Repercussões do hipotireoidismo tratado com levotiroxina sódica sobre o assoalho pélvico e a função vesical feminina: avaliação clínica e urodinâmica

Abstract

Pelvic floor dysfunctions and thyroid diseases are prevalent in women. Clinical and pathophysiological studies show a correlation between hyperthyroidism and hypothyroidism and lower urinary tract dysfunctions such as urgency, urinary incontinence, changes in urinary flow, maximal cystometric capacity and perineal activation, urinary retention, bladder pain, among others, all reversible with thyroid treatment. Considering the hypothesis that the thyroid function influences the pelvic floor and female lower urinary tract, we retrospectively analyzed data from 397 urodynamics of adult women. This study was approved by Research Ethics Committee. A 95% confidence interval and statistical significance level of 5% were considered. Hyperthyroidism was reported by 1 participant, not being focused on this study. The median age was 69 years (62-75) and the prevalence of hypothyroidism in women with and without genital prolapse was 24.4% and 31.9%, both significantly higher than the higher prevalence reported in female Brazilian population, pointing to this correlation. In addition, the urodynamics of participants with genital prolapse confirmed an association with the risk factors: age, menopause, number of vaginal deliveries and vaginal deliveries and with a wide range of symptoms and urodynamic findings, compatible with urinary outlet obstruction, despite similar prevalence of hypothyroidism among participants with and without pelvic organs prolapse. As genital prolapse determines, itself, the deterioration of lower urinary tract function, analyses about the influence of the treated hypothyroidism on bladder function were performed only among patients without prolapse. Significatively greater prevalence of previous genital prolapses surgery was reported by participants with hypothyroidism, enhancing the study hypothesis. Patients with hypothyroidism were significantly older, had higher BMI scores, and referred more comorbidities (DM, dyslipidemia and use of AAS). LUTS and urodynamic parameters were similar between groups, except for the higher prevalence of insensitive urinary incontinence in a patient without hypothyroidism. Using the binary logistic regression to search for "indicators" of hypothyroidism in this population, it was found a positive odds ratio for BMI and previous genital prolapse surgery, and negative odds ratio for post-voiding residue (greater than 100ml). To increase statistical accuracy, we performed artificial neural network analysis that found a ROC area under the curve of 0.926 in the prediction of hypothyroidism. Age, ICIQ-SF values, and voiding interval pointed with normalized importance greater than 80% and detrusor pression in the maximum flow with importance of 79.3%. Higher TSH values in treated hypothyroid participants were associated with hesitance and abnormal voiding curve. Thus, considering that the diagnosis of thyroid dysfunction is well established and accessible, as well as its therapies, and that the treatment of thyroid diseases can virtually reestablish the bladder function impairments caused by thyroid alterations, we suggest thyroid investigation for all patients with LUTS. On the other hand, some LUTS and urodynamic findings may persist despite the thyroid treatment, so LUTS could indicate thyroid disease. Prospective studies are needed to better elucidate the correlation among thyroid, pelvic floor and lower urinary tract functions.