RT info:eu-repo/semantics/article T1 A pilot proteomic study of normal human tears: leptin as a potential biomarker of metabolic disorders A1 Byambajav, Mungunshur A1 Arroyo del Arroyo, Cristina A1 Enriquez De Salamanca Aladro, Amalia A1 Fernández Martínez, Itziar A1 Martin, Eilidh A1 Hagan, Suzanne K1 Ophthalmology K1 Endocrinology K1 Biomarker K1 Ocular surface K1 Metabolic protein K1 Tear fluid K1 Biomarcador K1 Superficie ocular K1 Proteína metabólica K1 Líquido lagrimal K1 3201.09 Oftalmología AB The concentrations of insulin, leptin, active ghrelin, C-peptide and gastric inhibitory polypeptide (GIP) and their inter-day variations were examined in normal human tears. In addition, correlations between the concentrations of these metabolic proteins and ocular surface parameters were determined. Subjects with healthy ocular surfaces attended three visits, with 7-day intervals. Tear evaporation rate (TER) and non-invasive tear break-up time (NITBUT) were assessed, and a total of 2 µL tears were collected from all subjects. Tear fluid concentrations of insulin, leptin, active ghrelin, C-peptide and GIP were measured by multiplex bead analysis. Insulin was the most highly expressed metabolic protein, followed by leptin, C-peptide, active ghrelin and GIP. Of these, only active ghrelin had a significant inter-day variation (p < 0.05). There was no inter-day variation in the mean concentrations of the other metabolic proteins. Leptin had a strong intra-class reproducibility. No correlation was detected between tear metabolic protein concentrations and ocular surface parameters. This pilot study shows, for the first time, that active ghrelin and GIP are detectable in healthy tears. The strong intra-class reproducibility for leptin shows that it could be used as a potential tear fluid biomarker and, possibly, in determining the effects of metabolic disorders on the ocular surface. PB MDPI YR 2021 FD 2021 LK https://uvadoc.uva.es/handle/10324/59547 UL https://uvadoc.uva.es/handle/10324/59547 LA eng NO Applied Sciences, 2021, vol. 11, n. 12, 5755 NO Producción Científica DS UVaDOC RD 19-may-2024