TY - JOUR

T1 - Salivary ghrelin response to drinks varying in protein content and quantity and association with energy intake and appetite.

AU - Crabtree, Daniel R.

AU - Buosi, William

AU - Fyfe, Claire L.

AU - Horgan, Graham W.

AU - Holst, Jens J.

AU - Johnstone, Alexandra M.

AU - Full4Health-study Group

N1 - Publisher Copyright: © 2021 Elsevier Inc.

PY - 2021

Y1 - 2021

N2 - Salivary hormone analysis is a non-invasive alternative to blood-borne hormone analysis. The orexigenic hormone ghrelin has been detected in human saliva, though the relationship between salivary and blood-borne ghrelin and salivary ghrelin's association with energy intake (EI) and appetite remains unclear. The primary aim of this study was to compare salivary and plasma ghrelin responses to dairy breakfast drinks varying in protein content and quantity, and to determine the relationship between salivary ghrelin and EI and appetite. Participants (n = 25) consumed four test drinks, varying in protein content and quantity, on four separate days in a double-blind randomized controlled study. Salivary and plasma total ghrelin were measured at 0, 30, 60 and 120 min and appetite perceptions at 0, 30, 60, 90 and 120 min. A buffet-style test meal was presented at 120 min to measure ad libitum EI. There was no correlation between the sample means for fasted salivary and plasma ghrelin (r = 0.099, p = 0.637). Furthermore, there was no within-participant association between fasted salivary and plasma ghrelin (r = -0.041, p = 0.725). Mean bias between fasted salivary and plasma ghrelin was -448 pg/ml (95% confidence intervals (CI) = -623 – -273 pg/ml) and upper and lower limits of agreement (LOA) were 427 pg/ml and -1324 pg/ml, respectively. Variation in postprandial levels of salivary and plasma ghrelin within-participants were not associated (r = -0.004, p = 0.943). There was no significant association between EI and salivary (r = 0.003, p = 0.979) or plasma (r = -0.080, p = 0.492) ghrelin. Salivary ghrelin was not significantly correlated with composite appetite score (r = 0.023; p = 0.654), though plasma ghrelin was (r = 0.225, p < 0.001). Mean bias between postprandial salivary and plasma ghrelin was -210 pg/ml (95% CI = -380 – -40 pg/ml) and upper and lower LOA were 641 pg/ml and -1061 pg/ml, respectively. These findings suggest that salivary and plasma ghrelin responses to drinks varying in protein content and quantity are unrelated and that salivary ghrelin is not associated with EI or appetite perceptions in healthy non-obese adults. This trial was registered at www.clinicaltrial.gov (NCT01597024).

AB - Salivary hormone analysis is a non-invasive alternative to blood-borne hormone analysis. The orexigenic hormone ghrelin has been detected in human saliva, though the relationship between salivary and blood-borne ghrelin and salivary ghrelin's association with energy intake (EI) and appetite remains unclear. The primary aim of this study was to compare salivary and plasma ghrelin responses to dairy breakfast drinks varying in protein content and quantity, and to determine the relationship between salivary ghrelin and EI and appetite. Participants (n = 25) consumed four test drinks, varying in protein content and quantity, on four separate days in a double-blind randomized controlled study. Salivary and plasma total ghrelin were measured at 0, 30, 60 and 120 min and appetite perceptions at 0, 30, 60, 90 and 120 min. A buffet-style test meal was presented at 120 min to measure ad libitum EI. There was no correlation between the sample means for fasted salivary and plasma ghrelin (r = 0.099, p = 0.637). Furthermore, there was no within-participant association between fasted salivary and plasma ghrelin (r = -0.041, p = 0.725). Mean bias between fasted salivary and plasma ghrelin was -448 pg/ml (95% confidence intervals (CI) = -623 – -273 pg/ml) and upper and lower limits of agreement (LOA) were 427 pg/ml and -1324 pg/ml, respectively. Variation in postprandial levels of salivary and plasma ghrelin within-participants were not associated (r = -0.004, p = 0.943). There was no significant association between EI and salivary (r = 0.003, p = 0.979) or plasma (r = -0.080, p = 0.492) ghrelin. Salivary ghrelin was not significantly correlated with composite appetite score (r = 0.023; p = 0.654), though plasma ghrelin was (r = 0.225, p < 0.001). Mean bias between postprandial salivary and plasma ghrelin was -210 pg/ml (95% CI = -380 – -40 pg/ml) and upper and lower LOA were 641 pg/ml and -1061 pg/ml, respectively. These findings suggest that salivary and plasma ghrelin responses to drinks varying in protein content and quantity are unrelated and that salivary ghrelin is not associated with EI or appetite perceptions in healthy non-obese adults. This trial was registered at www.clinicaltrial.gov (NCT01597024).

KW - Appetite

KW - Energy intake

KW - Ghrelin

KW - Protein

KW - Saliva

U2 - 10.1016/j.physbeh.2021.113622

DO - 10.1016/j.physbeh.2021.113622

M3 - Journal article

C2 - 34653498

AN - SCOPUS:85117213740

VL - 242

JO - Physiology & Behavior

JF - Physiology & Behavior

SN - 0031-9384

M1 - 113622

ER -