Table 1. Characteristics of included studies (dietary interventions and relevant CVD outcome measures with findings outlined).
| Author, year, setting, Country, study design & sample size | Subject Characteristics | Intervention | Control | Outcome measures and findings | Study quality1 |
|---|---|---|---|---|---|
| Szlachcic et al. 2001; Outpatient Center, CA; USA; Non-randomized, clinical controlled trial (n = 222)55 | 198 men, 24 women, 86 in treatment group & 136 in control. Age 38.5+/−11.1years, duration post injury 12.8+/−8.3yrs. 22% Caucasian, 21% African-American, 54% Hispanic, 2% Asian and 1% other. 38% complete paraplegia, 34% complete tetraplegia, 12% incomplete paraplegia and 16% incomplete tetraplegia. | Group 1 (n = 86) with >200 mg/dL referred to staff dietitian who completed food intake recall to review fat and cholesterol consumed in day. Dietary intervention based on American Heart Association and American dietetic association guidelines – nutritionally adequate, varied diet, ↓ intake of SFA & cholesterol, achieving and maintaining ideal body weight, ↓sodium intake, limiting alcohol. To ↓ CVD, subjects advised to ↓ daily fat intake to <30% and SFA to <10% of total calories, ↓ cholesterol to <300 mg and ↑ CHO to 60% of calories. Subjects were reviewed twice. | 136 subjects (group 2) with no dietary intervention. | Intervention group n = 86 (42.8+/−11.3yrs of age, 11.1+/−7.5yrs post injury), control n = 136 (35.7+/−10.2yrs, post injury 15.6+/−8.8yrs), (F = 16.9; df = 1.220; P < .0001). Multivariate analysis showed overall group difference and a significant group-by-examination (pre-post) interaction (F = 7.12; df = 4.214; P < .0001). Univariate analyses showed similar for lipids, not significant for HDL-C. Group 1 – significant ↓ in TC 234+/−31–224+/−31 mg/dL (F = 14.7; df = 1,85; P < 0.001). Group 2 – significant ↑ TC (162+/−23–166+/−30 mg/dL, F = 7.94; df = 1,135; P = .006). 69% group 1 ↓ cholesterol vs 43% group 2 (x2 = 14.2; df = 1; P < .0002). LDL ↓159+/−28–151+/−28 mg/dL in group 1 (F = 8.63; df = 1.85; P = .004); group 2 ↑ from 101+/−21–104+/−27 mg/dL (not significant).67% had LDL-C ↓ in group 1, 47% in group 2 (x2 = 7.28; df = 1; P = .007). Significant group-by-examination interaction for mean triglyceride values but univariate analyses – no significant difference in group 1. ↓ TG – 60% group 1, 45% group 2. HDL-C – nil significant effects. | Neutral (Ø) |
| Javierre et al. 2005; Community, Spain; Pre-post study (n = 19)57 | 19 adult males, 17 paraplegia & 2 tetraplegia, 64% ASIA A, 21% ASIA B, 10% ASIA C & 5% ASIA D, 12 months post injury. Fairly constant physical activity. | Total daily dose of 1.5 g of DHA and 0.75 g EPA given for 6 months in the form of gelatin pearls; 6 a day taken as 2 with each meal. | Evaluation protocol: control 1 – baseline; control 2 – review at 3 months; control 3 – evaluation at 6 months | Statistically significant ↑ in plasma EPA – 7.86 times between control 1 (basal) & control 2 (3 months), 10.01 times between control 1 & 3 – (F = 30.556, P < 0.05). DHA – doubled the level – control 1 at control 2 and ↑ 125% (F = 106.6, P < 0.05) between control 1 and 3. Plasma concentrations of glucose, total cholesterol, HDL-C, LDL-C, VLDL-C, TG showed no difference between controls. | Negative (−) |
