The Relationship Between Healthy Eating Index-2015 and Cardiometabolic Risk Factors in People with Long-Standing Spinal Cord Injury

The Healthy Eating Index (HEI)-2015 is a measure of diet quality in reference to the 2015 Dietary Guidelines for Americans. We examined the relationship between HEI-2015 and several indices of cardiometabolic risk factors among individuals with chronic spinal cord injury (SCI) (>3 years after injury). Twenty-four participants without type 2 diabetes were included (45 ± 12 y, 8F/16 M, 9 Tetraplegia/15 Paraplegia, time since injury: 20 ± 13 y). All participants underwent a 2-hour oral glucose tolerance test (OGTT), a Dual-energy X-ray absorptiometry scan (DXA), and 3 24-hour multiple-pass dietary recalls. HEI-2015 was calculated using the dietary recall data. To build the regression model, firstly, principal component (PC) analysis was used to reduce the number of covariates from 3 (level of injury, gender, percentage body fat estimated from the DXA) to 2 PCs. Multiple linear regression analyses were run to predict indices of lipid metabolism and glucose homeostasis as well as C-reactive protein (CRP) from the HEI and the 2 PC scores. The average HEI-2015 score was lower for participants with SCI compared to the general American population (48 ± 11 vs. 59, P < 0.05). The regression models for fasting glucose (FG), Cholesterol, HDL, LDL, and CRP had moderate to large effect sizes (adjusted R2 > 13%), indicating good explanatory ability of the predictors. Small or limited effect sizes were observed for other models (glucose tolerance, fasting insulin, triaglycerides, and Matsuda index, adjusted R2 < 13% for all). Furthermore, the HEI accounted for a moderate amount of variation in FG as evidenced by partial Omega-squared of 13%. Each 10-point increase of the HEI was associated with a 3.3 mg/dL decrease in FG concentrations. However, HEI accounted for a limited amount of variations in other indices (ωP2 < 5% for all). Our exploratory analyses suggest that HEI-2015 has limited effects on blood lipids and CRP but may be associated with lower FG concentrations in our sample group. Future larger studies are warranted to delineate the relationship between diet quality and cardiometabolic health outcomes in individuals with SCI. The National Institute on Disability, Independent Living, and Rehabilitation Research.