Disease causation definitions Flashcards
Epidemiological paradigms
frameworks or theories for explaining or guiding how we address patterns of disease
Programming approach
considers long term effects of environmental exposures during critical periods of development
The critical period model
assumes that certain exposures during specific periods will have a lasting effect on organ structure or function
Barker hypothesis
origins of chronic disease in adult life lie in foetal responses to intrauterine environment
Adult risk factor approach
considers the impact of lifestyle and behaviours on the onset and development of chronic disease
Life course model
combines the adult risk factor and programming models and considers how various social and biological factors throughout gestation and life can affect health and disease later in life. These factors may act independently
Health protection
The protection of individuals
Prevention
the practice of keeping people healthy and reducing the risk of illness
Health promotion
the process of enabling people to increase control over
Autosomal chromosomes
non-sex chromosomes. There are 23 pairs of chromosomes
Codon
a group of three DNA bases (A
Exon
protein encoding sections of the genome (only about 2%)
Allele
a for of a gene. Everyone inherits two alleles for each gene (one from each parent). The full set of alleles someone possesses is their genotype. How this is expressed is their phenotype - is it that of the dominant allele.
Epigenetics
alterations to how the genome is expressed which do not involve changes to the genome e.g. DNA methylation
Multifactorial diseases
have genetic and environmental factors. The presence of a genetic variant might increase risk of a disease but does not cause disease on its own - the interaction with environmental exposures causes disease (e.g. infections
Single gene disorder/mendelian disease
caused by a single faulty gene
Autosomal domination
e.g. Huntington’s disease
Autosomal recessive
people can be asymptomatic carriers (e.g. cystic fibrosis
X- linked recessive
more likely to occur in men as they only require one copy of the gene e.g. haemophilia
X-linked dominant
very rare
Y-linked
very rare
Mitochondrial genetic disorders
(non-mendelian
Chromosomal disorders
caused by a difference in the number of chromosomes (numerical disorders e.g. downs syndrome) or structural abnormalities (Charcot-Marie-tooth)
Polygenic disorders
several gene variants increase risk of developing disease. Non-mendelian inheritance. Complex inheritance and interaction patterns between different variants of disease + interaction with the environment.
Penetrance
the proportion of people who possess a genetic mutation who express it in their phenotype i.e. have signs and symptoms of disease. E.g. Huntington’s disease has 100% penetrance so all those who have the disease allele will have the disease.
Pharmacogenomics
uses individuals’ genetics to understand relative effectiveness of different pharmaceutical treatments
Genetic testing
can be predictive (identify whether someone has a genetic variant that may increase their risk of developing a condition in the future) or individual carrier testing (identify whether someone is an asymptomatic carrier of a genetic variant). Predictive testing likely to increase as our understanding of genetic components of disease and disease aetiology improves. allows targeted screening
Nutritional surveillance
the continuous monitoring of a population’s nutritional status and dietary intake. Uses food supply data (production
Malnutrition
refers to deficiencies
Marasmus
a severe form of malnutrition that occurs when the body doesn’t have enough calories
Anthropometry
way of assessing nutritional status by assessing body composition (e.g. BMI
Indices of malnutrition
can be used to screen for nutritional deficiencies
Biochemical test
(urinary sodium
Bioelectrical impendance analysis
measures body composition
Imaging
e.g. MRI
Food consumption surveys
(food diaries
Dietary guidelines
aimed at individuals to promote healthy eating. E.g. 5 fruit and veg a day
Dietary reference values
a set of values that indicate the amount of nutrients a healthy person needs to consume to maintain their health. DRVs are used in nutrition recommendations
Estimated average requirements (EAR)
average daily nutrient intake for a group of people - it is enough to meet the requirements of 50% of healthy individuals at a particular life stage/gender
Reference nutrient intake
amount of a nutrient that is needed by 97.5% of individuals in the group of interest
Lower reference nutrient intake
the amount of nutrients that is enough only to meet the needs of a few individuals with low requirements (2.5%)
Safe intake
used when there is not enough information for EAR or RNI. It is the intake considered safe for most people.
Sources of evidence
major cohort studies - UK Biobank
Western diet
high in processed foods
South Asian diet
Rich in fibre and plant-based proteins
Mediterranean diet
whole foods
Environmental determinants of health
factors which affect health outcomes. They include global factors (climate change
Environmental Health
is concerned with all aspects of the natural and built environment that may affect human health i.e. physical
Environmental justice
the notion of equity and justice in relation to environmental exposures and related health burdens borne by groups. Without environmental justice
Hazard
a factor which can cause harm to health.
Chemical
heavy metals (lead)
Biological
infectious diseases
Physical
extreme weather (floods
Living and work conditions
work
Global factors
climate change
Risk
likelihood of occurrence x size of impact
Exposure
degree of contact with a hazardous agent
Dose
total amount of a substance or agent taken up by
Dose-response
the relationship between the dose of substance and the resulting changes in body function or health.
Exposure assessment
is the process of finding out how people come into contact with a hazardous agent
Risk management
estimating the risk to individuals/populations from a hazard and seeking to minimise the likelihood of exposure and/or the size of the impact.
Risk characterisation
estimating the occurrence of adverse health effects in a population and identifying who might be at risk.
Risk assessment
systematic examination of potential hazards that could cause harm to people. The goal is to identify and mitigate risks to health and safety.
Process involves:
Hazard identification (think: physical, biological/microbiological, chemical, mechanical/infrastructure, psychological),
Dose response assessment ,
Exposure assessment,
Risk characterisation,
Risk management (ECCM+L) - Evaluation (compare hazard levels against known standards) Communication Control (source, pathway, receptor, secondary prevention), Monitoring (surveillance, detection systems), Lessons
