BRHS 20 Year Follow up Survey 1998-2000

The BRHS participants, who attended for the physical examination in 1998-2000, were given the BRHS Q20 main 20 year follow -up survey 1998-2000 (sometimes referred to as the blue or main questionnaire) to complete.

BRHS Q20 Main 20 year follow-up survey questionnaire 1998-2000

The participants were asked to complete the questionnaire while waiting to begin their physical examination (see section 2.2.2 BRHS Q20 Physical examination protocol 1998-2000)

Open ended questions included in the questionnaire were coded using a coding protocol

4252 men completed the questionnaire.

Q20 Survey- Physical assessment

The measurements from the physical examination, carried out in 1998-2000, were recorded onto a data collection form/ datasheet by a team of three trained research nurses who followed a measurement procedures protocol in carrying out the physical examination.

Q20 Electrocardiography

During their physical examination in 1998-2000(Q20) the BRHS participants underwent a resting 12-lead electrocardiogram (ECG) using a Siemens Sicard 460 instrument. The ECG test involved attaching a number of small, sticky sensors called electrodes to the participant’s arms, legs and chest. These were connected by wires to an ECG recording machine. The ECG recordings were analysed at the University of Glasgow using the Minnesota Coding Classification system which utilizes a defined set of measurement rules to assign specific numerical codes according to severity of ECG findings. ECG Protocol

Q20 Physical Activity & Diet Questionnaire

Prior to the 1998-2000 physical examination the BRHS participants were sent a self-administered Physical Activity and Diet questionnaire (sometimes referred to as the “yellow Questionnaire”), which aimed to provide detailed information on their diet and physical activity patterns.

This questionnaire also asks about participant’s birthweight and the birthweight of their children.

The coding protocol is available.

4582 men completed the questionnaire.

Q20 Blood biomarkers

Fasting blood samples

At the physical examination in 1998-2000 (Q20), the BRHS study participants were asked to fast for a minimum of 6 hours, during which they were instructed to drink only water and to attend for measurement at a prespecified time between 0800 and 1800 h. All men were asked to provide a blood sample, collected using the Sarstedt Monovette system. The samples were frozen and stored at −20°C on the day of collection and transferred in batches for storage at −70 ^oC until analysis, performed after no >1 freeze-thaw cycle. Q20 Biomarkers

The blood sampling procedure is described in section 4.2.6 of the BRHS Q20 Physical examination protocol 1998-2000.

The handling of the blood samples is decribed in (sections 5.1 to 5.5) of the BRHS Q20 Physical examination protocol 1998-2000.

Q20 Metabolite data

Q20 Metabolite data details

Methods

A high‐throughput serum nuclear magnetic resonance (NMR) metabolomics platform was used to quantify >200 metabolite markers from unthawed serum samples that represent a broad molecular signature of systemic metabolism metabolic markers, The metabolites were measured in a single experimental setup that allows for the simultaneous quantification of fatty acid composition (including monounsaturated fatty acids , saturated fatty acids, and polyunsaturated fatty acids, lipoprotein subclasses, α‐1 acid glycoprotein, amino acids, glycolysis‐related measures, and ketone bodies (Nightingale Health Ltd., Helsinki, Finland). Applications of this high-throughput platform have been described elsewhere [1,2.3]

1. Soininen P, Kangas AJ, Wurtz P, Tukiainen T, Tynkkynen T, Laatikainen R. High‐throughput serum NMR metabonomics for cost‐effective holistic studies on systemic metabolism. Analyst. 2009;134:1781–1785.

2. Soininen P, Kangas AJ, Wurtz P, Suna T, Ala‐Korpela M. Quantitative serum nuclear magnetic resonance metabolomics in cardiovascular epidemiology and genetics. Circ Cardiovasc Genet. 2015;8:192–206.

3. Wurtz P, Kangas AJ, Soininen P, Lawlor DA, Davey Smith G, Ala‐Korpela M. Quantitative serum nuclear magnetic resonance metabolomics in large‐scale epidemiology: a primer on ‐omic technologies. Am J Epidemiol. 2017;186:1084–1096.

Q20 derived and adjusted variables

A number of key variables were derived by BRHS researchers working with the BRHS data. These variables have been shared and widely used by other researchers working with the BRHS data. Some of the physiological measurements were adjusted for observer error and a number of blood markers were adjusted for the participant’s fasting duration.

A number of key variables were derived by BRHS researchers working with the BRHS data collected in 1998-2000 (Q20). These are variables that were created by calculating or categorising new variables using existing BRHS data. These variables have been shared and widely used by other researchers working with the BRHS data.

Available Q20 derived and adjusted variables

External data linked to Q20 BRHS data

Air pollution exposure and Climate data have been linked to BRHS data

Air pollution exposure data