| Chen et al. 2006; Rehabilitation Center outpatients; USA; Pre-post study (n = 16)56 | Chronic SCI community-dwelling, overweight or obese; average weight 97.4 kg & BMI 34.3. >19years; 9 male, 7 female; White (n = 13), African American (n = 3); paraplegia (n = 12), tetraplegia (n = 4); 17.5yrs (mean) since SCI. | Face to face interview to collect weight/other. FFQ collected. Time-calorie displacement diet developed at the center in 1976 was utilized. This pattern promotes high bulk, low energy dense foods prolonging eating time; reducing energy density. 1200 kcal for women and 1400 kcal for men with number of servings from 5 food groups prescribed. Specific nutrients for SCI was taken into account. Once a week, the subjects with spouses attended a 90 min education class on nutrition and weight management. From week 6, 30 min exercise (of home-based activities) segment was introduced. | NA | 6 month program – average weight gain post injury was 20.7 kg (n = 13). Over the 12-week program intervention, 14 subjects lost weight (4.2 +/− 2.7 kg), one subject maintained his initial weight, one gained 2.3 kg. Overall weight loss = 3.5 kg, (3.8% of the initial weight). Significant ↓ in BMI, WC, neck circumference, and skinfold thickness seen. Among 12 subjects with DXA scan, total body fat significantly ↓, unlike lean mass & bone mineral. The HDL-C ↓ 3.2 mg/dl from 43.1 mg/dl, LDL-C – not significant. Nil significant change in blood pressure, Hb, albumin. Average energy intake ↓ 219.5 kcal/d, increased fiber and ↓ SFA. Moderate to strong correlation with the weight loss and WC, cholesterol and increase in diet’s nutritional quality. Not statistically significant due to sample size. | Neutral (Ø) |
| Radomski et al., 2011; Community; USA; Quasi-experimental, single-group pre-post study (n = 15)60 | SCI individuals 1 year post injury, no upper extremity pathology limiting exercise, BMI >20, complete SCI below cervical level. Paraplegia subjects only enrolled for same diagnostic group. 15 out of 38 people met criteria. | "Take Action”, a 12-week program including assessment by a nutritionist, exercise physiologist, physical therapist for individualized diet and exercise program. Exercise 3/7. Nutrition component included individualized meal plan. Weekly exercise classes with discussion about nutrition, behavior management, mind-body connection, motivation, life-long change and stress mastery. | NA | Outcomes measured at baseline, 12 and 24 weeks. Only 12 weeks results reported in the study secondary health issues seen in subjects at 24 week follow-up. Of 15 individuals – 2 failed screening at pre-test evaluation; one due to cardiac issues, second was at ideal bodyweight. 3 subjects withdrew in week 5 - 1 due to unrelated personal reasons, 1 due to schedule conflicts. 12 week data is reported for 10 subjects (6 male and 4 female); median age 53yrs (25–64yrs), median years with SCI 8.5 (1.5–37); all had complete injuries; SCI levels T12–4, T3–2, 1 each for T1, T5–T6, T7 & T9. Significant improvement in skinfold body fat percent (P = .013). Median improvement of 8% (>2.5% goal). Other anthropometric measures also showed significant improvements. Changes in physiological measures not statistically significant. Median weight reduction of 6% seen (P = .037). | Neutral (Ø) |
| Gorgey et al. 2012; Community; USA; Randomized controlled trial (n = 9)53 | SCI Paraplegia adults (n = 9); Group 1 (n = 5; RT and diet) and group 2 (n = 4; diet only group) | Intervention group (n = 5): diet and RT group. Anthropometric measurements taken; follow a standard diet (45% CHO, 30% fat and 25% protein) protocol. RMR using indirect calorimetry. Food diaries recorded for 12 weeks. RT twice weekly. DXA for FFM and FM was used. Screening was done 1 week pre-intervention and 1 week post-intervention. Dietitian devised the diet protocol. | Diet only group n = 4. Diet adherence was checked in both groups by the dietitian via interview, telephone call, email. Daily Food diary kept. | Groups not significantly different in age or time since injury. Mean caloric intake = 1781 +/− 228 and 1731 +/− 127 kcal/day for the RT + diet and diet groups, respectively (P < 0.05). % energy distribution similar across groups. Body weight and BMI not significantly different. For the RT + diet group, skeletal muscle