In
snoring men improved nasal breathing during sleep has been shown to decrease
snoring and morning tiredness. The aim was to evaluate whether improved nasal breathing had any effect on
growth hormone (GH) secretion, the nocturnal secretion of GH being associated with deep sleep. Forty-two
snoring men, mean age 45 years and mean body mass index 26 kg.m-2, slept every night during one month with the Nozovent nostril dilator. Before and at the end of the test period, we analysed serum
insulin-like growth factor 1 (IGF-1),
thyrotropin (TSH), free
thyroxine (free T4), free 3,5,3'-triiodothyronine (free T3),
cortisol and
testosterone in blood sampled at 08:00 h. Fifteen of the 37
snoring men who completed the study experienced a reduction in
snoring and were less tired in the morning during the test period. In this group, the mean
IGF-1 concentration was significantly increased (p < 0.05) after one month. There was no significant difference in mean
IGF-1 level between the snorers and a population sample. Likewise, TSH, free T4, free T3,
cortisol and
testosterone concentrations were within normal limits. Snorers with reduced
snoring and morning tiredness due to improved nasal breathing showed an increase in morning
IGF-1 concentration which can probably be explained by higher nocturnal GH secretion induced by more deep sleep.