BACKGROUND: Dyslipidemia and low-grade inflammation are integral in the pathogenesis of atherosclerosis. We aim to compare the effects of a considerable weight loss and intensive exercise training on lipid atherogenicity and low-grade inflammation in a high-risk population with coronary artery disease (CAD).

METHODS: Seventy non-diabetic participants with CAD, BMI 28-40 kg/m(2), age 45-75 years were randomized to 12 weeks' aerobic interval training (AIT) at 85-90% of peak heart rate three times/week or a low energy diet (LED, 800-1000 kcal/day) for 8-10 weeks followed by 2-4 weeks' weight maintenance diet. Lipid profile atherogenicity was described using lipoprotein particle size and density profiling. Low-grade inflammation was evaluated by tumor necrosis factor alpha (TNFα), C-reactive protein, interleukin 6 and soluble urokinase plasminogen activator receptor.

RESULTS: Twenty-six (74%) AIT and 29 (83%) LED participants completed intervention per protocol. AIT and LED decreased total (AIT: -518 {-906;-129},P = 0.011, LED: -767 {-1128:-406},P < 0.001) and low-density lipoprotein (LDL, AIT: -186 {-306;-65},P = 0.004, LED: -277 {-433;-122},P < 0.001) assessed as the area under the density profile curve. LED was superior to AIT in decreasing atherogenicity reflected by increased LDL (between-group: 1.0 Å {0.4; 1.7},P = 0.003) and high-density lipoprotein (between-group: 1.2 Å {0.2; 2.4},P = 0.026) particle size and a decreased proportion of total lipoprotein constituted by the small, dense LDL5 subfraction (between-group: -5.0% {-8.4;-1.7},P = 0.004). LED decreased TNFα (9.5% {-15.8;-2.6},P = 0.009). No changes were seen following AIT.

CONCLUSION: LED and AIT decreased total and LDL lipoprotein. LED was superior in decreasing atherogenicity assessed by a shift in density profile and increased particle size. Effect on low-grade inflammation was limited.