Consequences of Comorbid Sleep Apnea in the Metabolic Syndrome-Implications for Cardiovascular Risk

Study Objectives: Metabolic syndrome (MetSyn) increases overall cardiovascular risk. MetSyn is also strongly associated with obstructive sleep apnea (OSA), and these 2 conditions share similar comorbidities. Whether OSA increases cardiovascular risk in patients with the MetSyn has not been investigated. We examined how the presence of USA in patients with MetSyn affected hemodynamic and autonomic variables associated with poor cardiovascular outcome. Design: Prospective clinical study. Participants: We studied 36 patients with MetSyn (ATP-III) divided into 2 groups matched for age and sex: (1) MetSyn+OSA (n = 18) and (2) MetSyn-OSA (n = 18). Measurements: USA was defined by an apnea-hypopnea index (AHI) > 15 events/hour by polysomnography. We recorded muscle sympathetic nerve activity (MSNA - microneurography), heart rate (HR), and blood pressure (BP - Finapres). Baroreflex sensitivity (BRS) was analyzed by spontaneous BP and HR fluctuations. Results: MSNA (34 +/- 2 vs 28 +/- 1 bursts/min, P = 0.02) and mean BP (111 +/- 3 vs. 99 +/- 2 mm Hg, P = 0.003) were higher in patients with MetSyn+OSA versus patients with MetSyn-USA. Patients with MetSyn+OSA had lower spontaneous BRS for increases (7.6 +/- 0.6 vs 12.2 +/- 1.2 msec/mm Hg, P = 0.003) and decreases (7.2 +/- 0.6 vs 11.9 +/- 1.6 msec/mm Hg, P = 0.01) in BP. MSNA was correlated with AHI (r = 0.48; P = 0.009) and minimum nocturnal oxygen saturation (r = -0.38, P = 0.04). Conclusion: Patients with MetSyn and comorbid USA have higher BP, higher sympathetic drive, and diminished BRS, compared with patients with MetSyn without USA. These adverse cardiovascular and autonomic consequences of USA may be associated with poorer outcomes in these patients. Moreover, increased BP and sympathetic drive in patients with MetSyn+OSA may be linked, in part, to impairment of baroreflex gain.

Influence of Parasympathetic Modulation in Doppler Mitral Inflow Velocity in Individuals without Heart Disease

Background: The relation between left ventricular filing velocities determined by Doppler echocardiography and autonomic nervous system function assessed by heart rate variability (HRV) is unclear. The aim of this study was to evaluate the influence of the autonomic nervous system assessed by the time and frequency domain indices of HRV in the Doppler indices of left ventricular diastolic filling velocities in patients without heart disease. Methods: We studied 451 healthy individuals (255 female [56.4%]) with normal blood pressure, electrocardiogram, chest x-ray, and treadmill electrocardiographic exercise stress test results, with a mean age of 43 +/- 12 (range 15-82) years, who underwent transthoracic Doppler echocardiography and 24-hour electrocardiographic ambulatory monitoring. We studied indices of HRV on time (standard deviation [SD] of all normal sinus RR intervals during 24 hours, SD of averaged normal sinus RR intervals for all 5-minute segments, mean of the SD of all normal sinus RR intervals for all 5-minute segments, root-mean-square of the successive normal sinus RR interval difference, and percentage of successive normal sinus RR intervals > 50 ms) and frequency (low frequency, high frequency, very low frequency, low frequency/high frequency ratio) domains relative to peak flow velocity during rapid passive filling phase (E), atrial contraction (A), E/A ratio, E-wave deceleration time, and isovolumic relaxation time. Statistical analysis was performed with Pearson correlation and logistic regression. Results: Peak flow velocity during rapid passive filling phase (E) and atrial contraction (A), E/A ratio, and deceleration time of early mitral inflow did not demonstrate a significant correlation with indices of HRV in time and frequency domain. We found that the E/A ratio was < 1 in 45 individuals (10%). Individuals with an E/A ratio < 1 had lower indices of HRV in frequency domain (except low frequency/high frequency) and lower indices of the mean of the SD of all normal sinus RR intervals for all 5-minute segments, root-mean-square of the successive normal sinus RR interval difference, and percentage of successive normal sinus RR intervals > 50 ms in time domain. Logistic regression demonstrated that an E/A ratio < 1 was associated with lower HF. Conclusion: Individuals with no evidence of heart disease and an E/A ratio < 1 demonstrated a significant decrease in indexes of HRV associated with parasympathetic modulation. (J Am Soc Echocardiogr 2010;23: 762-5.)

