The Acute Effect of Protein or Carbohydrate Intake on Testosterone Levels and Food Intake in Children and Adolescent Boys

Study Overview
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Brief Summary
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The purpose of this study was to determine the effect of acute protein and glucose intake on testosterone levels measured in adolescent boys and determine whether changes in testosterone levels are associated with alterations in short-term food intake. It was hypothesized that 1) ingestion of a protein beverage would result in no change of testosterone levels whereas glucose would result in a significant decrease of testosterone levels 60 minutes after ingestion and 2) decreases of testosterone levels as a result of the glucose preload would predict food intake for boys of similar body size. The first objective was to investigate the effect of an acute protein or glucose drink on testosterone levels and the second objective was to determine whether changes of testosterone levels associate with food intake.

Official Title
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Acute Decrease in Serum Testosterone After Glucose and Protein Beverages in Adolescent Males

Conditions
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Appetitive Behavior, Pediatric Obesity

Intervention / Treatment
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* Dietary Supplement: Control
* Dietary Supplement: Glucose
* Dietary Supplement: Protein


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 9-18 years, healthy, male. Exclusion Criteria: History of prematurity, chronic illness, were taking any medications known to affect glucose homeostasis, appetite or pubertal development.

Ages Eligible for Study
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Minimum Age: 9 Years
Maximum Age: 18 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: In a randomized, crossover study, sixteen 9-18 y old males were given beverages containing either: 1) whey protein (1g/kg bodyweight), 2) glucose (1g/kg bodyweight) or a calorie-free control (C). Serum testosterone, appetite biomarkers and subjective appetite were measured prior (0) and at 20, 35 and 65 minutes after the consumption of the beverage. Food intake at an ad libitum pizza meal was assessed 20 min later (65-85min).
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Control<br> | Dietary Supplement: Control<br>* Participants were given 5 minutes to ingest the non-caloric beverage which contained 1.5ml of chocolate extract (Vanilla Food Company, Markham, Ontario, Canada) to account for the flavor differences and mixed with 500ml of water and sweetened with 0.2g sucralose (Tate & Lyle, Stoney Creek, Ontario, Canada) in order to match sweetness with the glucose beverage.<br>|
| Experimental: Glucose<br> | Dietary Supplement: Glucose<br>* Participants were given 5 minutes to ingest the beverage which contained either 1g of protein (plain whey-protein isolate; BiPro USA., Eden Prairie, Minnesota, U.S.A) per kg of bodyweight and was flavoured with 1.5ml of chocolate extract (Vanilla Food Company, Markham, Ontario, Canada) to account for the flavor differences and mixed with 500ml of water.<br>|
| Experimental: Protein<br> | Dietary Supplement: Protein<br>* Participants were given 5 minutes to ingest the beverage which contained 1g of glucose monohydrate (BioShop Canada Inc., Burlington, Ontario, Canada) per kg of bodyweight and flavoured with 1.5ml of chocolate extract (Vanilla Food Company, Markham, Ontario, Canada) to account for the flavor differences and mixed with 500ml of water.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Testosterone Change | The first blood draw was taken prior to ingesting the experimental beverage at baseline (0 minutes). Participants were then given 5 minutes to ingest the beverage, and blood was later obtained 20, 35 and 65 minutes after baseline blood draw. Units were measured in ng/dl. | 0-65 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Appetite Biomarkers- Glucose | Glucose. Units were measured in mg/dl. | 0-85 minutes | 
| Appetite Biomarkers- Glucagon-like peptide-1 | Glucagon-like peptide-1. Units were measured in pM. | 0-85 minutes | 
| Appetite Biomarkers- Active Ghrelin | Active Ghrelin. Units were measured in pg/ml. | 0-85 minutes | 
| Appetite Biomarkers- Insulin | Insulin. Units were measured in uIu/ml. | 0-85 minutes | 
| Subjective Appetite- Determination to eat | Visual Analog Scales were employed to assess subjective appetite based on the Determination to Eat. Units were measured in mm (based on a 100mm scale). | 0-85 minutes | 
| Subjective Appetite- Hunger | Visual Analog Scales were employed to assess subjective appetite based on feelings of Hunger. Units were measured in mm (based on a 100mm scale). | 0-85 minutes | 
| Subjective Appetite- Fullness | Visual Analog Scales were employed to assess subjective appetite based on feelings of FullnessUnits were measured in mm (based on a 100mm scale). | 0-85 minutes | 
| Subjective Appetite- Prospective Food Consumption | Visual Analog Scales were employed to assess subjective appetite based on Prospective Food Consumption. Units were measured in mm (based on a 100mm scale). | 0-85 minutes | 
| Food Intake | Participants were provided an ad libitum pizza meal. The participants were instructed to eat during the next 20 min until they were comfortably full. Based on the participant preferences determined during screening, two varieties of Deep 'N Delicious 5-inch-diameter pizza were provided for consumption; pepperoni and three-cheese pizzas (McCain Canada Ltd., Florenceville, Ontario, Canada). Units were measuring in kcal. | 65-85 minutes | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Testosterone, Food Intake, Appetite