The effects of high-fat diet, branched-chain amino acids and exercise on female C57BL/6 mouse Achilles tendon biomechanical properties

Abstract

ObjectivesThe goals of this study were: 1) to determine if high-fat diet (HFD) feeding in female mice would negatively impact biomechanical and histologic consequences on the Achilles tendon and quadriceps muscle; and 2) to investigate whether exercise and branched-chain amino acid (BCAA) supplementation would affect these parameters or attenuate any negative consequences resulting from HFD consumption.MethodsWe examined the effects of 16 weeks of 60% HFD feeding, voluntary exercise (free choice wheel running) and BCAA administration in female C57BL/6 mice. The Achilles tendons and quadriceps muscles were removed at the end of the experiment and assessed histologically and biomechanically.ResultsHFD feeding significantly decreased the Achilles tendon modulus without histological alterations. BCAA administration significantly decreased the stiffness of Achilles tendons in the exercised normal diet mice. Exercise partially ameliorated both the weight gain and glucose levels in the HFD-fed mice, led to a significant decrease in the maximum load of the Achilles tendon, and an increase in the average fibril diameter of the quadriceps femoris muscle. There were significant correlations between body weight and several biomechanical properties, demonstrating the importance of controlling obesity for maintaining healthy tendon properties. ConclusionsIn summary, this study showed a significant impact of obesity and body weight on tendon biomechanical properties with limited effects of exercise and BCAAs.Cite this article: Bone Joint Res 2013;2:186–92.

Systemic stiffening of mouse tail tendon is related to dietary advanced glycation end products but not high-fat diet or cholesterol

“…Total modulus was not reported in that study, but, when trying to calculate this parameter from the data provided (maximum stress divided by maximum strain), there was an 8% decrease in total modulus in obese rats (obese: 938 MPa vs. lean: 1,024 MPa) compared with a 13% decrease in the present study. Supporting these findings, another study also found decreased modulus in the Achilles tendon of mice fed with a HFD (11). In the present study, we found almost similar results, a softening of the tail tendons in HFD mice compared with ND mice.…”

“…The elastic modulus of different hypercholesterolemic animal tendons has been reported to decrease (6) or increase (7); and, furthermore, in mice fed with a high-fat diet (HFD), tendon modulus has been reported to decrease (11), while deformation as well as strain of collagen fibrils have been reported to increase in obese rats (9). Thus the results are not only sparse and conflicting, but most studies are performed on weight-bearing tissue, which makes it difficult to separate the potential influence of metabolic deterioration from that of mechanical loading, especially with increased body weight as in obesity.…”

Branched-Chain Amino Acid Supplementation in Combination with Voluntary Running Improves Body Composition in Female C57BL/6 Mice

“…BCAA supplementation did not significantly affect glucose tolerance (p = 0.93, p = 0.70 for main effect of BCAA at 5 and 15 weeks, respectively). Data at the 10 week time point followed a similar trend to the 5 and 15 week data (Boivin et al, 2013). …”

“…Instead, we found that voluntary exercise significantly protected against HFD-induced obesity and glucose intolerance, and while BCAA supplementation did not significantly alter glucose tolerance, it did significantly improve lean to fat mass ratio in combination with voluntary exercise. We previously reported the body weight at the end of the study and glucose tolerance after 10 weeks in these same mice, but the focus was on the effects and correlation with Achilles tendon properties (Boivin et al, 2013). …”

Accumulation of Oxidized LDL in the Tendon Tissues of C57BL/6 or Apolipoprotein E Knock-Out Mice That Consume a High Fat Diet: Potential Impact on Tendon Health

“…Another study reported an increase in the tendon stiffness and modulus in the supraspinatus tendons of hypercholesterolemic (ApoE -/-) mice compared to control mice [24] , whereas a subsequent study by the same group reported a reduced modulus in the patellar tendons of aging ApoE -/- mice compared to controls [25] . Boivin et al studied the influence of high fat diet on C57Bl/6 female mice, and reported a reduced modulus and increased CSA of the Achilles tendon compared to standard diet [26] . It is possible that the increased CSA observed in the study by Boivin et al (measured at the surface of the tendon with digital calipers) resulted from the deposition of peritendinous fat, which was excluded from our US-based CSA measures.…”