Effects of positive airway pressure therapy on cardiovascular and metabolic markers in males with obstructive sleep apnea.

INTRODUCTION: Obstructive sleep apnea syndrome (OSAS) is associated with cardiovascular/metabolic complications. Some analytical parameters (homocysteine, glycemic and lipidic profiles) are recognized markers of these consequences. Limited data is available on the association of these markers and OSAS's severity/response to positive airway pressure therapy (PAP). MATERIAL AND METHODS: In this prospective study we analyzed polysomnographic and analytical data of male patients admitted to sleep laboratory. The aim was to evaluate metabolic/cardiovascular markers in snorers and OSAS patients, to relate with sleep parameters and PAP response. One-hundred and three patients were included, and 73 (71%) were OSAS patients. OSAS patients were similar to snorers except for higher body mass index (BMI) and dyslipidemia. Severe OSAS patients showed higher glycemia, HbA1c, insulin, and insulin resistance, and lower HDL cholesterol in comparison to mild-moderate (p<0.05, p<0.05, p<0.001, p<0.001, p<0.05, respectively). Glycemic profile and triglycerides were slightly correlated with OSAS severity. 46 OSAS patients were submitted to 6 months of PAP, with a statistical decrease in mean values of homocysteine, glycemia, total and LDL cholesterol (p<0.05, p<0.05, p<0.05, respectively), and in glycemia and LDL cholesterol in severe group only (p<0.05, p<0.05, respectively). RESULTS: This study demonstrated an association between glucose metabolism parameters and triglycerides with OSAS severity underlying the complexity of the process leading to cardiovascular/metabolic complications in this disorder. Moreover, homocysteine, glycemic and lipidic profiles changed significantly after 6 months of PAP therapy in OSAS, supporting its cardiovascular and metabolic protective effect. CONCLUSION: Our study has reinforced the importance of analytical cardiovascular/metabolic evaluation as complementary tool of diagnosis/treatment response in OSAS.

Hematological evaluation in males with obstructive sleep apnea before and after positive airway pressure.

Obstructive sleep apnea syndrome (OSAS) is a systemic inflammatory disease associated with cardiovascular consequences. Red blood cell distribution width (RDW), mean platelet volume (MPV), and platelet distribution width (PDW) are recognized biomarkers of cardiovascular morbidity/mortality. Limited data is available on the association between these parameters and OSAS severity and the relationship with positive airway pressure therapy (PAP). In this prospective study of male OSAS patients we analyzed hematological data in order to evaluate their value in predicting OSAS severity, the relationship with sleep parameters, and their behavior under PAP. Seventy-three patients were included (mean age 46.5 years), of which 36 were mild (49.3%), 10 moderate (13.7%), and 27 severe (37%). The mean RDW increased significantly with OSAS severity and showed a positive correlation with respiratory disturbance index and hypoxemic burdens. Additionally, a group of 48 patients (mean age 47.2 years) were submitted to PAP. After six months, red blood cell count, hemoglobin, hematocrit, and platelet count showed a significant decrease (p<0.0001; p<0.0001; p=0.001; p<0.0001; respectively). Concerning OSAS severity, these parameters also significantly decreased in mild patients (p=0.003; p=0.043; p=0.020; p=0.014; respectively) but only hemoglobin, hematocrit, and platelet count decreased in severe cases (p<0.0001; p=0.008; p=0.018; respectively). This study demonstrated an association between RDW values and OSAS severity. Moreover, red cell and platelet parameters changed significantly after PAP, supporting its cardiovascular protective effect. RDW may become a simple/inexpensive blood biomarker, making it useful in prioritizing OSAS patients waiting for polysomnography, and red cell and platelet parameters could be useful in PAP follow up.

