Apolipoprotein C-III bound to apolipoprotein B-containing lipoproteins in obese girls

Visceral Adiposity and Apolipoprotein C-III in Apolipoprotein B-Containing Lipoproteins Are Independent Predictors in Determining Atherogenic Lipid Profiles

BACKGROUND/AIMS

Little is known about how visceral adiposity and apolipoprotein CIII in apoB-containing lipoproteins influence atherogenic lipids profiles. The purpose of this study was to determine the relationships of visceral adiposity and apoC-III in apoB-containing lipoproteins (LpB:C-III) with lipoprotein lipids in circulating plasma.

METHODS

A subgroup of 46 men (n = 20, aged 29.1-33.4 years) and women (n = 26, aged 29.1-33.8 years) were recruited from an ongoing population study at our institution. Anthropometric variables including weight, height, and waist circumference were measured using standard procedures, and body mass index was calculated (kg/m(2)). Visceral adipose tissue (VAT) was measured with magnetic resonance imaging. Plasma apolipoproteins, lipids, glucose, and insulin were measured after an overnight fasting.

RESULTS

The men had a significantly higher waist circumference, glucose, and TC/HDL-C ratio, while the women had a significantly higher HDL-C and apoA-I. In particular, this is the first study to report that VAT and LpB:C-III were independent predictors in determining plasma triglyceride concentrations.

CONCLUSION

The relations of plasma triglyceride concentration with VAT and LpB:C-III suggest that information on VAT and apoC-III in apoB-containing lipoproteins may provide additional information on the atherogenic lipid profiles.

Carbohydrate intake is correlated with biomarkers for coronary heart disease in a population of overweight premenopausal women

The associations between macronutrient intake and plasma parameters associated with increased risk for coronary heart disease (CHD) were evaluated in 80 overweight premenopausal women. We hypothesized that higher carbohydrate intake would be associated with a more detrimental plasma lipid profile. Dietary data were collected using a validated food frequency questionnaire (FFQ). Plasma total cholesterol (TC), triglycerides (TGs), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were determined from two fasting blood samples. In addition, selected apolipoproteins (apo) and LDL peak size were measured. Values for TC, TG and HDL were not in the range of risk classification; however, the mean values of LDL-C, 2.7 +/- 0.7 mmol/L, were higher than the current recommendations. Carbohydrate intake was positively associated with TG and apo C-III (P < .01) concentrations, and negatively associated with LDL diameter (P < .01). Participants were divided into low (<53% of energy) or high (> or = 53% energy) carbohydrate intake groups. Individuals in the <53% carbohydrate group consumed more cholesterol and total fat, but also had higher intake of polyunsaturated and monounsaturated fatty acids (SFAs). In contrast, subjects in the > or =53% group consumed higher concentrations of glucose and fructose than those in the low-carbohydrate (LC) group. In addition, subjects consuming <53% carbohydrate had lower concentrations of LDL-C and apo B (P < .01) and a larger LDL diameter (P < .05) than the > or =53% group. These results suggest that the lower LDL-C in the LC group may be related to both the amount of carbohydrate and the type of fatty acids consumed by these subjects.

ApoC-III bound to apoB-containing lipoproteins increase with insulin resistance in Cherokee Indian youth

Because Native Americans are predisposed to obesity and type 2 diabetes associated with coronary artery disease, we assessed whether apoC-III bound to apoB-containing (LpB:C-III) and apoA-containing (LpA:C-III) lipoproteins, total apoC-III, apoB, and plasma lipids are associated with insulin resistance, body mass index (BMI), and waist circumference in Cherokee children and adolescents aged 5 to 19 years (n = 975). A cross-sectional analysis was done to determine associations of the lipoproteins with the homeostasis index (HOMA-IR) and BMI. When the data were grouped by quartiles for HOMA-IR and separated by three 5-year age groups (5-9, 10-14, and 15-19 years), the trend for LpB:C-III, triglyceride, and BMI z score to increase was significant for all age groups and both genders (P < .001). The trend to increase LpB:C-III with age was greater in boys (P < .0001) than in girls (P < .05) who tended to plateau after the age of 10 years. In contrast, the ratio of LpA:C-III to LpB:C-III decreased and the decrease was greater in boys (P < .0001) than girls (P < .01). Body mass index z score and waist circumference were correlated with LpB:C-III, triglyceride, apoB, and non-high-density lipoprotein cholesterol within each gender (P < .001). In multiple regression models, LpB:C-III, the dependent variable, was associated with HOMA-IR for both genders. We conclude that increases in LpB:C-III in childhood and adolescence are associated with insulin resistance and obesity supporting the need for prevention programs.