Background
Obesity exacerbates age-related effects on body composition, physical and metabolic function. Which exercise mode is most effective in mitigating these deleterious changes in dieting obese older adults is unknown.
Methods
In a randomized controlled trial, we performed a head-to-head comparison of aerobic (AEX), resistance (REX), or combination (COMB) exercise during matched weight loss in 160 obese older adults. Prespecified analyses compared 6-month changes in intermuscular adipose tissue (IMAT) and visceral adipose tissue (VAT) assessed using MRI, insulin sensitivity index (ISI) by oral glucose tolerance test, physical function using Modified Physical Performance Test (PPT), VO2peak, gait-speed, and knee strength by dynamometry.
Results
IMAT and VAT decreased more in COMB than AEX and REX groups (IMAT; -41% vs. -28% and -23% and VAT: -36% vs. -19% and -21%; p=.003 to .01); IMAT and VAT decreased in all groups more than control (CON) (between-group p<.001). ISI increased more in COMB than AEX and REX groups (86% vs. 50% and 39%; p=.005 to .03). PPT improved more in COMB than AEX and REX groups, while VO2peak improved more in COMB and AEX than REX group (all p<.05). Knee strength improved more in COMB and REX than AEX group (all p<.05). Changes in IMAT and VAT correlated with PPT (r=-.28 and -.39), VO2peak (r=-.49 and -.52), gait-speed (r=-.25 and -.36), and ISI (r=-.49 and -.52) (all p<.05).
Conclusions
Weight loss plus combination aerobic and resistance exercise was most effective in improving ectopic fat deposition and physical and metabolic function in older adults with obesity.
Introduction
Obesity and type 2 Diabetes (T2D) are both associated with greater bone mineral density (BMD) but increased risk of fractures. The effect of the combination of both conditions on bone metabolism, microarchitecture and strength in the obese population remains unknown.
Methods
Data from 112 obese men were collected. Bone turnover and biochemical markers were measured by enzyme-linked immunosorbent assay (ELISA), body composition and BMD at all sites were assessed by dual energy X-ray absorptiometry (DXA), whereas bone microarchitecture and strength (stiffness and failure load) were measured by high-resolution peripheral computed tomography (HR-pQCT). Data were compared among metabolically healthy obese (MHO) and metabolically unhealthy obese (MUHO) with and without T2D and between obese without and with T2D.
Results
Compared to MHO and MUHO without T2D, MUHO with T2D had significantly lower levels of osteocalcin ((7.49±3.0 and 6.03±2.47, vs 4.24±2.72 ng/ml, respectively, p=0.003) and C-terminal telopeptide of type I collagen (CTx) (0.28±0.10 and 0.29±0.13 vs. 0.21±0.15 ng/ml, respectively, p=0.02). Dividing our subjects simply into those with and without T2D showed that obese men with T2D had significantly lower levels of osteocalcin (p=0.003) and CTx (p=0.005), greater trabecular separation at the tibia and radius (p=0.03 and p=0.04, respectively) and lower tibial failure load and stiffness (both p=0.04), relative to obese men without T2D.
Conclusion
In men, the combination of obesity and T2D is associated with reduced bone turnover, poorer trabecular bone microarchitecture and bone strength compared to those who are obese but without T2D suggesting worse bone disease.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.