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Effect of Dietary Conjugated Linoleic Acid (CLA) on Parathyroid Hormone in Men

NCT00608400 · Status: COMPLETED · Phase: PHASE1 · Type: INTERVENTIONAL · Enrollment: 55

Last updated 2012-03-02

No results posted yet for this study

Summary

The parathyroid gland and its hormone have a major impact on the endocrine control of bone metabolism and mineralization and parathyroid hormone (PTH) has been identified in some epidemiological reports to relate adversely to mortality. Previously, the applicant has demonstrated in two models that dietary cis-9, trans-11 conjugated linoleic acid (CLA) reduces PTH by over 30% in as little as 4 weeks in male rats without adversely affecting bone density. Both bioactive PTH and intact PTH assays have been used and both are reduced by CLA. In one rat model, rats had normal PTH and a sub-group had high PTH due to chronic renal disease. In the second study, the rats were healthy young males and females. Regardless of the model and health state, PTH was reduced 30 to 40% by CLA. Of interest, other isoforms of CLA such as trans-10, cis-12 CLA do not alone result in reduced PTH. The selected CLA isomer proven to reduce PTH, cis-9, trans 11 CLA, is common to food products such as milk fat and beef and is thus more physiologically relevant to the human diet. The global objective of this study is to, for the first time; assess the effects of CLA on PTH in humans, specifically men.

Healthy men 19-53 years of age are selected since bone mass will have reached a peak by this age. Beginning with healthy relatively young men is important versus aging or ill individuals since the effect of CLA on PTH has not been examined and aging and illness might confound the results.

Subjects will be recruited using posters and local newspaper advertisements from the general population. Men (n=30/group) with healthy weights will be randomized to receive 0, 1.5 or 3 g CLA/d for a period of 4 months. At baseline, body weight will be assessed along with whole body bone, lean and fat mass using dual energy x-ray absorptiometry (DXA). Regional bone mass (lumbar spine, total hip, femoral neck) will also be examined using DXA. A blood sample will be taken in the fasted state between 9:00 and 10:00 to examine PTH, ionized Ca, and biomarkers of bone metabolism. After each 1 month on the study, the measurements will be repeated until end of study.

Dietary intake will be monitored along with a survey for possible mild side-effects such as gastrointestinal discomfort. Data will be examined using a mixed model for random (age, weight, vitamin D status) and fixed effects (diet, time) with post-hoc comparisons using Bonferroni correction.

Conditions

  • Healthy

Interventions

DIETARY_SUPPLEMENT

Clarinol CLA

0, 1.5 or 3.0 g/d dietary conjugated linoleic acids glycerides for 4 months, capsule form

Sponsors & Collaborators

Principal Investigators

  • Hope A Weiler, PhD · McGill University

Study Design

Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
QUADRUPLE
Model
PARALLEL

Eligibility

Min Age
19 Years
Max Age
53 Years
Sex
MALE
Healthy Volunteers
Yes

Timeline & Regulatory

Start
2008-12-31
Primary Completion
2011-03-31
Completion
2011-12-31

Countries

  • Canada

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00608400 on ClinicalTrials.gov