The Effects of Orange Juice on Insulin Sensitivity and Plasma Lipids

This study has been completed.
Sponsor:
Collaborator:
Florida Department of Citrus
Information provided by (Responsible Party):
University of Nottingham
ClinicalTrials.gov Identifier:
NCT01201603
First received: September 13, 2010
Last updated: January 24, 2014
Last verified: January 2014
  Purpose

The aim of this study is primarily to investigate the ability of antioxidants found in orange juice (OJ) to increase the body's sensitivity to the hormone insulin. Overweight or mildly obese women, who are otherwise healthy, will be recruited. The time commitment for subjects is ~14wks. Subjects will attend the laboratory on 5 occasions after fasting from midnight. The 1st is a medical screening. Laboratory visits 2 & 5 will take ~5hrs and will be separated by 3 months, during which time subjects will consume 250ml of an orange drink (either OJ or an orange flavoured control drink) once a day. During visits 2 & 5, subjects will have a scan to assess their %body fat using a low-dose x-ray machine, and have their insulin sensitivity measured using a technique called a 'Glucose Clamp'. During the 3hr glucose clamp, subjects receive an infusion of the hormone insulin and a glucose solution directly into their blood stream, with insulin sensitivity determined from the amount of glucose required to maintain blood glucose at normal levels. In addition, a small sample of fat tissue (about the size of a haricot bean) will be taken from underneath the skin of the belly. Subjects will record their food intake for 3-days in weeks 3, 7 and 11 of consuming the drink, and come to the lab for visits 3&4 during weeks 4&8. Laboratory visits 3&4 repeat measurements taken in the 1st (screening) visit.


Condition Intervention
Insulin Resistance
Obesity
Dietary Supplement: orange juice

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Subject)
Primary Purpose: Basic Science
Official Title: The Effects of Orange Juice on Insulin Sensitivity and Plasma Lipids

Resource links provided by NLM:


Further study details as provided by University of Nottingham:

Primary Outcome Measures:
  • Insulin sensitivity ('M' value) [ Time Frame: after 3 months' intervention ] [ Designated as safety issue: No ]
    Insulin sensitivity (mg glucose disposal from the blood/kg body weight/min)calculated from glucose disposal during a hyperinsulinemic, euglycemic glucose clamp


Secondary Outcome Measures:
  • Glucose Oxidation rate [ Time Frame: after 3 months' intervention period ] [ Designated as safety issue: No ]
    Measured by ventilated hood indirect calorimetry

  • High Density Cholesterol [ Time Frame: after 3 months' intervention ] [ Designated as safety issue: No ]
    Serum HDL concentration

  • Low density cholesterol [ Time Frame: after 3 months' intervention ] [ Designated as safety issue: No ]
    Serum LDL concentration

  • Gene expression in adipose tissue [ Time Frame: after 3 months' intervention ] [ Designated as safety issue: No ]
    Expression of genes related to insulin sensitivity in adipose tissue


Enrollment: 36
Study Start Date: July 2010
Study Completion Date: November 2013
Primary Completion Date: December 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Orange Juice Dietary Supplement: orange juice
250ml of orange juice or a sugars matched orange drink
Placebo Comparator: Orange drink
Sugars matched orange drink
Dietary Supplement: orange juice
250ml of orange juice or a sugars matched orange drink

Detailed Description:

Background:

Overweight and mild obesity are associated with insulin resistance and mild elevations in lipid risk factors which are not usually sufficiently abnormal to merit treatment. Such people are encouraged to lose weight to reduce their risk of progressing to type 2 diabetes and coronary heart disease, but there is clearly a potential role for dietary modifications to maximize any potential benefit of this weight loss. Flavonoids are known to have vascular effects which might enhance substrate delivery to metabolically active tissues, and thus improve insulin sensitivity. There are many different dietary sources of flavonoids, with fruits such as apples, berries and citrus being rich sources. However, some researchers have expressed concern that a high dietary intake of 100% juice may contribute to the development of insulin resistance, obesity and the Metabolic Syndrome (Bazzano, Li et al. 2008), although this is not universally accepted (Fujioka, Greenway et al. 2006; O'Neil and Nicklas 2008). To date, there have been no studies investigating the effects of citrus fruits on indices of cardio-metabolic health in people who are presently healthy but are at risk of developing some features of the Metabolic Syndrome.

Aims:

To investigate the effects of orange juice (OJ) intake on insulin sensitivity, appetite hormones, blood pressure and plasma lipids. In addition we aim to investigate any gene expression changes associated with OJ consumption, in particular in adipose tissue.

Experimental protocol and methods:

Overweight or obese women (BMI 27-35), who are otherwise healthy, will be recruited onto the study. They will attend the 'David Greenfield Human Physiology' laboratories on 5 convenient mornings, following an overnight fast. The 1st visit is a medical screening and will involve signing a consent form, completing medical screening, food frequency and activity questionnaires, having height, weight, and hip/waist circumference measurements taken and a sample of blood taken for CBC, urea, electrolytes, LFT, TFT, glucose and insulin analysis. Subjects will then be asked to complete a 3-day diet diary for macronutrient assessment and to consume a diet providing 50% of energy as carbohydrate for 3 days prior to the 2nd laboratory visit. This 2nd visit will involve having a DEXA body composition scan, an adipose tissue biopsy and a 3-hr hyperinsulinemic, euglycemic glucose clamp. Starting on the following morning, subjects will then consume an orange drink (either OJ or a carbohydrate matched orange flavoured drink) once a day for 12 wks. A 3-day diet diary for macronutrient assessment will be recorded during wks 3,7and 11 of taking the drink, and measurements made at screening will be repeated on visits 3 and 4 which will take place in weeks 4 and 8. A standardized diet will be consumed for 3 days prior to the final laboratory visit, as before. This 5th visit will be identical to visit 2.

  Eligibility

Ages Eligible for Study:   18 Years to 55 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • pre-menopausal or post-menopausal and taking HRT
  • BMI 27-35kg/m2
  • HOMA-IR value > 1.5
  • healthy

Exclusion Criteria:

  • pregnant or breast feeding,
  • any metabolic or endocrine abnormalities,
  • clinically significant abnormalities on screening,
  • fasting glucose > 6.0mmol/l,
  • taking medication other than the contraceptive pill or HRT
  • herbal supplement use,
  • food allergies/intolerances related to the investigational product (citrus juices, fructose)
  • daily consumption of >100ml citrus juices
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01201603

Locations
United Kingdom
University of Nottingham
Nottingham, Notts, United Kingdom, NG7 2UH
Sponsors and Collaborators
University of Nottingham
Florida Department of Citrus
Investigators
Principal Investigator: Ian A Macdonald, PhD University of Nottingham
  More Information

Publications:
Responsible Party: University of Nottingham
ClinicalTrials.gov Identifier: NCT01201603     History of Changes
Other Study ID Numbers: RIS 100058
Study First Received: September 13, 2010
Last Updated: January 24, 2014
Health Authority: United Kingdom: Research Ethics Committee

Keywords provided by University of Nottingham:
Women
Orange Juice
Insulin Resistance
Obesity

Additional relevant MeSH terms:
Insulin Resistance
Obesity
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases
Overnutrition
Nutrition Disorders
Overweight
Body Weight
Signs and Symptoms
Insulin
Hypoglycemic Agents
Physiological Effects of Drugs
Pharmacologic Actions

ClinicalTrials.gov processed this record on April 23, 2014