Resultados econômicos de sistemas de produção de leite com diferentes níveis tecnológicos na região de Lavras, MG / Economic results of milk production systems with different technological levels in the area of Lavras, Minas Gerais, Brazil

Estudou-se a rentabilidade da atividade leiteira na região de Lavras, MG, analisando a influência do nível tecnológico sobre o custo de produção do leite. Foram identificados os componentes com maior influência sobre os custos finais da atividade e calculado o ponto de equilíbrio. Os dados, provenientes de 16 sistemas de produção, representando os níveis tecnológicos baixo, médio e alto, foram coletados mensalmente, entre janeiro de 2002 e junho de 2003. Consideraram-se a margem bruta, a margem líquida e o resultado (lucro ou prejuízo) como indicadores de eficiência econômica. O nível tecnológico influenciou o custo total de produção do leite - lucratividade e rentabilidade. Os sistemas de produção com nível tecnológico baixo apresentaram o menor custo unitário. O nível tecnológico influenciou os itens componentes do custo operacional efetivo da atividade leiteira. A margem líquida positiva e a lucratividade negativa, nos três níveis tecnológicos, indicaram que os pecuaristas estarão se descapitalizando a longo prazo, mas não a médio prazo.

Análise de sensibilidade da margem bruta da receita e dos custos do confinamento de diferentes grupos genéticos / Gross margin sensitivity analyses of the income and costs of feedlot for different genetic groups

Análises de sensibilidade da margem bruta foram realizadas com dados de desempenho e custos de 149 animais confinados por períodos variáveis de acordo com acabamento de carcaça dos grupos genéticos: Nelore sobreano, Nelore desmamado, ½ Valdostana ½ Nelore, ½ Simental ½ Nelore, ½ Braford ½ Brangus, ½ Braford » Angus » Nelore, Brangus, ½ Canchim » Angus » Nelore e ½ Canchim » Simental » Nelore. Sensibilidade da margem bruta foi realizada com variações nos preços de venda da carne e de compra do milho, soja, silagem de milho e boi magro, mantendo-se os demais preços fixos. Com o preço da carne a 0,99 US$/kg, o Nelore sobreano foi mais eficiente nas variações do milho, soja e silagem de milho; Brangus foi mais eficiente nas variações do preço de compra do boi. Com preço da carne a 1,27 US$/kg, a margem bruta foi positiva para todos grupos genéticos nas variações do milho, soja e silagem de milho, exceto Nelore desmamado. Na variação de preços de compra do boi, apenas Brangus apresentou margem bruta positiva. A margem bruta foi mais sensível às variações no preço de compra dos animais do que no preço de venda da carne.

Análise de custos de diferentes grupos genéticos de bovinos de corte terminados em confinamento / Cost analyses on different beef cattle genetic groups finished in feedlot condition

O desempenho de 149 animais, machos inteiros, confinados por períodos variáveis de acordo com acabamento de carcaça, foi utilizado para avaliar a eficiência econômica dos grupos genéticos Nelore sobreano, Nelore desmamado, ® Valdostana ® Nelore, ® Simental ® Nelore, ® Braford ® Brangus, ® Braford » Angus » Nelore, Brangus, ® Canchim » Angus » Nelore e ® Canchim » Simental » Nelore. O custo operacional variável, o custo por quilograma de carne produzida e a margem bruta foram analisados pelo método dos quadrados mínimos ordinários, mediante modelo estatístico que incluiu o efeito do grupo genético e o peso inicial como covariável, comparando-se as médias pelo teste Duncan (P<0,05). Os maiores custos operacionais variáveis no período, em US$, foram do ® Canchim » Simental » Nelore (160,8), Nelore desmamado (158,7) e ® Canchim » Angus » Nelore (155,1). Os menores custos por quilograma de carne, em US$, foram do Nelore sobreano (0,79) e Brangus (0,82). A maior margem bruta, em US$, foi obtida pelo grupo genético Nelore sobreano (94,6), seguida do Brangus (71,5) e do ® Simental ® Nelore (46,6). Os grupos genéticos mais pesados no início do confinamento e que permaneceram menos tempo confinados apresentaram maior margem bruta.

[Prognosis of mitral commissurotomy. Study of 1134 mitral patients 20 years later]. / Prognóstico da comissurotomia mitral. Estudo, 20 anos depois, de 1134 doentes mitrais.

