Non-communicable diseases (NCD)

Week 6

Define what non-communicable diseases (NCD) are

Diseases that are non-communicable - meaning that the disease is not transmittable from one person to another.

Sometimes referred to as silent diseases as there are no clear signs of the developing the disease. Typically first discovered when the disease is presents - especially in low-income countries where they do not screen.

Many NCDs are chronic - but not all!

This include a wide range of diseases!

• external causes: injuries, poisonings ect.

• Mental disorders - also including dementia

• Systemic diseases: diabetes, cancer, CVD, kidney and respiratory diseases

What are the four main NCDs?

1. hypertension and other cardiovascular diseases (CVDs)

2. cancers

3. Chronic respiratory diseases

4. Diabetes

What is a communicable disease?

Infections - A disease that can be transmitted from one person to another.

Those where disease is directly due to the action of a communicable agent.

Explain the epidemiologic transition - regarding motality rates between the infectious and chronic diseases

Motality rates of infectious diseases decrease and chronic disease motality rates increase.

But it is important to remember that these two interact. Bidirectional connections can be seen between many infections and NCDs - meaning that one can cause the other in both directions.

Describe and discuss the impact of physical activity on development of NCD in low-income settings

Physical activity has a preventative effect on the development of NCD - among many reasons:

• Insulin sensitive tissue

• Possibility to change body composition

• Helps maintain energy balance

Discuss the impact on the development of NCDs:

Decrease in physical activity (likely because motorbikes available, more sedentary jobs, bad infrastructure and no green areas ect.)

Physical activity may be a more feasible way to intervene and prevent NCD rather than diet because:

Changes in diet can be impossible due lack of other food choices or economy.

Describe and discuss the impact of nutrition on development of NCD in low-income settings

Malnutrition early in life affects development of NCD:

• A diet can be nutrient poor but energy dense – thereby inducing overweight and malnutrition at the same time. Evident as an adequate BMI but a poor body composition (bad bone and muscle development/health).

• Both over- and under-nutrition can lead to NCDs

Globally over-nutrition is a larger problem compared to under-nutrition.

Malnutrition and lack of important nutrients impacts development of NCDs in many ways:

• Immune function

Reflect on the challenges related to obtaining evidence on the aetiology (cause) of NCDs

NCDs are multifactorial diseases:

So many different factors can influence the development of NCD. There is not one single cause that can be attributed the cause of NCD these diseases are multifactorial.

Develops over time:

NCDs can take a long time to develop – to explore the cause we would need to follow a person/population for a very long time which is really expensive and resource demanding

Issues in studies of NCDs

Recruitment issues in low-income countries:

• The control: if controls a those who receive standard care – the standard care can be very different from community to community and sometimes no care is available

Infrastructure:

There can be long distance between clinics or homes in studies. In low-income countries infrastructure is often not very good. This makes it hard for participants to reach clinics or hard for investigators to reach their homes or clinics. Furthermore, if samples need to be transported it can be hard also keeping samples on -80 degrees which is often required.

Name some of the behavioral risk-factors often shared between NCDs

The behavioural risk factors are also the modifable risk factors. These include:

• tobacco

• alcohol

• inactivity

• Diet

Name some of the metabolic risk-factors often shared between NCDs

The metabolic risk factors are like the behavioral modifiable.

These include:

• Blood pressure

• weight

• blood glucose

Name some of the non-modifiable risk-factors often shared between NCDs

Ager, gender and genetics

Mention risk factors for NCDs that are more prominent in low-income countries compared to high-income countries

Generally NCDs in low-income settings are often related to exposure to under-nutrition and infections (HIV, malaria).

These are both risk factors that are more prominent in low-income countries compared to high-income countries.

What is the relation between foetal environment and the environment exposed to to in later life?

Mismatch between foetal environment and environment living in as an adult increase the risk of T2D.

Staying in the same environment decrease the risk.

The change in environment can happen because of two reasons:

• Moving

• Change of an environment: ex urbanization of a rural area.

In low-income countries non-communicable disease and communicable diseases are present at the same time in these populations and often also at the same time in the same individual. For example tuberculosis and diabetes that persists in the same individual.

What term can be used to describe this?

Double-burden of disease

In societies in fast transition, there may be a high burden of both simultaneously, a double burden

Discuss how low- or high birthweight can affect later risk for NCDs