TY - JOUR
T1 - Dietary supplement increases plasma norepinephrine, lipolysis, and metabolic rate in resistance trained men
AU - Bloomer, Richard J.
AU - Fisher-Wellman, Kelsey H.
AU - Hammond, Kelley G.
AU - Schilling, Brian K.
AU - Weber, Adrianna A.
AU - Cole, Bradford J.
N1 - Funding Information:
Funding for this work was provided in part by Vital Pharmaceuticals, Inc. and the University of Memphis.
Funding Information:
This study was financially supported by Vital Pharmaceuticals, Inc. Although the authors or the University of Memphis do not directly endorse the dietary supplement, the lead author (RJB) has been involved in scientific writing for Vital Pharmaceuticals, Inc.
PY - 2009/1/28
Y1 - 2009/1/28
N2 - Background: Dietary supplements targeting fat loss and increased thermogenesis are prevalent within the sport nutrition/weight loss market. While some isolated ingredients have been reported to be efficacious when used at high dosages, in particular in animal models and/or via intravenous delivery, little objective evidence is available pertaining to the efficacy of a finished product taken by human subjects in oral form. Moreover, many ingredients function as stimulants, leading to increased hemodynamic responses. The purpose of this investigation was to determine the effects of a finished dietary supplement on plasma catecholamine concentration, markers of lipolysis, metabolic rate, and hemodynamics. Methods: Ten resistance trained men (age = 27 ± 4 yrs; BMI = 25 ± 3 kg· m-2; body fat = 9 ± 3%; mean ± SD) ingested a dietary supplement (Meltdown®, Vital Pharmaceuticals) or a placebo, in a random order, double blind cross-over design, with one week separating conditions. Fasting blood samples were collected before, and at 30, 60, and 90 minutes post ingestion and were assayed for epinephrine (EPI), norepinephrine (NE), glycerol, and free fatty acids (FFA). Area under the curve (AUC) was calculated for all variables. Gas samples were collected from 30-60 minutes post ingestion for measurement of metabolic rate. Heart rate and blood pressure were recorded at all blood collection times. Results: AUC was greater for the dietary supplement compared to the placebo for NE (1332 ± 128 pg·mL-1·90 min-1 vs. 1003 ± 133 pg·mL-1·90 min-1; p = 0.03), glycerol (44 ± 3 μg·mL-1·90 min-1 vs. 26 ± 2 μg·mL-1·90 min-1; p < 0.0001), and FFA (1.24 ± 0.17 mmol·L-1·90 min-1 vs. 0.88 ± 0.12 mmol·L-1·90 min-1; p = 0.0003). No difference between conditions was noted for EPI AUC (p 0.05). For all variables, values were highest at 90 minutes post ingestion. Total kilocalorie expenditure during the 30 minute collection period was 29.6% greater (p = 0.02) for the dietary supplement (35 ± 3 kcal) compared to placebo (27 ± 2 kcal). A condition main effect was noted for systolic blood pressure (p = 0.04), with values increasing from 117 ± 2 mmHg to 123 ± 2 mmHg with the dietary supplement, while remaining unchanged for placebo. No other hemodynamic changes were noted (p< 0.05). Conclusion: The dietary supplement results in an acute increase in plasma NE and markers of lipolysis, as well as metabolic rate. This occurs without altering hemodynamic variables in a clinically significant manner. Intervention studies to determine the impact of this dietary supplement on weight/fat loss are warranted.
AB - Background: Dietary supplements targeting fat loss and increased thermogenesis are prevalent within the sport nutrition/weight loss market. While some isolated ingredients have been reported to be efficacious when used at high dosages, in particular in animal models and/or via intravenous delivery, little objective evidence is available pertaining to the efficacy of a finished product taken by human subjects in oral form. Moreover, many ingredients function as stimulants, leading to increased hemodynamic responses. The purpose of this investigation was to determine the effects of a finished dietary supplement on plasma catecholamine concentration, markers of lipolysis, metabolic rate, and hemodynamics. Methods: Ten resistance trained men (age = 27 ± 4 yrs; BMI = 25 ± 3 kg· m-2; body fat = 9 ± 3%; mean ± SD) ingested a dietary supplement (Meltdown®, Vital Pharmaceuticals) or a placebo, in a random order, double blind cross-over design, with one week separating conditions. Fasting blood samples were collected before, and at 30, 60, and 90 minutes post ingestion and were assayed for epinephrine (EPI), norepinephrine (NE), glycerol, and free fatty acids (FFA). Area under the curve (AUC) was calculated for all variables. Gas samples were collected from 30-60 minutes post ingestion for measurement of metabolic rate. Heart rate and blood pressure were recorded at all blood collection times. Results: AUC was greater for the dietary supplement compared to the placebo for NE (1332 ± 128 pg·mL-1·90 min-1 vs. 1003 ± 133 pg·mL-1·90 min-1; p = 0.03), glycerol (44 ± 3 μg·mL-1·90 min-1 vs. 26 ± 2 μg·mL-1·90 min-1; p < 0.0001), and FFA (1.24 ± 0.17 mmol·L-1·90 min-1 vs. 0.88 ± 0.12 mmol·L-1·90 min-1; p = 0.0003). No difference between conditions was noted for EPI AUC (p 0.05). For all variables, values were highest at 90 minutes post ingestion. Total kilocalorie expenditure during the 30 minute collection period was 29.6% greater (p = 0.02) for the dietary supplement (35 ± 3 kcal) compared to placebo (27 ± 2 kcal). A condition main effect was noted for systolic blood pressure (p = 0.04), with values increasing from 117 ± 2 mmHg to 123 ± 2 mmHg with the dietary supplement, while remaining unchanged for placebo. No other hemodynamic changes were noted (p< 0.05). Conclusion: The dietary supplement results in an acute increase in plasma NE and markers of lipolysis, as well as metabolic rate. This occurs without altering hemodynamic variables in a clinically significant manner. Intervention studies to determine the impact of this dietary supplement on weight/fat loss are warranted.
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U2 - 10.1186/1550-2783-6-4
DO - 10.1186/1550-2783-6-4
M3 - Article
C2 - 19175919
AN - SCOPUS:61849140757
VL - 6
JO - Journal of the International Society of Sports Nutrition
JF - Journal of the International Society of Sports Nutrition
SN - 1550-2783
M1 - 4
ER -