, the clinical use of unattended home-based polysomnography (PSG) is not recommended. To assess whether sleep efficiency is better at home, we have performed a prospective, crossover, single-blind study comparing unattended home-versus attended in-hospital PSG in a population referred for high clinical suspicion of obstructive sleep apnoea syndrome (OSA). Within 2 weeks, all the patients underwent both PSG performed by the same sleep technician, which were analysed by another blinded technician. Payments for each procedure were also calculated. Sixty-six patients (mean age: 49 ± 13 years; mean body mass index: 30 ± 7; mean Epworth Sleepiness Scale: 10 ± 5) were included. The quality of recordings was poor in 1.5% of the attended PSG versus 4.7% for unattended PSG (P = 0.36). Sleep efficiency at home was better (82% versus 75%, P < 0.001), and sleep duration longer (412 min versus 365 min, P < 0.001). Sleep latency was also shorter at home (28 min versus 45 min, P = 0.004), and patients spent more time in rapid eye movement sleep (19% versus 16%, P = 0.006). Apnoea-hypopnoea index (23 versus 26, P = 0.08) was similar at home and in the sleep lab. Sixty-seven per cent of patients preferred home-based PSG. PSG payment was also lower at home (268 Euros versus 1057 Euros). We conclude that home-based PSG is associated with a better sleep efficiency. It also appears as feasible and reliable in patients with high preclinical suspicion for OSA. It is also more comfortable for the patients whose sleep efficiency is better and allows cost saving related to the absence of hospitalization. k e y w o r d s cost, diagnosis, obstructive sleep apnoea, polysomnography, sleepdisordered breathing

No abstract

The aim of the study was to determine the main metabolic parameters of 11-beta-hydroxy-androstenedione (11 OHAD) in man. Seven normal subjects were investigated at 1-3 months interval by 2 types of isotope dilution techniques using a tritiated tracer: constant infusion and bolus iv injection. 3H-11 OHAD and 3H-11-beta-hydroxy-androsterone (3H-11 OA) were isolated by gel column chromatography, unlabeled 11 OHAD was determined by RIA, unlabelled 11 OA by GLC. The results included computation of free and conjugated catabolite fractions. 3H-11 OHAD MCR determined from the infusion or the injection data averaged ca 1250 ml/min or 1800 L/d (CV: +/- 10%) providing a mean estimation of unlabelled 11 OHAD BPR of 1.5 +/- 0.15 mg/d. UPR estimations gave similar values. 3H-11 OHAD fractional catabolic rate drawn from the postinfusion or the injection curve averaged ca 1.4% per min (CV: +/- 7%). Mean total distribution volume ranged between 90 and 120 L according to the type of experiment. Extrapolation to time zero of the injection curve (2 exponentials) provided an estimation of 32 +/- 5 L for rapid exchange compartment. Urinary recovery of labelled compounds was complete within 24 h whereas the excretion of undegraded 3H-11 OHAD was undetectable; urinary clearance rate of 3H-conjugates approached that of creatinine. The present data show that: the secretion rate of 11 OHAD is equivalent to that of its direct precursor, adrenal androstenedione; its large MCR value results from the size of its exchange volume-equivalents.(ABSTRACT TRUNCATED AT 250 WORDS)