Characteristics and Predictors of Obstructive Sleep Apnea in Patients With Systemic Hypertension

Obstructive sleep apnea (OSA) is a secondary cause of hypertension and independently associated with target-organ damage in hypertensive patients. However, OSA remains largely underdiagnosed and undertreated. The aim of the present study was to evaluate the characteristics and clinical predictors of OSA in a consecutive series of patients followed up in a hypertension unit. A total of 99 patients (age 46 +/- 11 years, body mass index 28.8 kg/m(2), range 25.1 to 32.9) underwent polysomnography. The clinical parameters included age, gender, obesity, daytime sleepiness, snoring, Berlin Questionnaire, resistant hypertension, and metabolic syndrome. Of the 99 patients, 55 (56%) had OSA (apnea-hypopnea index >5 events/hour). Patients with OSA were older and more obese, had greater levels of blood pressure, and presented with more diabetes, dyslipidemia, resistant hypenension, and metabolic syndrome than the patients without OSA. Of the patients with OSA, 51% had no excessive daytime sleepiness. The Berlin Questionnaire and patient age revealed a high sensitivity (0.93 and 0.91, respectively) but low specificity (0.59 and 0.48, respectively), and obesity and resistant hypertension revealed a low sensitivity (0.58 and 0.44, respectively) but high specificity (0.75 and 0.91, respectively) for OSA. Metabolic syndrome was associated with high sensitivity and specificity for OSA (0.86 and 0.85, respectively). Multiple regression analysis showed that age of 40 to 70 years (odds ratio 1.09, 95% confidence interval 1.03 to 1.16), a high risk of OSA on the Berlin Questionnaire (odds ratio 8.36, 95% confidence interval 1.67 to 41.85), and metabolic syndrome (odds ratio 19.04, 95% confidence interval 5.25 to 69.03) were independent variables associated with OSA. In conclusion, more important than the typical clinical features that characterize OSA, including snoring and excessive daytime sleepiness, the presence of the metabolic syndrome is as an important marker of OSA among patients with hypertension. (C) 2010 Elsevier Inc. All rights reserved. (Am J Cardiol 2010;105:1135-1139)

Ex Vivo Lung Perfusion: Early Report of Brazilian Experience

Introduction. Only about 15% of the potential candidates for lung donation are considered suitable for transplantation. A new method for ex vivo lung perfusion (EVLP) can be used to evaluate and recondition ""marginal,"" nonacceptable lungs. We have herein described an initial experience with ex vivo perfusion of 8 donor lungs deemed nonacceptable. Materials and Methods. After harvesting, the lungs were perfused ex vivo with Steen Solution, an extracellular matrix with high colloid osmotic pressure. A membrane oxygenator connected to the circuit received gas from a mixture of nitrogen and carbon dioxide, maintaining a normal mixed venous blood gas level in the perfusate. The lungs were gradually rewarmed, reperfused, and ventilated for evaluation through analyses of oxygenation capacity, pulmonary vascular resistance (PVR), lung compliance (LC), and biopsy. Results. The arterial oxygen pressure (with inspired oxygen fraction of 100%) increased from a mean of 206 mm Hg in the organ donor at the referring hospital to a mean of 498 mm Hg during the ex vivo evaluation. After 1 hour of EVLP, PVR varied from 440-1454 dynes/sec/cm(5); LC was in the range of 26-90 mL/cmH(2)O. There was no histological deterioration after 10 hours of cold ischemia and 1 hour of EVLP. Conclusions. The ex vivo evaluation model can improve oxygenation capacity of ""marginal"" lungs rejected for transplantation. It has great potential to increase lung donor availability and, possibly, reduce time on the waiting list.

