General Principles of Control of Chronic Non-Communicable Diseases

Definition of NCD

  • A non-communicable disease (NCD) is a medical condition or disease which is non-infectious and cannot be transmitted from one person to another.
  • Non-communicable diseases (NCDs) are mostly of long duration and slow progression.
  • They are also known as chronic diseases.

Characteristics of NCDs

  • Complex etiology (causes)
  • Multiple risk factors
  • Long latency period
  • Non-contagious origin (non-communicable)
  • Prolonged course of illness
  • Functional impairment or disability
  • Incurability
  • Insidious onset
  • The epidemiological transition of diseases from predominance of infectious diseases to chronic or degenerative diseases is believed to be responsible for the emerging pandemic of NCDs, sequel to globalization, urbanization and changes in lifestyles.

Global Burden of NCDs

  • Non-communicable diseases are the leading causes of death globally, killing more people each year than all other causes combined.
  • According to the World Health Organization (WHO) estimates, 41 million deaths each year are attributable to NCDs, equivalent to 74% of all deaths globally. In Africa, the range is 50-88% (WHO 2022).
  • Nearly 80% of NCD deaths occur in low- and middle-income countries.
  • About one fourth of global NCD-related deaths occur before the age of 60.
  • NCDs were estimated to account for 24% of all deaths in Nigeria in 2020.

Global Burden of Cardiovascular Diseases (CVDs)

  • CVDs are the number 1 cause of death globally.
  • An estimated 17.9 million people died from CVDs in 2022. One person dies every 34 seconds (30% of all global deaths).
    • 7.3 million were due to coronary heart disease.
    • 6.2 million were due to stroke.
  • Over 80% of CVD deaths occur in low- and middle-income countries.
  • By 2030, almost 25 million people will die from CVDs.

Global Burden of Diabetes

  • 347 million people worldwide have diabetes.
  • In 2021, an estimated 2.3 million people died from consequences of high blood sugar.
  • More than 80% of diabetes deaths occur in low- and middle-income countries.
  • WHO projects that diabetes deaths will increase by two thirds between 2008 and 2030.

Global Burden of Cancer

  • 10 million people died from cancer in 2020.
  • 70% of all cancer deaths occur in low- and middle-income countries.
  • Deaths from cancer are estimated to reach 13.1 million by 2030.
  • About 30% of cancers are attributable to behavior risk factors.

Global Burden of Chronic Respiratory Disease

  • 65 million people worldwide have moderate to severe Chronic Obstructive Pulmonary Disease (COPD).
  • More than 3.3 million people died of COPD in 2019.
  • Almost 90% of COPD deaths occur in low- and middle-income countries.

Risk Factors of NCDs

  • Unlike infectious diseases that have agents (bacterial, viruses, protozoa) that must be present for the respective disease to develop, non-communicable diseases have risk-factors.
  • A risk-factor for a disease or condition is that whose presence or relative lack is associated with an increased likelihood of developing the disease or condition.

Non-modifiable Risk Factors

  • These are risk factors that cannot be reduced or controlled by intervention.
    • Age
    • Sex
    • Race
    • Family history (genetics)

Modifiable Risk Factors

  • These are risk factors that can be reduced or controlled by intervention, thereby reducing the probability of disease.
  • The WHO has prioritized the following four:
    • Tobacco use
    • Alcohol use
    • Unhealthy diets
    • Physical inactivity

Risk Factors - 4 Diseases, 4 Modifiable Shared Risk Factors

  • The 4 most common NCDs share the 4 prioritized modifiable risk factors.
  • (A table was shown indicating Cardiovascular disease, Cancer, Diabetes, Chronic Respiratory Disease and their shared modifiable risks which includes; Tobacco use, Physical inactivity, harmful use of alcohol, unhealthy diet.)

