The Ever Growing Menace of Diabetes

Introduction

Type 2 diabetes has become a global epidemic. According to the International Diabetes Federation, the number of diabetics is expected to cross 438 million by the year 2030, with two-thirds of all diabetes cases occurring in low- to middleincome countries. The number of adults with impaired glucose tolerance will rise from 344 million in 2010 to an estimated 472 million by 2030.  The greatest burden will be felt by developing countries like India. Fuelled by rapid urbanization, nutrition transition, and increasingly sedentary lifestyles, the epidemic has grown in parallel with the worldwide rise in obesity. Asia’s large population and rapid economic development have made it an epicentre of the epidemic. Asian populations tend to develop diabetes at younger ages and lower BMI levels than Caucasians.

Epicenters of Diabetes

The ICMR-INDIAB study (2011) showed that 62.4 million Indians have diabetes and an additional 77.2 million have pre-diabetes.  Indians develop diabetes at younger ages, at least a decade earlier, at lower BMI and at much higher rates given the same amount of weight gain compared with Western populations.¹ Asian women are also at greater risk of gestational diabetes, thereby putting their children at risk for type 2 diabetes later in life. We are now seeing Indians in their 20s and early 30s with diabetes.

Diabetes in Indians- Is the phenotype different?

This term refers to a combination of characteristics that predisposes Indians to the development of insulin resistance, type 2 diabetes, and cardiovascular disease.

1. It has been shown that type 2 diabetes occurs at younger ages and at lower levels of BMI in Indians compared with Caucasians.¹
2. In spite of a relatively lower rate of obesity as defined by BMI cut points, Indians tend to have larger waist measurements and waist-to-hip ratios, indicating a greater degree of central body obesity.²
3. Indians appear to have a greater predilection for cardiovascular complications whereas the prevalence of microvascular complications appears to be lower than in Europeans.³
4. The prevalence of coronary artery disease was 21.4 per cent among diabetic subjects compared to 9.1 per cent in subjects with normal glucose tolerance.³ The prevalence of CAD in IGT subjects were 14.9 per cent in the same study.
5. It was also seen that the diabetic subjects had increased subclinical atherosclerosis as measured by intimal medial thickness (IMT) at every age point.³
6. At any body mass index (BMI) and age, Asian Indians have higher body fat, visceral fat and waist circumference (WC); lower skeletal muscle mass; thinner hips; short legs; profoundly higher rates of insulin resistance, metabolic syndrome, diabetes, dyslipidemia hypoadiponectinemia, and increased cardiovascular risk than Europids.^4,5
7. These unique clinical and biochemical characteristics that are commonly found among Asian Indians in particular and South Asians in general are collectively referred to as the “Asian Indian Phenotype” or thin –fat phenotype.⁶

Changing face of India contributing to the epidemic of diabetes

Rapid Urbanization, industrialization, increasing income levels, changing lifestyles, values and culture, increased calories intake, sedentary life style are fueling the present epidemic of diabetes.

Urbanisation- Mobile population

• Busy, career oriented life style
• Distance of work place from the home
• No opportunity to go for exercise
• Irregular meal timings
• Availability of fast food

Nuclear families: Reduced number of family members

• Husband wife both are working.
• Most of the time utilized in the office work and traveling.
• Not enough time to prepare food or do exercise.
• Easy availability of Ready to eat food stuff.

Today’s trend

• According to one survey done on Gujaratis, nearly 80 % are eating out at least once a week.
• Advances in civilization and rapid industrialization have changed our dietary pattern.
• Tends to eat out more often now for business or for pleasure. Even it is interwoven with religious and social customs.
• Do not eat when hunger demands- but rather eat when tongue tempts, when company warrants.
• There is progressive substitution of complex CHO by dietary fats and sugar.
• Alteration in eating pattern is due to shift in income, prices, advertising and exposure to mass media.

Magnitude of the Problem-Indian diabetic scenario

Slow in onset,

asymptomatic,

66% remain undiagnosed,

Delay in the diagnosis by 8-12 years,

> 50% have complications at diagnosis, Unawareness that- DM and its complications are potentially preventable.

Diabetes prevention - is it possible?

Fortunately, the natural history of diabetes, provides the opportunity. Diabetes usually progresses from impaired glucose tolerance (IGT) or pre-diabetes stage to an early asymptomatic stage to onset of clinical diabetes and then to the stage of complications.

In the natural history of diabetes, there is a long prediabetic stage, during which adequate prevention strategies can help delay the onset of diabetes. IGF-impaired fasting glucose (100-124 mg/dl) and IGT-impaired glucose tolerance (140-199mg/ dl)  are both considered to be metabolic disease abnormalities with elevated plasma glucose values but not high enough to meet the diagnostic criteria of diabetes( fasting>125mg/dl and PP>200mg/dl) and hence are termed as “pre-diabetes”.

Both IFG and IGT have more or less similar risk developing diabetes. Behavioural changes or pharmacological interventions can help in the prevention of diabetes. Lifestyle modifications, inclusive of dietary modification, regular physical activity and weight reduction are indicated for prevention of diabetes.

Surprisingly, in spite of the enormous progress in understanding the natural history of diabetes, efforts taken for prevention of diabetes are all still grossly inadequate.

Diabetes prevention trials-non-Pharmacological Interventions

The Da Qing study, the first well-known prevention study (published in 1997).

In finish study, they adopted an intensive dietexercise programme.

DPP Study was monumental in its size, design and execution.

The most important observation of these interventional studies was that it was possible to prevent diabetes in subjects with IGT using lifestyle modification.

Diabetes prevention trials-Pharmacological Interventions

The STOP-NIDDM trial is the first prospective intervention study showing that treatment with an glucosidase inhibitor in IGT patients is associated with a significant reduction in the incidence of CVD and hypertension.

TRIPOD, PIPOD, DREAM, ADOPT and ACTNOW used the glitazones for diabetes prevention and showed 55-72% reduction in onset of new diabetes in IGT subjects.

What did we learn from these well-controlled trials?

Behavioural changes or pharmacological interventions can help in the prevention of diabetes. Lifestyle modifications, inclusive of dietary modification, regular physical activity and weight reduction are indicated for prevention of diabetes. Early intervention with lifestyle modifications has beneficial effects on obesity, blood lipids and blood pressure, reduces the CV risk  and glucose tolerance profile simultaneously.

Thus lifestyle modification is the first option for prevention of diabetes and presents an integrated approach to correct negative environmental, factors as major causes for the epidemic.

Conclusion

Type 2 diabetes is a global crisis that threatens the health and economy of all nations, particularly developing countries.

Accumulating evidence strongly demonstrates that the majority of type 2 diabetes cases can be prevented through diet and lifestyle modification. However, the adoption of a healthy diet and lifestyle requires not only individual behavioral changes, but also changes in our food, built, and social environments. Public health strategies that target the obesogenic environment are critical. Translating clinical and epidemiologic findings into practice requires fundamental shifts in public policies and health systems. To curb the diabetes epidemic, primary prevention through the promotion of a healthy diet and lifestyle should be a global public policy priority.