Obstructive Sleep Apnea, Masked Hypertension, and Arterial Stiffness in Men

BACKGROUND Obstructive sleep apnea (OSA) is an established cause of hypertension However, it is not clear whether the frequency of masked hypertension in patients with OSA and whether OSA have an independent role on arterial stiffness taking into account ambulatory blood pressure (BP) monitoring (ABPM) METHODS We evaluated 61 male normotensive participants as determined by casual clinic BP level <140/90 mm Hg without clinical evidence of cardiovascular disease and on no medications (43 patients with moderate-to-severe OSA (apnea-hypopnea index (AHI) >= 15 events/hour by polysomnography) and 18 age- and body mass index-matched controls without OSA (AHl <5 events/hour)) Pulse wave velocity (PWV), an index of arterial stiffness, and 24-h ABPM were performed in a blinded fashion Masked hypertension was defined when abnormal daytime ABPM was >= 135 or >= 85 mm Hg RESULTS The AHI and lowest oxygen saturation were 26 +/- 16 and 90 +/- 2 vs 528 +/- 210 events/hour and 75 +/- 10% for controls and OSA patients, respectively, P < 0 001. Compared with controls, patients with OSA had higher office systolic BP (113 +/- 9 vs 118 +/- 10 mm Hg, P=0 05) and a higher unadjusted proportion of masked hypertension (2 controls (11.1%)vs 13 patients (30 2%), P < 005) PWV was 87 +/- 0.7, 9.4 +/- 1.0, and 10.6 +/- 1.1 m/s in the control, OSA without and with masked hypertension groups, respectively (P < 0 01 for each comparison) Multiple regression showed that systolic daytime ABPM and the lowest oxygen saturation were independently related to PWV (adjusted R(2) = 0 34, P < 0 01) CONCLUSIONS Patients with OSA presented a higher unadjusted rate of masked hypertension than matched controls. Lowest oxygen saturation has an independent association with arterial stiffness

The incremental role of obstructive sleep apnoea on markers of atherosclerosis in patients with metabolic syndrome

Objective: Metabolic syndrome (MS) is associated with subclinical atherosclerosis, but the relative role of obstructive sleep apnoea (OSA) is largely unknown. The main objective of this study is to determine the impact of OSA on markers of atherosclerosis in patients with MS. Methods: Eighty-one consecutive patients with MS according to the Adult Treatment Panel III underwent a clinical evaluation, polysomnography, laboratory and vascular measurements of carotid intima media thickness (IMT), carotid-femoral pulse wave velocity (PWV) and carotid diameter (CD) in a blind fashion. OSA was defined as an apnoea-hypopnoea index (AHI) >= 15 events/hour. Multiple linear regression was performed to determine the variables that were independently associated with the vascular parameters. Results: Fifty-one patients (63%) had OSA. No significant differences existed in age, sex, MS criteria, and cholesterol levels between patients with (MS+OSA) and without OSA (MS-OSA). Compared with MS-OSA patients, MS+OSA patients had higher levels of IMT (661 +/- 117 vs. 767 +/- 140 mu m), PWV (9.6 +/- 1.0 vs. 10.6 +/- 1.6 m/s), and CD (6705 +/- 744 vs. 7811 +/- 862 mu m) (P < 0.001 for each comparison). Among patients with MS+OSA, all vascular parameters were similar in patients with and without daytime sleepiness. The independent parameters associated with IMT, PWV, and CD were AHI, abdominal circumference, and systolic blood pressure (R(2) = 0.42); AHI and systolic blood pressure (R(2) = 0.38); and AHI, age, abdominal circumference and systolic blood pressure (R(2) = 0.45), respectively. The R(2) of AHI for IMT, PWV and CD was 0.12, 0.10 and 0.20, respectively. Conclusions: OSA is very common and has an incremental role in atherosclerotic burden in consecutive patients with MS. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Effect of Femtosecond Laser Energy Level on Corneal Stromal Cell Death and Inflammation

