Proton magnetic resonance spectroscopy in skeletal muscle: Experts' consensus recommendations

Families predisposed to longevity show enhanced glucose tolerance and skeletal muscle insulin sensitivity compared with controls, independent of body composition and physical activity. Intramyocellular lipid (IMCL) accumulation in skeletal muscle has been associated with insulin resistance. Here, we assessed whether subjects enriched for familial longevity have lower IMCL levels. We determined IMCL levels in 48 subjects from the Leiden Longevity Study, comprising 24 offspring of nonagenarian siblings and 24 partners thereof as control subjects. IMCL levels were assessed noninvasively using short echo time proton magnetic resonance spectroscopy (1H-MRS) of the tibialis anterior muscle with a 7 Tesla human MR scanner. IMCL levels were calculated relative to the total creatine (tCr) CH3 signal. Physical activity was assessed using the International Physical Activity Questionnaire (IPAQ). After correction for age, sex, BMI, and physical activity, offspring of long-lived nonagenarian siblings tended to show lower IMCL levels compared with controls (IMCL/tCr: 3.1 ± 0.5 vs. 4.5 ± 0.5, respectively, P = 0.051). In a pairwise comparison, this difference reached statistical significance ( P = 0.038). We conclude that offspring of nonagenarian siblings predisposed to longevity show lower IMCL levels compared with environmentally matched control subjects. Future research should focus on assessing what mechanisms may explain the lower IMCL levels in familial longevity.

Download Full-text

Cores of Reproducibility in Physiology (CORP): quantification of human skeletal muscle carnosine concentration by proton magnetic resonance spectroscopy

Journal of Applied Physiology ◽

10.1152/japplphysiol.00056.2021 ◽

2021 ◽

Author(s):

Eline Lievens ◽

Kim Van Vossel ◽

Freek Van de Casteele ◽

Martin Krššák ◽

James B. Murdoch ◽

...

Keyword(s):

Skeletal Muscle ◽

Magnetic Resonance ◽

Magnetic Resonance Spectroscopy ◽

Proton Magnetic Resonance ◽

Proton Magnetic Resonance Spectroscopy ◽

Fiber Type ◽

Resonance Spectroscopy ◽

Muscle Carnosine ◽

Beta Alanine

Non-invasive techniques to quantify metabolites in skeletal muscle provide unique insight into human physiology and enable the translation of research into practice. Proton magnetic resonance spectroscopy (1H-MRS) permits the assessment of several abundant muscle metabolites in vivo, including carnosine, a dipeptide composed of the amino acids histidine and beta-alanine. Muscle carnosine loading - accomplished by chronic oral beta-alanine supplementation - improves muscle function, exercise capacity and has pathophysiological relevance in multiple diseases. Moreover, the marked difference in carnosine content between fast-twitch and slow-twitch muscle fibers has rendered carnosine an attractive candidate to estimate human muscle fiber type composition. However, the quantification of carnosine using 1H-MRS requires technical expertise in order to obtain accurate and reproducible data. In this review, we describe the technical and physiological factors that impact the detection, analysis and quantification of carnosine in muscle using 1H-MRS. We discuss potential sources of error during the acquisition and pre-processing of the 1H-MRS spectra, and present best practices to enable the accurate, reliable and reproducible application of this technique.

Download Full-text