EPIDEMIOLOGY OF NON COMMUNICABLE DISEASES

Definition of a non communicable disease

Non-communicable diseases include diseases which do not have infectious agents which

make them spread from one person to another.

It might result from hereditary factors, improper diet, smoking, or other factors.

WHO (World Health Organization) cluster of non communicable disease include

Cardiovascular diseases, Cancer, Diabetes, chronic respiratory diseases, mental illness and

injuries.

They are causes of enormous morbidity, premature mortality and a threat to the economic

resources of many countries

The major non communicable diseases in India are:-

Cancer and cardio vascular diseases

Respiratory tract infections

Occupational hazards

Psychiatric disorders

Accidents

Addiction

Diabetes

Blindness

STANDARD METHODS OF STUDYING A NON COMMUNICABLE DISEASE

The standard format for description of non communicable diseases:-

Introduction

Magnitude

Pre-pathogenesis

1. Agent factors:-physical, chemical or nutrient agents.

2. Host factors:-age, sex, heredity, habits, lifestyle.

3. Environmental factors:-social status, educational level, economic pattern, housing, sanitation.

Pathogenesis:- refers to the evolution of the disease in the following sequence.

1. Latent period

2. Early manifestation

3. Late stage

4. Remote effects

5. Chronicity and death

Prevention and control

Health promotion

Early diagnosis and treatment

Disability limitation

Rehabilitation:-physical, social, psychological and vocational.

DIABETES Diabetes is an iceberg disease.

It is a metabolic disorder where the blood sugar level is higher than normal.

Currently the number of diabetics world wide is estimated at 150 million.

The WHO reports found that the prevalence of the disease in Indian adults is 2.4% in rural

areas and 4.0-11.6% in the urban areas.

Classification of Diabetes: (As given by WHO)

1. Diabetes mellitus (DM)

Insulin dependent Diabetes Mellitus (IDDM, type 1)- most severe form of the disease.

Non-Insulin dependent Diabetes Mellitus (NIDDM, type 2)-more common than IDDM.

Malnutrition Related Diabetes Mellitus (MRDM)- in developing countries like India a special

type of diabetes was identified by WHO in 1995. This was called as malnutrition related

diabetes mellitus & affects nearly 1% of the county's diabetic population..

Other Types( genetic, hormonal, drug induced)

Impaired Glucose Tolerance (IGT)-an intermediate state between diabetes mellitus &

normality. It represents the risk groups.

Gestational Diabetes Mellitus-Gestational diabetes affects about 4% of all pregnant women

(temporarily). It is believed that the hormones produced during pregnancy reduce a woman's

receptivity to insulin, leading to high blood sugar levels.

Host factors

Age:- Diabetes can occur at any age, but the prevalence rises with age (NIDDM is more

common in the middle aged & elderly, IDDM is seen in individuals less than 30 years of age.

MRDM occurs largely in young malnourished individuals in developing countries).

Sex :-in some countries like U.K, male : female ratio is almost equal, while in South east Asia it

has been seen to occur more in males.

Obesity has been accepted as a risk factor for diabetes, particularly NIDDM.

Maternal Diabetes- research shows that offspring of diabetic mothers (including gestational

diabetes) tend to develop obesity in childhood & hence have a high risk of developing type 2

diabetes.

Environmental Factors

Sedentary life styles and lack of exercise appears to be a major risk factor for NIDDM.

Diet:-consumption of more saturated and fatty diet reduces the insulin sensitivity and results

in hyperglycemia. Hence it is a risk factor for IGT and also imposes greater risk for type 2

diabetes. Intake of more dietary fibres help to reduce the blood glucose levels in people with

type 2 diabetes and IGT.

Malnutrition in infancy and childhood results in the failure of B-cell function and hence

associated with IGT.

Stress factors & alcoholism also increases the risk factors of the disease.

Other factors like changes in life styles, education, urbanization have been linked to diabetes

causation.

Screening for Diabetes

Urine examination for the presence of glucose in urine (glycosuria) is conducted 2 hrs after a

meal.

Blood sugar testing:-the measurements of glucose levels in fasting, post prandial or random

blood samples. The criteria for the diagnosis of diabetes proposed by WHO is:-

Glucose (mg/dl)

Whole blood

Venous capillary

Diabetes Mellitus

a) Fasting > 120 > 120

a) 2 hrs after glucose load > 180 > 200

Impaired glucose tolerance

a) Fasting value < 120 < 120

a) 2hrs after glucose load 120-180 140-200

What are the symptoms of diabetes?

The early symptoms of untreated diabetes are elevated blood sugar levels, loss of glucose in

the urine & increased urine output. Extremely elevated glucose levels can lead to lethargy and

coma.

Increased urine output leads to dehydration. Dehydration causes increased thirst and water

consumption(polydipsia).

A relative or absolute insulin deficiency eventually leads to weight loss despite an increase in

appetite(polyphagia).

Some untreated diabetes patients also complain of fatigue, nausea and vomiting.

Fluctuations in blood glucose levels can lead to blurred vision and in acute cases cause

diabetic retinopathy.

Diabetes accelerates hardening of the arteries (atherosclerosis) of the larger blood vessels,

leading to coronary heart disease (heart attack, strokes )

Kidney damage from diabetes is called diabetic nephropathy. Initial malfunctioning of the

kidneys cause the leakage of protein in the urine. Later on, the kidneys lose their ability to

cleanse and filter blood.

The accumulation of toxic waste products in the blood leads to the need for dialysis. (Dialysis

involves using a machine that serves the function of the kidney by filtering and cleaning the

blood)

Prevention and Control

Primary prevention is based on basically eliminating the environmental risk factors e.g.

maintaining of normal body weight, good nutritional habits, intake of dietary fibres in diet.

Arranging of community based programmes to make people aware are also helpful.

Secondary prevention:- As soon as diabetes is detected, it must be treated properly. This is

done by routine checking of blood sugar, urine, blood pressure, intake of oral anti diabetic

drugs, home blood sugar monitoring etc.

Tertiary prevention:-diabetes causes disability and severe complications like blindness,

kidney failure, gangrene etc. Diabetic clinics and rehabilitation centres can provide diagnostic

& management skills of high quality to the patients.