Social Determinants of Health
Date: July 11 2020
Summary: The comprehensive inception of social determinants in healthcare and society
Keywords: ##bibliography ##publichealth ##anthropology ##health #social #determinants #society #archive
Bibliography
M. Marmot and R. Wilkinson, Social Determinants of Health, 2nd ed. Oxford University Press, 2006.
Table of Contents
Poverty of material conditions alone does not explain a biological explanation for causes of impaired lifespans.
It is historically noted that there is a general shortage of randomized control trials to determine the utility of interventions in all areas of public health. DIscussion about the lack of controlled trials in public health pertaining to the social determinants area and the field of public health in general.
James Lind is rightly acknowledged as an exceptional public health figure because as early as the 18th century he conducted controlled investigations to show citrus fruit cured scurvy. By contrast, John Snow’s determination in the 19th century that ingestion of contaminated water led to cholera, relied on careful observation and the exercise of reasoned judgement rather than his uncontrolled experiment of removing the handle of the Broad Street pump.
When approaching the area of social determinants, risk factors were first separated from behaviours and biological markers.
Causes of the causes can be thought of as the underlying issues that give rise or is directly related to a given issue.
Second method of approach by Marmot to examine the social determinants of health. To give an example: "It is not an accident that people consume diets high in saturated fat and salt. It represents the nature of the food supply, culture, affordability, and availability, among other influences."
The psychosocial understanding of the social determinants of health emphasizes experiential personal accounts. Negative accounts which induce acute and chronic stress affect human biology. This ultimately leads to impairment of physical and mental health.
The social gradient of health goes from the high echelons of society to those living in dire conditions. Each step down this hierarchy also lowers standards of health.
The Fallacy of Diseases of the Rich and Poor
There existed the notion that there were diseases of the rich and of the poor. Mortality rate reflected this belief. However, this was false.
The impoverished are not the only ones to anguish. An example being that despite civil servants being economically well-off, it was found there was an inverse relationship between employment grade and risk for causes of death.
Stress does not only affect senior managers or others in positions of great public responsibility. High effort linked to high reward is generally health promoting. [1] Poor health is seen where there is limited, real or perceived, control over a situation with a small chance of reward where the situation is psychologically demanding during an extended period of time. [2]
Recent research suggests that infectionand immunity may also be important in two poorly recognized ways
A contributory cause of diseases not previously considered to be due to infection
Chronic stress may alter susceptibility to infection and its severity.
The Fight Or Flight Response and Its Role in Disease
The fight or flight response is brief and rather unusual for animals. The response can be vital for an animal's survival. For humans, emergencies are comparatively rare. However, for people, regular psychological demands and challenges may activate the fight or flight response too often.
Fight-or-flight adapts well to acute stress but may not to chronic stress in today’s urban environment. [4]
Prolonged elevated cortisol amounts can manifest paranoia or depression.
Sympatho-Adrenal Pathway
Heart rate is directly impacted by sympathetic nerve impulses. It is indirectly affected by circulating adrenaline level.
Increased "stickiness" in platelets occurs due to increases in adrenaline in the blood. Blood tends to become more concentrated and viscous at the same time. Stress-related hormones can increase the output of fibrinogen from the liver. This may add to formation of arterial plaques and increased risks of heart disease and stroke [5], [6]
The sympatho-adrenal pathway activates, prepares for, or maintains physical exertion. It causes psychological arousal and energy mobilization. It inhibits functions irrelevant to immediatesurvival. Degree of activation depends on stressorand its duration. Thesympatho-adrenal pathway can be switched off rapidly.
The first pathway is the sympatho-adrenal pathway and activates quickly. It consists of the sympathetic branch of the autonomic nervous system. The pathway produces two hormones:
Noradrenaline at nerve endings
Adrenaline directly into the bloodstream by the medulla (or middle part) of the adrenal glands.
This produces the sensation of our stomach tightening when being exposed to sudden shock.
Hypothalamus-Pituitary-Adrenal (HPA) Axis
Figure from Chapter 2 of [7]
The Hypothalamus-Pituitary-Adrenal (HPA) Axis operates over minutes and hours. Its key components are the three corresponding hormone secreting glands. The Hypothalamic-Pituitary-Adrenal (HPA) axis is the slower, seconday response to stress. It results in cortisol release into the bloodstream from adrenal glands. The dotted lines show feedback controls which regulate release of cortisol and other corticosteroids from the adrenal cortex.