PURPOSE: To analyze the effects of variations in femtosecond laser energy level on corneal stromal cell death. and inflammatory cell influx following flap creation in a rabbit model. METHODS: Eighteen rabbits were stratified in three different groups according to level of energy applied for flap creation (six animals per group). Three different energy levels were chosen for both the lamellar and side cut; 2.7 mu J (high energy), 1.6 mu J (intermediate energy), and 0.5 mu J (low energy) with a 60 kHz, model II, femtosecond laser (IntraLase). The opposite eye of each rabbit served as a control. At the 24-hour time point after surgery, all rabbits were euthanized and the comeoscleral rims were analyzed for the levels of cell death and inflammatory cell influx with the terminal uridine deoxynucleotidyl transferase dUTP-nick end labeling (TUNEL) assay and immunocytochemistry for monocyte marker CD11b, respectively. RESULTS: The high energy group (31.9 +/- 7.1 [standard error of mean (SEM) 2.9]) had significantly more TUNEL positive cells in the central flap compared to the intermediate (22.2 +/- 1.9 [SEM 0.8], P=.004), low (17.9 +/- 4.0 [SEM 1.6], P <= .001), and control eye (0.06 +/- 0.02 [SEM 0.009], P <= .001) groups. The intermediate and low energy groups also had significantly more TUNEL positive cells than the control groups (P <= .001). The difference between the intermediate and low energy levels was not significant (P=.56). The mean for CD11b-positive cells/400x field at the flap edge was 26.1 +/- 29.3 (SEM 11.9), 5.8 +/- 4.1 (SEM 1.6), 1.6 +/- 4.1 (SEM 1.6), and 0.005 +/- 0.01 (SEM 0.005) for high energy, intermediate energy, low energy, and control groups, respectively. Only the intermediate energy group showed statistically more inflammatory cells than control eyes (P = .015), most likely due to variability between eyes. CONCLUSIONS: Higher energy levels trigger greater cell death when the femtosecond laser is used to create corneal flaps: Greater corneal inflammatory cell infiltration is observed with higher femtosecond laser energy levels. [J Refract Surg. 2009;25:869-874.] doi:10.3928/1081597X-20090917-08

Treatment of obstructive sleep apnea syndrome in patients from a teaching hospital in Brazil: is it possible?

The aim of this study was to evaluate the efficacy of a cost-effective intra-oral appliance for obstructive sleep apnea syndrome built into a large teaching hospital. Out of 20 evaluated and treated patients, 14 concluded the study: eight men and six women, with a mean age of 42-46 (mean + SD) years and mean body mass index of 27.66. Inclusion criteria were mild or moderate apnea-hypopnea index (AHI) according to a polysomnographic study. All patients were treated with the monobloco intra-oral appliance. They were then submitted to a follow-up polysomnographic study after 60 days using the appliance. An orofacial clinical evaluation was carried out with the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) questionnaire and with clinical evaluation questionnaire devised by the Orofacial Pain Team before and 60 days after fitting the intra-oral appliance. The AHI showed a statistically meaningful (p = 0.002) reduction from 15.53 to 7.82 events per hour, a non-statistically significant oxygen saturation increase from 83.36 to 84.86 (p = 0.09), and Epworth`s sleepiness scale reduction from 9.14 to 6.36 (p = 0.001). Three patients did not show any improvement. The most common side effect during the use of the appliance/device was pain and facial discomfort (28.57%), without myofascial or temporomandibular joint pain as evaluated by the RDC/TMD questionnaire. The intra-oral device produced a significant reduction of the apnea-hypopnea index during the study period with the use of the monobloco intra-oral appliance. Patients did not show prior myofascial pain or 60 days after use of the intra-oral appliance.

