The variation in cervical hydroxyproline and cervical water with age

Diffuse reflectance spectroscopy and imaging for non-invasive objective assessment of genitourinary syndrome of menopause: a pilot study

The genitourinary symptom of menopause (GSM) affects up to 65% of women, resulting in symptoms such as vulvovaginal dryness, discomfort, and dysuria, which significantly impacts quality of life. The current assessment methods rely on subjective questionnaires that can be influenced by individual differences, as well as invasive measurements that are time-consuming and not easily accessible. In this study, we explore the potential of a non-invasive and objective assessment tool called diffuse reflectance spectroscopy and imaging (DRSI) to evaluate tissue chromophores, including water, lipid, oxyhemoglobin, and deoxyhemoglobin. These measurements provide information about moisture content, lipid levels, oxygen saturation, and blood fraction, which can serve as surrogate markers for genital estrogen levels. Our findings reveal distinct differences in these chromophores among pre, peri, and postmenopausal subjects. By using lipid and blood fraction tissue chromophores in a K-Nearest Neighbour classifier model, we achieved a prediction accuracy of 65% compared to vaginal maturation index (VMI) that is clinically used to assess estrogen-related hormonal changes. When age was included as the third feature, the accuracy increased to 78%. We believe that by refining the study protocol and configuring the fiber probe to examine tissue chromophores both in the superficial vulva skin for epidermal water content and the deeper layers, DRSI has the potential to provide objective diagnosis and aid in monitoring the treatment outcome of GSM.

Collagen concentration and biomechanical properties of samples from the lower uterine cervix in relation to age and parity in non-pregnant women

BACKGROUND

During normal pregnancy the cervix has a load bearing function. The cervical tissue consists mainly of an extracellular matrix (ECM) rich in collagen; important for the biomechanical properties. The aim of the present study was to evaluate how the biomechanical strength of samples from the distal cervix is associated with collagen content in relation to age and parity. This study demonstrates a method to investigate cervical tissue from women who still have their uterus in situ.

METHODS

Cervical punch biopsies (2 x 15 mm) were obtained from 57 healthy women (median age: 39 years, range: 29-49 years). Biomechanical tensile testing was performed, and collagen concentration (as % of dry defatted weight (DDW)) and content (mg of collagen per mm of specimen length) was determined. Histomorphometry was used to determine the volume densities of extracellular matrix and smooth muscle cells. Smooth muscle cells were identified by immunohistochemistry. Finally, orientation of collagen fibers was estimated. Data are given as mean +/- SD.

RESULTS

The mean collagen concentration (62.2 +/- 6.6%) increased with age (0.5% per year, r = 0.45, p = 0.003) and decreased with parity (1.7% per birth, r = -0.45, p = 0.033). Maximum load was positively correlated with collagen content (mg of collagen per mm of specimen length) (r = 0.76, p < 0.001). Normalized maximum stiffness was increased with age (r = 0.32, p = 0.017), whereas no correlation was found with regard to parity. In tissue samples with a length of approximately one cm, volume density of smooth muscle cells increased gradually from 8.9% in the distal part near the epithelium, to 15.5% in the proximal part (p < 0.001).

CONCLUSIONS

The present study shows that cervical collagen concentration increases with age and decreases with parity in non-pregnant women. In addition, collagen stiffness increased with age, whereas no change in collagen tensile strength with respect to age and parity was found. These results show that collagen contributes to cervical tissue tensile strength and age and parity should be considered confounding factors.

Cervical collagen in non-pregnant women with previous cervical incompetence

OBJECTIVE

To study the cervical collagen in non-pregnant women with a history of congenital cervical incompetence.

SUBJECTS

Ten non-pregnant women with congenital cervical incompetence, defined as cervical incompetence in the first pregnancy in a woman without previous cervical trauma. Seventy-one normal non-pregnant women (31 nulligravidae, nine nulliparous and 31 parous women) served as controls.

METHOD

Cervical biopsies were analysed for the hydroxyproline concentration and extractability to express the concentration and the stability of the collagen.

RESULTS

Women with cervical incompetence had markedly lower median cervical hydroxyproline concentration when compared to normal parous women (11.1 (range 6.11-18.5) micrograms/mg wet weight vs. 16.9 (range 7.7-29.8) micrograms/mg wet weight; P = 0.003, Mann Whitney test) and the extractability was almost twice the value found in normal parous women (80.2% vs. 49.5%; P = 0.03, Mann Whitney test). Both pregnancy per ce and parturition caused a significant decrease in the hydroxyproline concentration when compared to values found in nulligravidae (P < 0.0001, Kruskall Wallis test).

CONCLUSIONS

Congenital cervical incompetence seems associated with a low collagen concentration in the cervical connective tissue in the non-pregnant state.