Respiratory panic disorder subtype and sensitivity to the carbon dioxide challenge test

The aim of the present study was to verify the sensitivity to the carbon dioxide (CO2) challenge test of panic disorder (PD) patients with respiratory and nonrespiratory subtypes of the disorder. Our hypothesis is that the respiratory subtype is more sensitive to 35% CO2. Twenty-seven PD subjects with or without agoraphobia were classified into respiratory and nonrespiratory subtypes on the basis of the presence of respiratory symptoms during their panic attacks. The tests were carried out in a double-blind manner using two mixtures: 1) 35% CO2 and 65% O2, and 2) 100% atmospheric compressed air, 20 min apart. The tests were repeated after 2 weeks during which the participants in the study did not receive any psychotropic drugs. At least 15 of 16 (93.7%) respiratory PD subtype patients and 5 of 11 (43.4%) nonrespiratory PD patients had a panic attack during one of two CO2 challenges (P = 0.009, Fisher exact test). Respiratory PD subtype patients were more sensitive to the CO2 challenge test. There was agreement between the severity of PD measured by the Clinical Global Impression (CGI) Scale and the subtype of PD. Higher CGI scores in the respiratory PD subtype could reflect a greater sensitivity to the CO2 challenge due to a greater severity of PD. Carbon dioxide challenges in PD may define PD subtypes and their underlying mechanisms.

Sleep-wake pattern of medical students: early versus late class starting time

The sleep-wake cycle of students is characterized by delayed onset, partial sleep deprivation and poor sleep quality. Like other circadian rhythms, the sleep-wake cycle is influenced by endogenous and environmental factors. The aim of the present study was to determine the effects of different class starting times on the sleep-wake pattern of 27 medical students. The data were collected during two medical school semesters having different class starting times. All subjects answered the Portuguese version of the Horne and Östberg Morningness/Eveningness Questionnaire, the Pittsburgh Sleep Quality Index (PSQI) and kept a sleep diary for two weeks during each semester. Better sleep quality (PSQI = 5.3 vs 3.4), delayed sleep onset (23:59 vs 0:54 h) and longer sleep duration (6 h and 55 min vs 7 h and 25 min) were observed with the late schedule. We also found reduced sleep durations during weekdays and extended sleep durations during weekends. This pattern was more pronounced during the semester with the early class schedule, indicating that the students were more sleep deprived when their classes began earlier in the morning. These results require further investigation regarding the temporal organization of our institutions.

Transitory increased blood pressure after upper airway surgery for snoring and sleep apnea correlates with the apnea-hypopnea respiratory disturbance index

A transitory increase in blood pressure (BP) is observed following upper airway surgery for obstructive sleep apnea syndrome but the mechanisms implicated are not yet well understood. The objective of the present study was to evaluate changes in BP and heart rate (HR) and putative factors after uvulopalatopharyngoplasty and septoplasty in normotensive snorers. Patients (N = 10) were instrumented for 24-h ambulatory BP monitoring, nocturnal respiratory monitoring and urinary catecholamine level evaluation one day before surgery and on the day of surgery. The influence of postsurgery pain was prevented by analgesic therapy as confirmed using a visual analog scale of pain. Compared with preoperative values, there was a significant (P < 0.05) increase in nighttime but not daytime systolic BP (119 ± 5 vs 107 ± 3 mmHg), diastolic BP (72 ± 4 vs 67 ± 2 mmHg), HR (67 ± 4 vs 57 ± 2 bpm), respiratory disturbance index (RDI) characterized by apnea-hypopnea (30 ± 10 vs 13 ± 4 events/h of sleep) and norepinephrine levels (22.0 ± 4.7 vs 11.0 ± 1.3 µg l-1 12 h-1) after surgery. A positive correlation was found between individual variations of BP and individual variations of RDI (r = 0.81, P < 0.01) but not between BP or RDI and catecholamines. The visual analog scale of pain showed similar stress levels on the day before and after surgery (6.0 ± 0.8 vs 5.0 ± 0.9 cm, respectively). These data strongly suggest that the cardiovascular changes observed in patients who underwent uvulopalatopharyngoplasty and septoplasty were due to the increased postoperative RDI.

