Abstract
BACKGROUND: An Okinawa-based Nordic diet with moderately low carbohydrate content and high fat and protein content has been shown to improve anthropometry and metabolism in type 2 diabetes. OBJECTIVE: The objectives of this study were to measure plasma or serum levels of hormones regulating energy metabolism and metabolic control, that is, cholecystokinin (CCK), Cortisol, C-peptide, ghrelin, glucagon, glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), insulin, leptin, plasminogen activator inhibitor-1 (PAI-1), polypeptide YY (PYY), resistin, and visfatin after this diet intervention, and to determine partial correlations between hormonal levels and anthropometric and metabolic responses. DESIGN: A total of 30 patients (17 women) with type 2 diabetes, mean age 57.5 ± 8.2 years, and body mass index (BMI) 29.9 ± 4.1 kg/m(2) were served the diet for 12 weeks. Fasting hormones were measured by Luminex and enzyme-linked immunosorbent assay (ELISA) before study start and after 12 and 28 weeks, along with anthropometric and metabolic parameters. RESULT: The levels of CCK (P = 0.005), cortisol (P = 0.015), C-peptide (P = 0.022), glucagon (P = 0.003), GLP-1 (P = 0.013), GIP (P < 0.001), insulin (P = 0.004), leptin (P < 0.001), and PYY (P < 0.001) were lowered after dietary intervention. These reduced levels only remained for PYY at week 28 (P = 0.002), when also ghrelin (P = 0.012) and visfatin (P = 0.021) levels were reduced. Changes of glucose values correlated with changed levels of C-peptide and PYY (P < 0.001), insulin (P = 0.002), and PAI-1 (P = 0.009); changes of triglyceride values with changed levels of C-peptide, insulin, and PYY (P < 0.001) and PAI-1 (P = 0.005); changes of insulin resistance with changes of leptin levels (P = 0.003); and changes of BMI values with changed levels of C-peptide, insulin, and leptin (P < 0.001). CONCLUSIONS: Okinawa-based Nordic diet in type 2 diabetes has significant impact on the endocrine profile, which correlates with anthropometric and metabolic improvements.