BMI and all-cause mortality in older adults: a meta-analysis.
BACKGROUND
Whether the association between body mass index (BMI) and all-cause mortality for older adults is the same as for younger adults is unclear.


OBJECTIVE
The objective was to determine the association between BMI and all-cause mortality risk in adults ≥65 y of age.


METHODS
A 2-stage random-effects meta-analysis was performed of studies published from 1990 to 2013 that reported the RRs of all-cause mortality for community-based adults aged ≥65 y.


RESULTS
Thirty-two studies met the inclusion criteria; these studies included 197,940 individuals with an average follow-up of 12 y. With the use of a BMI (in kg/m2) of 23.0-23.9 as the reference, there was a 12% greater risk of mortality for a BMI range of 21.0-21.9 and a 19% greater risk for a range of 20.0-20.9 [BMI of 21.0-21.9; HR (95% CI): 1.12 (1.10, 1.13); BMI of 20.0-20.9; HR (95% CI): 1.19 (1.17, 1.22)]. Mortality risk began to increase for BMI >33.0 [BMI of 33.0-33.9; HR (95% CI): 1.08 (1.00, 1.15)]. Self-reported anthropometric measurements, adjustment for intermediary factors, and exclusion of early deaths or preexisting disease did not markedly alter the associations, although there was a slight attenuation of the association in never-smokers.


CONCLUSIONS
For older populations, being overweight was not found to be associated with an increased risk of mortality; however, there was an increased risk for those at the lower end of the recommended BMI range for adults. Because the risk of mortality increased in older people with a BMI <23.0, it would seem appropriate to monitor weight status in this group to address any modifiable causes of weight loss promptly with due consideration of individual comorbidities.
School of Exercise and Nutrition Sciences, Deakin University, Burwood, Melbourne, Australia (JEW, NW, and CAN); the Cancer Epidemiology Centre, Cancer Council Victoria, Melbourne, Australia (RJM); and the Centre for MEGA Epidemiology, University of Melbourne, Melbourne, Australia (RJM).
Jane E
JE
Winter
Robert J
RJ
MacInnis
Naiyana
N
Wattanapenpaiboon
Caryl A
CA
Nowson
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D015992:Body Mass Index; D006801:Humans; D008137:Longitudinal Studies; D009026:Mortality; D009765:Obesity / Q000503:physiopathology; D050177:Overweight / Q000503:physiopathology*; D013851:Thinness / Q000503:physiopathology*; D015431:Weight Loss