India’s diabetes burden likely to increase

By the end of 2011, India is likely to have 62.4 million diabetics as against 50 million in 2010. What's more, the number of prediabetics (people with impaired glucose tolerance) will be higher at 77.2 million, says a recent study conducted jointly by the Indian Council of Medical Research (ICMR) and INdia DIABetes (INDIAB).

The study is the first multi-centre diabetes study in India to take urban-rural population proportions meticulously into account in estimating the prevalence of diabetes and prediabetes. The study was conducted at 188 urban and 175 rural sites, in three states—Maharashtra, Tamilnadu and Jharkhand—and one union territory, namely Chandigarh. A total of 14,277 individuals participated in the study.

While it was found, quite predictably, that prevalence of both diabetes and prediabetes is high everywhere and is higher in urban than in rural areas, the prevalence ratio of diabetes to prediabetes and known cases to newly detected cases, indicates that overall prevalent patterns might change in the coming years, says V Mohan of Madras Diabetic Research Foundation (MDRF), the principal investigator of the study.

Urbanisation, affluence to be blamed

The prevalence of diabetes, says the study, appears directly related to urbanization, rise in income levels and consequent change in lifestyle. The total prevalence was found to be highest in Chandigarh at 13.6 per cent of the population, and both urban and rural prevalence rates were found to be high, at 14.2 and 8.3 per cent respectively. Tamil Nadu was second in total prevalence with 10.4 per cent of the population suffering from it, Maharashtra followed with 8.4 per cent and Jharkhand with 5.3 per cent.

Urban-rural prevalence ratio also appears to have the same determinants. For instance, in Tamil Nadu and Chandigarh, the difference between urban and rural prevalence was found to be moderate, at 5.9 per cent of population in both places. In Jharkhand, where rural poverty is high but urban areas are developed around industrial townships where people have fairly high levels of income, the urban-rural difference was more marked at 13.5 and 3.0 per cent respectively.

Prevalence in rural areas rises

The study confirms the findings of other recent diabetes studies which shows that prevalence of diabetes is on the rise in rural areas. Zaheer Qazi, associate professor with the Department of Public Health and Community Medicine at the Acharya Vinoba Bhave Gramin Rugnalaya in Wardha, says that a study conducted by his department two years back in Deoli tehsil of the district found a rising prevalence of diabetes in rural areas.

Pradeep Deshmukh, professor of community medicine at the Mahatma Gandhi Institute of Medical Sciences at Sewagram in Wardha, says that studies in metabolic syndrome, a cluster of risk factors which are a precursor of diabetes, hypertension and cardiovascular diseases, shows that the trend is on the rise both among adults and adolescents. Both studies identified changes in diet and lifestyle consequent upon rise in income as the main reason behind this trend.

“The ratio of known and newly detected cases appears to be directly proportionate to intensity of screening activities,” says he. “The rule of thumb is 1:1, that is for every known case of diabetes, there is one undetected case. But in Tamil Nadu, where intensive and repeated screening has been carried out by the government, the ratio was found to be 1:0.6 in urban and 1.09 in rural areas. In Jharkhand, however, while the urban ratio was found to be the same as is Tamil Nadu, in rural areas, more than three undetected cases were found for each known case.

Preventive action needed

One of the most important findings in the study was that barring Tamil Nadu, prevalence of prediabetes was found to be higher than diabetes. The difference was the highest in Maharastra, with overall prevalence of prediabetes being 12.8 per cent as compared to diabetes (8.4 per cent), followed by Jharkhand (8.1 per cent and 5.3 per cent respectively) and Chandigarh (14.6 per cent and 13.6 per cent respectively).

“This pattern shows that there is a large pool of people waiting to convert to diabetes,” says Mohan, “Diabetes numbers are spiraling in India, rising from 30 million in the year 2000 to 40 million in 2007, to 50 million in 2010. And now, in just a single year, a 12 million rise is expected in 2011.” He says that the large number of prediabetics shows that the epidemic is not yet over. “It indicates that the spurt in numbers will continue for some time to come, and then probably level off.”

However, Mohan adds that the large number of prediabetics also offers a window of opportunity for prevention. “Most prediabetics can convert to normal with moderate changes in diet and exercise habit,” he says. “Even a five per-cent reduction in weight can make a big difference, and that is where future prevention measures should be targeted.”

Mohan says the current study published in Diabetologia on September 30, 2011, was the first phase of a nation-wide study. The second phase, comprising the eight states of the north-east, has just commenced and is expected to be completed in about two years. The final phase will include the rest of India. He said that while mostly the prevalence patterns are likely to follow the trends that surfaced in the current study, there might be a few surprises. “I won’t be surprised if, for instance, the rural prevalence of diabetes in states like Kerala, where there is not much of an urban-rural divide, turn out to be higher than the urban,” he says.