EAN/ERS/ESO/ESRS statement on the impact of sleep disorders on risk and outcome of stroke.

BACKGROUND: Sleep disorders are highly prevalent in the general population and may be linked in a bidirectional fashion to stroke, which is one of the leading causes of morbidity and mortality. AIM: Four major scientific societies established a task force of experts in neurology, stroke, respiratory medicine, sleep medicine and methodology to critically evaluate the evidence regarding potential links and the impact of therapy. MATERIALS AND METHODS: Thirteen research questions were evaluated in a systematic literature search using a stepwise hierarchical approach: first, systematic reviews and meta-analyses; second, primary studies post-dating the systematic reviews/meta-analyses. A total of 445 studies were evaluated and 88 were included. Statements were generated regarding current evidence and clinical practice. RESULTS: Severe obstructive sleep apnoea (OSA) doubles the risk for incident stroke, especially in young to middle-aged patients. Continuous positive airway pressure (CPAP) may reduce stroke risk, especially in treatment-compliant patients. The prevalence of OSA is high in stroke patients and can be assessed by polygraphy. Severe OSA is a risk factor for recurrence of stroke and may be associated with stroke mortality, whilst CPAP may improve stroke outcome. It is not clear if insomnia increases stroke risk, whilst the pharmacotherapy of insomnia may increase it. Periodic limb movements in sleep (PLMS), but not restless limb syndrome (RLS), may be associated with an increased risk of stroke. Preliminary data suggest a high frequency of post-stroke insomnia and RLS and their association with a less favourable stroke outcome, whilst treatment data are scarce. DISCUSSION/CONCLUSION: Overall, the evidence base is best for OSA relationship with stroke and supports active diagnosis and therapy. Research gaps remain especially regarding insomnia and RLS/PLMS relationships with stroke.

Hyperlipidaemia prevalence and cholesterol control in obstructive sleep apnoea: Data from the European sleep apnea database (ESADA).

BACKGROUND AND OBJECTIVE: Obstructive sleep apnoea (OSA) and hyperlipidaemia are independent risk factors for cardiovascular disease. This study investigates the association between OSA and prevalence of hyperlipidaemia in patients of the European Sleep Apnea Database (ESADA) cohort. METHODS: The cross-sectional analysis included 11 892 patients (age 51.9 ± 12.5 years, 70% male, body mass index (BMI) 31.3 ± 6.6 kg/m2 , mean oxygen desaturation index (ODI) 23.7 ± 25.5 events/h) investigated for OSA. The independent odds ratio (OR) for hyperlipidaemia in relation to measures of OSA (ODI, apnoea-hypopnoea index, mean and lowest oxygen saturation) was determined by means of general linear model analysis with adjustment for important confounders such as age, BMI, comorbidities and study site. RESULTS: Hyperlipidaemia prevalence increased from 15.1% in subjects without OSA to 26.1% in those with severe OSA, P < 0.001. Corresponding numbers in patients with diabetes were 8.5% and 41.5%, P < 0.001. Compared with ODI quartile I, patients in ODI quartiles II-IV had an adjusted OR (95% CI) of 1.33 (1.15-1.55), 1.37 (1.17-1.61) and 1.33 (1.12-1.58) (P < 0.001), respectively, for hyperlipidaemia. Obesity was defined as a significant risk factor for hyperlipidaemia. Subgroups of OSA patients with cardio-metabolic comorbidities demonstrated higher prevalence of HL. In addition, differences in hyperlipidaemia prevalence were reported in European geographical regions with the highest prevalence in Central Europe. CONCLUSION: Obstructive sleep apnoea, in particular intermittent hypoxia, was independently associated with the prevalence of hyperlipidaemia diagnosis.

Biodegradation ability of two selected microbial autochthonous consortia from a chronically polluted marine coastal area (Priolo Gargallo, Italy).

