Background

For this study, a multidisciplinary team drawing expertise from social epidemiology, public health, biochemistry, psychology, neuroscience and genetics has come together to examine the pathways between people's social circumstances, mental wellbeing, and biological markers of disease. The study is called pSoBid1 (pronounced 'so-bid') because it seeks to integrate established and new knowledge relating to the psychological, social, and biological determinants of health. The study is innovative, both in the leading-edge measurements involved and the range of perspectives being brought together to develop a more holistic understanding of the pathways to good (or bad) health.

Heart disease, diabetes, some cancers and rheumatoid arthritis are examples of the burden of ill-health that is carried disproportionately by people from poorer circumstances. Not only is the incidence of disease higher in these communities but also the nature of the problem (tumour type, severity of stroke, etc) appears to be qualitatively different (more aggresive with poorer prognosis). Whilst much of this variation can be laid at the door of classical risk factors such as smoking, physical activity, poorer diets and so on, these factors fail to account for the totality of the variation. There is some indication that activated psychological and physiological stress responses may be contributing to the higher levels of chronic diseases in less affluent communities. pSoBid seeks to identify a range of measures of these stress responses, and to examine to which they pattern according to stress in people's lives (including social circumstances as a proxy measure of chronic stress). In the longer term, such markers could be important intermediate indicators of the impact of social policy interventions on population health.

Because of the growing evidence that risk factors measured as far back as in utero (in the womb), and even between generations, may be associated with the risk of cardiovascular disease and cancer in later life, pSoBid1 is also seeking to tae account of some early life experiences.

A central theme of this work is hte concept of 'biological age' (as compared with 'chronological age'). People experiencing chronic stress will ofte have a biological age older than their chronological age. This is sometimes described as having 'more miles on the clock'. Biological ageing is the progressive impairment of biological systems over time, creating a platform for disease development. Accelerated biological ageing in linked with earlier onset of diseases associated with ageing. Two novel measures of biological ageing are being used in pSoBid1:

• Measurement of the intima-media thickness (IMT) of the carotid artery by high resolution ultrasound is now widely accepted non-invasive surrogate measure of atherosclerosis, and a reliable indicator of future risk of major coronary event. Since age is the strongest determinant of IMT, evaluation of carotid IMT as a marker of the degree of atherosclerosis and vascular ageing is one outcome measure used in pSoBid1, giving an index of the age of an individual's artery.
• Biological ageing is also being assessed at the molecular level, through measurement of telomere length. Telomeres are sequences of DNA at the end of chromosomes, and shorten slightly each time a cell divides.

A further feature that might either contribute to the poorer health associated with deprivation, or might act in a protective way, is mental state or outlook. pSoBid1 is using a range of tests of cognitive function and psychological state as a means of examining whether certain personality and other factors modify responses to stress and challenge, conferring either vulnerability or protection. The study will also deploy neuroimaging techniques with a small sub-sample of participants, to add to understanding about brain changes associated with stress.

Aim

pSoBid1 aims to explore the extent to which the syndrome of central obesity/chronic inflammation contributes to the social gradient in vascular disease and is associated with variation in mental outlook. The study is examining, among the most and least affluent communities in Glasgow:

• the relationship between markers of biological age and chronological age
• the relationships between biological ageing (as measured by IMT and telmore length) ad (i) early life and current socioeconomic status, (ii) biochemical markers of inflammation, (iii) health-related behaviours, (iv) psychological profile, (v) cognitive function and (vi) risk of vascular disease
• the relationships between chronic inflammation and (i) early life and current socioeconomic status, (ii) congitive function, (iii) psychological profile, (iv) neuroimages and (v) risk of vascular disease.

Milestones

Links

Velupillai YN, packrd CJ, Batty GD, Bezylak V, Burns H, Cavanagh J, Dean K, Ford I, McGinty A, Millar K, Sattar N, Shiels P, Tannahill C. Psychological, social and biological determinants of ill health (pSoBid): Study protocol of a population-based study. BMC Public Health 2008, 8:126
http://www.biomedcentral.com/1471-2458/8/12

Deans KA, Bezylak V, Ford I, batty GD, Burns H, Cavanagh J, de Groot E, McGinty A, Millar K, Shiels PG, Tannahill C, Velupillai VN, Sattar N, Packard CJ. Differences in atherosclerosis according to area level socioeconomic deprivation: cross sectional, population based study. British Medical Journal 2009, 339:b4170
http://www.bmj.com/cgi/reprint/339/oct27_4/b4170

pSoBid1 key messages
pSoBid1 proposal document
pSoBid1 project plan
pSoBid study flowchart
pSoBid study subjects
Maps showing study areas: distribution of practices sampled and practices inlcuded in study
pSoBid participant information booklet
Frontline Scotland programme on pSoBid1: 'The Great Health Divide'
Prof Bruce McEwen seminar
Prof Steptoe seminar
List of key references 

Contact

Prof Chris Packard
Principal Investigator, pSoBid1
Glasgow Royal Infirmary
Phone: 0141 211 4979
This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

Dr Jennifer McLean  
Public Health Programme Manager (pSoBid and GoWell)
Glasgow Centre for Population Health
Phone: 0141 287 6959

This e-mail address is being protected from spam bots, you need JavaScript enabled to view it