Background

Total daily energy expenditure (TEE) is composed of resting metabolic rate (RMR), post-prandial thermogenesis and activity energy expenditure (AEE). Higher AEE is strongly associated with lower mortality and physical limitations among older adults, but factors that predict changes in AEE in septu and octogenarians are not clearly understood.

Objective

To identify factors associated with late-life longitudinal change in AEE.

Design

Energy expenditure was re-assessed in 83 participants (average age at baseline, 74.4±3.2 years)-an average of 7.5±0.54 years since the baseline measure. RMR was measured using indirect calorimetry and the thermic effect of meals was estimated at 10% of TEE. AEE was calculated as: TEE(0.9)-RMR. Participants were categorized into two groups according to the estimated day-to-day precision of the doubly-labeled water technique. Those who were within 10% or increased relative to their initial AEE measurement were categorized as having preserved AEE. Participants who declined greater than 10% of their initial measurement were categorized as having reduced AEE. A variety of socio-demographic, functional and mental factors, body composition, community and personal behaviors, blood measurements and health conditions were evaluated between groups at baseline and changes during follow-up.

Results

Daily AEE declined 106.61±293.25 kcal, which equated to a 14.63±40.57 kcal/d decrease per year. Fifty-nine percent (n = 49) preserved their AEE and 41% (n = 34) declined. Those who demonstrated a decline in AEE were older, had lower walking speed at baseline and showed a higher lean mass loss during follow up. Otherwise, groups were similar for socio-demographic characteristics, body composition, mental and physical function, health conditions and community and personal behaviors at baseline and change in these factors during follow-up.

Conclusions

This study demonstrates that AEE declines through the 8th decade of life and is associated with age, lower walking speed at baseline and lean mass loss. Additionally, there are a significant number of individuals who appear to be resilient to these declines despite having health events that are expected to have a negative impact on their physical activity.

Objective

To examine whether weight history and weight transitions over adult lifespan contribute to physical impairment among postmenopausal women.

Design

BMI categories were calculated among postmenopausal women who reported their weight and height at age 18 years. Multiple-variable logistic regression was used to determine the association between BMI at age 18 years and BMI transitions over adulthood on severe physical impairment (SPI), defined as scoring <60 on the Physical Functioning subscale of the Rand thirty-six-item Short-Form Health Survey.

Setting

Participants were part of the Women's Health Initiative Observational Study (WHI OS), where participants' health was followed over time via questionnaires and clinical assessments.

Subjects

Postmenopausal women (n 76 016; mean age 63·5 (sd 7·3) years).

Results

Women with overweight (BMI=25·0-29·9 kg/m2) or obesity (BMI≥30·0 kg/m2) at 18 years had greater odds (OR (95 % CI)) of SPI (1·51 (1·35, 1·69) and 2·14 (1·72, 2·65), respectively) than normal-weight (BMI=18·5-24·9 kg/m2) counterparts. Transitions from normal weight to overweight/obese or to underweight (BMI<18·5 kg/m2) were associated with greater odds of SPI (1·97 (1·84, 2·11) and 1·35 (1·06, 1·71), respectively) compared with weight stability. Shifting from underweight to overweight/obese also had increased odds of SPI (1·52 (1·11, 2·09)). Overweight/obese to normal BMI transitions resulted in a reduced SPI odds (0·52 (0·39, 0·71)).

Conclusions

Higher weight history and transitions into higher weight classes were associated with higher likelihood of SPI, while transitioning into lower weight classes for those with overweight/obesity was protective among postmenopausal women.