Moreno Zanardo1, Anna Colarieti1, Paolo Vitali1, Giovanni Di Leo1, Anna Ferrulli2, Stefano Massarini2, Livio Luzi3, and Francesco Sardanelli3
1IRCCS Policlinico San Donato, Milan, Italy, 2IRCCS MultiMedica, Milan, Italy, 3Università degli Studi di Milano, Milan, Italy
Synopsis
Motivation: This research is driven by the pivotal role of 1H-MRS in comprehending the relationship between bone marrow fat (BMF), metabolic conditions, and lifestyle interventions.
Goal(s): This research holds the potential to uncover 1H-MRS as a tool for comprehending metabolic health through lifestyle interventions.
Approach: It seeks to elucidate the therapeutic potential of lifestyle interventions in regulating BMF and its implications for metabolic health.
The study employs a prospective cohort design, utilizing 1H-MRS to quantify vertebral BMF before and after an 8-week dietary intervention incorporating nuts and physical activity.
Results: The research observed a non-significant trend towards reduced BMF following the intervention.
Impact: The study's results underscore the
potential of 1H-MRS in assessing BMF in the context of lifestyle
interventions. These findings
stimulate further investigations, encouraging scientists and clinicians to
explore larger cohorts to elucidate the role of BMF in metabolic health.
Background or Purpose
The growing interest in adipose tissue physiology stems from its potential to enhance our understanding of the mechanisms underpinning obesity and metabolic abnormalities. Bone
marrow fat (BMF) is recognized as a pivotal player in obesity and metabolism [1-3].
Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) can be used to noninvasively measure bone marrow lipids [4-6].
This study aims to
investigate the impact of lifestyle modifications on bone marrow adiposity and
its potential association with improved metabolic health. To determine whether an 8-week dietary intervention (incorporation of nuts) and physical activity program can effectively reduce bone marrow fat (BMF) levels, utilizing magnetic resonance spectroscopy (MRS) as a quantitative assessment tool. By quantifying BMF
changes pre- and post-intervention, the study seeks to elucidate the
therapeutic potential of lifestyle interventions in regulating bone marrow fat
content and its implications for metabolic health outcomes.Methods
After obtaining Ethical Committee approval, we recruited a prospective cohort of healthy volunteers aged 18-50, with a stable body mass index, and a consistent six-month history of diet and physical activity.
Exclusion criteria included diabetes, impaired glucose tolerance, dyslipidemia, metabolic syndrome, pregnancy, substance abuse, and contraindications for MRI.
We utilized 1H-MRS to measure vertebral
BMF fat content at the L4 vertebral level content and composition before and after an 8-week dietary intervention involving the incorporation of nuts and physical activity. The dietary intervention required participants to consume 30 grams of nuts daily.
A single voxel was carefully positioned to encompass a significant portion of the L4 vertebral body, with a deliberate avoidance of cortical bone and surrounding tissues. We employed a point-resolved spectroscopy sequence without fat or water saturation or saturation bands (TR 2000 ms, TE 190 ms, NEX 192, TA 360 s). The resulting spectrum was further processed to identify and analyze peaks corresponding to water, saturated lipids, and unsaturated lipids.
Calculations were executed as follows: Fat content (%) = (Ifat/(Ifat + Iwater)) × 100, and unsaturation index = (Iolefinic/(Iolefinic + Imethylene + Imethyl)), with "I" denoting peak area.
Descriptive statistics and two-sample t-tests were employed for analysis. The study underscores the potential of 1H-MRS in assessing the effects of lifestyle interventions on BMF, enhancing our comprehension of bone marrow adiposity.Results
The study
enrolled 42 participants with aged 25.7 ± 8.2 years (mean ± standard deviation). Among them,
19/42 (45%) were males, aged 27.2 ± 7.5
years, and 23/42 (55%) were female, aged 30.0 ± 8.0 years. The study observed a non-significant trend towards reduced BMF following an 8-week dietary and physical activity intervention. Before the diet/training
program, women had an average BMF of 0.46 ± 0.14, after the program 0.44 ± 0.15 (p = 0.27); men had 0.64 ± 0.18 and 0.63 ± 0.14, respectively (p = 0.22). Although BMF reductions did not
reach statistical significance (p=0.22 for men, p=0.27 for women), the findings
suggest potential benefits in mitigating bone marrow adiposity. Fat content displayed
a slight, statistically non-significant decrease, while the unsaturation index,
indicative of fatty acid saturation, remained relatively stable
post-intervention.
A 14% dropout rate, involving six participants, may have
impacted the study's statistical power in detecting significant BMF changes.
Further research with larger cohorts may provide deeper insights into the
effects of lifestyle modifications on BMF.Conclusions
Our study focused on the pivotal role of 1H-MRS in assessing changes in bone marrow fat (BMF) in response to dietary and physical activity interventions. The observed trend toward BMF reduction following the 8-week program, while not reaching statistical significance, underscores the potential benefits of lifestyle modifications in mitigating bone marrow adiposity.
One possible explanation for the lack of statistical significance could be the relatively small sample size in our study. A larger cohort might provide the statistical power needed to detect significant changes in BMF.
In conclusion, our study underscores the promising role of 1H-MRS as a valuable tool for evaluating BMF in the context of dietary and physical activity interventions. To obtain more definitive conclusions and deeper insights, future studies with larger sample sizes and longer intervention periods are warranted.
Additionally, addressing participant dropout and retention issues could enhance the statistical power of such investigations. Our research contributes to the growing body of knowledge on the relationship between lifestyle interventions and BMF, opening doors for further exploration and potential clinical applications in the realm of obesity and metabolic health.Acknowledgements
This research was partially and unconditionally supported by Soremartec, who provided the nuts for this study. We also extend our appreciation to all the radiologists and radiographers who played a vital role in this research and generously shared their expertise and support.References
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