Published in:
01-02-2018
Association between body mass index and all-cause mortality among oldest old Chinese
Published in: The journal of nutrition, health & aging | Issue 2/2018
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Objectives
To examine the association between BMI and all-cause mortality in the oldest old (≥80 years).
Design
The study used a prospective cohort study design.
Setting
Chinese Longitudinal Healthy Longevity Survey (CLHLS) between 1998/99 and 2011.
Population
8026 participants aged 80 years and older were followed every two to three years.
Measurements
Body weight and knee height were measured. Height was calculated based on knee height using a validated equation. Deaths were ascertained from family members during follow-up.
Results
The mean BMI was 19.8 (SD 4.5) kg/m2. The prevalence of underweight, overweight and obese was 37.5%, 10.2% and 4.4%, respectively. There were 5962 deaths during 29503 person-years of follow-up. Compared with normal weight, underweight was associated with a higher mortality risk (HRs: 1.20 (95%CI 1.13-1.27) but overweight (HR 0.89 (95%CI 0.81-0.99)) were associated with a lower risk. Obesity had a HR 0.91 (95%CI 0.78-1.05) for mortality.
Conclusion
Among oldest old Chinese, underweight is associated with an increased risk of all-cause mortality but overweight is associated with a reduced risk. Interventions to reduce undernutrition should be given priority among the oldest old Chinese.