Diabetes mellitus the 'Silent Killer' of mankind: An overview on the eve of upcoming World Health Day!

Abstract

In a multinational study, 50% of people with diabetes die of cardiovascular disease (primarily heart disease and stroke)8 · Combined with reduced blood flow, neuropathy (nerve damage) in the feet increases the chance of foot ulcers, infection and eventual need for limb amputation · Diabetic retinopathy is an important cause of blindness, and occurs as a result of long-term accumulated damage to the small blood vessels in the retina. Simple measures like life style modifications, healthy diet and regular physical exercise have been shown to be effective in prevention and delay of onset of Type 2 DM and its complications too.\n The cutoff levels of blood sugar levels recommended by WHO for diagnostic purpose are shown in table 1.

Diabetes Mellitus (DM) is a metabolic, endocrine disorder. It is a chronic noncommunicable disease which generally starts insidiously (over a period of long time), and even in the absence of symptoms (hence called as a silent killer). Many individuals are accidently detected as a case of DM when they are investigated for some other reasons like preoperative investigations. It is characterized by a state of hyperglycemia (high blood sugar level) due to insulin deficiency. Insulin is essential hormone produced by the beta cells of Langerhans of pancreas. It is required for metabolism of glucose. In the absence of insulin body cannot metabolize glucose hence it cannot be utilized for body functions leading to a state of chronic hyperglycemia. If this hyperglycemia is not treated in due time it can lead to serious consequences on body like damage to nerves (neuritis) and blood vessels (micro-angiopathies and atherosclerosis).

In the year 2012, DM was a direct cause of death of 1.5 million people and most of them (80%) belonged to low and middle income countries. Asian countries contribute to more than 60% of world's diabetic burden. The prevalence of DM is expected to raise from 285 million in 2010 to 438 million cases of diabetes in 2030. WHO projects that DM will be a 7th leading cause of death in 20301.

There are two major forms of DM, type 1 DM also previously called as Insulin dependent DM (IDDM) where a person's body is unable to produce insulin. So they require exogenous insulin injections for life long to survive. Type 2 DM, previously known as Non-Insulin dependent DM (NIDDM), where person is able to produce insulin but not adequate to meet body demands. It is the most common form of DM and the common risk factors attributed to NIDDM are overweight / obesity and sedentary life styles2.

WHO has recently announced that the upcoming world health day theme on 07th April 2016 will be on "Diabetes Mellitus" because the DM epidemic is rapidly increasing in many countries. Also DM (Type 2) is a preventable disease with simple life style modifications like diet and regular physical exercise. And thirdly DM is a treatable disease. DM can be controlled and complications can be prevented with early diagnosis and prompt treatment. Early initiation of mass IEC activities is important to prevent the diabetes in order to achieve global sustainable development goal 3 target of prevention of premature deaths and disabilities due to chronic non communicable diseases (NCDs) by one third by 20301. All sectors of society have a role to play, including governments, employers, educators, manufacturers, civil society, private sector, the mass media and individuals themselves in this mission of prevention of DM.

The main goal of World Health day 07th April 2016 will be to scale up preventive measures, strengthen the care and to enhance surveillance of DM. The other goals of World Health day 07th April 2016 campaign are:

· To Increase the awareness about the rise in diabetes, and its staggering burden and consequences, particularly in low-and middleincome countries

· To set up specific, effective and affordable actions to tackle diabetes. These will include steps to prevent diabetes; and diagnose, treat and care for people with diabetes

The first global report on diabetes, which described the burden, consequences of diabetes and advocate for stronger health systems to ensure improved surveillance, enhanced prevention, and more effective management of diabetes1

Key facts about DM

In 2014 the global prevalence of diabetes was estimated to be 9% among adults aged 18+ years3

· In 2012, an estimated 1.5 million deaths were directly caused by diabetes4

· More than 80% of diabetes deaths occur in low- and middle-income countries4

· WHO projects that diabetes will be the 7th leading cause of death in 20305

· Healthy diet, regular physical activity, maintaining a normal body weight and avoiding tobacco can prevent or delay the onset of type 2 diabetes6

Impaired glucose tolerance (IGT) and IFG

Impaired glucose tolerance (IGT) and impaired fasting glycaemia (IFG) are intermediate conditions in the transition between normality and diabetes. People with IGT or IFG are at high risk of progressing to type 2 diabetes, although this is not inevitable. Impaired Glucose Tolerance test is important in early diagnosis of diabetes. A loading dose of 75 grams glucose is given orally to the subject undergoing GTT. After a two hours of glucose load the blood is monitored for raise in sugar levels. In a normal healthy individual the blood sugar level comes to normal in 3-4 hours, while in persons with impaired glucose tolerance the blood sugar level remains high indicating deficiency of insulin.

