Age‐related changes in skin barrier function – Quantitative evaluation of 150 female subjects

Abstract

The protection against water loss and the prevention of substances and bacteria penetrating into the body rank as the most important functions of the skin. This so-called 'skin barrier function' is the natural frontier between the inner organism and the environment, and is primarily formed by the epidermis. An impairment of the skin barrier function is often found in diseased and damaged skin. An influence of ageing on skin barrier function is widely accepted, but has not been conclusively evaluated yet. Therefore, the aim of this clinical study was to assess the potential influence of ageing on skin barrier function, including transepidermal water loss (TEWL), stratum corneum hydration, sebum content and pH value. One hundred and fifty healthy women aged 18-80, divided into five age groups with 30 subjects each, were evaluated in this study. TEWL, hydration level, sebum secretion and pH value of hydro-lipid acid film were measured with worldwide acknowledged biophysical measuring methods at cheek, neck, décolleté, volar forearm and dorsum of hand. Whereas TEWL and stratum corneum hydration showed only very low correlation with subject's age, the sebum production decreased significantly with age, resulting in the lowest skin surface lipids levels measured in subjects older than 70 years. The highest skin surface pH was measured in subjects between 50 and 60 years, whereas the eldest age group had the lowest mean pH. The dorsum of the hand was the location with the highest TEWL and lowest stratum corneum hydration in all age groups. The results show that only some parameters related to skin barrier function are influenced by ageing. Whereas sebum production decreases significantly over lifetime and skin surface pH is significantly increased in menopausal woman, TEWL and stratum corneum hydration show only minor variations with ageing.

Natural and Sun-Induced Aging of Human Skin

“…Flattening of the dermal -epidermal junction also reduces epidermal resistance to shearing forces and thereby makes the epidermis more fragile (Lavker et al 1989). However, thickness of the stratum corneum remains unaltered with advanced age (Lavker et al 1989;Lavker 1995) and stratum corneum hydration is modestly lowered or unchanged in aged versus young individuals (Man et al 2009;Luebberding et al 2013). Accordingly, transepidermal water loss (a measure of stratum corneum integrity) is unaltered with chronological aging (Luebberding et al 2013).…”

“…However, thickness of the stratum corneum remains unaltered with advanced age (Lavker et al 1989;Lavker 1995) and stratum corneum hydration is modestly lowered or unchanged in aged versus young individuals (Man et al 2009;Luebberding et al 2013). Accordingly, transepidermal water loss (a measure of stratum corneum integrity) is unaltered with chronological aging (Luebberding et al 2013). However, surface lipid production decreases significantly with age on some areas of the skin (Man et al 2009;Luebberding et al 2013), increasing incidence of xerosis (dry skin), pruritus (itchy skin), and skin irritation in elderly populations (Kligman 1979).…”

Effects of Orally Administered Pyrroloquinoline Quinone Disodium Salt on Dry Skin Conditions in Mice and Healthy Female Subjects

“…Therefore, orally administered PQQ at 20 mg/d is most likely to be safe in humans. Aging often leads to dry skin accompanied by a reduced ability of the skin to perspire and secrete sebum and other skin-protecting factors (22). Moreover, aged skin cells replicate more slowly than younger cells, and aged skin becomes thick and takes a longer time to repair (23).…”

Clinical Efficacy of Dermocosmetic Formulations Containing Spirulina Extract on Young and Mature Skin: Effects on the Skin Hydrolipidic Barrier and Structural Properties

“…It also selectively regulates the in and output of substances from the human body towards the environment and vice-versa. This is called "the skin barriers function" [19]. The main constitution from this barrier is the epidermis; this layer acts as a dynamic physical and biochemical frontier.…”

“…Moreover, in this film, it's possible to find sebaceous gland lipids, corneocytes remains and sweat which together play the role of the biochemical barrier. This way, the stratum corneum hydration, transepidermal water loss and sebum level parameters contribute to the maintenance of skin barrier functionability [19].…”