1
|
McMillan DW, Bigford GE, Farkas GJ. The Physiology of Neurogenic Obesity: Lessons from Spinal Cord Injury Research. Obes Facts 2023; 16:313-325. [PMID: 37231872 PMCID: PMC10427964 DOI: 10.1159/000530888] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Accepted: 04/25/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND A spinal cord injury (SCI) from trauma or disease impairs sensorimotor pathways in somatic and autonomic divisions of the nervous system, affecting multiple body systems. Improved medical practices have increased survivability and life expectancy after SCI, allowing for the development of extensive metabolic comorbidities and profound changes in body composition that culminate in prevalent obesity. SUMMARY Obesity is the most common cardiometabolic component risk in people living with SCI, with a diagnostic body mass index cutoff of 22 kg/m2 to account for a phenotype of high adiposity and low lean mass. The metameric organization of specific divisions of the nervous system results in level-dependent pathology, with resulting sympathetic decentralization altering physiological functions such as lipolysis, hepatic lipoprotein metabolism, dietary fat absorption, and neuroendocrine signaling. In this manner, SCI provides a unique opportunity to study in vivo the "neurogenic" components of certain pathologies that otherwise are not readily observable in other populations. We discuss the unique physiology of neurogenic obesity after SCI, including the altered functions mentioned above as well as structural changes such as reduced skeletal muscle and bone mass and increased lipid deposition in the adipose tissue, skeletal muscle, bone marrow, and liver. KEY MESSAGE The study of neurogenic obesity after SCI gives us a unique neurological perspective on the physiology of obesity. The lessons learned from this field can guide future research and advancements to inform the study of obesity in persons with and without SCI.
Collapse
Affiliation(s)
- David W. McMillan
- Christine E. Lynn Rehabilitation Center for The Miami Project to Cure Paralysis at UHealth/Jackson Memorial, Miami, FL, USA
- Department of Neurological Surgery, University of Miami Leonard M. Miller School of Medicine, Miami, FL, USA
| | - Gregory E. Bigford
- Christine E. Lynn Rehabilitation Center for The Miami Project to Cure Paralysis at UHealth/Jackson Memorial, Miami, FL, USA
- Department of Neurological Surgery, University of Miami Leonard M. Miller School of Medicine, Miami, FL, USA
| | - Gary J. Farkas
- Christine E. Lynn Rehabilitation Center for The Miami Project to Cure Paralysis at UHealth/Jackson Memorial, Miami, FL, USA
- Department of Physical Medicine and Rehabilitation, University of Miami Leonard M. Miller School of Medicine, Miami, FL, USA
| |
Collapse
|
2
|
Awolaja OO, Lawal AO, Folorunso IM, Elekofehinti OO, Umar HI. Silibinin ameliorates the cardiovascular oxidative and inflammatory effects of type-2-diabetic rats exposed to air particulate matter. Polycycl Aromat Compd 2022. [DOI: 10.1080/10406638.2022.2123536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Olamide O. Awolaja
- Molecular Biology and Bioinformatics Unit, Department of Biochemistry, School of Sciences, Federal University of Technology, Akure, Nigeria
| | - Akeem O. Lawal
- Molecular Biology and Bioinformatics Unit, Department of Biochemistry, School of Sciences, Federal University of Technology, Akure, Nigeria
| | - Ibukun M. Folorunso
- Molecular Biology and Bioinformatics Unit, Department of Biochemistry, School of Sciences, Federal University of Technology, Akure, Nigeria
| | - Olusola O. Elekofehinti
- Molecular Biology and Bioinformatics Unit, Department of Biochemistry, School of Sciences, Federal University of Technology, Akure, Nigeria
| | - Haruna I. Umar
- Computer-Aided Therapeutic Discovery and Design Group, FUTA, Akure, Nigeria
| |
Collapse
|
3
|
McMillan DW, Maher JL, Jacobs KA, Mendez AJ, Nash MS, Bilzon JLJ. Effects of Exercise Mode on Postprandial Metabolism in Humans with Chronic Paraplegia. Med Sci Sports Exerc 2021; 53:1495-1504. [PMID: 33433151 DOI: 10.1249/mss.0000000000002593] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE The purpose of this study was to assess the acute effects of exercise mode and intensity on postprandial macronutrient metabolism. METHODS Ten healthy men age 39 ± 10 yr with chronic paraplegia (13.2 ± 8.8 yr, ASIA A-C) completed three isocaloric bouts of upper-body exercise and a resting control. After an overnight fast, participants completed circuit resistance exercise (CRE) first and the following conditions in a randomized order, separated by >48 h: i) control (CON), ~45-min seated rest; ii) moderate-intensity continuous exercise (MICE), ~40-min arm cranking at a resistance equivalent to ~30% peak power output (PPO); and iii) high-intensity interval exercise (HIIE), ~30 min arm cranking with resistance alternating every 2 min between 10% PPO and 70% PPO. After each condition, participants completed a mixed-meal tolerance test consisting of a 2510-kJ liquid meal (35% fat, 50% carbohydrate, 15% protein). Blood and expired gas samples were collected at baseline and regular intervals for 150 min after a meal. RESULTS An interaction (P < 0.001) was observed, with rates of lipid oxidation elevated above CON in HIIE until 60 min after a meal and in CRE at all postprandial time points up to 150 min after a meal. Postprandial blood glycerol was greater in MICE (P = 0.020) and CRE (P = 0.001) compared with CON. Furthermore, nonesterified fatty acid area under the curve had a moderate-to-strong effect in CRE versus MICE and HIIE (Cohen's d = -0.76 and -0.50, respectively). CONCLUSIONS In persons with paraplegia, high-intensity exercise increased postprandial energy expenditure independent of the energy cost of exercise. Furthermore, exercise combining resistance and endurance modes (CRE) showed the greater effect on postprandial lipid oxidation.
