We read with great interest the article by Turkan Mete et al., entitled: “Relationship between obstructive sleep apnea syndrome and thyroid diseases”. In this article, the authors studied 182 obese patients with different severity of OSAS, according to Apnea–hypopnea index (AHI), and observed no significant differences between the OSAS groups and the control group without OSAS, in terms of hypothyroidism [1].

These results are very consistent and similar to our previous study, in which we showed that the subclinical hypothyroidism and treatment with the levothyroxine do not influence the prevalence and severity of OSA, while sleep propensity is increased by the untreated subclinical hypothyroidism [2]. However, recent studies have documented in obese women a statistical association between OSAS and hypothyroidism [3].

The results of this study highlighted the increasing risk of women, who are 5–8 times more likely to have thyroid dysfunction than men, which might often to be associated with sleep disorders.

Taken all the data together, we suggest to always perform further investigations about relationship between OSAS and thyroid diseases, as well as auto-immune thyroiditis, and to develop a screening schema for severe-OSAS patients for early diagnosis of hypothyroidism. Furthermore, the evaluation for sleep disorders in women with hypothyroidism may lead to an early diagnosis of OSAS, to prevent long-term metabolic consequences.