Objectives

The association between weight change and cognition is controversial. We examined the association between 20-year weight change and cognitive function in late life.

Design

Cohort study.

Setting

Study of Osteoporotic Fractures (SOF).

Participants

One thousand two hundred eighty-nine older, community-dwelling women (mean baseline age 68 (65-81) and 88 (82-102) at cognitive testing).

Measurements

Study of Osteoporotic Fractures participants had body weight measured repeatedly over 20 years (mean 8 weights). Adjudicated cognitive status was classified as normal (n = 775) or mild cognitive impairment (MCI)/dementia (n = 514) at Year 20. Logistic models were used to evaluate whether absolute weight change, rate of weight loss per year, presence of abrupt, unrecovered weight loss, and weight variability were associated with MCI or dementia.

Results

Women with greater rate of weight loss over 20 years had increased chance of developing MCI or dementia. In age/education/clinic-adjusted "base" models, each 0.5 kg/yr decrease resulted in 30% increased odds of MCI/dementia (OR = 1.30 [95% CI: 1.14, 1.49]). After adjustment for age, education, clinic, depression, and walking speed, there was 17% (OR = 1.17 [95% CI: 1.02, 1.35]) increased odds of MCI/dementia for each 0.5 kg/yr decrease in weight. In base models, variability in weight was significant. Each 1% average deviation from each woman's predicted weight curve was associated with 11% increased odds of MCI/dementia (OR = 1.11 [95% CI: 1.04, 1.18]). The estimate was attenuated after full adjustment (OR = 1.06 [95% CI: 0.99, 1.14]). The presence of an abrupt weight decline was not associated with MCI/dementia.

Conclusions

Rate of weight loss over 20 years was associated with development of MCI or dementia in women surviving past 80 years, suggesting that nutritional status, social-environmental factors, and/or adipose tissue function and structure may affect cognitive function with aging.

Objectives

To determine the association between weight trajectory, health status, and mortality in older women.

Design

Cohort study.

Setting

Study of Osteoporotic Fractures.

Participants

Older community-dwelling women (age: baseline (1986-88), mean 68, range 65-81; Year 20 (2006-08), mean 88, range 83-102 (N = 1,323)).

Measurements

Body weight measured repeatedly over 20 years (mean 8 times). Logistic and Cox proportional hazard models were used to evaluate whether 20-year weight trajectory measures were associated with hip fracture, falls, physical performance, and mortality.

Results

In models adjusted for age, clinic, calcium use, Year 20 weight, walking speed, comorbidity score, smoking, self-reported health, and walking for exercise, women with moderate weight loss (>9.0 kg) over 20 years had a 74% greater risk of death (hazard ratio (HR) = 1.74, 95% confidence interval (CI) = 1.37-2.20) in the 5 years after the Year 20 visit than those with no weight loss and more than twice the risk of hip fracture (HR = 2.56, 95% CI = 1.39-4.70). They were 3.6 times (odds ratio (OR) = 3.60, 95% CI = 1.86-6.95) as likely to have poor physical function at the Year 20 visit as women with no weight loss but no greater risk of 2 or more falls in the 1.5 years after the Year 20 visit. Weight variability and abrupt weight decline were not associated with adverse health oucomes (falls, fractures, mortality), but those in the highest quartile of variability were 2.3 times (OR = 2.26, 95% CI = 1.34-3.80) as likely to have poor physical function scores.

Conclusion

In women surviving past 80 years of age, moderate weight loss over 20 years was associated with greater risk of hip fracture, poor physical function, and mortality but not of falls. Future work should separate voluntary from involuntary weight loss.