A comparison of public and private obstructive sleep apnea clinics

The aim of the present study was to compare the clinical findings and polysomnography results obtained at public and private clinics in Brazil, the follow-up after diagnosis, and the therapeutic aspects related to continuous positive airway pressure. Patients who snore and who have obstructive sleep apnea were retrospectively divided into two groups, i.e., public clinic (N = 307) and private clinic (N = 317). Data concerning age, sex, body mass index (BMI), neck circumference, medical history, sleepiness scale, follow-up after diagnosis, and acceptance of continuous positive airway pressure therapy were collected. Mean age was 50 ± 12 (range: 15-80) for public patients and 48 ± 12 years (range: 19-91) for private patients. Mean BMI was 30 ± 6 (range: 19-67) for public patients and 31 ± 6 kg/m² (range: 21-59) for private patients. The public clinic had a significantly higher frequency of women than the private clinic (M:F ratio of 2.0:1 and 6.9:1, respectively). The condition of private patients (apnea-hypopnea index = 31 ± 25) was more severe than that of public patients (apnea-hypopnea index = 25 ± 24 events/h; P = 0.0004). In the public and private clinics, 19 and 15% of patients were snorers, respectively, and 81 and 85% of them had sleep apnea. After diagnosis, follow-up was longer in the private group. The continuous positive airway pressure acceptance was similar for both groups (32 vs 35%), but patients from the public clinic abandoned treatment more than private ones (65 vs 13%). Social status was significant in terms of the severity of obstructive sleep apnea age and gender distribution. Private patients look for a diagnosis earlier in the course of the disease than public patients, adhere more to follow-up, and abandon continuous positive airway pressure treatment less than public patients do.

The size and prevalence of the cavum septum pellucidum are normal in subjects with panic disorder

Panic disorder is thought to involve dysfunction in the septohippocampal system, and the presence of a cavum septum pellucidum might indicate the aberrant development of this system. We compared the prevalence and size of cavum septum pellucidum in 21 patients with panic disorder and in 21 healthy controls by magnetic resonance imaging. The length of the cavum septum pellucidum was measured by counting the number of consecutive 1-mm coronal slices in which it appeared. A cavum septum pellucidum of >6 mm in length was rated as large. There was no significant difference in the proportion of patients (16 of 21 or 76.2%) and controls (18 of 21 or 85.7%) with a cavum septum pellucidum (P = 0.35, Fisher's exact test, one-tailed), and no members of either group had a large cavum septum pellucidum. The mean cavum septum pellucidum rating in the patient and control groups was 1.81 (SD = 1.50) and 2.09 (SD = 1.51), respectively. There were also no significant differences between groups when we analyzed cavum septum pellucidum ratings as a continuous variable (U = 196.5; P = 0.54). Across all subjects there was a trend towards a higher prevalence of cavum septum pellucidum in males (100%, 10 of 10) than females (75%, 24 of 32; P = 0.09, Fisher's exact test, one-tailed). Thus, we conclude that, while panic disorder may involve septo-hippocampal dysfunction, it is not associated with an increased prevalence or size of the cavum septum pellucidum.

Is avoidant disorder part of the social phobia spectrum in a referred sample of Brazilian children and adolescents?

The diagnosis of avoidant disorder was deleted from the Diagnostic and Statistical Manual of Mental disorders - fourth edition (DSM-IV) based on a `committee decision' suggesting that avoidant disorder is part of the social phobia spectrum. The objective of the present study was to examine the nature of this clinical association in a referred sample of Brazilian children and adolescents. We assessed a referred sample of 375 youths using semi-structured diagnostic interview methodology. Demographic (age at admission to the study and sex) and clinical (level of impairment, age at onset of symptoms and pattern of comorbidity) data were assessed in subsamples of children with avoidant disorder (N = 7), social phobia (N = 26), and comorbidity between both disorders (N = 24). Although a significant difference in the male/female ratio was detected among groups (P = 0.03), none of the other clinical variables differed significantly among subjects that presented each condition separately or in combination. Most of the children with avoidant disorder fulfilled criteria for social phobia. Thus, our findings support the validity of the conceptualization of avoidant disorder as part of the social phobia spectrum in a clinical sample.

Social disability of Brazilian mood disorder patients

Mood disorders cause many social problems, often involving family relationships. Few studies are available in the literature comparing patients with bipolar, unipolar, dysthymic, and double depressive disorders concerning these aspects. In the present study, demographic and disease data were collected using a specifically prepared questionnaire. Social adjustment was assessed using the Disability Adjustment Scale and family relationships were evaluated using the Global Assessment of Relational Functioning Scale. One hundred patients under treatment for at least 6 months were evaluated at the Psychiatric Outpatient Clinic of the Botucatu School of Medicine, UNESP. Most patients were women (82%) more than 50 (49%) years old with at least two years of follow-up, with little schooling (62% had less than 4 years), and of low socioeconomic level. Logistic regression analysis showed that a diagnosis of unipolar disorder (P = 0.003, OR = 0.075, CI = 0.014-0.403) and dysthymia (P = 0.001, OR = 0.040, CI = 0.006-0.275) as well as family relationships (P = 0.002, OR = 0.953, CI = 0914-0.992) played a significant role in social adjustment. Unipolar and dysthymic patients presented better social adjustment than bipolar and double depressive patients (P < 0.001), results that were not due to social class. These patients, treated at a teaching hospital, may represent the severest mood disorder cases. Evaluations were made knowing the diagnosis of the patients, which might also have influenced some of the results. Social disabilities among mood disorder patients are very frequent and intensive.

