Promotion of intramuscular fat accumulation in porcine muscle by nutritional regulation

ObjectivesHereditary sensory neuropathy type 1 (HSN1) is a rare, slowly progressive neuropathy causing profound sensory deficits and often severe motor loss. L-serine supplementation is a possible candidate therapy but the lack of responsive outcome measures is a barrier for undertaking clinical trials in HSN1. We performed a 12-month natural history study to characterise the phenotype of HSN1 and to identify responsive outcome measures.MethodsAssessments included Charcot-Marie-Tooth Neuropathy Score version 2 (CMTNSv2), CMTNSv2-Rasch modified, nerve conduction studies, quantitative sensory testing, intraepidermal nerve fibre density (thigh), computerised myometry (lower limbs), plasma 1-deoxysphingolipid levels, calf-level intramuscular fat accumulation by MRI and patient-based questionnaires (Neuropathic Pain Symptom Inventory and 36-Short Form Health Survey version 2 [SF-36v2]).Results35 patients with HSN1 were recruited. There was marked heterogeneity in the phenotype mainly due to differences between the sexes: males generally more severely affected. The outcome measures that significantly changed over 1 year and correlated with CMTNSv2, SF-36v2-physical component and disease duration were MRI determined calf intramuscular fat accumulation (mean change in overall calf fat fraction 2.36%, 95% CI 1.16 to 3.55, p=0.0004), pressure pain threshold on the hand (mean change 40 kPa, 95% CI 0.7 to 80, p=0.046) and myometric measurements of ankle plantar flexion (median change −0.5 Nm, IQR −9.5 to 0, p=0.0007), ankle inversion (mean change −0.89 Nm, 95% CI −1.66 to −0.12, p=0.03) and eversion (mean change −1.61 Nm, 95% CI −2.72 to −0.51, p=0.006). Intramuscular calf fat fraction was the most responsive outcome measure.ConclusionMRI determined calf muscle fat fraction shows validity and high responsiveness over 12 months and will be useful in HSN1 clinical trials.

Download Full-text

Adipocyte hyperplasia: the primary mechanism of supraspinatus intramuscular fat accumulation after a complete rotator cuff tendon tear: a study in the rabbit

Adipocyte ◽

10.1080/21623945.2019.1609201 ◽

2019 ◽

Vol 8 (1) ◽

pp. 144-153

Author(s):

Guy Trudel ◽

Hans K. Uhthoff ◽

Kayleigh Wong ◽

Josée Dupuis ◽

Odette Laneuville

Keyword(s):

Rotator Cuff ◽

Intramuscular Fat ◽

Tendon Tear ◽

Fat Accumulation ◽

Rotator Cuff Tendon ◽

Primary Mechanism ◽

Adipocyte Hyperplasia

Download Full-text

Impact of intramuscular fat accumulation on survival in stage II/III gastric cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2019.37.4_suppl.19 ◽

2019 ◽

Vol 37 (4_suppl) ◽

pp. 19-19

Author(s):

Yuhei Waki ◽

Rie Makuuchi ◽

Tomoyuki Irino ◽

Satoshi Kamiya ◽

Yutaka Tanizawa ◽

...

Keyword(s):

