Aging is associated with significant changes in body composition. Both malnutrition and obesity are related to chronic diseases and functional and cognitive decline. The value of BMI for indicating fatness in old age has been questioned and anthropometric measures of body composition that are more predictive of health outcomes have been searched. We examined the relation of BMI and other body composition indexes (both muscle mass and body fat) with functional ability (mobility, independence, cognitive ability) in very old age. The study comprised 328 individuals (83 men ; 245 women) aged 85-101 yrs living in old people's homes (Zagreb, Croatia). According to Mini-Nutritional-Assessment (MNA), 4.6% were malnourished and 53.1% had normal nutritional status. Underweight subjects (BMI<18.5) had exceptionally low mobility and independence ranks (50% were chair/bed bound and dependent on assistance). The majority of overweight (BMI 25.0-29.99) and obese subjects (BMI 30.0-39.99) were completely mobile (78% and 86% respectively) and independent (83% and 93% respectively). Those with normal body weight (BMI 18.5-24.99) had lower functional ability compared to the overweight subjects. Waist circumference and waist-to-hip ratio showed little relation with mobility and independence, while midarm muscle circumference, particularly top sex-specific tertile, was associated with their highest levels. No association of anthropometric measures with cognitive ability, indicated by Minimental Score (MMS), was found. The findings confirm the role of BMI in predicting functional outcomes and strongly suggest higher optimal BMI range for very old individuals. The midarm muscle circumference provides additional measure of body composition to predict functional ability in very old age.

Biologija,Javno zdravstvo i zdravstvena zaštita,Etnologija i antropologija