The Beverage Hydration Index: Influence of Electrolytes, Carbohydrate and Protein

The beverage hydration index (BHI) facilitates a comparison of relative hydration properties of beverages using water as the standard. The additive effects of electrolytes, carbohydrate, and protein on rehydration were assessed using BHI. Nineteen healthy young adults completed four test sessions in randomized order: deionized water (W), electrolytes only (E), carbohydrate-electrolytes (C + E), and 2 g/L dipeptide (alanyl-glutamine)-electrolytes (AG + E). One liter of beverage was consumed, after which urine and body mass were obtained every 60 min through 240 min. Compared to W, BHI was higher (p = 0.007) for C + E (1.15 ± 0.17) after 120 min and for AG + E (p = 0.021) at 240 min (1.15 ± 0.20). BHI did not differ (p > 0.05) among E, C + E, or AG + E; however, E contributed the greatest absolute net effect (>12%) on BHI relative to W. Net fluid balance was lower for W (p = 0.048) compared to C + E and AG + E after 120 min. AG + E and E elicited higher (p < 0.001) overall urine osmolality vs. W. W also elicited greater reports of stomach bloating (p = 0.02) compared to AG + E and C + E. The addition of electrolytes alone (in the range of sports drinks) did not consistently improve BHI versus water; however, the combination with carbohydrate or dipeptides increased fluid retention, although this occurred earlier for the sports drink than the dipeptide beverage. Electrolyte content appears to make the largest contribution in hydration properties of beverages for young adults when consumed at rest

Hypertonic Saline Infusion Acutely Degrades Mood in Healthy Volunteers (P23-014-19)

Objectives: Mild and moderate dehydration adversely affect mood and cognitive function. During dehydration, hypertonic hypovolemia activates both osmo- and baro-receptors but it is not known which physiological pathway is associated with degraded mood state. This study examined the acute effect of osmoreceptor stimulation on mood.Methods: Sixty healthy adults (50% females, 30 ± 1 y; BMI: 26.9 ± 4.0 kg·m-2) were infused intravenously with 3.0% (HYPER) or 0.9% (ISO) NaCl for 2 h (0.1 ml·kg-1·min-1) using a counterbalanced, crossover design. Blood samples were collected every 30 minutes to measure plasma osmolality (POsm), copeptin (a surrogate marker of vasopressin), and renin-angiotensin-aldosterone system (RAAS) hormones. Mood was assessed with the short version of Profile of Mood State (POMS) questionnaire before and after the infusion.Results: POsm and copeptin increased from 286 ± 3 mmol·kg-1 to 305 ± 4 mmol·kg-1 and from 4.5 ± 3.7 pmol·L-1 to 20.4 ± 12.8 pmol·L-1, respectively in HYPER (P 0.05). No hormonal differences were observed between trials for RAAS hormones (P > 0.05). During HYPER copeptin, following the 2-h infusion, was greater in females than in males (female: 23.4 ± 13.9 pmol·L-1, male: 17.4 ± 10.9 pmol·L-1; P 0.05). Among POMS subscales, depression-dejection and fatigue-inertia increased in HYPER compared to ISO (P 0.05). The confusion-bewilderment subscales and fatigue-inertia of the POMS were also elevated post HYPER in females (P 0.05) in either sex.Conclusions: Hypertonic saline infusion acutely degrades mood state, and women appear to have a more pronounced response. The underlying mechanisms remain to be determined but may be related to higher copeptin levels in women.The study was registered at ClinicalTrials.gov as NCT02761434.Funding Sources: Danone Research.Supporting Tables Images and/or Graphs

Hypertonic Saline Infusion Acutely Degrades Mood in Healthy Volunteers (P23-014-19)

Objectives: Mild and moderate dehydration adversely affect mood and cognitive function. During dehydration, hypertonic hypovolemia activates both osmo- and baro-receptors but it is not known which physiological pathway is associated with degraded mood state. This study examined the acute effect of osmoreceptor stimulation on mood.Methods: Sixty healthy adults (50% females, 30 ± 1 y; BMI: 26.9 ± 4.0 kg·m-2) were infused intravenously with 3.0% (HYPER) or 0.9% (ISO) NaCl for 2 h (0.1 ml·kg-1·min-1) using a counterbalanced, crossover design. Blood samples were collected every 30 minutes to measure plasma osmolality (POsm), copeptin (a surrogate marker of vasopressin), and renin-angiotensin-aldosterone system (RAAS) hormones. Mood was assessed with the short version of Profile of Mood State (POMS) questionnaire before and after the infusion.Results: POsm and copeptin increased from 286 ± 3 mmol·kg-1 to 305 ± 4 mmol·kg-1 and from 4.5 ± 3.7 pmol·L-1 to 20.4 ± 12.8 pmol·L-1, respectively in HYPER (P 0.05). No hormonal differences were observed between trials for RAAS hormones (P > 0.05). During HYPER copeptin, following the 2-h infusion, was greater in females than in males (female: 23.4 ± 13.9 pmol·L-1, male: 17.4 ± 10.9 pmol·L-1; P 0.05). Among POMS subscales, depression-dejection and fatigue-inertia increased in HYPER compared to ISO (P 0.05). The confusion-bewilderment subscales and fatigue-inertia of the POMS were also elevated post HYPER in females (P 0.05) in either sex.Conclusions: Hypertonic saline infusion acutely degrades mood state, and women appear to have a more pronounced response. The underlying mechanisms remain to be determined but may be related to higher copeptin levels in women.The study was registered at ClinicalTrials.gov as NCT02761434.Funding Sources: Danone Research.Supporting Tables Images and/or Graphs