Metabolic Risk Factors

  • Behaviors (modifiable risk factors) can lead to metabolic/physiologic changes.
  • WHO has prioritized the following four metabolic risk factors:
    • Raised blood pressure
    • Raised total cholesterol
    • Elevated glucose
    • Overweight and obesity
  • Carcinogens:
    • Physical: Ultraviolet and ionizing radiations.
    • Chemical: Asbestos, cigarette smoke, aflatoxins (food contaminant), arsenic (water contaminant), vinyl chloride etc.
    • Biological: Viruses (Hepatitis B virus, Human papilloma virus), parasites (schistosomiasis) etc. They are therefore communicable.

Tobacco Use

  • Tobacco use has become a public health problem in Nigeria.
  • The Global Youth Tobacco Survey in 2008 showed that 15% of children between 13 years and 15 years are already smoking.
  • The Global Adult Tobacco Survey on its part showed that 10% of men and 1.1% of women in Nigeria smoke cigarette.
  • Tobacco kills one person every six seconds.
  • Tobacco kills a third to half of all people who use it, on average 15 years prematurely.
  • Today, tobacco use causes 1 in 10 deaths among adults worldwide – more than five million people a year.
  • Tobacco will kill over 175 million people worldwide between now and the year 2030.
  • By 2030, unless urgent action is taken, tobacco’s annual death toll will rise to more than eight million.
  • Cigarette smoking cause one in every five deaths in the USA.
  • If current trends continue unchecked, it is estimated that around 500 million people alive today will be killed by tobacco

Alcohol Consumption

  • Alcohol consumption is the world’s third largest risk factor for disease and disability.
  • In middle-income countries, it is the greatest risk.
  • Alcohol is a causal factor in 60 types of diseases and injuries and a component cause in 200 others.
  • Almost 4% of all deaths worldwide are attributed to alcohol, greater than the deaths caused by HIV/AIDS, violence or tuberculosis.
  • Harmful use of alcohol is the leading risk factor for death in males aged 15 to 59 years, mainly due to injuries, violence and cardiovascular diseases.
  • Globally, 6.2% of all male deaths are attributable to alcohol, compared to 1.1% of female deaths.
  • More than 140,000 people die from excessive alcohol use in the US each year
  • Men also have far greater rates of total burden attributed to alcohol than women – 7.4% for men compared to 1.4% for women (WHO, 2011).

Unhealthy Diet

  • Most countries have increased overall daily consumption of calories, fat and meats, and energy dense and nutrient-poor foods (such as: starches, refined sugars and trans-fats).
  • Health effects of unhealthy diet include:
    • Coronary heart disease and stroke
    • Cancer
    • Type 2 diabetes
    • Hypertension
    • Diseases of the liver and gallbladder
    • Obesity

Physical Inactivity

  • Physical inactivity has become a public health problem all over the world.
  • Globally, around 25% of adults aged 15 years and over were insufficiently active in 2022.
  • Approximately 3.2 million deaths each year are attributable to insufficient physical activity. (WHO, 2022).
  • Many social and economic changes contribute to this trend:
    • Aging populations,
    • Transportation, and
    • Communication technology.

Prevention of NCDs

  • Prevention of NCDs is by: Primary, Secondary and, Tertiary prevention.
  • Primary prevention: This involves preventing the risk factors of the disease to stop development of the disease.