Use of cholesterol-rich nanoparticles that bind to lipoprotein receptors as a vehicle to paclitaxel in the treatment of breast cancer: pharmacokinetics, tumor uptake and a pilot clinical study

Purpose In animal experiments paclitaxel oleate associated with a cholesterol-rich nanoemulsion concentrated in the neoplastic tissues and showed reduced toxicity and increased antitumor activity compared with paclitaxel-Cremophor EL. Here, a clinical study was performed in breast cancer patients to evaluate the tumoral uptake, pharmacokinetics and toxicity of paclitaxel associated to nanoemulsions. Methods Twenty-four hours before mastectomy [(3)H]paclitaxel oleate associated with [(14)C]-cholesteryl oleatenanoemulsion or [(3)H]- paclitaxel in Cremophor EL were injected into five patients for collection of blood samples and fragments of tumor and normal breast tissue. A pilot clinical study of paclitaxel-nanoemulsion administered at 3-week intervals was performed in four breast cancer patients with refractory advanced disease at 175 and 220 mg/m(2) dose levels. Results T(1/2) of paclitaxel oleate associated to the nanoemulsion was greater than that of paclitaxel (t(1/2) = 15.4 +/- 4.7 and 3.5 +/- 0.80 h). Uptake of the [(14)C]-cholesteryl ester nanoemulsion and [(3)H]- paclitaxel oleate by breast malignant tissue was threefold greater than the normal breast tissue and toxicity was minimal at the two dose levels. Conclusions Our results suggest that the paclitaxel-nanoemulsion preparation can be advantageous for use in the treatment of breast cancer because the pharmacokinetic parameters are improved, the drug is concentrated in the neoplastic tissue and the toxicity of paclitaxel is reduced.

Obstructive Sleep Apnea in Patients on Conventional and Short Daily Hemodialysis

Obstructive sleep apnea (OSA) is common among patients on maintenance hemodialysis. However, the factors associated with the origin of OSA as well as the cardiovascular consequences in this population are not completely understood. We evaluated, by standard overnight polysomnography, 24-hour ambulatory blood pressure (BP) monitoring and echocardiography in 30 patients (14 males, age 34 +/- 11 years, BMI 23.2 +/- 5.2) - 15 on short daily hemodialysis (SDH) and 15 matched patients on conventional hemodialysis (CHD). The hemodialysis dose (standard Kt/V) was higher in patients on SDH than on CHD (p = 0.001). OSA (apnea-hypopnea index 1 5 events/h) was present in 13 patients (43%). Patients with OSA were predominantly males (77 vs. 44%), presented a higher BMI (25.5 +/- 6.2 vs. 21.5 +/- 3.6), a larger neck circumference (38 +/- 1 vs. 34 +/- 1 cm) and a lower Kt/V (2.6 +/- 0.3 vs. 2.2 +/- 0.1) than patients with no OSA (p < 0.05). Neck circumference and lower Kt/V were independently associated with OSA on multivariate analysis. No patient with Kt/V > 2.5 (n = 10) presented OSA. On the other hand, hypertensive patients with OSA needed more BP control pills (p = 0.03). Despite similar BP control, patients with OSA presented a higher interventricular septum thickness (11.5 +/- 0.5 vs. 9.9 +/- 0.3 mm; p = 0.011). In conclusion, among patients on maintenance hemodialysis, the traditional risk factors for OSA are present and interact with hemodialysis efficiency. Among these patients, OSA is associated with difficult BP control and heart remodeling suggesting that OSA may contribute to poor cardiovascular outcome. Copyright (c) 2008 S. Karger AG, Basel

Evolutive physicochemical characterization of diabetic ketoacidosis in adult patients admitted to the intensive care unit

