Relationship between colposcopy and bioelectric parameters in cervical squamous epithelium in women in Caldas, Colombia in premenopausal, menopausal and postmenopausal stages

The aim of this research was to measure the structural changes in the squamous epithelium of women in the perimenopausal stages through colposcopic and electrical impedance spectroscopy (EIS). 167 women between 44 and 69 years of age were classified into three groups: premenopausal, menopausal and postmenopausal. Each of them underwent colposcopic examinations and were evaluated by electrical impedance spectroscopy to measure the resistivity of those tissues in two sets of measurements: firstly, after the application of normal saline solution (NSS) at 0.9% and secondly, after being impregnated with 4% acetic acid (AA). It was found that the resistivity of the extracellular matrix (R) of the cervical squamous tissue, measured with NSS and with AA, decreases progressively from the premenopausal stage (NSS 16.7 +/-15 Ω-m; AA 22.3 +/-14.2 Ω-m) until the postmenopausal stage (NSS 7.0 +/-8.1 Ω-m; AA 9.6 +/- 10.6 Ω-m). The characteristic frequency (Fc) of the impedance spectra increases significantly for the mentioned stages from 38.6 kHz to 102.3 kHz with NSS and from 29.5 kHz to 86.4 kHz with AA. It was evidenced that, as the years of amenorrhea increase, the electrical resistivity of the tissues decreases progressively. (paper)