Effect of caloric restriction with or without n-3 polyunsaturated fatty acids on insulin sensitivity in obese subjects: A randomized placebo controlled trial

• Published in: BBA clinical Vol. 4; pp. 7 - 13
• Main Authors: Razny, Urszula, Kiec-Wilk, Beata, Polus, Anna, Goralska, Joanna, Malczewska-Malec, Malgorzata, Wnek, Dominika, Zdzienicka, Anna, Gruca, Anna, Childs, Caroline E., Kapusta, Maria, Slowinska-Solnica, Krystyna, Calder, Philip C., Dembinska-Kiec, Aldona
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.12.2015; Elsevier
• Subjects: Caloric restriction; Docosahexaenoic acid; Eicosapentaenoic acid; Insulin resistance; n-3 polyunsaturated fatty acids; Obesity; Regular; Obesity; PUFA; OGIS; IGI; Docosahexaenoic acid; AUC; GIP; PC; NEFA; EPA; n-3 polyunsaturated fatty acids; Insulin resistance; DHA; OGTT; Eicosapentaenoic acid; BMI; Caloric restriction; PC, phosphatidylcholine; AUC, area under curve; NEFA, non esterified fatty acids; DHA, docosahexaenoic acid; BMI, body mass index; OGIS, oral glucose insulin sensitivity index; GIP, glucose dependent insulinotropic polypeptide; IGI, insulinogenic index; OGTT, oral glucose tolerance test; EPA, eicosapentaenoic acid; PUFA, polyunsaturated fatty acids
• ISSN: 2214-6474; 2214-6474
• DOI: 10.1016/j.bbacli.2015.05.001

Caloric restriction and n-3 polyunsaturated fatty acid (PUFA) supplementation protect from some of the metabolic complications. The aim of this study was to assess the influence of a low calorie diet with or without n-3 PUFA supplementation on glucose dependent insulinotropic polypeptide (GIP) output and insulin sensitivity markers in obese subjects. Obese, non-diabetic subjects (BMI 30–40kg/m2) and aged 25–65yr. were put on low calorie diet (1200–1500kcal/day) supplemented with either 1.8g/day n-3 PUFA (DHA/EPA, 5:1) (n=24) or placebo capsules (n=24) for three months in a randomized placebo controlled trial. Insulin resistance markers and GIP levels were analysed from samples obtained at fasting and during an oral glucose tolerance test (OGTT). Caloric restriction with n-3 PUFA led to a decrease of insulin resistance index (HOMA-IR) and a significant reduction of insulin output as well as decreased GIP secretion during the OGTT. These effects were not seen with caloric restriction alone. Changes in GIP output were inversely associated with changes in red blood cell EPA content whereas fasting GIP level positively correlated with HOMA-IR index. Blood triglyceride level was lowered by caloric restriction with a greater effect when n-3 PUFA were included and correlated positively with fasting GIP level. Three months of caloric restriction with DHA+EPA supplementation exerts beneficial effects on insulin resistance, GIP and triglycerides. Combining caloric restriction and n-3 PUFA improves insulin sensitivity, which may be related to a decrease of GIP levels. •Caloric restricted diet with n-3 PUFA improves insulin sensitivity in obese subjects•n-3 PUFA supplementation combined with low calorie diet decrease GIP output•Blood triglycerides level reduces after caloric restriction diet combined with n-3 PUFA•GIP level positively correlates with HOMA-IR index and triglycerides