Effect of Cold Exposure and Exercise on Carbohydrate and Lipid Metabolism in Persons with Cervical Spinal Cord Injury
Authors: Nishiyama Kazunari , Kamijo Yoshi-ichiro , Nakata Tomonori , van der Scheer Jan W. , Tajima Fumihiro 
Published: April 2020

ObjectiveRates of retiring for Oita International Wheelchair Marathon in the last decade were higher with the lower atmospheric temperature below 22°C. The tendency was stronger in persons with cervical spinal cord injury (CSCI) than the other classes (unpublished data), which may be associated with deteriorated lipid utilization and a faster depletion of glycogen in a whole body. Our purpose was to examine whether serum profile of lipid in CSCI during cold stress and exercise was different from able‐body persons (AB) or varied dependent on the injury level.Methods[Protocol1] Nine CSCI and 11 AB wore a water‐perfused suit and took a supine position then 33‐°C water was perfused into the suit. After 10‐min measurement of thermoneutral condition, 25‐°C water was perfused for 20min (CS), then perfused 33‐°C water for 60min, while monitoring esophageal (Tes) and mean skin temperatures (Tsk). Blood samples were taken before, just after, 60‐ and 120min after CS. [Protocol2] Six of each CSCI and AB did a 30‐min arm crank exercise at 50% VO2peak then took a sitting position for 60min as a recovery. Blood samples were taken before, just after and an hour after exercise. [Protocol3] Bloods were sampled from 5 CSCI and 9 thoracic and lumbar SCI (LSCI), who completed a half marathon, before, just after and an hour after the race. Plasma concentrations of adrenaline ([Ad]p), noradrenaline ([Nor]p), and glucose ([Glc]p), and serum concentrations of insulin ([Ins]s), free fatty acid ([FFA]s), and total ketone bodies ([tKB]s) were assessed in all protocols.Results[Protocol1] Tsk decreased by ~2 °C during CS and Tes decreased by ~0.2 °C after CS with no significant differences between groups. VO2 was similar between groups and remained unchanged throughout the study. Respiratory quotient was significantly decreased in AB after CS but remained unchanged in CSCI. [Ad]p and [Nor]p were lower in CSCI than AB and [Nor]p significantly increased only in AB during recovery. [Glc]p before, immediately and one hour after CS was higher in CSCI but it decreased to the same level as AB 2 hours later. [FFA]s did not differ between groups and decreased after CS in only AB. [tKB]s significantly increased after CS in both groups, but the increase started from 1‐hour recovery in CSCI. [Protocol2] [Ad]p and [Nor]p increased just after exercise in AB but not in CSCI. [Glc]p remained unchanged in both groups but [Ins]s started to decrease just after exercise in CSCI, earlier than AB. [tKB]s increased from the baseline an hour after exercise in CSCI but not in AB, while [FFA]s did not differ between groups. [Protocol3] [Ad]p and [Nor]p was lower in CSCI than LSCI and increased just after the race only in LSCI and returned to the baseline at an hour after the race. [FFA]s increased just after the race in CSCI and remained the higher level at an hour after race, then [tKB]s increased an hour after the race only in CSCI. Both lipid profiles remained unchanged throughout the study in LSCI.ConclusionIt is suggested that lipolysis and ketogenesis are likely to enhance in CSCI during cold or exercise. Lipid and glucose metabolisms vary dependent on the injury level with SCI.Support or Funding InformationThis work was funded by Nachikatsuura Research foundation and Kyoten, Wakayama Med. Univ.