With a test sample (n = 323), consisting of the answers to an inquiry about the patients with operated mitral stenosis (n = 1134), between 1952 and 1978, in "Hospital Pulido Valente", Lisbon, we compared the group of survivors with the decreased in the relation to sex, age, valvular lesion, type of surgery, valvular area before and after surgery and existence of incompetence. We concluded that mitral stenosis was more frequent in females (4/1), but it had a worse prognosis in males. The lower the age at the time of surgery the better long time prognosis. Digital and instrumental valvulotomy had similar mortality. Valvular incompetence had a worse prognosis and is associated with larger valvular area.

[Can blood homocysteine explain the family history of vascular diseases?]. / Poderá a homocisteinemia explicar a história familiar da doença vascular?

INTRODUCTION AND AIMS: Family history of vascular disease is an important risk factor for vascular disease, independent of conventional risk factors. Homocysteinemia, a newly defined risk factor, is caused by genetics, such as cystathionine beta synthase deficiencies, and metabolic deficiencies. With the present work we intend to study the influence of family history of vascular disease in homocysteinemia. METHODS: We studied 204 normal persons (153 males), average age 38.7 +/- 10.9 years, in terms of family history of vascular disease (death due to myocardial infarction or a stroke), conventional risk factors, routine laboratory tests, fasting homocysteinemia and after oral methionine loading (0.1 g/Kg body weight). We compared laboratory results, conventional risk factors and homocysteinemia levels in persons with and without a family history of vascular disease. We performed covariance analysis to evaluate, in a multivariate model, factors that were related to basal or after methionine loading homocysteinemia. RESULTS: 35% of persons presented a family history of vascular disease (FHVD). Persons with FHVD presented higher age (45.6 +/- 8.9 versus 35.0 +/- 10.1, p < 0.001), and higher prevalence of hypertension (p = 0.002), dyslipidemia (p = 0.001), obesity (p = 0.03), and physical inactivity (p = 0.03). They presented a tendency, without statistical significance, to have a higher prevalence of diabetes and of hyperhomocysteinemia, and to present higher levels of basal and afterload homocysteinemia. Performing covariance analysis, basal homocysteinemia did not present any relation to FHVD. After methionine load homocysteinemia was strongly influenced by basal homocysteinemia (p = 0.0000), and significantly related to FHVD (p = 0.039). CONCLUSIONS: Homocysteinemia cannot explain most of the risk of family history of vascular disease, not explained by conventional risk factors. The only significant relationship between homocysteinemia and FHVD was observed with afterload homocysteinemia in the multivariate model. FHVD is clearly related to conventional risk factors.

Longitudinal left ventricular function in a population of healthy adults: a tissue Doppler imaging study.

BACKGROUND: Longitudinal left ventricular function is a major determinant of global ventricular function and is probably more sensitive than radial function in the detection of disease. Tissue Doppler imaging of the mitral annulus allows the study of longitudinal left ventricular function. METHODS: Forty-five healthy volunteers divided into two groups (younger and older than 45 years) were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 apical chamber views. In each wave (systolic-s, rapid filling-e, atrial contraction-a) we analyzed velocities, time intervals and velocity-time integrals, as well as heterogeneity and asynchrony indexes. Data were compared between the different sides in each group, between groups and with conventional Doppler data. RESULTS: In contrast to the septal side, the lateral side of the annulus shows higher velocities and velocity-time integrals of the s and e waves, with non-significantly shorter isovolumic relaxation time and shorter time to peak e. There is functional agreement between the lateral and inferior sides versus the septal and anterior sides of the annulus. Most systolic parameters remained unchanged with aging; however, aging was associated with decreased e velocity, increased a velocity and inverted e/a ratio. The relation between s and fractional shortening also did not change with aging. Annular isovolumic contraction time and isovolumic relaxation time were shorter than their respective global time intervals. CONCLUSIONS: This study shows that there are physiological differences in velocities, time intervals and velocity-time integrals between the 4 sides of the mitral annulus, reflecting physiological heterogeneity and asynchrony, and that some of these parameters are age dependent. These data also contribute to a better understanding of longitudinal left ventricular function and may be useful in future studies as reference values in control groups.

[Prognosis significance of blood homocysteine after myocardial infarction]. / Significado prognóstico da homocisteinemia após enfarte do miocárdio.