The aims of this study were: (i) the characterization of the structure of the indigenous microbial community associated with the sediments under study; (ii) the isolation and characterization of microbial consortia able to degrade the aged hydrocarbons contaminating the sediments, and (iii) the assessment of related biodegradation capability of selected consortia. Samples of surface sediments were collected in Priolo Gargallo harbour (Sicily, Italy). The samples were analysed for physical, chemical (GC-FID analysis) and microbiological characteristics (qualitative (16S rDNA clone library) and quantitative (DAPI, CFU and MPN count) analysis). The sediment samples were used for the selection of two microbial consortia (indicated as PSO and PSM) with high biodegradation capacity for crude oil (∼95%) and PAHs (∼63%) respectively. Genetic analysis showed that Alcanivorax and Cycloclasticus were the dominant genera in both the PSO and PSM consortia. Oil-polluted environments naturally develop an elevated biorecovery potential. The presence of a highly specialized microbial flora (adapted to support the contamination) and their stimulation through favourable induced conditions provides a promising recovery strategy. The chance to identify and select indigenous bacteria and/or consortia with a high biodegradation capacity is fundamental for the development and optimization of bioaugmentation strategies especially for those concerning in situ applications.

[Perspectives for anesthesiologists in hospital hygiene]. / Perspektiven für Anästhesisten in der Krankenhaushygiene.

BACKGROUND: It is mandatory for hospitals in Germany to employ infection control physicians and have an external consultation. The recommended coverage has substantially increased in the last years. Typically, infection control physicians are specialists for hygiene and environmental medicine and/or for microbiology. As there is already a shortage of these specialists, a curricular educational program in infection control was developed by the German Medical Association in 2011. This program addresses specialists of different clinical disciplines. It covers a period of 24 months and includes 200 h of courses, divided into 6 modules. In addition, 7 weeks of internships must be absolved in hospital hygiene, in a microbiological laboratory and in the public health service. During the program, the trainee must be accompanied by a qualified supervisor, who is a specialist in hygiene. The aim of this article is to describe the current status of this program. METHODS: A total of 91 infection control physicians, organized in different networks, were invited by email to take part in a survey with the online tool Survey Monkey (San Mateo, USA). The questions in the survey aimed at the characteristics of the participants as well as the conditions of the program. Further information about the various general regulations and conditions of the course was gathered through internet research, and from telephone and email contact with the State Medical Associations. RESULTS: Approximately 250 physicians completed the program between 2011 and 2017. The graduates were mostly anesthesiologists (45%) and 81% had a leading position (consultant or higher) before beginning the program. Most of them also had further education in antibiotic stewardship and/or infectious diseases. The requirements regarding training hours, examination and certification varied between the State Medical Associations. The supervision, a mandatory part of the program, is also implemented differently from state to state. Of the participants 49% felt well-qualified for the challenges ahead after finishing this program. DISCUSSION: The program was able to increase the number of infection control physicians in a relatively short period of time; however, to guarantee a comparable quality of education it is necessary to standardize the requirements on a national level. The supervision also needs to be further specified. A new program is currently being developed by the German Medical Association, which will hopefully lead to an improvement of the educational program. Special strengths of the new infection control physicians are the broad clinical experience as well as the additional qualifications in antibiotic stewardship and/or infectious diseases. The weaknesses are the lack of practical experience and knowledge of technical hygiene. A mandatory inclusion of antibiotic stewardship and infectious diseases in the program would increase its impact. Anesthesiologists are well-suited for training as infection control physicians. For them, a new, exciting field of activity has opened up with the chance to be the head of their own department.

[Antibiotic stewardship in a basic care hospital : A retrospective observational study]. / Antibiotic stewardship an einem Krankenhaus der Grund- und Regelversorgung : Eine retrospektive Observationsstudie.

