SINGAPORE - Significant weight gain or loss among middle-aged and elderly Chinese Singaporeans can increase the risk of an early death, especially from cardiovascular diseases, a study has found.
Led by Professor Koh Woon Puay of Duke-NUS Medical School and the National University of Singapore's Saw Swee Hock School of Public Health, a team of researchers discovered that Chinese Singaporeans aged 45 to 74 who experienced weight loss of 10 per cent or more over a period of about five to six years were found to have a 39 per cent higher risk of death from all causes compared to those who maintained their weight.
A large weight gain of 10 per cent or more was associated with a smaller but significant 13 per cent increased risk of death.
This was about the same as the risk increase associated with a small weight loss of between 5 to 10 per cent.
A small weight gain was not associated with a greater risk of death.
However, for overweight Chinese Singaporeans with a body mass index (BMI) higher than 23, a small weight loss did not increase their risk of dying.
Similar patterns were found across the age range for both men and women of all body weights.
Prof Koh, the principal investigator of the study, said excessive weight loss, especially among the elderly, could indicate that they are losing muscle mass because of malnutrition or poor control of chronic diseases rather than shedding fat through exercise.
As part of the Singapore Chinese Health Study, researchers collected the height and weight data of about 63,000 Chinese Singaporeans between 1993 and 1998. About six years after the first survey, a follow-up survey was conducted to measure their weight gain or loss. Those who had been diagnosed with cancer, heart disease or stroke at this point were then excluded from the study as the researchers wanted to track only those who were relatively healthy.
About 36,000 people were then surveyed again in 2016. Of this number, about 7,500 deaths and their causes were collected from the National Death Registry.
Of those surveyed, the top causes of death were cancer and cardiovascular diseases, consistent with national averages. Over a third died from cancer while 16.7 per cent died from heart disease and 8 per cent died from strokes.
Weight changes did not affect the rate of cancer deaths significantly.
Although the survey only observed Chinese Singaporeans, Prof Koh said that the findings would be largely applicable to people of all races.
"Our findings were consistent with those of studies done in Western societies as well as some conducted among Japanese and Korean populations," said Prof Koh during a media briefing on Tuesday (Dec 18) at Duke-NUS.
The study also found that women were more likely to gain weight than men, while older people were more likely to lose weight than younger people.
The researchers cautioned that more research is needed to better understand the underlying associations between weight change and mortality.