Purpose: The aim of this study was to characterize the first 48-hour evolution of metabolic acidosis of adult patients with diabetic ketoacidosis admitted to the intensive care unit. Materials and Methods: We studied 9 patients retrieved from our prospective collected database, using the physicochemical approach to acid-base disturbances. Results: Mean (SD) age was 34 (13) years; mean (SD) Acute Physiology and Chronic Health Evaluation II score was 16 (10); mean (SD) blood glucose level on admission was 480 (144) mg/dL; mean (SD) pH was 7.17 (0.18); and mean (SD) standard base excess was -16.8 (7.7) mEq/L. On admission, a great part of metabolic acidosis was attributed to unmeasured anions (strong ion gap [SIG], 20 +/- 10 mEq/L), with a wide range of strong ion difference (41 +/- 10 mEq/L). During the first 48 hours of treatment, 297 +/- 180 IU of insulin and 9240 +/- 6505 mL of fluids were used. Metabolic improvement was marked by the normalization of pH, partial correction of standard base excess, and a reduction of hyperglycemia. There was a significant improvement of SIG (7.6 +/- 6.2 mEq/L) and a worsening of strong ion difference acidosis (36 +/- 5 mEq/L) in the first 24 hours, with a trend toward recuperation between 24 and 48 hours (38 +/- 6 mEq/L). Conclusion: Initial metabolic acidosis was due to SIG, and the treatment was associated with a significant decrease of SIG with an elevation of serum chloride above the normal range. (C) 2011 Elsevier Inc. All rights reserved.

EFFECTS OF A POTENT PEROXYNITRITE DECOMPOSITION CATALYST IN MURINE MODELS OF ENDOTOXEMIA AND SEPSIS

Excessive free-radical production due to various bacterial components released during bacterial infection has been linked to cell death and tissue injury. Peroxynitrite is a highly reactive oxidant produced by the combination of nitric oxide (NO) and superoxide anion, which has been implicated in cell death and tissue injury in various forms of critical illness. Pharmacological decomposition of peroxynitrite may represent a potential therapeutic approach in diseases associated with the overproduction of NO and superoxide. In the present study, we tested the effect of a potent peroxynitrite decomposition catalyst in murine models of endotoxemia and sepsis. Mice were injected i.p. with LPS 40 mg/kg with or without FP15 [Fe(III) tetrakis-2-(N-triethylene glycol monomethyl ether) pyridyl porphyrin] (0.1, 0.3, 1, 3, or 10 mg/kg per hour). Mice were killed 12 h later, followed by the harvesting of samples from the lung, liver, and gut for malondialdehyde and myeloperoxidase measurements. In other subsets of animals, blood samples were obtained by cardiac puncture at 1.5, 4, and 8 h after LPS administration for cytokine (TNF-alpha, IL-1 beta, and IL-10), nitrite/nitrate, alanine aminotransferase, and blood urea nitrogen measurements. Endotoxemic animals showed an increase in survival from 25% to 80% at the FP15 doses of 0.3 and 1 mg/kg per hour. The same dose of FP15 had no effect on plasma levels of nitrite/nitrate. There was a reduction in liver and lung malondialdehyde in the endotoxemic animals pretreated with FP15, as well as in hepatic myeloperoxidase and biochemical markers of liver and kidney damage (alanine aminotransferase and blood urea nitrogen). In a bacterial model of sepsis induced by cecal ligation and puncture, FP15 treatment (0.3 mg/kg per day) significantly protected against mortality. The current data support the view that peroxynitrite is a critical factor mediating liver, gut, and lung injury in endotoxemia and septic shock: its pharmacological neutralization may be of therapeutic benefit.