INTRODUCTION AND AIMS: Homocysteinemia is an independent risk factor of coronary artery disease and of myocardial infarction. In the present study we intend to relate fasting homocystein levels to prognosis after a myocardial infarction. METHODS: From 1990 to 1992, we studied fasting homocysteinemia levels on a group of 112 patients aged under 56 years that had suffered a myocardial infarction between 3 and 12 months before. We obtained, the patients names, addresses, phone numbers and physicians' name. Seven years later (on average) we collected data regarding the patients evolution, consulting medical records, their physicians or by personal contact. We evaluated complications, namely mortality, vascular morbidity, such as unstable angina, re-infarction, stroke, and the need for invasive procedures (catheterism, PTCA, CABG). According to previous studies of the group, we used a cut-point of 10.10 mumol/L to define patients with normal or pathological levels of homocysteinemia. We excluded all patients that took vitamin B supplements, co-factors of HC metabolism, during this follow-up. RESULTS: We were able to obtain data on 110 patients. Patients with normal HC levels (n = 62) presented less global complications (26 versus 72%, p < 0.0001), non significant tendency to have lower mortality (1.6 versus 6%), had lower morbidity (14 versus 36%, p < 0.01) and lower invasive procedure need (18 versus 48%, p < 0.001). In the group with pathological homocystein levels (n = 48), those with higher homocystein levels presented a higher degree of complications. CONCLUSIONS: In this population with myocardial infarction under 56 years of age, a high homocysteinemia level is an important prognostic factor. This study suggests that we can improve the prognosis and decrease the complications after myocardial infarction by lowering elevated homocystein levels.

[Influence of smoking on homocysteinemia at baseline and after methionine load]. / Influência do tabagismo na homocisteinemia basal e após sobrecarga.

INTRODUCTION AND AIMS: Homocysteinemia (HC) and smoking are both important risk factors for vascular disease. In the present study, we intend to evaluate the influence of smoking habits on HC values as well as on vitamins B6, B12 and folic acid, co-factors of HC metabolism. METHODS: We measured fasting homocysteinemia (basal) and homocysteinemia 6 hours after an overload with 0.1 g methionine/kg body weight in 279 subjects. We also performed the dosage of plasma levels of B6 and B12 vitamins and of red cells folates. Smoking habits were inquired and the subjects were classified as non-smokers, current smokers or ex-smokers (if they had stopped smoking more than 1 month before the study). According to the smoking status, smokers were classified in three groups: less than 20 cigarettes a day, between 20 and 39 and 40 or more cigarettes a day. We studied basal and after methionine load homocysteinemia, B6, B12 and folic acid levels in each group. RESULTS: Smokers presented significantly higher levels of basal and after methionine load homocysteinemia then non-smokers (10.6 +/- 4.9 vs 9.4 +/- 2.6, and 26.8 +/- 10.0 vs 24.3 +/- 7.4 mumol/L, respectively, p < 0.05 for both and B6 levels (29.2 +/- 12.0 versus 32.6 +/- 12.0 mumol/L, p < 0.05). B12 and folic levels were similar in the two groups. These results were quite similar either in the normal subjects or in the subjects with a history of a cardiovascular event. The subjects who smoked 40 or more cigarettes per day, compared with those who smoked less then 20 cigarettes per day, presented higher levels of basal homocysteinemia (12.4 +/- 2.9 vs 10.0 +/- 5.5 mumol/L, p < 0.05) and lower levels of B6 (24.7 +/- 8.1 vs 31.7 +/- 12.6 mumol/L, p < 0.05). CONCLUSIONS: Smoking habits are related with the increase of basal and after methionine load homocysteinemia, probably because of a decrease in B6 vitamin levels. There is a proportional effect between the number of cigarettes smoked, B6 depletion and basal homocysteinemia increase. This study suggests that B6 vitamin supplements for smokers could decrease the vascular risk related with smoking habits.

[Homocysteinemia and vascular disease--a new risk factor is born]. / Homocisteiemia e doença vascular--o nascer de um novo factor de risco.