of the whole thigh (28%), knee extensor (35%), and flexor (16%) muscle groups ↑ significantly. Post intervention, there was a difference in the ratio of leg FFM to whole body FFM in the RT + diet group compared with the diet group (0.15 T 0.01 vs. 0.12 T 0.02, P = 0.043), a significant interaction effect (P = 0.01, partial G2 = 0.74). Plasma insulin to plasma glucose ratio ↓ in RT + diet group with nil effect on HOMA-IR in both groups. Significant ↓ in TG (P = 0.028), TC (P = 0.017) was seen in RT + diet group. Plasma FFA significantly ↓ in both groups. | Positive (+) |
| Myers et al. 2012; Outpatient Center; USA; Cohort (n = 26)59 | 26 male with SCI (57+/− 6yrs of age) with ↑ CVD risk. Cervical injury (10), thoracic (13) & lumbar (3). Non-ambulatory and patients, Framingham Risk Score (FRS) associated with age-adjusted >20% 10 yr absolute CVD risk with no overt CVD. | Pilot 2-year risk intervention program. At baseline, blood tests, diet, lifestyle & physical activity questionnaires completed with a maximal exercise test. Individualized exercise and nutrition recommendations given. Weekly phone contacts using case manager model in first 6 weeks, at 8 weeks, at 3, 4, 5 and 6 months. Cardiac risk – lipid profile, homocysteine, high sensitivity CRP, fasting glucose, insulin, homeostasis model of assessment-insulin resistance (HOMA-IR) determined at every study visit. BMI and blood pressure, exercise testing and activity monitoring done. Dietary intake using Block FFQ with intake of 3 days, including one weekend day. Total calorie intake, intake of macronutrients (fat, CHO, protein), % calories from fat, saturated fat, polyunsaturated to saturated fat ratio, fiber and cholesterol intake measured. Program – physician supervised, managed by non-physicians. Verbal and written material given at initial visit tailored to the risk profile. Nutritional counseling, smoking intervention and lipid lowering therapy provided individually. EBP interventions using American Heart Association Dietary Guidelines, National cholesterol educational program were used. Pharmacologic therapy revised during visits with additional diet and exercise assistance. | Each subject is own control | Baseline – 73% hyperlipidemia, 15% past or current smokers, 23% T2DM, & 81% overweight or obese. Dropouts due to medical issues, followed by personal reasons, inability to comply, travel and time barriers. 22 people completed 6mo, 18-12mo, 15-18mo & 10-24mo respectively. Medical reasons were pressure sores (2), back pain (2), hand surgery (1), uncontrolled dyslipidemia (1). Two subjects died between 12 & 18mo, from reasons unrelated to the study. Weight ↓ at each visit but significant at 6mo (∼4 lb, P = 0.004). Fasting glucose – no change, mean for both insulin and HOMA-IR significantly lower at each comparison from baseline. 90-94% – reduction in insulin & 85-88% of subjects showed reduced HOMA-IR at 6mo and 12mo (P < 0.01 for all). TC/HDL ratio lower at 6mo (P = 0.05), TG lower (∼10–20%). TC was 3-7% lower but, not statistically significant. Strong effect only seen for insulin and HOMA-IR (effect size ∼0.80–0.90 at each evaluation). Small effect size for weight and lipids (<0.20). No difference in subjective and objective physical activity patterns. No significant differences seen in total calories, % of fat, CHO, protein or macronutrient intake. However, average total calories considerably lower than US general population average. Caloric and macronutrient intake lower than RDI for age and sex. Fat and cholesterol intake higher at the end than baseline. Fiber lower at 24 months than baseline (17.3+/−8 g baseline and 11.1+/−5 g at 24mo). Protein lower at 24 months (47.6g+/−30 in comparison to 62.5+/−27 g at baseline). | Neutral (Ø) |