Fabry Disease in Hemodialysis Patients in Southern Brazil: Prevalence Study and Clinical Report

Background. Fabry disease (FD) is a lysosomal storage disorder caused by a deficiency of -Galactosidase A (-Gal A). Fabry nephropathy typically progresses throughout the fifth decade to end-stage renal disease (ESRD), requiring hemodialysis and/or kidney transplantation. Objective. To estimate the prevalence of FD among ESRD males on hemodialysis treatment in Rio Grande do Sul, the southernmost state of Brazil. Methods. Screening for -Gal A activity was performed by a dried blood spot (normal reference value: 1.5 nmoles/hour/mL). Positive screening results were confirmed by plasma -Gal A activity assay (reference value: 3.3 nmoles/hour/mL). Results. Five hundred fifty-eight male patients on hemodialysis were evaluated. Of these, only two had low -Gal A activity and were diagnosed with Fabry disease (0.36%). One of these, age 42, had left ventricular hypertrophy and renal manifestations of Fabry disease without the classic symptoms. The other, age 46, had the classical manifestations of angiokeratomas, acroparesthesias, hypohidrosis, and ocular opacities. Conclusions. Although the prevalence of Fabry disease was very low in our study (0.36%), routine screening of male hemodialysis patients would enable earlier identification of many other affected relatives in their families who might benefit from specific clinical treatment.

Comparison of Full Versus Short Induced-Sleep Polysomnography for the Diagnosis of Sleep Apnea

Objectives/Hypothesis: Polysomnography (PSG) is the gold-standard method for diagnosing obstructive sleep apnea (OSA). However, the gap between demand and capacity in performing PSG is a major health-care problem. We sought to validate a short day-time induced sleep for the diagnosis of OSA. Study Design: Prospective diagnostic method validation. Methods: We studied 25 consecutive patients referred to the sleep laboratory and 15 healthy volunteers. All subjects were evaluated by means of full overnight PSG (Full-PSG) and short day-time induced-sleep PSG (Induced-PSG). Sleep was monitored during both procedures (Embla, 16 channels). Sleep was induced by slow intravenous drip infusion of midazolam. Results: The population studied (N = 40) was 60% male (mean age, 42 +/- 10 years; body mass index, 29 +/- 6.5 kg/m(2)). Sleep was successfully induced in all subjects, and no complications were observed (midazolam doses, 6.2 +/- 3.8 mg; time of induced sleep 41.5 +/- 18.9 minutes). The apnea-hypopnea index (AHI) and minimal oxygen saturation during Full-PSG versus Induced-PSG were similar: median AHI (with 25%-75% interquartile range) was 13 (3-35) events per hour versus 17 (4-36) events per hour, and median oxygen saturation was 84% (75-90) versus 85% (76-92); P = .89 and P = .53, respectively. The majority of the respiratory events during induced sleep were obstructive and similar to those observed during Full-PSG. AHI and lowest oxygen saturation during Induced-PSG correlated significantly with Full-PSG (r = 0.67 and r = 0.77, respectively). Sensitivity and specificity for the diagnosis of OSA (AHI > 15 events per hour) by Induced-PSG were 0.83 and 0.72, respectively. Conclusions: Induced-PSG by midazolam during the day is safe and correlates with Full-PSG; it therefore is a promising alternative method in the diagnosis of OSA.

Effect of treadmill exercise on lumbar vertebrae in ovariectomized rats: anthropometrical and mechanical analyses

The purpose of this study was to examine the preventive effect of exercise on lumbar vertebrae in ovariectomized rats. Three-month-old female Wistar rats were divided into 3 groups: control group (A, n = 10); non-exercised ovariectomized group (B, n = 7) and exercised ovariectomized group (C, n = 7). The rats from group C were subjected to treadmill exercise (15 m/minute in the initial six weeks and 19 m/minute in the next six weeks, 1 hour/day, 4 days/week) for 12 weeks. At death, the fourth lumbar vertebrae were removed and an anthropometrical analysis by a paquimeter and a mechanical compression test by a universal test machine were performed. After 12 weeks, the ovariectomy decreased the superior-inferior vertebral height and the maximal braking load in group B compared to group A, while the exercise increased the vertebral mass in group C compared to both groups A and B (p < 0.01) and the stiffness compared to group B. We concluded the physical activity has an important role to prevent the osteopenia in lumbar vertebrae.