Prospective dietary polyunsaturated fatty acid intake is associated with trajectories of fatty liver disease: an 8 year follow-up study from adolescence to young adulthood.

BACKGROUND AND AIM: Dietary fat intake has long been associated with fatty liver. Our study aimed to determine the effect of dietary fats on longitudinal fatty liver index (FLI) trajectories from adolescence to young adulthood. METHODS: Nine hundred eighty-five participants in the Raine Study, Perth, Western Australia, Australia, had cross-sectional assessments at ages 14, 17, 20 and 22 years, during which anthropometric measurements and blood tests were obtained. FLI trajectories were derived from the longitudinal FLI results. Dietary fat intake was measured with a semi-quantitative food frequency questionnaire at 14 years and log multinominal regression analyses were used to estimate relative risks. RESULTS: Three FLI trajectories were identified and labelled as stable-low (79.1%, N = 782), low-to-high (13.9%, N = 132), and stable-high (7%, N = 71). The low-to-high group associated with an increased intake of the long-chain polyunsaturated fatty acids EPA, DPA and DHA (RR 1.27, 95% CI 1.10-1.48) relative to the stable-low group. Compared to the stable-low group, omega-6 and the ratio of omega-6 to omega-3 in the stable-high group were associated with an increased relative risk of 1.34 (95% CI 1.02-1.76) and 1.10 (95% CI 1.03-1.16), respectively. CONCLUSION: For those at high risk of fatty liver in early adolescence, high omega-6 fatty acid intake and a high ratio of omega-6 to omega-3 fatty acids are associated with increased risk of fatty liver. There should be caution in assuming these associations are causal due to possible undetected and underestimated confounding factors.

Effect of ω-3 fatty acid ethyl esters on apolipoprotein B-48 kinetics in obese subjects on a weight-loss diet: a new tracer kinetic study in the postprandial state.

CONTEXT: Dysregulated chylomicron metabolism may account for hypertriglyceridemia and increased risk of cardiovascular disease in obese subjects. Supplementation with ω-3 fatty acid ethyl ester (FAEE) decreases plasma triglyceride. However, its effect on postprandial chylomicron metabolism in obese subjects on a weight-loss diet has not yet been investigated. OBJECTIVE: We aimed to examine the effect of ω-3 FAEE supplementation on apolipoprotein (apo) B-48 kinetics in obese subjects on a weight-loss diet. DESIGN, SETTING, AND PATIENTS: We carried out a 12-week, randomized trial of a hypocaloric diet plus 4 g/d ω-3 FAEE supplementation (46% eicosapentaenoic acid and 38% docosahexaenoic acid) (n = 13) compared with a hypocaloric diet alone (n = 12) on postprandial apoB-48 kinetics in obese subjects after ingestion of an oral load. The apoB-48 kinetics were determined using stable isotope tracer kinetics and multicompartmental modeling. OUTCOMES MEASURES: We evaluated plasma total and incremental apoB-48 0- to 10-hour area under the curves (AUCs) as well as apoB-48 secretion and fractional catabolic rate. RESULTS: Weight loss with or without ω-3 FAEE supplementation significantly reduced body weight, total fat mass, homeostasis model assessment score, fasting triglyceride concentration, postprandial triglyceride AUC, and increased plasma high-density lipoprotein cholesterol concentration (P < .05 in all). Compared with weight loss alone, weight loss plus ω-3 FAEE significantly (all P < .05) decreased fasting triglyceride (-11%), apoB-48 (-36%) concentrations, postprandial triglyceride (-21%), and apoB-48 (-22%) total AUCs, as well as incremental postprandial triglyceride AUCs (-32%). The ω-3 FAEE also significantly decreased apoB-48 secretion in the basal state, without a significant effect during the postprandial period (3-6 hours). The fractional catabolic rate of apoB-48 increased with both interventions with no significant independent effect of ω-3 FAEE supplementation. CONCLUSION: Addition of ω-3 FAEE supplementation to a moderate weight-loss diet in obese subjects can significantly improve chylomicron metabolism by independently decreasing the secretion of apoB-48.

Low serum 25-hydroxyvitamin D concentrations associate with non-alcoholic fatty liver disease in adolescents independent of adiposity.

