The aim of the present investigation was to comparatively examine the effect of theophylline on various sleep-related breathing disorders of different severity. In a single-blind, placebo-controlled crossover study, 30 patients were polysomnographically diagnosed as suffering from primary snoring (n = 7), obstructive snoring (n = 12) or moderate sleep apnea (n = 11). Subsequent polysomnographic investigations included one baseline, one placebo and one theophylline (Respicur(R) retard 400 mg, Byk Gulden, Konstanz, Germany) night. Subjective sleep and awakening quality was evaluated by means of a test battery completed in the morning. Concerning respiratory variables, theophylline was most effective in patients with moderate sleep apnea. Obstructive snorers only showed a tendency towards improvement and primary snorers remained unchanged. Sleep architecture generally remained unchanged in all three patient groups. Objective awakening quality was partly improved in primary snorers, obstructive snorers, as well as in moderate sleep apnea patients as compared with baseline, bur not as compared with placebo. Regarding subjective sleep and awakening quality, only primary snorers and an improvement, as compared with baseline while sleep apnea patients remained unchanged. Based on intergroup comparison, we conclude that patients with moderate sleep apnea showed the most pronounced improvement in regard to respiratory events. Concerning sleep initiation and maintenance, sleep architecture and subjective sleep and awakening anality, no significant intergroup differences were found. Regarding objective awakening quality, attention showed a significantly greater improvement in primary than in obstructive snorers and sleep apnea patients, while motor performance was most improved in obstructive snorers. (C) 2000 Prous Science. All rights reserved.
