Utilizing a Low-Carbohydrate/High-Protein Diet to Improve Metabolic Health in Individuals With Spinal Cord Injury

Abstract

Abstract Objectives The purpose of this study is to determine if an 8-week low-carbohydrate/high-protein (LC/HP) dietary intervention will show improvements in clinically important metrics of metabolic function and body composition in individuals with spinal cord injury (SCI). Methods Twenty-one participants with long-standing SCI (≥3 years post-injury) (age: 45 ± 13 years) were randomly assigned to an 8-week iso-caloric high-protein/low-carbohydrate (HPLC) diet or their habitual control diets. Injury levels ranged between cervical vertebrate 4 to lumbar vertebrate 3. The HPLC diet included ∼30% total energy as protein (40% energy from carbohydrate) and participants were provided with all study meals if they were assigned to the HPLC group. Each participant underwent an oral glucose tolerance test (OGTT) and DXA scanning before and after the intervention after an overnight fast. Blood glucose and insulin during the OGTT were assessed, and their respective incremental areas under the curve were calculated, as well as Matsuda index, an indicator of insulin sensitivity. The blood lipid panel was analyzed using the fasting samples. A two-way repeated-measures ANOVA model was used to evaluate the main effect of diet, time, and their interaction. Results We observed no main effect of time, diet, and their interaction on the fasting concentrations of glucose, insulin, their respective concentrations at 120-minute during the OGTT, and areas under the curve, but a trend for decreased insulin AUC among participants in the HPLC group (P = 0.07). There is a trend for the diet by time interaction effect for the Matsuda index (P = 0.11). The Matsuda index quantitatively increased in the HPLC group while remained in the control group. In contrast, an interaction effect was observed for several outcomes. These outcomes were decreased in the HPLC group, and include total Cholesterol (−23.9mg/dL), LDL (−15.8 mg/dL), total body fat mass (−5%), and visceral fat mass (−11%) (P < 0.05 for all). Fat-free mass did not change over time. Conclusions Our results support that our HPLC diet can be safely adopted by individuals with SCI to achieve improvements in glucose metabolism and lipid profile and body composition. Funding Sources The study was funded by the National Institute on Disability, Independent Living, and Rehabilitation Research (#90SI5019).