Primary Prevention

  • A novel approach to primary prevention of NCDs is primordial prevention.
  • It involves preventing the emergence and spread of NCDs risk factors and lifestyles that have not yet appeared or become endemic.
  • This applies to developing countries in particular; they are expected to preserve their traditional eating patterns and lifestyles associated with low levels of NCDs risk factors.
  • Dietary modification is a very important component of NCDs preventive strategy.
  • Dietary changes recommended by the WHO Expert Committee for high incidence populations include:
    • reduction of fat intake to 20-30 percent of total energy intake,
    • reduction of dietary cholesterol to below 100mg per 1000 kcal per day,
    • an increase in complex carbohydrate consumption eg beans whole grains, peas etc
    • reduction of salt intake to 5g daily or less.
    • avoidance of excessive alcohol consumption.
    • consumption of saturated fats must be limited to less than 10 percent of total energy intake.
    • Some of the reduction in saturated fat may be made up by mono-unsaturated e.g avocados and poly-unsaturated fats e.g soybean oil corn oil
  • Regular moderate physical activity
    • The combined recommendation of Experts panel convened by Centers for Disease Control and Prevention (CDC), the American College of Sports Medicine (ACSM), and the American Heart Association (AHA), is for individuals to engage in at least 30 minutes of modest activity on most, preferably all days of the week (Jonathan, 2003).
    • Modest activity has been defined as any activity that is similar in intensity to brisk walking at a rate of about 3 to 4 miles per hour.
    • These activities can include any other form of occupational or recreational activity that is dynamic in nature and of similar intensity, such as cycling, swimming (Jonathan, 2003).
  • Cessation of smoking and harmful use of alcohol:
    • Individuals are expected to play a role in assessing their status with respect to dependence on tobacco and alcohol.
    • A valuable tool for this purpose is the CAGE questionnaire (Ewing, 1984).
    • The CAGE questionnaire, derived its name from the acronym of its four questions, it was originally developed for screening for alcoholism, and later modified for screening for smoking addiction.

The CAGE questionnaire (modified for smoking addiction) asks the following questions:

  • Have you ever felt you needed to Cut down or control your smoking but had difficulty doing so?
  • Do you ever get Annoyed or angry with people who criticize your smoking or tell you that you ought to quit smoking?
  • Have you ever felt Guilty about your smoking or about something you did while smoking?
  • Did you ever smoke within half an hour of waking up (Eye-opener)?
  • Two yes responses constitute a positive screening

Similarly, the CAGE questionnaire for alcohol addiction asks the following questions:

  • Have you ever felt you needed to Cut down on your drinking?

  • Have people Annoyed you by criticizing your drinking?

  • Have you ever felt Guilty about drinking?

  • Have you ever felt you needed a drink first thing in the morning (Eye-opener) to steady your nerves or to get rid of a hangover?

  • For cancers caused by biological carcinogens (viruses, bacteria or parasites) preventive measures include avoidance of exposure to the infections and immunization e.g.; vaccination against hepatitis B virus (using Hep B vaccine); and Human papilloma virus

    • Cervarix which contains antigen for HPV 16 and 18 (that causes cervical cancer) and is recommended for females aged 9 to 26 years.
    • Gerdasil contains antigen for HPV 6, 11 (that causes genital warts); and HPV 16 and 18 and it is recommended for both males and females.

Secondary Prevention

  • Secondary prevention consists of:
    • Early diagnosis through screening and,
    • Treatment.
  • Examples of screening methods include:
    • Visual inspection with acetic acid (VIA) for cervical cancer.
    • Pap smear test for cervical cancer.
    • Mammography screening for breast cancer.
    • Rectal examination and serum PSA estimation for prostate cancer.
  • Treatment options include one or a combination of surgery, radiotherapy and chemotherapy.
  • The goal is to cure the disease or considerably prolong life while improving the patient’s quality of life.
  • Palliative care to relieve symptoms rather than cure the disease is offered if presentation is late.

Tertiary prevention

  • Tertiary prevention consists of:
    • Limitation of disability and,
    • Rehabilitation (physical, occupational and psychological).

WHO response

  • In 2013, the World Health Organization (WHO) launched the Global Action Plan for the prevention and control of NCDs 2013 – 2030.
  • It aims to reduce by 25% premature mortality from cancer, cardiovascular diseases, diabetes and chronic respiratory diseases.
  • WHO and the International Agency for Research on Cancer (IARC) collaborate with other United Nations organizations and partners to implement the designed strategies (including screening of all patients presenting at the health facilities for hypertension and other risk factors of NCDs).