Effect of Baseline BMI and IL-6 Subgroup Membership on Gait Speed Response to Caloric Restriction in Older Adults with Obesity

• Published in: The Journal of nutrition, health & aging health & aging, 2023-04, Vol.27 (4), p.285-290
• Main Authors: Hsieh, Katherine L., Neiberg, R. H., Beavers, K. M., Rejeski, W. J., Messier, S. P., Nicklas, B. J., Beavers, D. P.
• Format: Article
• Language: English
• Subjects: Aged; Aging; Body Mass Index; Caloric Restriction; Cytokines; Gait; Geriatrics/Gerontology; Humans; Inflammation; Interleukin-6; Medicine; Medicine & Public Health; Neurosciences; Nutrition; Obesity; Older people; Original Research; Primary Care Medicine; Quality of Life Research; Velocity; Walking; Walking Speed
• ISSN: 1279-7707; 1760-4788; 1760-4788
• DOI: 10.1007/s12603-023-1909-1

Background Prior work shows caloric restriction (CR) can improve physical function among older adults living with obesity. However, the contribution of starting weight and inflammatory burden to CR-associated functional improvements is unclear. The primary purpose of this study was to determine if CR-associated gait speed change varied by body mass index (BMI) and plasma interleukin 6 (IL-6) at baseline and secondarily to determine the contribution of BMI change and IL-6 change to gait speed change. Design, Setting, Participants Data from eight randomized control trials were pooled, with 1184 participants randomized to CR (n=661) and No CR (n=523) conditions. All studies assessed outcomes before and five or six months after assignment to CR or No CR. Measurements BMI and IL-6 were assessed at baseline using standard procedures. Gait speed was assessed with the six-minute walk test or 400m walk test. Baseline BMI/IL-6 subgroups were constructed using BMI≥35 kg/m 2 and IL-6>2.5 pg/mL thresholds. Participants with BMI≥35 kg/m 2 were grouped into class 2+ obesity and BMI2.5 pg/mL were grouped into high IL-6, and