Gastric Cancer ◽

Overall Survival ◽

Prognostic Factor ◽

Subcutaneous Fat ◽

Lumbar Vertebra ◽

Intramuscular Fat ◽

Stage Ii ◽

Youden Index ◽

Fat Accumulation ◽

The Impact

19 Background: Intramuscular fat accumulation of skeletal muscle has been reported to be a prognostic factor in various cancers. To evaluate the intramuscular steatosis, intramuscular adipose tissue content (IMAC) measured by CT scan is thought to be an ideal method. However, this kind of study is very limited in curatively resected gastric cancer. So, this study was aimed to clarify the impact of IMAC on survival in stage II/III gastric cancer (GC). Methods: A total of 383 patients with pathological stage II/III GC after curative gastrectomy between January 2009 and December 2013 were included. IMAC was calculated by dividing the CT value of the multifidus muscles with that of the subcutaneous fat at the level of third lumbar vertebra. The IMAC cut-off values associated with cancer-specific survival (CSS) were separated by sex based on the maximum values of Youden index (sensitivity + specificity -1). Patients were classified into normal or high IMAC group according to this cut-off value. Clinicopathological factors and survival outcomes were compared between the two groups. Results: The median values of IMAC were -0.327 (IQR: -0.404- -0.250) in male and -0.239 (IQR: -0.335- -0.114) in female. The cut-off values of IMAC were -0.345 in male and -0.126 in female. Patients were classified into normal IMAC group (n = 204) and high IMAC group (n = 179). Patients in the high IMAC group were elderly, male, obese, having many comorbidities and with poor ECOG-PS compared to those in the normal IMAC group. Interestingly, despite the fact that no significant differences were observed in the pathological findings between the groups, the overall survival and CSS were significantly worse in the high IMAC group than in the normal IMAC group (p < 0.001 and p = 0.035). Moreover, the high IMAC was identified as an independent prognostic factor not only for overall survival but also for CSS (HR: 1.440, p = 0.021, HR: 1.646, p = 0.008, respectively). Conclusions: The high IMAC was significantly associated with worse survival, suggesting that IMAC represents certain oncological implications in patients with GC. Therefore, IMAC could be used as a new prognostic factor in curatively resected GC.

Download Full-text

Dietary calcium supplementation promotes the accumulation of intramuscular fat

Journal of Animal Science and Biotechnology ◽

10.1186/s40104-021-00619-6 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Zhiwang Zhang ◽

Tingli Pan ◽

Yu Sun ◽

Siqi Liu ◽

Ziyi Song ◽

...

Keyword(s):

Meat Quality ◽

Calcium Supplementation ◽

Intramuscular Fat ◽

Dietary Calcium ◽

Fat Content ◽

C2c12 Cells ◽

Longissimus Dorsi ◽

Fat Accumulation ◽

Calcium Addition ◽

Intramuscular Fat Content

Abstract Background In the livestock industry, intramuscular fat content is a key factor affecting meat quality. Many studies have shown that dietary calcium supplementation is closely related to lipid metabolism. However, few studies have examined the relationship between dietary calcium supplementation and intramuscular fat accumulation. Methods Here, we used C2C12 cells, C57BL/6 mice (n = 8) and three-way cross-breeding pigs (Duroc×Landrace×Large white) (n = 10) to study the effect of calcium addition on intramuscular fat accumulation. In vitro, we used calcium chloride to adjust the calcium levels in the medium (2 mmol/L or 3 mmol/L). Then we measured various indicators. In vivo, calcium carbonate was used to regulate calcium levels in feeds (Mice: 0.5% calcium or 1.2% calcium) (Pigs: 0.9% calcium or 1.5% calcium). Then we tested the mice gastrocnemius muscle triglyceride content, pig longissimus dorsi muscle meat quality and lipidomics. Results In vitro, calcium addition (3 mmol/L) had no significant effect on cell proliferation, but promoted the differentiation of C2C12 cells into slow-twitch fibers. Calcium supplementation increased triglyceride accumulation in C2C12 cells. Calcium addition increased the number of mitochondria and also increased the calcium level in the mitochondria and reduced the of key enzymes activity involved in β-oxidation such as acyl-coenzyme A dehydrogenase. Decreasing mitochondrial calcium level can alleviate lipid accumulation induced by calcium addition. In addition, calcium addition also reduced the glycolytic capacity and glycolytic conversion rate of C2C12 cells. In vivo, dietary calcium supplementation (1.2%) promoted the accumulation of triglycerides in the gastrocnemius muscle of mice. Dietary calcium supplementation (1.5%) had no effect on pig weight, but significantly improved the flesh color of the longissimus dorsi muscle, reduced the backfat thickness and increased intramuscular fat content in pigs. Besides, calcium addition had no effect on longissimus dorsi pH, electrical conductivity and shear force. Conclusions These results suggest that calcium addition promotes intramuscular fat accumulation by inhibiting the oxidation of fatty acids. These findings provide a new tool for increasing intramuscular fat content and an economical strategy for improving meat quality.

Download Full-text