An empirical comparison of atypical bulimia nervosa and binge eating disorder

The International Classification of Diseases, 10th edition (ICD-10) defines atypical bulimia nervosa (ABN) as an eating disorder that encompasses several different syndromes, including the DSM-IV binge eating disorder (BED). We investigated whether patients with BED can be differentiated clinically from patients with ABN who do not meet criteria for BED. Fifty-three obese patients were examined using the Structured Clinical Interview for DSM-IV and the ICD-10 criteria for eating disorders. All volunteers completed the Binge Eating Scale (BES), the Beck Depression Inventory, and the Symptom Checklist-90 (SCL-90). Individuals fulfilling criteria for both ABN and BED (N = 18), ABN without BED (N = 16), and obese controls (N = 19) were compared and contrasted. Patients with ABN and BED and patients with ABN without BED displayed similar levels of binge eating severity according to the BES (31.05 ± 7.7 and 30.05 ± 5.5, respectively), which were significantly higher than those found in the obese controls (18.32 ± 8.7; P < 0.001 and P < 0.001, respectively). When compared to patients with ABN and BED, patients with ABN without BED showed increased lifetime rates of agoraphobia (P = 0.02) and increased scores in the somatization (1.97 ± 0.85 vs 1.02 ± 0.68; P = 0.001), obsessive-compulsive (2.10 ± 1.03 vs 1.22 ± 0.88; P = 0.01), anxiety (1.70 ± 0.82 vs 1.02 ± 0.72; P = 0.02), anger (1.41 ± 1.03 vs 0.59 ± 0.54; P = 0.005) and psychoticism (1.49 ± 0.93 vs 0.75 ± 0.55; P = 0.01) dimensions of the SCL-90. The BED construct may represent a subgroup of ABN with less comorbities and associated symptoms.

Sleep disorders, sleepiness and traffic safety: a public health menace

Sleep disorders are not uncommon and have been widely reported throughout the world. They have a profound impact on industrialized 24-h societies. Consequences of these problems include impaired social and recreational activities, increased human errors, loss of productivity, and elevated risk of accidents. Conditions such as acute and chronic insomnia, sleep loss, excessive sleepiness, shift-work, jet lag, narcolepsy, and sleep apnea warrant public health attention, since residual sleepiness during the day may affect performance of daily activities such as driving a car. Benzodiazepine hypnotics and zopiclone promote sleep, both having residual effects the following day including sleepiness and reduced alertness. In contrast, the non-benzodiazepine hypnotics zolpidem and zaleplon have no significant next-day residual effects when taken as recommended. Research on the effects of wakefulness-promoting drugs on driving ability is limited. Countermeasures for excessive daytime sleepiness have a limited effect. There is a need for a social awareness program to educate the public about the potential consequences of various sleep disorders such as narcolepsy, sleep apnea, shift-work-related sleep loss, and excessive daytime sleepiness in order to reduce the number of sleep-related traffic accidents.

