep duration as >8 h/night. High risk of obstructive sleep apnea (OSA) was assessed using the STOP-Bang questionnaire. Possible confounders included socio-demographic characteristics, lifestyle, clinical comorbidities, and use of sedatives and hypnotics. The frequencies of sarcopenia, low muscle mass, and low muscle strength were 1.6, 21.1, and 4.1%, respectively. After adjustment for possible confounders, high risk of OSA was associated with low muscle mass (OR=2.17, 95%CI: 1.92-2.45). Among obese participants, high risk of OSA was associated with low muscle strength (OR=1.68, 95%CI: 1.07-2.64). However, neither short nor long sleep duration or frequent insomnia complaint were associated with sarcopenia or its defining components. In conclusion, high risk of OSA was associated with low muscle mass in the whole sample and with low muscle strength among obese participants. Future studies are needed to clarify the temporal relationship between both conditions.

Association of sleep disturbances with sarcopenia and its defining components: the ELSA-Brasil study

Sarcopenia and sleep problems share common physiopathology. We aimed to investigate the association of sleep disturbances with sarcopenia and its defining components in Brazilian middle-aged and older adults. In this cross-sectional analysis of the second wave of the ELSA-Brasil study, we included data from 7948 participants aged 50 years and older. Muscle mass was evaluated by bioelectrical impedance analysis and muscle strength by hand-grip strength. Sarcopenia was defined according to the Foundation for the National Institutes of Health criteria. Sleep duration and insomnia complaint were self-reported. Short sleep duration was considered as ≤6 h/night and long sleep duration as >8 h/night. High risk of obstructive sleep apnea (OSA) was assessed using the STOP-Bang questionnaire. Possible confounders included socio-demographic characteristics, lifestyle, clinical comorbidities, and use of sedatives and hypnotics. The frequencies of sarcopenia, low muscle mass, and low muscle strength were 1.6, 21.1, and 4.1%, respectively. After adjustment for possible confounders, high risk of OSA was associated with low muscle mass (OR=2.17, 95%CI: 1.92-2.45). Among obese participants, high risk of OSA was associated with low muscle strength (OR=1.68, 95%CI: 1.07-2.64). However, neither short nor long sleep duration or frequent insomnia complaint were associated with sarcopenia or its defining components. In conclusion, high risk of OSA was associated with low muscle mass in the whole sample and with low muscle strength among obese participants. Future studies are needed to clarify the temporal relationship between both conditions.

High Dialysate Calcium Concentration is Associated with Worsening Left Ventricular Function.

Dialysate calcium concentration (d[Ca]) might have a cardiovascular impact in patients on haemodialysis (HD) since a higher d[Ca] determines better hemodynamic tolerability. We have assessed the influence of d[Ca] on global longitudinal strain (GLS) by two-dimensional echocardiography using speckle-tracking imaging before and in the last hour of HD. This is an observational crossover study using d[Ca] 1.75 mmol/L and 1.25 mmol/L. Ultrafiltration was the same between interventions; patients aged 44 ± 13 years (N = 19). The 1.75 mmol/L d[Ca] was associated with lighter drop of blood pressure. Post HD serum total calcium was higher with d[Ca] 1.75 than with 1.25 mmol/L (11.5 ± 0.8 vs. 9.1 ± 0.5 mg/dL, respectively, p < 0.01). In almost all segments strain values were significantly worse in the peak HD with 1.75 mmol/L d[Ca] than with 1.25 mmol/L d[Ca]. GLS decreased from -19.8 ± 3.7% at baseline to -17.3 ± 2.9% and -16.1 ± 2.6% with 1.25 d[Ca] and 1.75 d[Ca] mmol/L, respectively (p < 0.05 for both d[Ca] vs. baseline and 1.25 d[Ca] vs. 1.75 d[Ca] mmol/L). Factors associated with a worse GLS included transferrin, C-reactive protein, weight lost, and post dialysis serum total calcium. We concluded that d[Ca] of 1.75 mmol/L was associated with higher post dialysis serum calcium, which contributed to a worse ventricular performance. Whether this finding would lead to myocardial stunning needs further investigation.

Critical analysis of autoregressive and fast Fourier transform markers of cardiovascular variability in rats and humans

The autonomic nervous system plays an important role in physiological and pathological conditions, and has been extensively evaluated by parametric and non-parametric spectral analysis. To compare the results obtained with fast Fourier transform (FFT) and the autoregressive (AR) method, we performed a comprehensive comparative study using data from humans and rats during pharmacological blockade (in rats), a postural test (in humans), and in the hypertensive state (in both humans and rats). Although postural hypotension in humans induced an increase in normalized low-frequency (LFnu) of systolic blood pressure, the increase in the ratio was detected only by AR. In rats, AR and FFT analysis did not agree for LFnu and high frequency (HFnu) under basal conditions and after vagal blockade. The increase in the LF/HF ratio of the pulse interval, induced by methylatropine, was detected only by FFT. In hypertensive patients, changes in LF and HF for systolic blood pressure were observed only by AR; FFT was able to detect the reduction in both blood pressure variance and total power. In hypertensive rats, AR presented different values of variance and total power for systolic blood pressure. Moreover, AR and FFT presented discordant results for LF, LFnu, HF, LF/HF ratio, and total power for pulse interval. We provide evidence for disagreement in 23 percent of the indices of blood pressure and heart rate variability in humans and 67 percent discordance in rats when these variables are evaluated by AR and FFT under physiological and pathological conditions. The overall disagreement between AR and FFT in this study was 43 percent.