Collapse
Affiliation(s)
| | - Jennifer L Maher
- Department for Health, University of Bath, Bath, Somerset, UNITED KINGDOM
| | - Kevin A Jacobs
- Department of Kinesiology and Sport Sciences, University of Miami, Miami, FL
| | - Armando J Mendez
- Division of Endocrinology, Diabetes and Metabolism, University of Miami Miller School of Medicine, Miami, FL
| | - Mark S Nash
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami FL
| | - James L J Bilzon
- Department for Health, University of Bath, Bath, Somerset, UNITED KINGDOM
| |
Collapse
|
4
|
Gorgey AS, Ennasr AN, Farkas GJ, Gater DR. Anthropometric Prediction of Visceral Adiposity in Persons With Spinal Cord Injury. Top Spinal Cord Inj Rehabil 2021; 27:23-35. [PMID: 33814881 DOI: 10.46292/sci20-00055] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over two-thirds of persons with spinal cord injury (SCI) experience neurogenic obesity-induced cardiometabolic syndrome (CMS) and other chronic comorbidities. Obesity is likely to impede social and recreational activities, impact quality of life, and impose additional socioeconomic burdens on persons with SCI. Advances in imaging technology facilitate the mapping of adiposity and its association with the cardiometabolic profile after SCI. Central adiposity or central obesity is characterized by increased waist (WC) and abdominal circumferences (AC) as well as visceral adipose tissue (VAT). A number of studies, while relying on expensive imaging techniques, have reported direct associations of both central obesity and VAT in imposing significant health risks after SCI. The mechanistic role of central obesity on cardiometabolic heath in persons with SCI has yet to be identified, despite the knowledge that it has been designated as an independent risk factor for cardiometabolic dysfunction and premature mortality in other clinical populations. In persons with SCI, the distribution of adipose tissue has been suggested to be a function of sex, level of injury, and age. To date, there is no SCI-specific WC or AC cutoff value to provide anthropometric prediction of VAT and diagnostic capability of persons at risk for central obesity, CMS, and cardiovascular disease after SCI. The purpose of the current review is to summarize the factors contributing to visceral adiposity in persons with SCI and to develop an SCI-specific anthropometric prediction equation for this population. Furthermore, a proposed WC cutoff will be discussed as a surrogate index for central obesity, CMS, and cardiovascular disorders after SCI.
Collapse
Affiliation(s)
- Ashraf S Gorgey
- Spinal Cord Injury and Disorders Center, Central Virginia VA Health Care System, Richmond, Virginia.,Department of Physical Medicine and Rehabilitation, Virginia Commonwealth University, Richmond, Virginia
| | - Areej N Ennasr
- Spinal Cord Injury and Disorders Center, Central Virginia VA Health Care System, Richmond, Virginia
| | - Gary J Farkas
- Department of Physical Medicine and Rehabilitation, University of Miami Miller School of Medicine, Miami, Florida
| | - David R Gater
- Department of Physical Medicine and Rehabilitation, University of Miami Miller School of Medicine, Miami, Florida.,Department of Physical Medicine and Rehabilitation, Virginia Commonwealth University, Richmond, Virginia
| |
Collapse
|
5
|
McMillan DW, Kressler J, Jacobs KA, Nash MS. Substrate metabolism during recovery from circuit resistance exercise in persons with spinal cord injury. Eur J Appl Physiol 2021; 121:1631-1640. [PMID: 33655367 DOI: 10.1007/s00421-021-04629-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 02/05/2021] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Whole body energy expenditure and lipid oxidation (Lox) are upregulated during and after exercise. Persons with spinal cord injury (SCI) generally have a blunted ability to utilize fat during exercise, but it is unknown if their substrate partitioning is affected during recovery from exercise. PURPOSE To determine the effect of a single session of upper body circuit resistance exercise (CRE) on energy expenditure and Lox during exercise recovery in persons with and without SCI. METHODS Twenty four persons (3 groups; 7 male and 1 female per group) without paralysis (neurologically intact; N) or with chronic (≥ 1 yr) paraplegia (P) or tetraplegia (T) participated. Energy expenditure and substrate partitioning were assessed via indirect calorimetry before, during, and three times after (up to 120 min after) a single session of CRE, or time-matched seated control (CON). RESULTS During CRE, all groups experienced a similar relative increase in oxygen consumption (49 ± 13, 55 ± 11, and 48 ± 15% VO2peak for N, P, and T, respectively). The Post0-120 energy expenditure was greater following CRE vs. CON (P < 0.01) and independent of injury characteristics (10.6, 22.6, and 14.3% higher than CON for N, P, and T; P = 0.21). The absolute increase in Lox above CON during recovery was similar for N, P, and T (5.74 ± 2.81, 6.62 ± 3.10, and 4.50 ± 3.91 g, respectively; P = 0.45). CONCLUSIONS Energy expenditure and lipid utilization was increased similarly following circuit exercise in persons without and with spinal cord injury in a manner independent of level of injury.