BACKGROUND: In response to the global increase in antibiotic resistance, the concept of antibiotic stewardship (ABS) has become increasingly important in recent years. Several publications have demonstrated the effectiveness of ABS, mainly in university facilities. This retrospective observational study describes the implementation of ABS in a basic care hospital. MATERIAL AND METHODS: Following existing national guidelines, an ABS team was set up and measures were launched. These included: hospital guidelines, teaching, weekly antibiotic ward rounds and the restriction of definite substances. The preinterventional/postinterventional data analysis compared the use of antibiotics and blood culture sets as well as the development of resistance, infection with Clostridium difficile (CDI), costs, mortality and length of hospital stay. RESULTS: The measures introduced led to a significant and continuous decline in total antibiotic use of initially 43 recommended daily doses (RDD)/100 patient days (PD) to 31 RDD/100 PD (p < 0.001). The largest decrease was observed in second generation (2G) cephalosporins (-67.5%), followed by 3G cephalosporins (-52.7%), carbapenems (-42.0%) and quinolones (-38.5%). The resistance rate of E. coli to 3G cephalosporins in blood cultures decreased from 26% to 9% (p = 0.021). The rate of blood cultures taken increased from 1.8 sets/100 PD to 3.2 sets/100 PD (+77%, p < 0.001). The pathogen detection rate, defined as one count when a minimum of one sample taken in a day is positive, also increased significantly from 4.0/1000 PD to 6.8/1000 PD (p < 0.001). The ABS had no effect on the overall mortality, the mean dwell time, and the preintervention low CDI incidence. CONCLUSION: The preinterventional/postinterventional comparison showed a significant reduction in the overall consumption of antibiotics with a redistribution in favor of antibiotics with a lower resistance selection. At the same time, the resistance rate of E. coli decreased. The increase of the blood culture rate indicates the optimization of diagnostic procedures. This ABS program had to be established with reduced resources but this seems to have been compensated by the more personal contact addressing the care takers and short chain of commands, as is possible in smaller hospitals. Presumably, the structure of basic care hospitals is particularly suitable for concepts covering entire hospitals. Further clusters of randomized studies are necessary to confirm this.

Adipose tissue in obesity and obstructive sleep apnoea.

A European Respiratory Society research seminar on "Metabolic alterations in obstructive sleep apnoea (OSA)" was jointly organised in October 2009 together with two EU COST actions (Cardiovascular risk in the obstructive sleep apnoea syndrome, action B26, and Adipose tissue and the metabolic syndrome, action BM0602) in order to discuss the interactions between obesity and OSA. Such interactions can be particularly significant in the pathogenesis of metabolic abnormalities and in increased cardiovascular risk in OSA patients. However, studying the respective role of OSA and obesity is difficult in patients, making it necessary to refer to animal models or in vitro systems. Since most OSA patients are obese, their management requires a multidisciplinary approach. This review summarises some aspects of the pathophysiology and treatment of obesity, and the possible effects of sleep loss on metabolism. OSA-associated metabolic dysfunction (insulin resistance, liver dysfunction and atherogenic dyslipidaemia) is discussed from the perspective of both obesity and OSA in adults and children. Finally, the effects of treatment for obesity or OSA, or both, on cardio-metabolic variables are summarised. Further interdisciplinary research is needed in order to develop new comprehensive treatment approaches aimed at reducing sleep disordered breathing, obesity and cardiovascular risk.

Burden of hospital-acquired SARS-CoV-2 infections in Germany: occurrence and outcomes of different variants.

BACKGROUND: Avoiding in-hospital transmissions has been crucial in the COVID-19 pandemic. Little is known on the extent to which hospital-acquired SARS-CoV-2 variants have caused infections in Germany. AIM: To analyse the occurrence and the outcomes of HAI with regard to different SARS-CoV-2 variants. METHODS: Patients with SARS-CoV-2 infections hospitalized between March 1st, 2020 and May 17th, 2022 in 79 hospitals of the Helios Group were included. Information on patients' characteristics and outcomes were retrieved from claims data. In accordance with the Robert Koch Institute, infections were classified as hospital-acquired when tested positive >6 days after admission and if no information hinted at a different source. FINDINGS: In all, 62,875 SARS-CoV-2 patients were analysed, of whom 10.6% had HAI. HAIs represented 14.7% of SARS-CoV-2 inpatients during the Wildtype period, 3.5% during Alpha (odds ratio: 0.21; 95% confidence interval: 0.19-0.24), 8.8% during Delta (2.70; 2.35-3.09) and 10.1% during Omicron (1.10; 1.03-1.19). When age and comorbidities were accounted for, HAI had lower odds for death than community-acquired infections (0.802; 0.740-0.866). Compared to the Wildtype period, HAIs during Omicron were associated with lower odds for ICU (0.78; 0.69-0.88), ventilation (0.47; 0.39-0.56), and death (0.33; 0.28-0.40). CONCLUSION: Hospital-acquired SARS-CoV-2 infections occurred throughout the pandemic, affecting highly vulnerable patients. Although transmissibility increased with newer variants, the proportion of HAIs decreased, indicating improved infection prevention and/or the effect of immunization. Furthermore, the Omicron period was associated with improved outcomes. However, the burden of hospital-acquired SARS-CoV-2 infections remains high.

