Measurements from the Alpha Omega Cohort

At baseline (2002-2006), patients were examined by trained research nurses, either at home or in the hospital. The nurses measured height, body weight, waist circumference and blood pressure. Blood samples were taken. Self-administered questionnaires were used to collect data on disease history, current health, medication use, dietary pattern, physical activity, smoking pattern and alcohol consumption.

Interviews and blood samples

We have a collection of blood samples that have been analyzed for the measurement of glucose, total cholesterol, HDL cholesterol, triglycerides and the fatty acid composition of cholesteryl esters. In addition to that, we have the processed annual telephone interviews that were done to collect data on health status and medication use.

Follow-up for morbidity and mortality

Follow-up for vital status and cause-specific mortality is ongoing. Data are obtained from the Dutch National Mortality Registry (Statistics Netherlands). One patient was lost to follow-up and censored after 2.9 y.

Fatal events were coded according to the International Classification of Diseases, 10th Revision, combining primary and secondary causes of death. CVD mortality included IHD (codes I20–I25), cardiac arrest (I46), heart failure (I50), stroke (I60–I69), and sudden death, undefined (R96). IHD mortality included codes I20–I25, I46, and R96.

The benefits of a large-scale trial:

The primary purpose of large-scale trials is to test hypotheses without the potential confounding that so often limits the interpretation of results of observational prospective cohort studies. Moreover, the data from large-scale trials can also be used for observational research. In the Alpha Omega Trial the patients were included between May 2002 and December 2006. The data can be used to study trends in cardiovascular risk management and risk factors at the population level. It is also possible to study cross-sectional and prospective associations of diet and lifestyle with risk factors, biomarkers and indicators of health.

Data collection

Download our questionnaires and data dictionaries, or find the tables below for an overview of our measurements.

Questionnaires (in Dutch)
Data dictionaries
MeasurementsVariable
DemographicsSex
Age
Marital status
Socioeconomic statusEducational level
Adherence to the protocolTreatment group
Compliance
Margarine use
MeasurementsVariable
Smoking
Alcohol use
Physical activityPhysical Activity (PASE)
General health Self-rated health
Weight loss and gain
Kidney function (eGFR)
Prescribed diet
History of:Hypertension
Stroke
Aneurysm
Diabetes
Cancer
Family history of:Myocardial infarction
Diabetes
Medication useCoded according to ATC classification index 2009
SupplementsVitamin pills and food supplements
Questions for female subjectsAge at menarche and menopause
Former use of oral contraception
Physical examinationWeight, height, waist
Blood pressure and heart rate

Baseline n=4837
20m follow-up n=810
40m follow-up n=4278

MeasurementsVariableTime pointN
Cognitive functioningMMSE (Mini-Mental State Examination)Baseline
20m follow-up
40m follow-up
4837
810
2530
Depression / optimismDepressive symptoms (GDS-15)Baseline
20m follow-up
40m follow-up
791
809
4155
Dispositional optimism (LOT-R and 4Q)Baseline
20m follow-up
40m follow-up
791
809
4155

Blood collection

VariableTime pointN
Serum, plasmaBaseline
20m follow-up
40m follow-up
4785
810
2503
Red blood cellsBaseline
40m follow-up
3956
97
DNAWhole genome genotypingBaseline4785
Date and time blood collectionHours fasting

Blood parameters

VariableTime pointN
Serum lipidsTotal cholesterolBaseline
20m follow-up
40m follow-up
4837
810
2530
HDL cholesterol
LDL cholesterol
Triglycerides
GlucoseBaseline
20m follow-up
40m follow-up
4837
810
2530
Plasma fatty acid profilesBaseline
20m follow-up
40m follow-up
4746
795
1267
BiomarkersPSABaseline
20m follow-up
40m follow-up
1622

1622
TestosteroneBaseline
20m follow-up
40m follow-up
1900

1900
pro-BNPBaseline
20m follow-up
40m follow-up
1375

643
Creatinine, CRP, Cystatin-CBaseline
20m follow-up
40m follow-up
4650

2468
FGF-23, PhosphateBaseline
20m follow-up
40m follow-up
490

490
MeasurementsVariable
 203-item FFQFoods
 Nutrients
Bioactives
Diet scores

Baseline n=4384
20m follow-up n=738
40m follow-up n=2233

MeasurementsVariable
Fatal events
Continuous follow-up
Cause of deathICD-10
Non-fatal events
40 m follow-up
MI
Stroke
Cardiac arrest
Cardiac interventionsPCI
CABG
ICD placement
 Diabetes