BACKGROUND AND AIMS: Non-alcoholic fatty liver disease (NAFLD) and serum 25-hydroxyvitamin D (s25[OH]D) concentrations are both associated with adiposity and insulin resistance (IR) and thus may be pathogenically linked. We aimed to determine the prevalence of vitamin D deficiency in adolescents with NAFLD and to investigate the prospective and cross-sectional associations between s25[OH]D concentrations and NAFLD. METHODS: Participants in the population-based West Australian Pregnancy (Raine) Cohort had seasonally adjusted s25(OH)D concentrations determined at ages 14 and then 17 years. NAFLD was diagnosed at 17 years using liver ultrasonography. Associations were examined after adjusting for potential confounders. Odds ratios (ORs) and confidence intervals (CIs) are reported per standard deviation in s25(OH)D concentrations. RESULTS: NAFLD was present in 16% (156/994) of adolescents. The majority of participants with NAFLD had either insufficient (51%) or deficient (17%) vitamin D status. s25(OH)D concentrations at 17 years were inversely associated with risk of NAFLD (OR 0.74, 95% CI 0.56, 0.97; P = 0.029), after adjusting for sex, race, physical activity, television/computer viewing, body mass index, and IR. The effect of s25(OH)D concentrations at 17 years was minimally affected after further adjusting for s25(OH)D concentrations at 14 years (OR 0.76, 95% CI 0.56, 1.03; P = 0.072). CONCLUSIONS: Lower s25(OH)D concentrations are significantly associated with NAFLD, independent of adiposity and IR. Screening for vitamin D deficiency in adolescents at risk of NAFLD is appropriate, and clinical trials investigating the effect of vitamin D supplementation in the prevention and treatment of NAFLD may be warranted.

Supplementation with n3 fatty acid ethyl esters increases large and small artery elasticity in obese adults on a weight loss diet.

Increased arterial stiffness is associated with enhanced risk of cardiovascular disease in obese individuals. Whether n3 fatty acid ethyl ester (FAEE) supplementation improves arterial stiffness in obese participants on a weight loss diet has not yet been investigated. The objective of the study was to carry out a 12-wk randomized, single-blind trial to test the effect of a 25% energy deficit weight loss diet alone (WL) (n = 12) or WL plus 4 g/d Omacor (46% EPA and 38% DHA) supplementation (WL+FAEE) (n = 13) on arterial elasticity in obese adults. Large (C1) and small artery elasticity (C2) were measured by pulse contour analysis of the radial artery. WL alone reduced (P < 0.05 in all) body weight (-3%), waist circumference (-4%), systolic (-3%) and diastolic (-3%) blood pressures, cardiac output (-4%), plasma TG concentration (-25%), and the homeostasis model assessment (HOMA) score (-12%) and increased plasma HDL cholesterol (+9%) and adiponectin (+18%) concentrations. However, WL alone did not alter C1 and C2. The WL+FAEE intervention significantly reduced body weight (-4%), waist circumference (-4%), systolic (-8%) and diastolic (-5%) blood pressures, pulse pressure (-5%), heart rate (-8%), plasma TG concentration (-36%), and HOMA score (-12%) and increased stroke volume (+3%), plasma HDL cholesterol (+6%) and adiponectin concentrations (+28%), and C1 (+20%) and C2 (+22%) artery elasticity. The changes in systolic blood pressure, heart rate, plasma TGs, C1, and C2 were significantly greater in the WL+FAEE group than in the WL group. Supplementation with n3 FAEEs improves C1 and C2 independently of weight loss in obese adults.

Nonalcoholic fatty liver disease and diabetes mellitus: pathogenesis and treatment.

Nonalcoholic fatty liver disease (NAFLD) and type 2 diabetes mellitus (T2DM) frequently coexist as they share the pathogenic abnormalities of excess adiposity and insulin resistance. Although type 1 diabetes mellitus (T1DM) is due to a relative lack of insulin, an increased prevalence of obesity and insulin resistance in this population means that NAFLD also commonly coexists with this condition. Both T2DM and NAFLD are associated with adverse outcomes of the other; T2DM is a risk factor for progressive liver disease and liver-related death in patients with NAFLD, whereas NAFLD may be a marker of cardiovascular risk and mortality in individuals with T2DM. Nonalcoholic steatohepatitis-a histological subtype of NAFLD characterized by hepatocyte injury and inflammation-is present in approximately 10% of patients with T2DM and is associated with an increased risk for the development of cirrhosis and liver-related death. Current treatment strategies aim to improve insulin resistance via weight loss and exercise, improve insulin sensitivity by the use of insulin-sensitizing agents (for example, pioglitazone) and reduce oxidative stress by the use of antioxidants, such as vitamin E. Pioglitazone and vitamin E supplementation show the most promise in improving hepatic steatosis and inflammation but have not yet been demonstrated to improve fibrosis, and concern remains regarding the toxicity of long-term use of both of these agents.