Are vitamins B12 causally related to cardiometabolic risk factors and disease?
| ISRCTN | ISRCTN47414943 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN47414943 |
| Protocol serial number | 123 |
| Sponsor | Oslo University Hospital |
| Funder | Helse Sør-Øst RHF |
- Submission date
- 15/11/2017
- Registration date
- 17/11/2017
- Last edited
- 10/07/2018
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Circulatory System
Plain English summary of protocol
Background and study aims
Low serum levels of vitamin B12 (vB12) have been associated with increased body mass index (BMI) and with increased cardiometabolic outcomes (risk of having diabetes, heart disease or stroke) in several studies. However, it is unclear what the relationship is between vB12 to cardiometabolic risk factors and diseases. This study aims to investigate if there is a relationship between vB12 and indicators of body fat, lipid and glucose (sugar) levels, type 2 diabetes (a condition where blood sugar levels become uncontrolled) and cardiovascular disease (diseases that involve the heart or blood vessels).
Who can participate?
Those who have participants in a previous genome-wide association study (GWAS)
What does the study involve?
This study uses information from a previous genome-wide associate study (GWAS). The researchers take information about serum levels of vB12. The researchers analyse the relationship between vB12 and cardiometabolic risk factors and diseases using publicly available GWAS summary statistics for 15 outcomes.
What are the possible benefits and risks of participating?
There are no benefits or risks of participation
Where is the study run from?
Oslo University Hospital (Norway)
When is the study starting and how long is it expected to run for?
March 2017 to October 2017
Who is funding the study?
Southern and Eastern Norway Regional Health Authority (Norway)
Who is the main contact?
Ms Gunn-Helen Moen
g.h.o.moen@studmed.uio.no
Contact information
Scientific
Oslo University Hospital
Oslo Universitetssykehus, Aker
Trondheimsveien 235
Oslo
0586
Norway
 ORCID ID |
0000-0002-8768-0904 |
|---|---|
| Phone | +47 (0)480 20554 |
| g.h.o.moen@studmed.uio.no |
Study information
| Primary study design | Observational |
|---|---|
| Study design | Observational cohort study |
| Secondary study design | Cohort study |
| Study type | Participant information sheet |
| Scientific title | Are serum levels of vitamin B12 causally related to cardiometabolic risk factors and disease? A Mendelian randomisation study |
| Study objectives | Is there a causal relationship between vB12 and indicators of body fat, lipid- and glucose parameters, T2D and cardiovascular disease? |
| Ethics approval(s) | Each of the studies used in this project have their own ethical approval and only publicly available data is used |
| Health condition(s) or problem(s) studied | The effect of vitamin B12 on cardiometabolic outcomes |
| Intervention | 11 single nucleotide polymorphisms (SNPs) robustly associated with serum levels of vB12 in a previous genome-wide association study (GWAS) of 45 576 individuals are selected. We performed two sample MR analyses of the relationship between vB12 and cardiometabolic risk factors and diseases using publicly available GWAS summary statistics for 15 outcomes in up to 339224 individuals. Robustness of results is tested with sensitivity analyses using MR Egger regression and Weighted Median estimation, and by performing additional analyses excluding a variant in the FUT2 gene which may be pleiotropic. This data is taken from publically available summary statistics – which means information regarding genotype/SNP, effect SNP, effect size, standard error, p-values, minor allele frequency etc that is available online. Summary results statistics on the same SNPs from 15 different GWAS of cardiometabolic outcomes are also taken. The cardiometabolic outcomes are selected on the basis of the following inclusion criteria: the outcome having been associated with vB12 level in observational epidemiological studies and the availability of large meta-GWAS analyses with publicly available summary statistics on the outcome. |
| Intervention type | Genetic |
| Primary outcome measure(s) |
1. Fasting glucose is measured using genetic data from available GWAS |
| Key secondary outcome measure(s) |
There are no secondary outcome measures |
| Completion date | 15/10/2017 |
Eligibility
| Participant type(s) | Other |
|---|---|
| Age group | Adult |
| Sex | All |
| Target sample size at registration | 45000 |
| Key inclusion criteria | Participants in the previous genome-wide association study (GWAS) |
| Key exclusion criteria | There is no participant exclusion criteria |
| Date of first enrolment | 15/04/2017 |
| Date of final enrolment | 29/07/2017 |
Locations
Countries of recruitment
- Norway
Study participating centre
Trondheimsveien 235
Oslo
0478
Norway
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan summary | Available on request |
| IPD sharing plan | All data are already publically available. The trialists will include a protocol of how they extracted the data in the publication. |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Results article | results | 01/08/2018 | Yes | No | |
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
10/07/2018: Publication reference added.
23/11/2017: Internal review.
