Histological evaluation of age-related changes in human respiratory mucosa of the middle turbinate.

Though the lining of the healthy human nose is subject of numerous investigations, age-related changes have attracted little attention. Furthermore, varying sampling sites complicate the evaluation of the available information. Reference is needed for evaluation of abnormal conditions, e.g. in persons with sleep apnea. Biopsy samples from the middle turbinate of 40 healthy humans aged 5 to 75 years were examined. Tissue samples were fixed immediately in glutaraldehyde and embedded in Epon for semi-thin sectioning and blind histological evaluation. In all age groups, patchy arrangement of different epithelial types were found. Ciliated epithelium decrease with age. Stratified and atrophic epithelial types show striking changes. Thin atrophic epithelium with conspicuously thickened basement membranes is only seen above the age of 40 years and is frequently found in older subjects. Stratified epithelial types initially increase with age, but decrease above 50 years. In the middle aged group (26 to 50 years) we found a remarkably high amount of squamous metaplasia, resulting in overall thicker epithelium becoming thinner in older subjects. In contrast, basement membranes are thinnest in the middle aged group. In conclusion, evaluating the histology of nasal respiratory epithelium must take pronounced age-related physiological changes into account.