ABSTRACT
PURPOSE: Organic conditions underlying secondary hypogonadism (SH) may be ascertained by magnetic resonance imaging (MRI) of the hypothalamic-pituitary region that could not be systematically proposed to each patient. Based upon limited evidence, the Endocrine Society (ES) guidelines suggest total testosterone (T) < 5.2 nmol/L to identify patients eligible for MRI. The study aims to identify markers and their best threshold value predicting pathological MRI findings in men with SH. METHODS: A consecutive series of 609 men seeking medical care for sexual dysfunction and with SH (total T < 10.5 nmol/L and LH ≤ 9.4 U/L) was retrospectively evaluated. An independent cohort of 50 men with SH was used as validation sample. 126 men in the exploratory sample and the whole validation sample underwent MRI. RESULTS: In the exploratory sample, patients with pathological MRI findings (n = 46) had significantly lower total T, luteinizing hormone (LH), follicle stimulating hormone (FSH) and prostate specific antigen (PSA) than men with normal MRI (n = 80). Receiver Operating Characteristics analysis showed that total T, LH, FSH and PSA are accurate in identifying men with pathologic MRI (accuracy: 0.62-0.68, all p < 0.05). The Youden index was used to detect the value with the best performance, corresponding to total T 6.1 nmol/L, LH 1.9 U/L, FSH 4.2 U/L and PSA 0.58 ng/mL. In the validation cohort, only total T ≤ 6.1 nmol/L and LH ≤ 1.9 U/L were confirmed as significant predictors of pathologic MRI. CONCLUSION: In men with SH, total T ≤ 6.1 nmol/L or LH ≤ 1.9 U/L should arise the suspect of hypothalamus/pituitary structural abnormalities, deserving MRI evaluation.
Subject(s)
Eunuchism , Follicle Stimulating Hormone , Hypothalamus , Luteinizing Hormone , Magnetic Resonance Imaging/methods , Pituitary Gland , Sexual Dysfunction, Physiological , Testosterone , Eligibility Determination , Eunuchism/blood , Eunuchism/complications , Eunuchism/diagnosis , Follicle Stimulating Hormone/analysis , Follicle Stimulating Hormone/blood , Humans , Hypothalamus/abnormalities , Hypothalamus/diagnostic imaging , Italy/epidemiology , Luteinizing Hormone/analysis , Luteinizing Hormone/blood , Male , Middle Aged , Pituitary Gland/abnormalities , Pituitary Gland/diagnostic imaging , Sexual Dysfunction, Physiological/diagnosis , Sexual Dysfunction, Physiological/epidemiology , Sexual Dysfunction, Physiological/etiology , Testosterone/analysis , Testosterone/bloodABSTRACT
The oto-respiratory (O-R) reflex consists of the cough reflex produced by direct mechanical stimulation of the deep portion of the posterior wall of the external auditory meatus. Because the efferent pathways are different for coughing and bronchoconstriction, some subjects can have an O-R reflex (coughing) without the oto-bronchial (O-B) reflex (bronchoconstriction). This study also states that on stimulation of the mechanoreceptors in the external ear, 20 out of 125 normal subjects (16%) presented with the O-R reflex; in 7 of the 20 subjects, bronchoconstriction ('responders') was also documented (O-B reflex). The O-B reflex was particularly evident in 3 of the 7 responders. These normal subjects referred a family history of atopy. Only through animal experimentation can the exact nervous pathway of the O-R reflex be defined. From the physiological point of view, it is difficult to imagine how this 'irritative' reflex could have a protective function against auditory aggression.