Anthropometric changes over 5 years in elderly Canadians by age, gender, and cognitive status

Numerous changes in body composition occur with aging. This study reports on secondary analyses of data from a subsample of institutionalized and free-living elderly Canadians taking part in both phases of the Canadian Study of Health and Aging (CSHA-1 and CHSA-2; n = 10,263) to document and examine correlates of the evolution of anthropometric characteristics over a 5-year period.

In CSHA-1, community-dwelling (n = 1464) and institutionalized (n = 963) participants' height and weight were measured in clinics. Surviving participants were remeasured in CSHA-2; valid data were available for 487 community-dwelling respondents (66.9% of those seen in clinics in CSHA-2) and 140 institutionalized participants (46.9% of those reassessed). Body mass index (BMI = weight [kg]/height [m(2)]) was calculated. Paired t tests were used to test changes over the interval, and repeated-measures multivariate analysis of variance was used to examine the extent of differences within and across categories.

The average weight loss between study phases in community-dwelling and institutionalized participants was approximately 2 kg (p <.001). In institutions, this was statistically significant in most stratification categories, as was the case in community-dwelling participants (by gender, age, dementia screening score, and cognitive diagnosis). Among those who were cognitively intact, the greatest weight losses occurred in participants under 90 years old and in those aged 70 to 79 years with a diagnosis of dementia (p <.01). Stature decreased more in institutionalized (2 cm) than in community-dwelling participants (1.4 cm). In institutions, this was significant among the oldest men (p <.005), while in the community there were no differences in the extent of height lost in all stratification categories. The average BMI was largely stable.

Body weight and stature declined with aging among elderly Canadian CSHA participants, particularly in the very old and those with dementia. Such longitudinal anthropometric data are needed along with information on dietary intakes, and medical, cognitive, and functional measures to plan interventions geared to maximizing nutritional and overall health in the elderly population, whatever their cognitive status.