IS INCREASED SERUM PROLACTIN ASSOCIATED WITH EXCESSIVE DAYTIME SLEEPINESS? A PROOF-OF-CONCEPT ANALYSIS

Abstract Introduction With this study we aimed to: 1) identify subjects with hyperprolactinemia in a clinical sample of patients; 2) compare the neurologic, psychiatric, and sleep conditions found in patients subgrouped by excessive daytime sleepiness (EDS) and hyperprolactinemia; 3) identify patients with hyperprolactinemia and EDS not supported by the presence of any other neurologic, psychiatric, or sleep disorder, or substance/medication use. Methods A retrospective chart review of inpatients was carried out in order to identify all patients in whom the prolactin (PRL) serum levels were determined. A total of 130 subjects were retrieved: 55 had increased levels of PRL while the remaining 75 participants had normal PRL levels. Results EDS was reported by 32 (58.2%) participants with increased PRL and 34 (45.3%) with normal PRL. Obstructive sleep apnea or other sleep or neurologic/psychiatric conditions could explain EDS in all participants with normal PRL. Among subjects with increased PRL, eight had no other neurologic/psychiatric or sleep disorder (or drug) potentially causing EDS; these participants, at polysomnography, had time in bed, sleep period time, and total sleep time longer than those with EDS associated to another condition. Conclusion These findings can be considered as a preliminary indication of a role of hyperprolactinemia in EDS and represent a basis for future controlled studies able to test in a reliable, objective, and methodologically more appropriate way this hypothesis. Support (If Any) This study was partially supported by a fund from the Italian Ministry of Health “Ricerca Corrente” (RC n. 2764026) (Drs. Cosentino, Aricò, Lanuzza, Lanza, Tripodi, and Ferri)