Obstructive sleep apnoea and metabolic impairment in severe obesity.

Obstructive sleep apnoea (OSA) seems to worsen metabolism. This effect has not been evaluated in morbid obesity (MO). We hypothesised that the metabolic profile is more impaired in MO patients with OSA than in those without, and investigated whether any specific metabolic dysfunction is related to OSA in MO. A prospective multicentre cross-sectional study was conducted in consecutive subjects before bariatric surgery. OSA was defined as apnoea/hypopnoea index (AHI) ≥15 by overnight polysomnography. Anthropometrical, blood pressure (BP) and fasting blood measurements were obtained the morning after. Metabolic syndrome (MetS) was defined according to National Cholesterol Education Program Adult Treatment Panel III modified criteria. 159 patients were studied: 72% were female and 72% had OSA. MetS prevalence was 70% in OSA versus 36% in non-OSA (p<0.001). As AHI severity increased, metabolic parameters progressively worsened, even in those without type 2 diabetes (DM2). AHI was independently associated with systolic and diastolic BP, triglycerides and the percentage of glycosylated haemoglobin (HbA1c) in the total sample, and with systolic BP, high-density lipoprotein cholesterol and HbA1c in those samples without DM2. OSA increased the adjusted odds ratio of having MetS by 2.8 (95% CI 1.3-6.2; p=0.009). In MO, OSA is associated with major metabolic impairment caused by higher BP and poorer lipid and glucose control, independent of central obesity or DM2.

The European Sleep Apnoea Database (ESADA): report from 22 European sleep laboratories.

The European Sleep Apnoea Database (ESADA) reflects a network of 22 sleep disorder centres in Europe enabled by a COST action B26 programme. This ongoing project aims to describe differences in standard clinical care of patients with obstructive sleep apnoea (OSA) and to establish a resource for genetic research in this disorder. Patients with suspected OSA are consecutively included and followed up according to local clinical standards. Anthropometrics, medical history, medication, daytime symptoms and sleep data (polysomnography or cardiorespiratory polygraphy) are recorded in a structured web-based report form. 5,103 patients (1,426 females, mean±sd age 51.8±12.6 yrs, 79.4% with apnoea/hypopnoea index (AHI) ≥5 events·h(-1)) were included from March 15, 2007 to August 1, 2009. Morbid obesity (body mass index ≥35 kg·m(-2)) was present in 21.1% of males and 28.6% of females. Cardiovascular, metabolic and pulmonary comorbidities were frequent (49.1%, 32.9% and 14.2%, respectively). Patients investigated with a polygraphic method had a lower AHI than those undergoing polysomnography (23.2±23.5 versus 29.1±26.3 events·h(-1), p<0.0001). The ESADA is a rapidly growing multicentre patient cohort that enables unique outcome research opportunities and genotyping. The first cross-sectional analysis reveals a high prevalence of cardiovascular and metabolic morbidity in patients investigated for OSA.

Sleep, sleep-disordered breathing and metabolic consequences.

Sleep profoundly affects metabolic pathways. In healthy subjects, experimental sleep restriction caused insulin resistance (IR) and increased evening cortisol and sympathetic activation. Increased obesity in subjects reporting short sleep duration leads to speculation that, during recent decades, decreased sleeping time in the general population may have contributed to the increasing prevalence of obesity. Causal inference is difficult due to lack of control for confounders and inconsistent evidence of temporal sequence. In the general population, obstructive sleep apnoea (OSA) is associated with glucose intolerance. OSA severity is also associated with the degree of IR. However, OSA at baseline does not seem to significantly predict the development of diabetes. Prevalence of the metabolic syndrome is higher in patients with OSA than in obese subjects without OSA. Treatment with continuous positive airway pressure seems to improve glucose metabolism both in diabetic and nondiabetic OSA but mainly in nonobese subjects. The relative role of obesity and OSA in the pathogenesis of metabolic alterations is still unclear and is intensively studied in clinical and experimental models. In the intermittent hypoxia model in rodents, strong interactions are likely to occur between haemodynamic alterations, systemic inflammation and metabolic changes, modulated by genetic background. Molecular and cellular mechanisms are currently being investigated.

