Female sex hormones and symptoms of obstructive sleep apnea in European women of a population-based cohort.

BACKGROUND: The prevalence of obstructive sleep apnea is higher in women after menopause. This is suggested to be a result of an altered sex hormone balance but has so far not been confirmed in a population-based study. OBJECTIVE: To investigate whether serum concentration of estrogens and progesterone are associated with the prevalence of sleep apnea symptoms in middle-aged women of the general population. METHODS: We analyzed data from 774 women (40-67 years) from 15 study centers in seven countries participating in the second follow-up of the European Community Respiratory Health Survey (2010-2012). Multiple logistic regression models were fitted with self-reported symptoms of sleep apnea as outcomes and serum concentrations of various estrogens and progesterone as predictors. All analyses were adjusted for relevant covariates including age, BMI, education, study center, smoking habits, and reproductive age. RESULTS: Among all included women, a doubling of serum concentrations of estrone and progesterone was associated with 19% respectively 9% decreased odds of snoring. Among snorers, a doubling of the concentrations of 17ß-estradiol, estrone and estrone 3-sulfate was associated with 18%, 23% and 17% decreased odds of breathing irregularly, and a doubling of the progesterone concentration was further associated with 12% decreased odds of waking up suddenly with a chocking sensation. Other evaluated associations were not statistically significant. CONCLUSIONS: Middle-aged women with low serum estrogen and progesterone levels are more likely to snore and report symptoms of obstructive sleep apnea.

Group B Streptococcal Neonatal and Early Infancy Infections in Iceland, 1976-2015.

BACKGROUND: Despite a risk-based peripartum chemoprophylaxis approach in Iceland since 1996, Streptococcus agalactiae [group B streptococci (GBS)] remains an important cause of early-onset [<7 days, early-onset disease (EOD)] and late-onset disease (LOD; 7 days to 3 months). METHODS: We studied GBS invasive disease in children <1 year in Iceland in 1976-2015. Bacteria (n = 98) were characterized by susceptibility to a panel of antimicrobials, capsular serotyping, resistance genes, surface protein and pilus-locus profiling and multilocus sequence typing. RESULTS: Both EOD and LOD increased during the early years, but while EOD subsequently decreased from 0.7/1000 live births in 1991-1995 to 0.2/1000 in 2011-2015, LOD showed a nonsignificant decrease from its peak value of 0.6/1000 in 2001-2005 to 0.4/1000 in 2006-2015. Serotype III was the most frequently found (n = 48), represented mostly by the hypervirulent lineage CC17/III/rib/PI-1+PI-2b (62%), but also by CC19/III/rib/PI-1+PI-2a (35%) frequently associated with colonization. Serotype Ia (n = 22) was represented by CC23/Ia/eps/PI-2a (68%) and CC7/Ia/bca/PI-1+PI-2b (23%) of possible zoonotic origin. Resistance to erythromycin and clindamycin was increasingly detected in the last years of the study (5 of the 9 cases were isolated after 2013), including representatives of a multiresistant CC17/III/rib/PI-2b sublineage described recently in other countries and expressing resistance to erythromycin, clindamycin and streptomycin. CONCLUSIONS: The risk-based chemoprophylaxis adopted in Iceland possibly contributed to the decline of EOD but has had limited effect on LOD. GBS causing neonatal and early infancy invasive infections in Iceland are genetically diverse, and the recent emergence of antimicrobial resistant lineages may reduce the choices for prophylaxis and therapy of these infections.

Quantifying changes in EEG complexity induced by photic stimulation.

OBJECTIVES: This study aims to characterize EEG complexity, measured as the prediction error resulting from nonlinear prediction, in healthy humans during photic stimulation. METHODS: EEGs were recorded from 15 subjects with eyes closed (EC) and eyes open (EO), during the baseline condition and during stroboscopic photic stimulation (PS) at 5, 10, and 15 Hz. The mean squared prediction error (MSPE) resulting from nearest neighbor local linear prediction was taken as complexity index. Complexity maps were generated interpolating the MSPE index over a schematic scalp representation. RESULTS: Statistical analysis revealed that: i) EEG shows good predictability in all conditions and seems to be well explained by a linear stochastic process; ii) the complexity is lower with EC than with EO and increases significantly during PS, to a lesser extent during 10 Hz stimulation; iii) significant differences of EEG complexity are detectable between anterior-central and posterior scalp regions. CONCLUSIONS: Changes in EEG complexity during PS can be successfully assessed using nonlinear prediction. The observed modifications in the patterns of complexity seem to reflect neurophysiological behaviors and suggest future applicability of the method in clinical settings.