Diet and Omega-3 Intervention Trial on Atherosclerosis (DOIT)

University of Oslo, Ultrasound Laboratory at Malmoe University Hospital, Sweden, Norwegian Retail Company RIMI, Norwegian Cardiovascular Council

The study was actuated to evaluate the effects of a 3-year intervention with diet and/or very long chain omega-3 (VLC n-3 PUFA), in a randomized 2x2 factorial design on the progression of atherosclerosis in a high risk population. A total of 563 elderly men were included and randomized to receive usual care and VLC n-3 placebo capsules (control group), dietary advice and VLC n-3 placebo capsules, usual care and VLC n-3 capsules, and finally both VLC n-3 capsules and dietary advice. The evaluation of atherosclerosis were i) ultrasound measurement of carotid intima media thickening ii) pulse wave propagation time iii) circulating biomarkers of atherosclerosis.

The basis for recruitment was a follow up of subjects participating in the Oslo Diet and Anti Smoking Study (1972-1977) characterised as hypercholesterolemic in 1972. Measurements of the outcome variables were performed at baseline and after 36 m; blood sampling also after 6 and 18 m. In addition to the main outcome variables, a biobank was established for future analyses. Clinical events were also recorded.

Inclusion Criteria: Elderly men with long standing hypercholesterolemia (cholesterol > 6.45 mmol/L and < 8.00 mmol/L) with or without coronary heart disease. Exclusion Criteria: Cholesterol > 8.00 mmol/L, blood pressure > 170/100 Uncontrolled hypertension Socially or otherwise unsuitable subjects Anticipated non compliance Other major non cardiac illness expected to reduce life expectancy or interfere with study participation.

Awoyemi A, Troseid M, Arnesen H, Solheim S, Seljeflot I. Markers of metabolic endotoxemia as related to metabolic syndrome in an elderly male population at high cardiovascular risk: a cross-sectional study. Diabetol Metab Syndr. 2018 Jul 21;10:59. doi: 10.1186/s13098-018-0360-3. eCollection 2018.

Weiss TW, Arnesen H, Seljeflot I. Components of the interleukin-6 transsignalling system are associated with the metabolic syndrome, endothelial dysfunction and arterial stiffness. Metabolism. 2013 Jul;62(7):1008-13. doi: 10.1016/j.metabol.2013.01.019. Epub 2013 Feb 19.

Einvik G, Ekeberg O, Klemsdal TO, Sandvik L, Hjerkinn EM. Physical distress is associated with cardiovascular events in a high risk population of elderly men. BMC Cardiovasc Disord. 2009 Mar 30;9:14. doi: 10.1186/1471-2261-9-14.