Weight change linked to mortality risk
Analysis of data obtained from a study nested under the Singapore Chinese Health Study, led by Principal Investigator Professor Koh Woon Puay from Duke-NUS Medical School, discovered that a change in weight of 10 per cent or more in middle-aged to elderly Chinese Singaporeans — both weight gain and weight loss — is linked to increased risk of death, particularly from cardiovascular disease. The research also showed that weight loss was associated with a higher risk of mortality than weight gain. Additionally, excessive weight loss increased the risk in participants who were overweight to start with, while excessive weight gain increased risk even for subjects who had low body mass indices at the beginning of the study.
The results of this study align with those from similar studies conducted among European, Japanese and Korean populations, said Prof Koh, who also holds a position at the Saw Swee Hock School of Public Health.
“The findings suggest that moderate-to-large weight change in mid-life and older age should be monitored closely by health practitioners, and weight loss especially, should be considered critically in elderly individuals as it may be related to loss of muscle mass, frailty and poor control of chronic diseases,” she added.
The study used data from 36,338 participants with no history of cancer or cardiovascular disease who were able to report their weight and height during interviews at recruitment and at follow-up surveys on average six years later. Weight change was classified into moderate-to-large weight change of 10 per cent or more, small weight change of between 5.1 and 9.9 per cent, and stable weight with approximately 5 per cent change. The mortality of the participants was tracked using the Singapore Birth and Death Registry.
The researchers highlighted that the study did not look into whether weight loss was intentional or if it was due to loss of fat or lean mass, and urged caution in interpretation of the results. However, they added that the findings from this study and other populations suggest that it is prudent to maintain stability in body weight of elderly and middle-aged populations in the non-obese range to reduce risk of mortality.
“The observational nature of our study means we cannot generalise our findings to potential interventions at this point,” said Prof Koh, adding that further studies are needed to understand the mechanisms behind the association between weight change and mortality.
