Weight Loss-Associated Bone Loss Persists Despite Weighted Vest or Resistance Training: JAMA
Researchers have discovered in a 12-month randomized clinical trial that older adults with obesity experienced bone loss associated with weight loss, regardless of whether they engaged in resistance training or used a weighted vest. The study highlights the challenge of preserving bone health during weight reduction. The study was published in JAMA Network by Kristen M. and colleagues.
Weight loss in the elderly has traditionally been linked to reduced bone mass, an effect increasing the risk of fracture, especially in weight-bearing bones such as the hip. Tissue in the bones is very sensitive to stress caused by movement, and researchers were curious to see if external replacement of lost weight with weighted vests would preserve bone density. The main aim of this research was to contrast the impact of three interventions on bone: calorie-restricted weight loss alone (WL), weight loss with weighted vest use (WL+VEST), and weight loss with progressive resistance training (WL+RT).
This randomized clinical trial was performed at an academic medical center between September 1, 2019, and April 30, 2024. The study enrolled 150 older adults (mean age: 66.4 years; 74.7% female), all with obesity (mean BMI: 33.6), who were equally randomized to three intervention arms.
WL Group: Was given dietary intervention for 10% weight loss with proper intake of calcium, vitamin D, and protein.
WL+VEST Group: Followed the same diet regimen along with wearing a weighted vest for 8 hours per day, with weights being added incrementally to equate up to 10% of lost total body weight.
WL+RT Group: Fetched the diet regimen along with undergoing supervised progressive resistance training sessions, three times per week.
Bone health outcomes were assessed through computed tomography (CT) and dual-energy X-ray absorptiometry (DXA), which measured changes in trabecular volumetric bone mineral density (vBMD) and areal bone mineral density (aBMD) at the hip. Secondary outcomes were musculoskeletal changes and biomarkers of bone turnover.
Results
Of the 150 participants, 133 (88.7%) completed the 12-month study.
All three groups had comparable and considerable weight loss, from 9.0% to 11.2%.
Attendance was high, with WL+VEST group participants wearing the vest for an average of 7.1 hours per day and compensating externally for 78.0% of weight loss.
In WL+RT, exercise session attendance averaged 71.4%.
All groups showed statistically significant reduction in hip trabecular vBMD at 12 months:
WL group: −1.2%
WL+VEST group: −1.6%
WL+RT group: −1.9%
No considerable disparity in loss of vBMD was found between the WL and WL+VEST groups (estimated difference: +0.91 mg/cm³; 97.5% CI: −0.27 to 2.09 mg/cm³; P = 0.13).
Likewise, noninferiority of WL+VEST over WL+RT was not established (estimated difference: +0.29 mg/cm³; 98.75% lower bound: −1.05 mg/cm³). aBMD results were similar to those of vBMD.
This 12-month clinical trial shows that although both weighted vest use and resistance training were well tolerated and enabled participants to lose considerable weight, neither intervention was effective at preventing the concomitant loss of bone density in the hip.
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