Italian Association of Sleep Medicine (AIMS) position statement and guideline on the treatment of menopausal sleep disorders.

Insomnia, vasomotor symptoms (VMS) and depression often co-occur after the menopause, with consequent health problems and reductions in quality of life. The aim of this position statement is to provide evidence-based advice on the management of postmenopausal sleep disorders derived from a systematic review of the literature. The latter yielded results on VMS, insomnia, circadian rhythm disorders, obstructive sleep apnea (OSA) and restless leg syndrome (RLS). Overall, the studies show that menopausal hormone therapy (MHT) improves VMS, insomnia, and mood. Several antidepressants can improve insomnia, either on their own or in association with MHT; these include selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. Long-term benefits for postmenopausal insomnia may also be achieved with non-drug strategies such as cognitive behavioral therapy (CBT) and aerobic exercise. Continuous positive airway pressure (CPAP) and mandibular advancement devices (MADs) both reduce blood pressure and cortisol levels in postmenopausal women suffering from OSA. However, the data regarding MHT on postmenopausal restless legs syndrome are conflicting.

Medico-legal implications of sleep apnoea syndrome: driving license regulations in Europe.

BACKGROUND: Sleep apnoea syndrome (SAS), one of the main medical causes of excessive daytime sleepiness, has been shown to be a risk factor for traffic accidents. Treating SAS results in a normalized rate of traffic accidents. As part of the COST Action B-26, we looked at driving license regulations, and especially at its medical aspects in the European region. METHODS: We obtained data from Transport Authorities in 25 countries (Austria, AT; Belgium, BE; Czech Republic, CZ; Denmark, DK; Estonia, EE; Finland, FI; France, FR; Germany, DE; Greece, GR; Hungary, HU; Ireland, IE; Italy, IT; Lithuania, LT; Luxembourg, LU; Malta, MT; Netherlands, NL; Norway, EC; Poland, PL; Portugal, PT; Slovakia, SK; Slovenia, SI; Spain, ES; Sweden, SE; Switzerland, CH; United Kingdom, UK). RESULTS: Driving license regulations date from 1997 onwards. Excessive daytime sleepiness is mentioned in nine, whereas sleep apnoea syndrome is mentioned in 10 countries. A patient with untreated sleep apnoea is always considered unfit to drive. To recover the driving capacity, seven countries rely on a physician's medical certificate based on symptom control and compliance with therapy, whereas in two countries it is up to the patient to decide (on his doctor's advice) to drive again. Only FR requires a normalized electroencephalography (EEG)-based Maintenance of Wakefulness Test for professional drivers. Rare conditions (e.g., narcolepsy) are considered a driving safety risk more frequently than sleep apnoea syndrome. CONCLUSION: Despite the available scientific evidence, most countries in Europe do not include sleep apnoea syndrome or excessive daytime sleepiness among the specific medical conditions to be considered when judging whether or not a person is fit to drive. A unified European Directive seems desirable.

Reticulocytes in untreated obstructive sleep apnoea.

