METHODS: Using a randomized, crossover and double-blinded design, 15 men and 15 women with metabolic syndrome consumed high-fat meals enriched with SFA, MUFA or n-6 PUFA, or a low-fat/high-sucrose (SUCR) meal. C-peptide, insulin, glucose, gastrointestinal peptides and satiety were measured up to 6 h.
RESULTS: As expected, SUCR meal induced higher C-peptide (45 %), insulin (45 %) and glucose (49 %) responses compared with high-fat meals regardless of types of fatty acids (P < 0.001). Interestingly, incremental area under the curve (AUC0-120min) for glucagon-like peptide-1 was higher after SUCR meal compared with MUFA (27 %) and n-6 PUFA meals (23 %) (P = 0.01). AUC0-120min for glucose-dependent insulinotropic polypeptide was higher after SFA meal compared with MUFA (23 %) and n-6 PUFA meals (20 %) (P = 0.004). Significant meal x time interaction (P = 0.007) was observed for ghrelin, but not cholecystokinin and satiety.
CONCLUSIONS: The amount of fat regardless of the types of fatty acids affects insulin and glycemic responses. Both the amount and types of fatty acids acutely affect the gastrointestinal peptide release in metabolic syndrome subjects, but not satiety.
RESULTS: Both doses of the alcohol extract of S. polycystum and the 300 mg kg(-1) water extract, significantly reduced blood glucose and glycosylated haemoglobin (HbA1C ) levels. Serum total cholesterol, triglyceride levels and plasma atherogenic index were significantly decreased after 22 days treatment in all seaweed groups. Unlike metformin, S. polycystum did not significantly change plasma insulin in the rats, but increased the response to insulin.
CONCLUSION: The consumption of either ethanolic or water extracts of S. polycystum dose dependently reduced dyslipidaemia in type 2 diabetic rats. S. polycystum is a potential insulin sensitiser, for a comestible complementary therapy in the management of type 2 diabetes which can help reduce atherogenic risk.