Critical analysis of autoregressive and fast Fourier transform markers of cardiovascular variability in rats and humans.

The autonomic nervous system plays an important role in physiological and pathological conditions, and has been extensively evaluated by parametric and non-parametric spectral analysis. To compare the results obtained with fast Fourier transform (FFT) and the autoregressive (AR) method, we performed a comprehensive comparative study using data from humans and rats during pharmacological blockade (in rats), a postural test (in humans), and in the hypertensive state (in both humans and rats). Although postural hypotension in humans induced an increase in normalized low-frequency (LFnu) of systolic blood pressure, the increase in the ratio was detected only by AR. In rats, AR and FFT analysis did not agree for LFnu and high frequency (HFnu) under basal conditions and after vagal blockade. The increase in the LF/HF ratio of the pulse interval, induced by methylatropine, was detected only by FFT. In hypertensive patients, changes in LF and HF for systolic blood pressure were observed only by AR; FFT was able to detect the reduction in both blood pressure variance and total power. In hypertensive rats, AR presented different values of variance and total power for systolic blood pressure. Moreover, AR and FFT presented discordant results for LF, LFnu, HF, LF/HF ratio, and total power for pulse interval. We provide evidence for disagreement in 23% of the indices of blood pressure and heart rate variability in humans and 67% discordance in rats when these variables are evaluated by AR and FFT under physiological and pathological conditions. The overall disagreement between AR and FFT in this study was 43%.

Phenotypic characteristics associated with hypertension in patients with obstructive sleep apnea.

Obstructive sleep apnea (OSA) causes secondary hypertension. However, the reasons why the prevalence of hypertension among OSA patients varies widely (35-70%) are not clear. We sought to investigate the phenotypic characteristics of patients with and without hypertension among OSA patients who were matched for disease severity. We studied 152 OSA patients (76 normotensive and 76 hypertensive) diagnosed by polysomnography. Detailed phenotypic characteristics, including laboratorial analysis, were determined in all patients. Univariate analysis followed by multiple logistic regression analysis was used to identify variables that were independently associated with hypertension. The apnea-hypopnea index in normotensive and hypertensive patients was similar (48+/-26 and 48+/-26 events/h, respectively) as well as minimum arterial oxygen saturation (76+/-10 and 75+/-10%, respectively) and total sleep time with oxyhaemoglobin saturation <90% (25+/-25 and 28+/-26%, respectively). Hypertensive patients were older (57+/-11 vs 47+/-12 years; P<0.001), had a higher body mass index (BMI; 34+/-7 vs 30+/-5 kg/m(2); P<0.001), had a higher frequency of women (37 vs 8%; P<0.001), had a higher incidence of diabetes (25 vs 6%; P=0.002) and a higher family history of hypertension (75 vs 42%; P=0.01) than did the normotensive patients. Multiple logistic regression analysis indicated that age (P=0.004), familial history of hypertension (P=0.004), BMI (P=0.04) and female sex (P=0.03) were the independent variables associated with hypertension. We concluded that increasing age and BMI, familial history of hypertension as well as female gender are phenotypic characteristics associated with hypertension among OSA patients with similar disease severity.

Impact of clinical experience on quantification of clinical signs at physical examination.

PURPOSE: Although physical examination is a fundamental component of medical decision making, relatively few studies have evaluated how physicians quantify clinical signs and whether different methods of assessment have different effects on clinical practice. OBJECTIVES: To evaluate a possible impact of clinical experience when attending physicians, medical residents and medical students quantify qualitative signs of physical examination in a teaching hospital. SETTING: Hospital das Clínicas, University of São Paulo, Brazil. SUBJECTS: A total of 244 randomly selected physicians and medical students completed a reliable and consistent eight-item questionnaire. MAIN OUTCOME MEASURES: To compare how they quantified clinical signs of cyanosis, anaemia, jaundice, oedema and dehydration, why they used the method(s) they described, and whether the method used could affect diagnosis, further testing or patient management. A chi-square test was used to calculate differences between the groups. RESULTS: Whilst the majority of those surveyed tended to use a four-level evaluation for these clinical signs, attending staff physicians were more likely to employ two-level evaluations than were residents or medical students. For all five signs, attending physicians' use of dichotomous evaluations was significantly higher than that of residents or medical students: anaemia (P = 0.004), cyanosis (P < 0.001), oedema (P = 0.005), dehydration (P < 0.001) and jaundice (P = 0.002). CONCLUSION: Although medical students and residents are routinely taught to use a four-level evaluation for these clinical signs, many of those surveyed tend to abandon this experience for a dichotomous approach. Given that the clinicians in this survey tended not to change their initial approach to a patient based on the intensity of this semi-quantitative method, increased emphasis on teaching dichotomous approach evaluations in medical school should be encouraged.