Prenatal and perinatal risk factors for bipolar disorder

Bipolar disorder (BPD) is a severe mental disorder associated with considerable morbidity and mortality. Prenatal insults have been shown to be associated with later development of mental disorders and there is a growing interest in the potential role of prenatal and perinatal risk factors in the development of BPD. The aims of this thesis were to describe the overall study design of the Finnish Prenatal Study of Bipolar Disorders (FIPS-B) and demographic characteristics of the sample. Furthermore, it was aimed to examine the association of parental age, parental age difference, perinatal complications and maternal smoking during pregnancy with BPD. This thesis is based on FIPS-B, a nested case-control study using several nationwide registers. The cases included all people born in Finland between January 1st 1983 and December 31st 1998 and diagnosed with BPD according to the Finnish Hospital Discharge Register (FHDR) before December 31st 2008. Controls for this study were people who were without BPD, schizophrenia or diagnoses related to these disorders, identified from the Population Register Centre (PRC), and matched two-fold to the cases on sex, date of birth (+/- 30 days), and residence in Finland on the first day of diagnosis of the matched case. Conditional logistic regression models were used to examine the association between risk factors and BPD. This study included 1887 BPD cases and 3774 matched controls. The mean age at diagnosis was 19.3 years and females accounted for 68% of the cases. Mothers with the lowest educational level had the highest odds of having BPD in offspring. Being born in Eastern and Southern region of Finland increased the odds of having BPD later in life. A U-shaped distribution of odds ratio was observed between paternal age and BPD in the unadjusted analysis. Maternal age and parental age difference was not associated with BPD. Birth by planned caesarean section was associated with increased odd of BPD. Smoking during pregnancy was not associated with BPD in the adjusted analyses. Region of birth and maternal educational level were associated with BPD. Both young and old father’s age was associated with BPD. Most perinatal complications and maternal smoking during pregnancy were not associated with BPD. The findings of this thesis, considered together with previous literature, suggest that the pre- and perinatal risk factor profile varies among different psychiatric disorders.

Obese obstructive sleep apnea patients with tonsil hypertrophy submitted to tonsillectomy

The physiopathology of obstructive sleep apnea-hypopnea syndrome (OSAHS) is multifactorial and obesity has been shown to be one of the main factors correlated with its occurrence. In obese patients with anatomical alterations of the upper airways it is often difficult to predict success for surgical correction since obesity is a limiting factor. Therefore, the aim of the present study was to evaluate the results of tonsillectomy in a specific group of patients, i.e., obese OSAHS patients with tonsil hypertrophy. Seven OSAHS patients with moderate obesity with obstructive palatine tonsil hypertrophy were submitted to tonsillectomy. All patients were submitted to pre- and postoperative appraisal of body mass index, otorhinolaryngology examination and polysomnography. Patients' average age was 36.4 ± 10.3 years and average preoperative body mass index was 36.6 ± 6.3 kg/m². Postoperative weight did not differ significantly from preoperative weight (P = 0.27). Average preoperative apnea and hypopnea index (AHI) was 81 ± 26/h and postoperative AHI was 23 ± 18/h (P = 0.0005). Average preoperative minimum oxyhemoglobin saturation (SaO2 min) was 69 ± 14% and the postoperative value was 83 ± 3% (P = 0.038). In relation to AHI, 6 (86%) of the 7 patients studied showed a reduction of 50% in relation to preoperative level and of these, 4 (57%) presented AHI of less than 20%. Only one patient presented a reduction of less than 50% in AHI, but even so showed improved SaO2 min. Tonsillectomy treatment for OSAHS in obese patients with obstructive palatine tonsil hypertrophy caused a significant reduction in AHI, with improvement in SaO2 min. This procedure could be eventually considered as an option of treatment for obese OSAHS patients with significant tonsil hypertrophy when continuous positive air pressure therapy is not possible as the first choice of treatment.

Sleep deprivation reduces the lymphocyte count in a non-obese mouse model of type 1 diabetes mellitus

The objective of the present study was to determine whether sleep deprivation (SD) would promote changes in lymphocyte numbers in a type 1 diabetes model (non-obese diabetic, NOD, mouse strain) and to determine whether SD would affect female and male NOD compared to Swiss mice. The number of lymphocytes in peripheral blood after 24 and 96 h of SD (by multiple platform method) or equivalent period of time in home-cage controls was examined prior to the onset of diabetes. SD for 96 h significantly reduced lymphocytes in male Swiss mice compared to control (8.6 ± 2.1 vs 4.1 ± 0.7 10³/µL; P < 0.02). In male NOD animals, 24- and 96-h SD caused a significant decrease of lymphocytes compared to control (4.4 ± 0.3 vs 1.6 ± 0.5; P < 0.001 and 4.4 ± 0.3 vs 0.9 ± 0.1 10³/µL; P < 0.00001, respectively). Both 24- and 96-h SD induced a reduction in the number of lymphocytes in female Swiss (7.5 ± 0.5 vs 4.5 ± 0.5, 4.4 ± 0.6 10³/µL; P < 0.001, respectively) and NOD mice (4 ± 0.6 vs 1.8 ± 0.2, 1.2 ± 0.4 10³/µL; P < 0.01, respectively) compared to the respective controls. Loss of sleep induced lymphopenia in peripheral blood in both genders and strains used. Since many cases of autoimmunity present reduced numbers of lymphocytes and, in this study, it was more evident in the NOD strain, our results suggest that SD should be considered a risk factor in the onset of autoimmune disorders.