What are the most frequent consequences of diabetes mellitus?

Over a period of time diabetes can damage the heart, blood vessels, eyes, kidneys and nerves.

· Diabetes can increase the risk of heart disease (CAD) and stroke. In a multinational study, 50% of people with diabetes die of cardiovascular disease (primarily heart disease and stroke)8

· Combined with reduced blood flow, neuropathy (nerve damage) in the feet increases the chance of foot ulcers, infection and eventual need for limb amputation

· Diabetic retinopathy is an important cause of blindness, and occurs as a result of long-term accumulated damage to the small blood vessels in the retina. One percent of global blindness can be attributed to diabetes9

· Diabetes one of the leading causes of kidney failure6

· The overall the risk of dying among people with diabetes is at least double the risk of their peers without having diabetes10

How to reduce the burden of diabetes?

There is an old saying called "Prevention is better than cure!" holds good here!

Simple measures like life style modifications, healthy diet and regular physical exercise have been shown to be effective in prevention and delay of onset of Type 2 DM and its complications too. People in general should:

· Maintain optimum body weight

· Be physically active and should do at least 30 minutes of regular, moderate-intensity physical activity (brisk walking) at least 5 days a week

· Avoid processed foods like breads and butter. Prefer foods rich in natural carbohydrates like whole grain flour (Atta). Eat fresh fruits and vegetables everyday and reduce sugar and saturated fats intake

· Avoid any form of tobacco use - smoking increases the risk of cardiovascular diseases

Treatment strategy

Early diagnosis can be made by inexpensive test i.e. by blood sugar testing. Or based on common symptoms of diabetes like increased frequency of micturation, increased thirst and increased hunger or based on history of delayed wound healing the diagnosis of diabetes can be done easily. The cutoff levels of blood sugar levels recommended by WHO for diagnostic purpose are shown in table 1. Also all people above the age of 40 years and senior citizens must screen themselves for diabetes regularly (at least once in six months is recommended). Treatment of diabetes mainly consist of control and lowering blood glucose by means of using oral hypoglycaemic drugs with or without insulin for Type 2 DM and only insulin injections for Type 1 DM.

Trends in Diabetes Mellitus (Fig 1 & 2)

The trends in prevalence of diabetes in South Asian countries are shown in table 2 & 3. Over a period of last two decades the prevalence of diabetes has increased remarkably especially in developing countries like India15,16 and China21,22. This increased prevalence can be attributed mostly to the changes in lifestyle as a result of rapid socio- economic transition. The raised prevalence, therefore, is attributed to environmental and behavioural changes. It is estimated that the substantial increase in urbanization will occur in most Asian countries, although the rates are variable among these countries. The highest rates of urbanization (50%) were observed in Singapore, Korea, Malaysia, Philippines and Indonesia. China, India, Thailand have intermediate rates (30%) and Bangladesh and Sri Lanka have slow rates of urbanization38.

There are within-country regional disparities in prevalence rates from all the countries. A recent study from the Indian Council of Medical Research (ICMR-INDIAB) conducted in 3 states and in 1 union territory (UT) representing 213.5 million people in urban and rural settings, from November 2008 to April 2010, showed that the weighted 20 years prevalence of diabetes in adults was 10.4% in Tamil Nadu (South), 8.4% in Maharashtra (Central), 5.3% in Jharkhand. (East) and 13.6% in Chandigarh (UT) and of pre-diabetes (IGT and/or IFG) was 8.3%, 12.8%, 8.1% and 14.6%, respectively. Risk factors for diabetes and pre-diabetes comprise of age, family history of diabetes, urban residence, abdominal obesity, hypertension and income status39.

Summary

To summarize, diabetes is emerging as a global public health problem particularly in developing countries. As per WHO current morbidity and mortality statistics the problem of diabetes could be far bigger than present because of delayed case reporting and diagnosis. The global adult prevalence of DM is estimated to be 9% with 1.5 million deaths (2012) and more than 80% were from middle and lower income countries. But still diabetes will need further in depth exploration about morbidity profile. Also there are modifiable and non-modifiable risk factors which play an important role in the causation of diabetes especially type 2 DM. Diabetic epidemic is mainly driven by rapid urbanization, fast foods and sedentary lifestyles40. There is strong evidence which suggest that the majority of diabetes cases can be prevented through diet and lifestyle modification. However, adopting active lifestyle and healthy diet like avoiding saturated fat, refined carbohydrates and deliberate engaging in physical activities like walking and jogging can help to prevent this phenomenon of diabetic epidemic.

Acknowledgments: None

Conflict of interest: None

References

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