Effects
Circulating adrenaline and sympathetic nerve activity generated during the Fight or Flight response:
Accelerate heart rate
Increase metabolic rate
Increase blood pressure
Increase sensory vigilance
Increase sweat secretion
Dilate pupils
Dilate airways
Dilate blood vessels in skeletal muscles
Constrict blood vessels in skin and gut
Inhibit salivation
Glucocorticoid hormones, like cortisol, have metabolic and psychological effects. These hormones are vital to upkeep and regulation of resting and stress-related metabolic functions.
In emergency situations, glucocorticoid hormones are antagonistic to the insulin hormone, resulting in the mobilization of energy reserves via elevation of blood glucose and fatty acid release from fat tissues. This is very desirable in emergencies.
However, in non-emergencies, unneeded energy that can be released tends to increase output into the blood of cholesterol-carrying particles from the liver.
Overall Response to Stress
Shown are idealized representations of neuroendocrine and metabolic activity in the presence of stress. ( a ) depicts rapid baseline recovery as responsive and flexible ( b ) illustrates a slow recovery but an eventual delayed return to baseline ( c ) shows a weak reaction with an elevated baseline alongside a small response.
If a stress response is activated too regularly, feedback controls within the neuroendocrine system could reset one's baseline to a new elevated and potentially health-damaging level driven by environmental factors [8], [9]
Image from [7]
How the brain, HPA axis, and immunesystem communicate with one another. The brain perceives cognitive stimuli. This perception can influence immune function via neuropeptides, the ANS, and the HPA axis. The immune system responds to non-cognitive stimuli. Examples of non-cognitive stimuli are infection and tumour growth. Cytokines and peptidehormones are secreted which affect the brain and neuroendocrine system. RQ: ASD dysregulation of cytokines are directly impacted by the interference COVID19 thus further complicating response in the HPA axis.
Social Effects on Well-Being
Further, the balance of influences on health depends on geographical location and historical circumstances of the population in question.
This generalized diagram includes circumstances beyond individual control as well as personal situations. From the top left to the bottom right, there is a clear chain of influence between social structure and well-being.
Given the correct information, a similar pictogram could be made for each category of disease.
Current thoughts about everything which can impact overall well-being.
The social and cultural environment and organization of work are current factors in consideration in public policy. Psychological and biological factors are latent causes of disease. These tend to be the main focus of medical attention. In reality, these factors are intermediates on the pathway from social position to an individual's state of health. [10]
Social structure affects an individual via three primary influences:
Material circumstances are related to health directly through one's social and work environment.
Material circumstances then impacts psychological factors and health-related behaviours.
Early life experiences, cultural, and genetic factors also exert influences on health.
One example is a study of children at orphanages:
Under the same food conditions, children in the ‘Bienenhaus' orphanage under the control of a stern Fraülein Schwarz, gained less weight and grew slowly. This opposite to children under the care of the affectionate Fraülein Grün at the ‘Vogelnest' orphanage. Schwarz replaced Grün during the study at ‘Vogelnest' and growth rates were subsequently reversed. This controlled cross-over study provides evidence that adverse psychosocial circumstances in childhood can influence growth. [11]
How To Cite
Zelko, Jacob. Social Determinants of Health. https://jacobzelko.com/07112020161337-social-determinants-health. July 11 2020.
References
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[3] P. Vallance and J. Collier, “Infection, inflammation, and infarction: Does acute endothelial dysfunction provide a link?” The Lancet, vol. 349, no. 9062, pp. 1391–1392, 1997.
[4] R. M. Sapolsky, “Endocrinology alfresco: Psychoendocrine studies of wild baboons,” in Recent progress in hormone research, Elsevier, 1993, pp. 437–468.
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[7] R. Brown, R. E. Brown, and R. E. Brown, An introduction to neuroendocrinology. Cambridge University Press, 1994.
[8] A. Steptoe and M. Marmot, “The role of psychobiological pathways in socio-economic inequalities in cardiovascular disease risk,” Eur. Heart J., vol. 23, no. 1, pp. 13–25, 2002.
[9] A. Steptoe, P. J. Feldman, S. Kunz, N. Owen, G. Willemsen, and M. Marmot, “Stress responsivity and socioeconomic status. A mechanism for increased cardiovascular disease risk?” Eur. Heart J., vol. 23, no. 22, pp. 1757–1763, 2002.
[10] D. Blane, E. Brunner, and R. Wilkinson, “The evolution of public health policy,” Health Soc. Organ. Health Policy 21st Century, p. 1, 2002.
[11] E. Widdowson and R. McCance, “A review: New thoughts on growth,” Pediatr. Res., vol. 9, no. 3, pp. 154–156, 1975.