Dietary intervention induces flow of changes within biomarkers of lipids, inflammation, liver enzymes, and glycemic control

ObjectiveTo determine how changes in lipids, liver enzymes, and inflammatory and glycemia markers intercorrelate during prolonged dietary intervention in obese participants with or without type 2 diabetes (T2D).MethodsWe examined the dynamics and intercorrelations among changes in biomarkers during the 2-y Dietary Intervention Randomized Controlled Trial (DIRECT) in 322 participants (including 46 with T2D; 52 y of age, body mass index 31 kg/m²) throughout rapid weight loss (0–6 mo) and weight-maintenance/regain (7–24 mo) phases.ResultsThe 2-y increase of high-density lipoprotein cholesterol was greater in participants with T2D (+9.41 versus+6.57 mg/dL, P < 0.05), although they tended to have smaller waist circumferences (?2.1 versus ?4.0 cm, P = 0.08). In models adjusted for age, sex, and weight loss, the 2-year decrease of triacylglycerols was associated with increases of low-density and high-density lipoprotein cholesterol. An increase of apolipoprotein A1 was associated with a decrease in high-sensitive C-reactive protein (P < 0.05 for all comparisons). Exclusively in participants with T2D, the 2-year decrease in triacylglycerols was further correlated with decreases in apolipoprotein B100 and liver enzymes, and a decrease in fasting glucose correlated with decreases in low-density lipoprotein cholesterol, apolipoprotein B100, and alanine aminotransferase (P < 0.05 for all comparisons). In the entire group, multivariate models adjusted for age, sex, intervention group, and 6-mo weight loss identified decreased high-sensitive C-reactive protein at 6 mo as an exclusive predictor of a greater decrease in triacylglycerols (β = 0.154, P = 0.008) and a greater increase in high-density lipoprotein cholesterol (β = ?0.452, P = 0.005) during the subsequent 18 mo.ConclusionsLong-term dietary intervention induces a flow of changes within biomarkers and the cross-talk is likely to be stronger in T2D. A decrease in systemic inflammation during the weight-loss phase may predict greater long-term improvement in lipids (www.ClinicalTrials.gov, identifier NCT00160108).