Time-point measurement is critical in hormone characterization

In their recent study ‘Changes in appetite related gut hormones in intensive care unit patients: a pilot cohort study’ Nematy and colleagues further elucidated intensive care unit (ICU) patients’ poor nutritional status. They reported high levels of peptide YY (PYY) and low levels of ghrelin in fasting plasma samples from ICU patients compared with healthy, nonhospitalized controls [1]. While intriguing, this gives only a mere snapshot of PYY/ghrelin physiology in the ICU patient because PYY/ghrelin levels were measured only once per day.