Body Weight, BMI, Percent Fat and Associations with Mortality and Incident Mobility Limitation in Older Men

Abstract

How different measures of adiposity are similarly or differentially related to mobility limitation and mortality is not clear. In total, 5849 community-dwelling men aged ≥65 years (mean age: 72 years) were followed mortality over 10 years and self-reported mobility limitations (any difficulty walking 2–3 blocks or with climbing 10 steps) at six contacts over 14 years. Baseline measures of adiposity included weight, BMI and percent fat by DXA. Appendicular lean mass (ALM, by DXA) was analyzed as ALM/ht2. Proportional hazards models estimated the risk of mortality, and repeated measures generalized estimating equations estimated the likelihood of mobility limitation. Over 10 years, 27.9% of men died; over 14 years, 48.0% of men reported at least one mobility limitation. We observed U-shaped relationships between weight, BMI, percent fat and ALM/ht2 with mortality. There was a clear log-linear relationship between weight, BMI and percent fat with incident mobility limitation, with higher values associated with a greater likelihood of mobility limitation. In contrast, there was a U-shaped relationship between ALM/ht2 and incident mobility limitation. These observational data suggest that no single measure of adiposity or body composition reflects both the lowest risk of mortality and the lowest likelihood for developing mobility limitation in older men.

Association of muscle wasting with mortality risk among adults: A systematic review and meta‐analysis of prospective studies

“…As our meta‐analysis has found, the risk of all‐cause mortality was higher in the elderly than that in the younger populations. In our present study, participants were older than 75 years in 7 18,20,50,60,73,76,77 of 11 18,20,38,39,49,50,60,64,73,76,77 studies followed for <5 years, whereas participants were older than 75 years only in 5 46,48,69,70,74 of 22 16,19,40,41,43,46–48,51,53,55,56,58,61,66,69,70,74,75,78–80 studies followed for 10 years or longer. Therefore, our study could suggest that the length of follow‐up, which might be influenced by the age of participants, was a potential confounder in the muscle wasting and all‐cause mortality risk association.…”

“…Forty‐nine articles with 66 reports reported muscle wasting‐related effect sizes for mortality risks due to all causes, 16–20,37–79 eight articles with 11 reports due to CVD, 45,49,51,55,61,65,68,74 three articles with 4 reports due to cancer, 51,61,65 three articles with 4 reports due to respiratory disease 51,61,68 and one article with 2 reports due to diabetes 55 . No available information was found for mortality from other causes.…”

Low skeletal muscle mass index and all-cause mortality risk in adults: A systematic review and meta-analysis of prospective cohort studies

“…One possible reason might be that the subjects of the study with a follow-up of less than 5 years were older. In the studies we included, the average age of the participants was 81.8 years [ 37 , 41 , 45 , 47 ] for follow-up periods of less than 5 years, 68.0 years [ 32 , 33 , 35 , 38 – 40 , 42 , 44 ] for follow-up periods of 5 to 10 years, and 76.1 years [ 34 , 36 , 43 , 46 ] for follow-up periods of more than 10 years. Although the average age of participants with a follow-up duration of 5 to 10 years was older than that of those with a follow-up period of more than 10 years, the average age of those with a follow-up period of less than 5 years was the oldest.…”

Identification of three bacterial species associated with increased appendicular lean mass: the HUNT study

“…We conclude that the anabolic species count may be used as a marker of ALM and BMD. The therapeutic potential of these anabolic species to prevent sarcopenia and osteoporosis needs to be determined.Appendicular lean mass (ALM), measured by dual-energy x-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA), is associated with mobility, bone mineral density (BMD), and metabolic function [1][2][3][4] . With aging, there is a loss of skeletal muscle mass, and a concurrent increase in fatty infiltration and fibrosis of muscle.…”

“…Appendicular lean mass (ALM), measured by dual-energy x-ray absorptiometry (DXA) or bioelectrical impedance analysis (BIA), is associated with mobility, bone mineral density (BMD), and metabolic function [1][2][3][4] . With aging, there is a loss of skeletal muscle mass, and a concurrent increase in fatty infiltration and fibrosis of muscle.…”