Mechanisms by which fruit and vegetables influence postmenopausal bone health: a randomised controlled trial in a well-characterised population

ISRCTN	ISRCTN86186352
DOI	https://doi.org/10.1186/ISRCTN86186352
Protocol serial number	FSA project number: N05043
Sponsor	Food Standards Agency (UK)
Funder	Food Standards Agency (UK)

Submission date: 04/04/2007
Registration date: 30/04/2007
Last edited: 03/05/2011

Recruitment status: No longer recruiting
Overall study status: Completed
Condition category: Musculoskeletal Diseases

Prospectively registered

Protocol

Statistical analysis plan

Results

Individual participant data

Plain English summary of protocol

Not provided at time of registration

Contact information

Dr Helen Macdonald
Scientific

Osteoporosis Research Unit
Health Sciences Building
University of Aberdeen
Osteoporosis Research Unit
Foresterhill
Aberdeen
AB25 2ZD
United Kingdom

Phone	+44 (0)1224 559001
Email	h.macdonald@abdn.ac.uk

Study information

Primary study design	Interventional
Study design	Two year placebo-controlled randomised trial (double blind for potassium citrate arms and single blind for fruit and vegetable arm).
Secondary study design	Randomised controlled trial
Scientific title
Study acronym	ADAFVT (Aberdeen Dietary Acidity, Fruit and Vegetable Trial)
Study objectives	To test whether fruit and vegetable intake reduces the acidity of a mixed diet and the requirement of bone for buffering, or provide other dietary components important for bone health.
Ethics approval(s)	Grampian Research Ethics Committee on 23/12/2002 (ref: 02/0053).
Health condition(s) or problem(s) studied	Low bone mass/risk of osteoporosis
Intervention	Minimisation criteria included key genotypes (vitamin D receptor genotype and Apolipoprotein E genotype, smoking and dietary acidity (calculated from protein to potassium ratio). Group A: potassium citrate equivalent to 900 g fruit and vegetables (55.5 mEq) Group B: potassium citrate equivalent to 300 g fruit and vegetables (18.5 mEq) Group C: 300 g of fruit and vegetables Group D: placebo Duration of treatment was two years for each treatment arm.
Intervention type	Other
Primary outcome measure(s)	1. Bone turnover markers: a. serum N-terminal Propeptide of type 1 collagen (P1NP), measured at baseline, 3, 6, 12, 18 and 24 months b. serum C-terminal telopeptide of type I collagen (CTX), measured at baseline, 3, 6, 12, 18 and 24 months c. urinary free Deoxypyridinoline cross-links (fDPD), measured at baseline, 3, 6, 12, 18 and 24 months; women also posted a fasted urine sample 6 to 8 weeks after the baseline visit
Key secondary outcome measure(s)	Bone mineral density change over two years measured by DEXA at baseline and 24 months.
Completion date	01/12/2005

Eligibility

Participant type(s)	Patient
Age group	Adult
Sex	Female
Target sample size at registration	260
Key inclusion criteria	Women aged 55 years to 65 years who had taken part in a longitudinal study (Aberdeen Prospective Osteoporosis Screening Study). Includes: 1. Otherwise healthy women taking other types of diuretics (not potassium sparing diuretics) or hypertension tablets 2. Women on thyroxine treatment provided their thyroid function is stable (as assessed by free Thyroxine [T4] and Thyroid Stimulating Hormone [TSH] levels) and their dose had not changed in the year prior to study entry
Key exclusion criteria	1. Suffering from severe disease 2. Malabsorption 3. Having difficulties swallowing tablets/capsules 4. Taking oral corticosteroids 5. On or past bisphosphonate treatment (more than a few weeks) 6. Taking Hormone Replacement Therapy (HRT) in the last six months 7. Less than five years past the menopause 8. Currently taking potassium-sparing diuretics 9. Osteoporosis diagnosed from Dual Energy X-ray Absorptiometry (DEXA) scan at baseline visit
Date of first enrolment	01/03/2003
Date of final enrolment	01/12/2005

Locations

Countries of recruitment

United Kingdom
Scotland

Study participating centre

Osteoporosis Research Unit

Aberdeen
AB25 2ZD
United Kingdom

Results and Publications

Individual participant data (IPD) Intention to share	No
IPD sharing plan summary	Not provided at time of registration
IPD sharing plan

Study outputs

Output type	Details	Date created	Date added	Peer reviewed?	Patient-facing?
Results article	results	01/08/2008		Yes	No