Investigating the Effects of Beta-Hydroxy-Beta-Methylbutyrate on Glucose Handling in Older and Younger Men.

Study Overview
=================
Brief Summary
-----------------
This study intends to examine the effect of a commercially available nutritional supplement, Beta-hydroxy-beta-methylbutyrate(HMB) on whole-body responses to a sugar load.

Detailed Description
-----------------
One change associated with human aging is a reduction in fitness, both in terms of how far or quickly a person can run/cycle/swim and also in how well their blood vessels work. Additionally a person's metabolic fitness decreases; this is how well the body copes with nutrition and is why, for example, older people have a higher risk of diseases like type 2 diabetes. Previous studies have shown that as people become less fit, they are at increased risk of suffering a complication whilst undergoing surgery. It has also been shown that measuring how fit someone is, is better at predicting the risk of a surgical complication than purely using a person's age alone. Lots of research has shown that exercise can potentially reverse some of the age-related declines in fitness, however most has used long sessions of continuous exercise over a long period of time. High-intensity interval training (HIT), whereby people cycle on an exercise bike very hard for a minute, followed by a short rest, repeated over the course of 15 minutes can rapidly improve a person's fitness. However not everyone will be able to, or indeed want to participate in exercise this strenuous; therefore this research seeks to explore whether other options, such as dietary supplements can improve aspects of fitness This study intends to examine the effect of giving a dietary supplement on the way a person's body handles the glucose (from carbohydrates/ sugars) in a meal. Previous work has shown that taking a beta-hydroxy beta-methyl butyrate (HMB) supplement may improve may improve a patient's response to glucose, however the evidence is not clear. HMB is a commercially available nutritional supplement providing a compound that the body produces each time protein is consumed, and is most commonly used by bodybuilders to help gain muscle.

Official Title
-----------------
Investigating the Effects of Beta-Hydroxy-Beta-Methylbutyrate on Glucose Handling in Older and Younger Men.

Conditions
-----------------
Insulin Resistance, Age Problems

Intervention / Treatment
-----------------
* Dietary Supplement: Beta-Hydroxy-Beta-Methylbutyrate
* Other: Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Healthy volunteers Aged 18-35 or 65-85 Male Exclusion Criteria: Current participation in a formal exercise regime A BMI < 18 or > 32 kg·m2 Active cardiovascular disease: o uncontrolled hypertension (BP > 160/100), angina, heart failure (class III/IV), Significant arrhythmia, right to left cardiac shunt, recent cardiac event Taking beta-adrenergic blocking agents, Cerebrovascular disease: o previous stroke, aneurysm (large vessel or intracranial), epilepsy Respiratory disease including: o pulmonary hypertension, significant COPD, uncontrolled asthma, Metabolic disease: o hyper and hypo parathyroidism, untreated hyper and hypothyroidism, Cushing's disease, type 1 or 2 diabetes Active inflammatory bowel or renal disease Malignancy Clotting dysfunction Significant musculoskeletal or neurological disorders Family history of early (<55y) death from cardiovascular disease

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 85 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Older Men<br>Healthy male adults aged 18-35 Subjects will receive both HMB and placebo on separate visits in a crossover fashion | Dietary Supplement: Beta-Hydroxy-Beta-Methylbutyrate<br> <br> * Other names: HMB;Other: Placebo<br> <br> |
| Experimental: Younger Men<br>Healthy male adults aged 65-85 Subjects will receive both HMB and placebo on separate visits in a crossover fashion | Dietary Supplement: Beta-Hydroxy-Beta-Methylbutyrate<br> <br> * Other names: HMB;Other: Placebo<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Matsuda Index of insulin sensitivity | Assessed from arterialised venous blood samples | 180 minutes after a 75g oral glucose load | 
| Cederholm index of insulin sensitivity | Assessed from arterialised venous blood samples | 180 minutes after a 75g oral glucose load | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area-Under-Curve Glucose Concentration | Assessed from arterialised venous blood samples | 180 minutes after a 75g oral glucose load | 
| Area-Under-Curve Insulin Concentration | Assessed from arterialised venous blood samples | 180 minutes after a 75g oral glucose load | 
| Femoral Artery Blood flow | Assessed using duplex ultrasonography of the superficial femoral artery of the right leg | 15 minutes, 60 minutes and 120 minutes after a 75g oral glucose load |