Sleep habits and complaints of adults in the city of São Paulo, Brazil, in 1987 and 1995

This study compares the prevalence of complaints of insomnia, excessive diurnal sleepiness, parasomnias, and sleep habits of the adult population in the city of São Paulo, Brazil, estimated in surveys carried out in 1987 and 1995. Representative samples of 1000 adult residents per survey were interviewed using a validated structured sleep questionnaire, the "UNIFESP Sleep Questionnaire". Difficulty maintaining sleep, difficulty initiating sleep and early morning awakening, occurring at least three times a week, were reported in 1987 and 1995, by 15.8/27.6, 13.9/19.1, and 10.6/14.2% of the interviewees, respectively, significantly increasing throughout time. These sleep problems were more often found among women. Frequencies of excessive diurnal sleepiness and sleep attacks were unchanged comparing 1987 with 1995 (4.5 vs 3.8 and 3.1 vs 3.0%, respectively). Parasomnia complaints remained unchanged, with the exception of leg cramps, which doubled in prevalence from 1987 to 1995 (2.6 to 5.8%). Snoring was the most common parasomnia (21.5% in 1995), reported more often by men than by women, and somnambulism was the least common (approximately 1%). Besides sleeping slightly less, interviewees went to bed and woke up later in 1995. Approximately 12% of the subjects in both surveys had consulted a physician due to sleep problems and 3.0% reported habitual use of sleep-promoting substances in 1995. Overall, there was a significant increase in insomnia complaints from 1987 to 1995 in the general population of the city of São Paulo. This major change over a little under a decade should be considered as an important public health issue.

Effect of sildenafil (Viagra®) on the genital reflexes of paradoxical sleep-deprived male rats

Since there is evidence that paradoxical sleep deprivation (PSD) elicits penile erection (PE) and ejaculation (EJ), and that the erectile response of rats is mediated by nitric oxide, the present study sought to extend the latter finding by assessing the effects of sildenafil on the genital reflexes of male Wistar rats subjected to PSD. We also determined the influence of sildenafil on hormone concentrations. In the first experiment, sildenafil at doses ranging from 0.08 to 0.32 mg/kg was administered intraperitoneally to rats that had been deprived of sleep for 4 days and to home cage controls (N = 8-10/group). The frequency of PE and EJ was measured for 60 min. PSD alone induced PE in 50% of the animals; however, a single injection of sildenafil did not significantly increase the percentage of rats displaying PE compared to PSD-saline or to home cage groups. PSD alone also induced spontaneous EJ, but this response was not potentiated by sildenafil in the dose range tested. Testosterone concentrations were significantly lower in PSD rats (137 ± 22 ng/dL) than in controls (365 ± 38 ng/dL), whereas progesterone (0.9 ± 0.1 vs 5.4 ± 1 ng/mL) and plasma dopamine (103.4 ± 30 vs 262.6 ± 77 pg/mL) increased. These changes did not occur after sildenafil treatment. The data show that although sildenafil did not alter the frequency of genital reflexes, it antagonized hormonal (testosterone and progesterone) and plasma dopamine changes induced by PSD. The stimulation of the genital reflexes by sildenafil did not result in potentiating effects in PSD rats.

The reciprocal interaction between sleep and type 2 diabetes mellitus: facts and perspectives

Type 2 diabetes mellitus is a systemic disease characterized by intolerance to glucose and peripheral resistance to insulin. This endocrine disease affects fundamental mechanisms of the central nervous system and jeopardizes the balance of vital functions such as the cardiovascular and circadian rhythm. The increased prevalence of metabolic disorders in our society is aggravated by endemic voluntary postponement of bedtime and by the current sedentary lifestyle, leading to epidemic proportions of obese people. Diabetes and chronic loss of sleep share the fact that both affect millions and one is detrimental to the other. Indeed, sleep deficits have marked modulatory effects on glucose metabolism and insulin sensitivity and foster metabolic syndrome that culminates in sleep disorders like restless syndrome and sleep apnea, which in turn lead to poor sleep quality. We examine the hypothesis that these two worldwide emerging disorders are due to two interlinked cycles. In our paradigm, we establish an intimate relationship between diabetes and sleep disturbances and postulate possible mechanisms that provide support for this conjecture. In addition, we propose some perspectives about the development of the reciprocal interaction between predictor components of metabolic syndrome and sleep disturbances that lead to poor sleep quality. The ability to predict the development and identify or associate a given mode of sleep disturbance to diabetes would be a valuable asset in the assessment of both. Furthermore, major advances in care coupled with healthy lifestyles can ensure a higher quality of life for people with diabetes.