In recent years there has been growing evidence that high levels of plasmatic homocysteine constitute an independent risk factor for early cardiovascular disease. In this article we review the main theories of atherosclerosis which take into account the proteins, namely homocysteine, homocysteine metabolism, the cause that may be responsible for high levels of homocysteinemia, the pathophysiologic mechanisms of vascular lesion induced by hyperhomocysteinemia, the clinical evidence that homocysteinemia constitutes a vascular risk factor and finally, the evidence that it is possible to control homocysteinemia with supplementation of co-factors of homocysteine metabolism, namely vitamin B6, B12 or folic acid.

[The effect of sex and menopause on basal blood levels of homocysteine and after methionine loading]. / Influência do sexo e da menopausa nos níveis de homocisteinemia basal e após sobrecarga com metionina.

INTRODUCTION AND OBJECTIVES: We have already proved that basal and after load homocysteinemia are risk factors for vascular disease and it is also known that premenopausal women are relatively protected against this disease. The objective of this paper was the assess whether there are any differences in the plasma levels of homocystein which might contribute to explain the differences in the incidence of vascular diseases found in both sexes. PATIENTS AND METHODS: Two hundred and four patients (153 males) without previous vascular disease were enrolled in the study. These patients were participating in a screening program for cardiovascular risk factors in a central hospital in Lisbon. We evaluated the basal homocysteinemia and homocysteinemia 6 hours after an oral load with methionine (0.1 g/kg body weight). Basal and after load homocysteinemia in men and women, as well as in women before and after menopause, was compared. Because homocysteinemia does not have a normal distribution, we used non-parametric statistical tests, namely the Mann-Whitney test. RESULTS: Men had higher values for basal homocysteinemia than women (mean and standard deviation)--9.64 +/- 3.15 versus 8.56 +/- 2.82 mumol/l, (p = 0.0018)--as well as for after load homocysteinemia--24.40 +/- 7.84 versus 23.71 +/- 10.16 mumol/L, non significant difference. Premenopausal women (n = 42) had lower basal homocysteinemia values than post menopausal women (n = 9)--8.41 +/- 3.02 versus 9.23 +/- 1.38 mumol/L, p < 0.05--and similarly after load homocysteinemia values--23.86 +/- 10.65 versus 23.01 +/- 7.47 mumol/L. CONCLUSIONS: Basal homocysteinemia is significantly higher in men than in women. After menopause, basal homocysteinemia levels increase significantly in women, approaching those in men. The levels of after load homocystein are not dependent on sex or pre- or postmenopausal condition. Homocysteinemia might explain, at least partly, the differences in the incidence of vascular disease in both sexes and the increased vascular risk in postmenopausal women.

The natural history of closed mitral commissurotomy--a 20 year follow-up.

AIM: To study the natural history of mitral stenosis in a Portuguese population submitted to closed commissurotomy. METHODS-POPULATION: All the patients submitted to closed mitral commissurotomy in Pulido Valente Hospital. The commisurotomies were performed from 1956 to 1978 and included a total of 1,134 patients (220 males). Based on the clinical records, we studied the baseline characteristics of all the patients (n = 1134) at the time of surgery. An average of 20 years after surgery, we sent a questionnaire to all these patients. The patients who filled out the questionnaire (n = 352) represented the total Population in terms of the principal clinical characteristics. Based on these answers, we studied the long-term results of closed commissurotomy. RESULTS: Closed commissurotomy was performed before the age of 20 in about 10% of the patients and after the age of 49 in only 1.6%. The initial symptoms occurred at 22.0 years and commissurotomy was performed at 30.4 years (averages). The procedure was successful: 99% of patients improved significantly after commissurotomy and two thirds had major or total improvement. CONCLUSIONS: In the natural history of these commissurotomized patients the events were early, with symptoms in their twenties and surgery in their thirties. The events occurred earlier in males than in females. Closed commissurotomy presented, in this study and with these patients, very good results with improvement in 99% of the patients. The positive results the commissurotomies were important and long lasting: there was a low rate of re-intervention (16%) and hospitalization (35%) twenty years after surgery and 53% of the patients are still alive. These good results can be, at least in part, explained by the low age of this population at the time of surgery.