South Asian countries have failed to keep their ageing populations healthy and face a growing crisis that is adding to broad income inequalities across the region, the World Bank has warned.

Rates of heart ailments, diabetes, obesity and other chronic diseases were dangerously high in much of South Asia, the result of many poor people living longer but without healthy lifestyles and access to affordable, quality preventive care.

Heart disease had become the chief cause of death among people ages 15-69 in South Asia, the World Bank said in a new report on the phenomenon Tuesday.

The region's population on an average suffered their first heart attack at age 53, six years earlier than the rest of the world.

Michael Engelgau, a co-author of the World Bank report, said the region's poor were often caught in a 'poverty trap' after suffering heart attacks, which forced them to pay for life-long expensive treatments they could ill afford.

The dangers are in some ways the result of progress. People in South Asia have been living longer on average because of successes in tackling infectious diseases like AIDS and tuberculosis.

But the report warned that many countries had failed to pivot toward tackling more chronic diseases that are suffered by older people in all countries. Much of the poor still lacked access to basic health services, even as they lived longer.

The World Bank urged the region to clamp down on tobacco use and improve awareness of healthy diets.