Point-of-care testing for measuring haemolymph glucose in invertebrates is not a valid method

Author(s)

Principe, Silas C. ^{[1, 2]} ; Augusto, Alessandra ^{[1, 3]} ; Costa, Tania M. ^{[1, 2]}

Affiliation

^[1] Sao Paulo State Univ, UNESP, Biosci Inst, Coastal Campus, Praca Infante Dom Henrique, S-N, POB, BR-11380972 Sao Vicente, SP - Brazil

^[2] Sao Paulo State Univ, UNESP, Biosci Inst, Botucatu Campus, R Prof Dr Antonio Celso 250, BR-18618000 Botucatu, SP - Brazil

^[3] Sao Paulo State Univ, UNESP, CAUNESP, Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal, SP - Brazil

• Document type: Journal article
• Source: CONSERVATION PHYSIOLOGY; v. 7, NOV 28 2019.
• Web of Science Citations: 0

Abstract

Blood glucose is widely used as a physiological parameter for vertebrates and invertebrates. However, its measurement in the field is often difficult due to the need for expensive and non-portable equipment. Point-of-care (POC) devices, originally intended for human use, are increasingly being used for measuring blood parameters of animals in the field. In this regard, POC glucose meters are becoming valuable tools for conservation physiologists, as glucose can be a useful indicator of stress response. In invertebrates, the use of POC glucose meters is still scarce, and no study yet has evaluated their usability in crustaceans and molluscs. We tested if a POC device can be used to measure haemolymph glucose in two widely used models, Leptuca thayeri and Perna perna, compared with a standard laboratory method. The device was unable to measure glucose in P. perna haemolymph due to equipment inaccuracy and low glucose concentration in this species (10.13 +/- 6.25 mg/dL). Additionally, despite the device being capable of measuring glucose in L. thayeri haemolymph, Bland-Altman plots showed a strong bias and wide limits of agreement, and Lin's concordance correlation coefficient showed a weak concordance between methods. When simulating experimental conditions, POC results differed from those found using the standard method. We conclude that POC glucose meters are unsuitable for assessing glucose in mussels and should not be used in crabs as results are inaccurate. (AU)

• FAPESP's process: 15/50300-6 - Climate change impact on São Paulo's estuarine fauna at pertinent parameter ranges and spatial scales: the effects of temperature and pH on fiddler crab larval development
• Grantee: Tânia Marcia Costa
• Support Opportunities: Research Program on Global Climate Change - Regular Grants