Protein-Added Healthy Lunch-Boxes Combined with Exercise for Improving Physical Fitness and Vascular Function in Pre-Frail Older Women: A Community-Based Randomized Controlled Trial

Purpose: Preventive or therapeutic interventions are key to maintaining independence in pre-frail and/or frail elderly. Therefore, we investigated whether multi-component interventions were effective in physical fitness levels and vascular functions in pre-frail older women. Patients and Methods: Sixty participants aged ≥ 65 years (81.5 ± 4.3 yrs) were divided equally into control group, diet group, aerobic exercise and diet group, and aerobic exercise with electromyostimulation and diet group. For 8 weeks, the participants received a set of protein-added meals twice daily on weekdays. The aerobic exercise groups performed 45 mins of stepping exercise at 50– 70% of the maximal heart rate for 3 days/week, and the aerobic exercise with electromyostimulation was applied on each limb in 8 weeks. Blood pressure, physical fitness, cardiovascular biomarkers, pulse wave velocity, and flow-mediated dilation were measured before and after the 8-week. Results: There were no group differences in age, height, weight, body mass index, free fat mass, and %body fat at baseline. The right grip strength significantly increased in the diet group, aerobic exercise and diet group, and aerobic exercise with electromyostimulation and diet group (p < 0.05). Short physical performance battery, 6-min walking distance, and flow-mediated dilation significantly increased in the aerobic exercise and diet group and aerobic exercise with electromyostimulation and diet group (p < 0.05). Blood pressure and pulse wave velocity did not differ between interventions. High-density lipoprotein-cholesterol levels significantly increased after 8 weeks in all intervention groups (p < 0.05). There were no significant differences in glucose, HbA1c, total cholesterol, low-density lipoprotein-cholesterol, triglyceride, insulin, Homeostatic Model Assessment for Insulin Resistance, nitric oxide, and C-reactive protein levels. Conclusion: These results show that multi-component interventions appear to improve physical fitness and vascular function in pre-frail older women. Thus, possible strategies to prevent early frailty including proper nutrition and exercise may be needed. Keywords: pre-frail, protein-added, aerobic exercise, electromyostimulation, physical fitness, vascular function