Collapse
Affiliation(s)
- David W McMillan
- The Miami Project To Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA.
- Department of Physical Medicine & Rehabilitation, University of Miami Leonard M. Miller School of Medicine, Miami, FL, USA.
| | - Jochen Kressler
- Department of Exercise and Nutritional Sciences, San Diego State University, San Diego, CA, USA
| | - Kevin A Jacobs
- Department of Kinesiology and Sport Sciences, University of Miami, Miami, FL, USA
| | - Mark S Nash
- The Miami Project To Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA
| |
Collapse
|
6
|
McMillan DW, Henderson GC, Nash MS, Jacobs KA. Effect of Paraplegia on the Time Course of Exogenous Fatty Acid Incorporation Into the Plasma Triacylglycerol Pool in the Postprandial State. Front Physiol 2021; 12:626003. [PMID: 33613318 PMCID: PMC7887382 DOI: 10.3389/fphys.2021.626003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 01/18/2021] [Indexed: 11/25/2022] Open
Abstract
Spinal cord injury (SCI) results in disordered fat metabolism. Autonomic decentralization might contribute to dyslipidemia in SCI, in part by influencing the uptake of dietary fats through the gut-lymph complex. However, the neurogenic contributions to dietary fat metabolism are unknown in this population. We present a subset of results from an ongoing registered clinical trial (NCT03691532) related to dietary fat absorption. We fed a standardized (20 kcal⋅kgFFM–1) liquid meal tolerance test (50% carb, 35% fat, and 15% protein) that contained stable isotope lipid tracer (5 mg⋅kgFFM–1 [U-13C]palmitate) to persons with and without motor complete thoracic SCI. Blood samples were collected at six postprandial time points over 400 min. Changes in dietary fatty acid incorporated into the triacylglycerol (TAG) pool (“exogenous TAG”) were used as a marker of dietary fat absorption. This biomarker showed that those with paraplegia had a lower amplitude than non-injured participants at Post240 (52.4 ± 11.0 vs. 77.5 ± 16.0 μM), although this failed to reach statistical significance (p = 0.328). However, group differences in the time course of absorption were notable. The injury level was also strongly correlated with time-to-peak exogenous TAG concentration (r = −0.806, p = 0.012), with higher injuries resulting in a slower rise in exogenous TAG. This time course documenting exogenous TAG change is the first to show a potential neurogenic alteration in SCI dietary fat absorption.
Collapse
Affiliation(s)
- David W McMillan
- Department of Physical Medicine and Rehabilitation, University of Miami Miller School of Medicine, Miami, FL, United States.,The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Gregory C Henderson
- Department of Nutrition Science, Purdue University, West Lafayette, IN, United States
| | - Mark S Nash
- The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, United States
| | - Kevin A Jacobs
- Department of Kinesiology and Sport Sciences, University of Miami, Miami, FL, United States
| |
Collapse
|
7
|
Abstract
PURPOSE OF REVIEW This review assembles recent understanding of the profound loss of muscle and bone in spinal cord injury (SCI). It is important to try to understand these changes, and the context in which they occur, because of their impact on the wellbeing of SC-injured individuals, and the urgent need for viable preventative therapies. RECENT FINDINGS Recent research provides new understanding of the effects of age and systemic factors on the response of bone to loading, of relevance to attempts to provide load therapy for bone in SCI. The rapidly growing dataset describing the biochemical crosstalk between bone and muscle, and the cell and molecular biology of myokines signalling to bone and osteokines regulating muscle metabolism and mass, is reviewed. The ways in which this crosstalk may be altered in SCI is summarised. Therapeutic approaches to the catabolic changes in muscle and bone in SCI require a holistic understanding of their unique mechanical and biochemical context.
Collapse
Affiliation(s)
- Jillian M Clark
- Discipline of Orthopaedics and Trauma, The University of Adelaide, North Terrace, Adelaide, South Australia, 5000, Australia.
| | - David M Findlay
- Discipline of Orthopaedics and Trauma, The University of Adelaide, North Terrace, Adelaide, South Australia, 5000, Australia
| |
Collapse
|