| Sabour et al. 2016; Rehabilitation center; Iran; Randomized Controlled Trial (n = 60)54 | SCI adults >18yrs referred to Brain and Spine Center, with BMI 22 or more, SCI >2yrs and both male and female (n = 45 were male). | Nutrition education – Standard brochures with general recommendations about healthy diets & maintaining weight provided to all. Intervention group attended a monthly educational session for the first 3 months; then every 2 months as 5 sessions in a 7 month period. Also, received a tailored diet plan with energy and recommended foods. Total energy ∼1200–1800 kcal with ∼20% from fat. Allowed to be modified by clients as long as the total calorie restriction is adhered to. Weekly phone follow-up was done as 28 calls in 7 months. | 30; 3 failed to return for review at the end. n = 27, received only standard nutrition brochures. | TC = 186.01 ± 36.48 mg/dL and 195.24 ± 41.88 mg/dL in the education group at the beginning of the trial and after 7 months. In the control group, TC levels were 179.69 ± 38.37 mg/dL and 178.68 ± 39.54 mg/dL at the beginning and end of the trial. Changes in TC were not statistically different between groups (P = 0.224). Also, nutrition education program showed no significant effect on the levels of TG, LDL-C and HDL-C (P = 0.172, 107 & 0.081). No significant difference in the anthropometric measurements between groups at the beginning of the trial (P = 0.64, 0.10, 0.92 and 0.71). After 7 months, no significant changes in weight and WC observed (P = 0.970 and 0.361). |
Neutral (Ø) |
| Bigford et al. 2017; Community; USA; Prospective Case Series (n = 3)58 | Chronic complete SCI 3 males 42-56yrs; chronic neurologically complete SCI T3-T7 (1.5-29 years duration). | 6mo program of circuit resistance exercise, dietitian assisted nutrition plan using Mediterranean diet and behavior support followed by 6mo of maintenance phase with minimal support. | NA | Subject 1 – BMI 28.9, insulin resistance (HOMA-IR = 3.42), T2DM. Post 6mo – ↓ BMI by 6.8 kg (8.3%), fBGL from 138 to 123 mg/dL, insulin resistance by 0.45. Post 1 year – BMI ↓ 7.9 kg (9.7%), fBGL ↓ to 114 mg/dL. Calorie intake <553 kcal/d at intervention and ↑ 148 kcal by the end. Subject 2 – baseline BMI 44, insulin resistance (HOMA-IR = .03), ↑ TG (158 mg/dL), low HDL (30 mg/dl). Post 6mo – BMI ↓ 18.2 kg (7.3%), fBGL <10 mg/dL, TG <97 mg/dL, insulin resistance <2.61. HDL-C ↑ 5 mg/dL. Post 1 year – fBGL 6 mg/dL ↓ than 6mo, HDL-C stable at 36 mg/dL. HOMA-IR ↓ & was normal post 1 year. Caloric intake ↑ 40 kcal per day at 6mo, another 148 kcal/d at the end. Subject 3 – BMI 29.6 at baseline, insulin resistance (HOMA-IR = 4.34), ↑ TG (205 mg/dL), ↓ HDL (35 mg/dL). After 6mo – BMI ↓ by 5.7 kg (6.8%), fBGL by 10 mg/dL, TG by 9 mg/dL and insulin resistance by 0.33. HDL-C ↑ 5 mg/dL. Post 1 year – fBGL ↓ 6 mg/dL, HDL ↓ 2 mg/dL. HOMA-IR significantly ↓ at 6mo but ↑ past baseline at end. Calorie intake ↑ by 250 kcal/d at 6mo and remained as is. | Negative (−) |
1Assessment of Quality and risk of bias using the Quality Criteria Checklist.50
SFA, Saturated fatty acid; BMI, Body mass index; CVD, Cardiovascular disease; ↓ – decrease; ↑ – increase; SCI, spinal cord injury; CHO, Carbohydrates; HDL-C, High density lipoprotein cholesterol; LDL-C, Low density lipoprotein cholesterol; VLDL, Very low density lipoprotein; HOMA-IR, Homeostatic model assessment of insulin resistance; BGL, Blood glucose level; GAS, Goal attainment scale; TG, Triglycerides; TC, Total cholesterol; fBGL, fasting blood glucose level; FFM, Fat free mass; FM, Fat mass; Hb, Haemoglobin; DHA, Docosahexaenoic acid; EPA, Eicosapentaenoic acid; NA: Not applicable; FFQ: Food frequency questionnaire; RT, Resistance training; WC, Waist circumference/circumflex; RMR, Resting metabolic rate; FFA, Free fatty acid; EBP, Evidence based practice; T2DM, Type 2 Diabetes Mellitus.