Sonographic comparison of subcutaneous fat layer thickness in the scalp area in patients with androgenetic alopecia compared to healthy individuals: Cross-sectional.

INTRODUCTION: Androgenetic alopecia (AGA) is one of the most common alopecia among men and women worldwide. It is a nonscarring alopecia that has a characterized pattern. In female pattern AGA, the hairline is stable but general thinning occurs most notably in the frontal region. In male-pattern AGA, the hairline is receding and the thinning is most notable in the frontotemporal region. AGA has a complex pathogenesis and relation of subcutaneous fat in the scalp region and the miniaturization of terminal hair follicles is vague. In this study, subcutaneous fat in the frontal scalp an important region for AGA is compared to the occipital scalp that is spared in AGA. METHOD: Our study is a cross-sectional study that has four groups. Male patient, female patient, male control, female control. Every group has 15 individuals. All of the people in the study are those referred to Rasoul Akram's dermatology clinic. The severity of alopecia is classified by Norwood scaling for male pattern AGA and Ludwig scaling for female pattern AGA. Subcutaneous tissue in the frontal and occipital regions is measured by ultrasonography. For evaluating the effect of aging on subcutaneous fat thickness, we subdivided any group into more than 40 years old and between 20 and 40 years old and compared these two subgroups. RESULTS: The mean age of the three groups of male patient, female patient, and female control is 40 y/o and the mean age of male control is 41 y/o. The mean subcutaneous fat layer thickness in frontal region in male patients group is 6.0 mm (more than 40 y/o = 6.6 mm, between 20 and 40 y/o = 5.5 mm), in female patients group 5.1 mm (more than 40 y/o = 5.7 mm, between 20 and 40 y/o = 4.6 mm), in the male control group is 4.4 mm (more than 40 y/o = 4.7 mm, between 20 and 40 y/o = 4 mm) and in the female control group is 4.1 mm (more than 40 y/o = 4.5 mm, between 20 and 40 y/o = 3.6 mm). The mean subcutaneous fat layer thickness in the occipital region in the male patient's group is 6.4 mm (more than 40 y/o = 6.7 mm, between 20 and 40 y/o = 6 mm), in the female patient's group 6.1 mm (more than 40 y/o = 6.5 mm, between 20 and 40 y/o = 5.7 mm), in the male control group is 6.3 mm (more than 40 y/o = 6.8 mm, between 20 and 40 y/o = 5.7 mm) and in the female control group is 6.2 mm (more than 40 y/o = 6.6 mm, between 20 and 40 y/o = 5.8 mm). CONCLUSION: This study demonstrates that the subcutaneous fat layer in the frontal region in both males and females is thicker in AGA patients than healthy group and the more severe the AGA, the thicker is subcutaneous layer in the frontal region. In the male patients group, the subcutaneous fat layer in the frontal region is thicker than in the female patients group but in the male and female control groups is not so different. The subcutaneous fat layer in the occipital region is thicker in older individuals in both patients and control groups but is not different when compared to AGA patients and control individuals.

An Approach to Using Electrical Impedance Myography Signal Sensors to Assess Morphofunctional Changes in Tissue during Muscle Contraction.

This present work is aimed at conducting fundamental and exploratory studies of the mechanisms of electrical impedance signal formation. This paper also considers morphofunctional changes in forearm tissues during the performance of basic hand actions. For this purpose, the existing research benches were modernized to conduct experiments of mapping forearm muscle activity by electrode systems on the basis of complexing the electrical impedance signals and electromyography signals and recording electrode systems' pressing force using force transducers. Studies were carried out with the involvement of healthy volunteers in the implementation of vertical movement of the electrode system and ultrasound transducer when the subject's upper limb was positioned in the bed of the stand while performing basic hand actions in order to identify the relationship between the morphofunctional activity of the upper limb muscles and the recorded parameters of the electro-impedance myography signal. On the basis of the results of the studies, including complex measurements of neuromuscular activity on healthy volunteers such as the signals of electro-impedance myography and pressing force, analyses of the morphofunctional changes in tissues during action performance on the basis of ultrasound and MRI studies and the factors influencing the recorded signals of electro-impedance myography are described. The results are of fundamental importance and will enable reproducible electro-impedance myography signals, which, in turn, allow improved anthropomorphic control.

Age-related changes in the fiber structure around adipocytes in the subcutaneous fat layer and their association with skin viscoelasticity.

OBJECTIVE: Age-related changes in the fiber structure around adipocytes were investigated via scanning electron microscopy (SEM) of excised skin tissues. In addition, the viscoelasticity of the subcutaneous fat layer was evaluated via elastography, and the association between the fiber structure and the viscoelastic properties was assessed. METHODS: Skin tissues excised from the facial cheek area were used. Then, SEM images of these tissues were obtained. The thickness and quantity of the fibers around adipocytes were assessed using a 5-point scale. The score was used to grade 18 tissue samples. Moreover, the viscoelasticity of the subcutaneous fat layer in the same samples was evaluated via ultrasound elastography. RESULTS: Based on the SEM image score, an association was observed between the fiber status score and age, thereby indicating a tendency toward age-related fibrosis. Fiber structures with high scores, which indicate fibrosis, had a significantly lower viscoelasticity based on ultrasound elastography. CONCLUSION: The thickness and quantity of fibrous structures around adipocytes in the subcutaneous fat layer increase with age, and these changes can be associated with decreased viscoelasticity in the subcutaneous fat layer.