Endocrine Abstracts

Despite the common clinical opinion that thyrotoxicosis is associated with quantitative and qualitative sleep alterations, at present, an objective evaluation of sleep quality and quantity in this clinical condition has never been performed so far. Based on this foregoing, in order to perform a qualitative and quantitative description of sleep in this clinical condition, we enrolled 6 normal-weighted patients suffering from naïve overt hyperthyroidism due to Basedow Disease (BD) and 11 healthy age-, sex- and BMI-matched control subjects (CS). In both groups, the presence of clinical conditions or drug therapies known to affect per se sleep architecture was considered as exclusion criteria. In all the subjects, sleep recording was performed with wrist actigraphy (Actiwatch, Mini Mitter Co., Inc.; Bend, OR, USA) on three consecutive days in free living conditions. In all BD patients TSH levels were lower ([mean±SD] 0.0±0.0 mU/l), while fT3 (8.7±2.1 ng/l), fT4 (30.5±5.6 ng/l) and TRAb (47.5±9.3 U/l) were higher than the normal range. The study had been approved by local Ethical Committee. No significant differences between BD and CS were observed in terms of time in bed (7 h 44′±0 h 47′ vs 7 h 54′±1 h 03′). In BD, however, actual sleep time (6 h 35′±0 h 50′) was significantly lower (P<0.01) than in CS (6 h 54′±0 h 58′), although sleep latency in the two groups were similar (9′±5′ vs 12′±8′). Moreover, in BD, a significant impairment of sleep quality compared with CS was recorded, as indicated by an increase of fragmentation index (21.06±8.37 vs 14.06±3.92; P<0.05) and of moving time percentage (10.04±2.66% vs 7.20±1.26%; P<0.05). In conclusion, these data describe for the first time the presence of quantitative and qualitative sleep disruptions in patients with thyrotoxicosis. Taking into account the well-known modulatory effect of sleep on hormonal secretions and glucose metabolism, the present results deserve further investigations to better characterize the role of sleep alterations as potential adjunctive determinant of the metabolic and hormonal alterations in hyperthyroidism.