BACKGROUND AND AIM: The short, repetitive hypoxaemic episodes observed in obstructive sleep apnoea (OSA) may determine small augmentations in mature red blood cells. It is unknown whether they affect reticulocyte release. This study explored whether the number and degree of maturation of circulating reticulocytes may be altered in OSA, possibly through the effect of erythropoietin. METHODS: Fifty male adult patients with suspected OSA, normoxic during wakefulness, were studied. After nocturnal polysomnography, a blood sample was withdrawn for blood cells count, erythropoietin, iron and transferrin determination. Reticulocyte concentration and degree of immaturity [high (H), medium (M), or low (L)] were also determined. Immature reticulocyte fraction (IRF) was calculated as (M+H) percentage of reticulocytes. RESULTS: A wide range of OSA severity was found [apnoea/hypopnoea index (AHI): 44.3 +/- 30.4, range 0.3-105; sleep time spent at oxyhaemoglobin saturation <90%: 18.1 +/- 22.2%, range 0-81%]. Both reticulocyte count and IRF slightly exceeded the normal range. Patients with a reticulocyte concentration > 2% had higher EPO levels (p < 0.05), but not worse nocturnal desaturations, than those with values < 2%. By contrast, subjects with IRF < 15% showed worse desaturations (p < 0.05), but similar EPO concentrations, when compared to subjects whose IRF was < 10%. At univariate analysis, reticulocyte count correlated to erythropoietin, while IRF to transferrin saturation, BMI and OSA severity. At multiple regression, only lowest nocturnal oxygen saturation remained a significant contributor to IRF (r2 0.223, p < 0.05). CONCLUSIONS: This data suggests that hypoxaemia due to OSA could influence the release of immature reticulocytes, but this effect is not mediated by erythropoietin.

Carbocysteine counteracts the effects of cigarette smoke on cell growth and on the SIRT1/FoxO3 axis in bronchial epithelial cells.

BACKGROUND: Cigarette smoke may accelerate cellular senescence by increasing oxidative stress. Altered proliferation and altered expression of anti-aging factors, including SIRT1 and FoxO3, characterise cellular senescence. The effects of carbocysteine on the SIRT1/FoxO3 axis and on downstream molecular mechanisms in human bronchial epithelial cells exposed to cigarette smoke are largely unknown. AIMS: Aim of this study was to explore whether carbocysteine modulated SIRT1/FoxO3 axis, and downstream molecular mechanisms associated to cellular senescence, in a bronchial epithelial cell line (16-HBE) exposed to cigarette smoke. METHODS: 16HBE cells were stimulated with/without cigarette smoke extracts (CSE) and carbocysteine. Flow cytometry and clonogenic assay were used to assess cell proliferation; western blot analysis was used for assessing nuclear expression of SIRT1 and FoxO3. The nuclear co-localization of SIRT1 and FoxO3 was assessed by fluorescence microscopy. Beta galactosidase (a senescence marker) and SIRT1 activity were assessed by specific staining and colorimetric assays, respectively. ChiP Assay and flow cytometry were used for assessing survivin gene regulation and protein expression, respectively. RESULTS: CSE decreased cell proliferation, the nuclear expression of SIRT1 and FoxO3 and increased beta galactosidase staining. CSE, reduced SIRT1 activity and FoxO3 localization on survivin promoter thus increasing survivin expression. In CSE stimulated bronchial epithelial cells carbocysteine reverted these phenomena by increasing cell proliferation, and SIRT1 and FoxO3 nuclear expression, and by reducing beta galactosidase staining and survivin expression. CONCLUSIONS: The study shows for the first time that carbocysteine may revert some senescence processes induced by oxidative stress due to cigarette smoke exposure.

Biodegradation potentiality of psychrophilic bacterial strain Oleispira antarctica RB-8(T).

The present study is focused on assessing the growth and hydrocarbon-degrading capability of the psychrophilic strain Oleispira antarctica RB-8(T). This study considered six hydrocarbon mixtures that were tested for 22days at two different cultivation temperatures (4 and 15°C). During the incubation period, six sub-aliquots of each culture at different times were processed for total bacterial abundance and GC-FID (gas chromatography-flame ionization detection) hydrocarbon analysis. Results from DNA extraction and DAPI (4',6-diamidino-2-phenylindole) staining showed a linear increase during the first 18days of the experiment in almost all the substrates used; both techniques showed a good match, but the difference in values obtained was approximately one order of magnitude. GC-FID results revealed a substantial hydrocarbon degradation rate in almost all hydrocarbon sources and in particular at 15°C rather than 4°C (for commercial oil engine, oily waste, fuel jet, and crude oil). A more efficient degradation was observed in cultures grown with diesel and bilge water at 4°C.

