To compare, under resting conditions, the plasma D2O accumulation profiles of water, and 4 CES differing in percentage (^, 8, 10%) and type (simple sugars, maltodextrins) of carbohydrate. 

Healthy, informed consent

none mentioned

Recruitment not mentioned

Design randomized crossover, 5 beverage conditions, each containig D2O:

water, 6% maltodextrin, 6%, 8%, 10% glucose-fructose

All CES contained 20 mmol/l Na, 3 mmol/l K

Blinding used (if applicable)

 Double-blind, counterbalanced assignment of conditions to subjects.

Intervention (if applicable)

 5 beverage conditions, each containig D2O:

water, 6% maltodextrin, 6%, 8%, 10% glucose-fructose

All CES contained 20 mmol/l Na, 3 mmol/l K

Statistical Analysis

 No statistical analysis section of paper (no analysis plan stated).

Timing of Measurements

 12 h fast prior to 5 experimental sessions (1 week washout); catheter inserted for blood sampling;

 Ingestion of 275 ml (within 60 sec) of 1 of 5 beverage conditions during rest (sitting quietly).

Blood samples taken before testing, and at 10, 20, 30, 40, 60, 90, 120, 180 min after ingestion.

Dependent Variables

• D2O accumulation (method not mentioned)
• Insulin (method not mentioned)
• glucose (glucose analyzer)

Independent Variables

 5 beverage conditions (275 ml), each containig 20 ml (22.1 g) of 99.8 atom D2O:

water, 6% maltodextrin, 6%, 8%, 10% glucose-fructose

All CES contained 20 mmol/l Na, 3 mmol/l K

Control Variables

 All subjects at rest; amt of beverage ingested; no others mentioned.

Initial N: N=8 M

Attrition (final N):N=8 M

Age: college-aged (no range or mean±SEM given)

Ethnicity: noty mentioned

Other relevant demographics: none mentioned

Anthropometrics (e.g., were groups same or different on important measures)  None mentioned

Location: Exercise Biochemistry Lab, Dept Exercise Science, school of Public Health, Univ SC, Columbia, SC

*No mean±SEM tabular data given - all data in 3 figures*

Other Findings

 Plasma D2O concentration and insulin not significantly different between the 5 drink conditions.

Changes in plasma glucose:  plasma cglu increased after ingestion of the CES, peaking at 20 min for 8% GF, and 30 min for % and 10% GF.  PLasma glu higher with ingestion of CES than water at 20 and 30 min (P<0.05) and returned to baseline (6% M and GF) or below (8%, 10% GF) (P<0.05).  No differences found among the drinks at or after 90 min.

2.5-10% CES beverages, regardlesss if maltodextrin or simple sugars, are not likely to enter the vascular system more slowly than water, and therefore will not compromise fluid replenishment.

Conclusions that can be made from this study are limited. 

No statistical plan was described (or P values expected for the sample size, i.e. effect size). 

No subject characteristics/anthrompometrics/demographics described for this small, limited sample. no info re: body weight/ht, activity level, etc

Much information missing from methods (drink temp, subjective feelings, environmental conditions, analysis of plasma measures, hydration status).

Could have done much more with respect to measures obtained.