Comparative effects of carbohydrate versus fat restriction on metabolic profiles, biomarkers of inflammation and oxidative stress in overweight patients with Type 2 diabetic and coronary heart disease: A randomized clinical trial

BACKGROUND: This study was conducted to establish the comparative effects of carbohydrate versus fat restriction on metabolic indices in Type 2 diabetic (T2D) patients with coronary heart disease (CHD). METHODS: This randomized, clinical trial was done among 56 overweight persons with T2D and CHD aged 40-85 years old. The patients were randomly allocated to take either a high-carbohydrate (HC) diet (60-65% carbohydrates and 20-25% fats) (n = 28) or a restricted carbohydrate (RC) diet (43-49% carbohydrate and 36-40% fats) (n = 28) for 8 weeks to determine metabolic status. RESULTS: After 8 weeks of treatment, RC diet decreased fasting plasma glucose (FPG) (−11.5 ± 28.3 vs. +7.0 ± 26.9 mg/dl, P = 0.010) and high-sensitivity C-reactive protein (hs-CRP) (−564.3 ± 1280.1 vs. +286.1 ± 1789.2 ng/ml, P = 0.040) compared with a HC diet. Moreover, compared with a HC diet, RC diet increased total antioxidant capacity (TAC) (+274.8 ± 111.5 vs. +20.2 ± 82.5 mmol/l, P < 0.001) and glutathione (GSH) levels (+51.6 ± 111.5 vs. −32.6 ± 88.5 µmol/l, P = 0.003). No significant alterations between the two groups were found in terms of their effect on other metabolic profiles. CONCLUSION: RC diet in overweight T2D with CHD had beneficial effects on FPG, hs-CRP, TAC, and GSH values.