Avaliação da função barreira da pele utilizando a modelação matemática das curvas de PTEA : diferenças relacionadas com o envelhecimento cutâneo
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Data
2010
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Edições Universitárias Lusófonas
Resumo
O presente estudo procurou investigar alterações na função de barreira cutânea causadas pelo envelhecimento, através da
metodologia POST (plastic occlusion stress test), e aplicando um modelo matemático compartimental aos dados de PTEA
(perda transepidérmica de água) obtidos após remoção da oclusão.
Participaram no estudo 32 voluntários de ambos os sexos, sem patologias cutâneas. Estes foram divididos em dois grupos:
I- idade inferior a 30 anos; II- mais de 30 anos. Foi aplicado no antebraço ventral de cada voluntário um penso oclusivo, e
após a remoção dessa oclusão mediu-se a PTEA por 30 min. Aplicou-se um modelo bicompartimental matemático a estes
dados, calculando-se o t1/2evap - tempo de semi-vida de evaporação- e a DWM – massa dinâmica de água.
Os resultados indicam diferenças discretas entre os parâmetros cinéticos obtidos nos dois grupos, o que sugere que o
equilíbrio hídrico e a função de barreira da pele não sofrem uma alteração significativa nas faixas etárias estudadas. No
entanto, observaram-se diferenças ligeiras na velocidade de decaimento da PTEA, sendo mais rápida e acentuada no grupo
jovem e decrescendo a um ritmo mais lento com o envelhecimento.
Conclui-se, a partir dos resultados obtidos, que através da metodologia dinâmica empregada foi possível detectar
diferenças discretas na dinâmica da água da pele senil, indicando potencial de aplicação na área de testes de eficácia de
produtos de aplicação cutânea.
The study aimed to investigate changes in the cutaneous barrier function caused by ageing using the POST (plastic occlusion stress test) methodology followed by mathematical modeling of the TEWL data obtained after removal of the occlusion. 32 healthy volunteers participated in the study. They were separated into two groups: one of volunteers under and the other of subjects over 30 years old. An occlusive patch was applied to the ventral forearm of each volunteer for 2 hours. After removal of the patch, the TEWL was measured for 30 minutes. A bi-compartmental mathematical model was fitted to the data and t1/2evap – evaporation half-life- and DWM – dynamic water mass- were calculated. Discrete differences were found between the kinetic parameters obtained for the two groups, which seems to indicate that the water balance and skin barrier were not severely altered in the age ranges included in the study. Nevertheless, the desorption curves of the under 30 volunteers presented a sharp decay, whereas in senile skin the decay occurred at a much slower pace. It can be concluded that the dynamic methodology was able to establish a mild differences in the water dynamics of aged skin, which can potentially be applied to the efficacy and safety testing of skin products.
The study aimed to investigate changes in the cutaneous barrier function caused by ageing using the POST (plastic occlusion stress test) methodology followed by mathematical modeling of the TEWL data obtained after removal of the occlusion. 32 healthy volunteers participated in the study. They were separated into two groups: one of volunteers under and the other of subjects over 30 years old. An occlusive patch was applied to the ventral forearm of each volunteer for 2 hours. After removal of the patch, the TEWL was measured for 30 minutes. A bi-compartmental mathematical model was fitted to the data and t1/2evap – evaporation half-life- and DWM – dynamic water mass- were calculated. Discrete differences were found between the kinetic parameters obtained for the two groups, which seems to indicate that the water balance and skin barrier were not severely altered in the age ranges included in the study. Nevertheless, the desorption curves of the under 30 volunteers presented a sharp decay, whereas in senile skin the decay occurred at a much slower pace. It can be concluded that the dynamic methodology was able to establish a mild differences in the water dynamics of aged skin, which can potentially be applied to the efficacy and safety testing of skin products.
Descrição
Revista Lusófona de Ciências e Tecnologias da Saúde
Palavras-chave
MEDICINA, ENVELHECIMENTO CUTÂNEO, MEDICINE, SKIN AGEING, DERMATOLOGIA, DERMATOLOGY, PELE, SKIN, ESTUDOS DE CASO, CASE STUDIES, BARREIRA CUTÂNEA, SKIN BARRIER, PERDA TRANSEPIDÉRMICA DE ÁGUA, TRANSEPIDERMAL WATER LOSS