Association between weight change over a period of 4 years and mortality in Korean older adults

AIM: This study aimed to evaluate the association between weight change and mortality in Korean older adults. METHODS: We collected data pertaining to National Screening Program participants aged ≥65 years from the Korean National Health Insurance Corporation records during 2005-2011. To this data, we included mortality data, such as the date of death, of these patients (up to and including 2017) from Statistics Korea. We defined weight change as a difference in bodyweight measured in the National Screening Program over a period of 4 years. Cox proportional hazards models were used to evaluate the association between weight change and mortality. RESULTS: The study population consisted of 1 100 256 participants, and a total of 46 415 deaths were observed during a mean follow-up period of 3.2 ± 0.8 years (maximum 5.0 years). For 3 531 585 person-year follow up, the mortality rate for stable weight was 10.79 per 1000 person-years (PY). Weight loss increased the mortality rate by 68%, whereas weight gain increased the rate by 10% compared with stable weight (weight loss: mortality rate 20.28 per 1000 PY, adjusted hazard ratio 1.68, 95% confidence interval 1.65-1.72; weight gain: mortality rate 12.86 per 1000 PY, adjusted hazard ratio 1.10, 95% confidence interval 1.07-1.13). However, in subgroup analysis, for participants who were underweight at baseline, current cigarette smokers or heavy alcohol drinkers, weight gain did not increase the mortality rate. CONCLUSIONS: In Korean older adults, regardless of the risk factors, both weight loss and weight gain increased the mortality rate compared with stable weight. Geriatr Gerontol Int 2020; 20: 474-481.