Metal-Free Reduction of Aromatic and Aliphatic Nitro Compounds to Amines: A HSiCl3-Mediated Reaction of Wide General Applicability.

A new, mild, metal-free, HSiCl3-mediated reduction of both aromatic and aliphatic nitro groups to amines that is of wide general applicability, tolerant of many functional groups, and respectful of the stereochemical integrity of stereocenters is reported.

Tracing mercury pathways in Augusta Bay (southern Italy) by total concentration and isotope determination.

The mercury (Hg) pollution of sediments is the main carrier of Hg for the biota and, subsequently, for the local fish consumers in Augusta Bay area (SE Sicily, Italy), a coastal marine system affected by relevant sewage from an important chlor-alkali factory. This relationship was revealed by the determination of Mass Dependent (MDF) and Mass Independent Fractionation (MIF) of Hg isotopes in sediment, fish and human hair samples. Sediments showed MDF but no MIF, while fish showed MIF, possibly due to photochemical reduction in the water column and depending on the feeding habitat of the species. Benthic and demersal fish exhibited MDF similar to that of sediments in which anthropogenic Hg was deposited, while pelagic organisms evidenced higher MDF and MIF due to photoreduction. Human hair showed high values of δ(202)Hg (offset of +2.2‰ with respect to the consumed fish) and Δ(199)Hg, both associated to fish consumption.

Autonomic cardiac regulation in obstructive sleep apnea syndrome: evidence from spontaneous baroreflex analysis during sleep.

OBJECTIVE: To assess spontaneous baroreceptor-heart rate reflex sensitivity during sleep in patients with obstructive sleep apnea syndrome, a condition associated with increased cardiovascular morbidity and mortality and characterized by marked sympathetic activation, which is believed to originate from hypoxic chemoreceptor stimulation, although little is known of other possible mechanisms such as baroreflex impairment. DESIGN AND METHODS: In 11 patients with severe obstructive sleep apnea syndrome (mean+/-SD age 46.8+/-8.1 years, apnea/hypopnea index 67.9+/-19.1 h), who were normotensive or borderline hypertensive during wakefulness by clinic blood pressure measurements, finger blood pressure was monitored beat-by-beat non-invasively (Finapres) at night during polysomnography. Periods of wakefulness and sleep were identified based on electroencephalographic recordings. Baroreflex sensitivity was assessed by the sequence technique, as the slope of the regression line between spontaneous increases or reductions in systolic blood pressure (SBP) and the related lengthening or shortening in the RR interval, occurring over spontaneous sequences of four or more consecutive beats. The number of these sequences was also computed, as an additional index of baroreflex engagement by the spontaneous blood pressure fluctuations. The controls were age-related normotensive or borderline hypertensive subjects without sleep apnea who had been investigated in previous studies; in these subjects blood pressure was recorded intra-arterially over 24 h in ambulatory conditions and spontaneous baroreflex sensitivity was assessed by the sequence technique. RESULTS: In our patients the lowest nocturnal arterial oxygen saturation was 78.6+/-12.1% (mean+/-SD). During sleep, the number of pooled +RR/+SBP and -RR/-SBP sequences per hour was 20.3+/-2.7 per h in patients with sleep apnea and 27.1+/-2.1 /h in controls (means+/-SEM). The average baroreflex sensitivity during sleep periods was 7.04+/-0.8 ms/mmHg in sleep apnea patients and 10.05+/-2.1 ms/mmHg in controls. Both the pooled number of sequences and baroreflex sensitivity values of the sleep apnea patients were significantly (P < 0.01) less than the corresponding night values of control subjects. In the sleep apnea patients, at variance from controls, baroreflex sensitivity did not show any increase during sleep compared with its values during wakefulness (6.9+/-1.0 ms/mmHg). CONCLUSIONS: Our data provide evidence that spontaneous baroceptor reflex sensitivity is depressed in severe obstructive sleep apnea syndrome. This suggests that in such patients baroreflex dysfunction and not only chemoreceptor stimulation by hypoxia may be involved in the sympathetic activation which occurs during sleep. Such dysfunction may contribute to the higher rate of cardiovascular morbidity and mortality reported in these patients.