Low-density lipoprotein particle size, central obesity, cardiovascular fitness, and insulin resistance syndrome markers in obese youths

Abstract

OBJECTIVE: (1) To determine the prevalence of small dense low-density lipoprotein (SDLDL) particles in obese youths and (2) to compare youths with SDLDL and large buoyant LDL (LBLDL) subclass phenotypes in total body and abdominal fatness, cardiovascular (CV) fitness, and markers of the insulin resistance syndrome (IRS). DESIGN: For group comparisons, subjects were dichotomized into either SDLDL phenotype group or LBDL phenotype group based on LDL particle size. SUBJECTS: Obese 13 to 16-y-olds (n ¼ 80) who had a triceps skinfold greater than the 85th percentile for gender, ethnicity, and age. MEASUREMENTS: LDL particle size, plasma lipids and lipoprotein concentrations, plasma glucose and insulin concentrations, and blood pressures; percentage body fat, visceral adipose tissue (VAT); VO 2 at a heart rate of 170 bpm as an index of CV fitness. RESULTS: The prevalence of the SDLDL phenotype was 54% among the 80 obese youths. Although overall body fatness (ie BMI and percentage body fat) and CV fitness were similar between the two LDL phenotype groups, the SDLDL phenotype group had significantly higher weight, waist circumference and VAT than the LBLDL phenotype group. With respect to the IRS markers, youths with the SDLDL phenotype had significantly higher triacylglycerol (TAG), very low-density lipoprotein cholesterol (VLDLC), apolipoprotein B (apo B), and total cholesterol-to-high-density lipoprotein ratio (TC=HDLC) than youths with the LBLDL phenotype. LDL particle size as a continuous variable was significantly correlated with TAG, VLDLC, apo B, HDLC, and TC=HDLC. Plasma TAG and HDLC concentrations were independent predictors of LDL particle size. CONCLUSION: (1) The SDLDL phenotype was common in obese youths and (2) the relationships of LDL particle size with several of the IRS markers suggested that already in adolescence the expression of the SDLDL phenotype might be an important risk factor for future coronary heart disease mortality and morbidity.

Low-Density Lipoprotein Sub-Fraction Profiles in Obese Children Before and After Attending a Residential Weight Loss Intervention

“…In these studies there was a propensity of those with pattern B to be more overweight than those categorised to pattern A. In support of this finding, 54% of obese children were characterised as pattern B in a cross sectional study 11) . The relationship of obesity to increased incidence rates of the metabolic syndrome in adolescents 19) and the associated pattern B phenotype 20) , provides a coherent rationale for engaging children with appropriate strategies for successful weight management, and CHD risk reduction.…”

“…There is a significant contribution of child obesity to pre clinical conditions such as dyslip-LDL-c particles, or what is regarded as a pattern B phenotype, it is unclear to what extent LDL-c particles are independently atherogenic or predictive of CHD. They are simultaneously associated with other lipid risk factors for CHD, such as moderately raised fasting levels of very low density lipoprotein cholesterol and triglyceride (VLDL-c and VLDL-tg respectively), apo B and lower levels of high density lipoprotein cholesterol (HDL-c) in children 11) . The prevalence of a pattern B phenotype is low in both young males and pre-menopausal females 12,13) .…”

LDL particle size, fat distribution and insulin resistance in obese children

“…Body fat accumulation also affects LDL particle size, even in children (Arisaka et al, 1997;Kuromori et al, 2002;Shimabukuro et al, 2004). Especially abdominal adiposity is reported to be associated with sdLDL in healthy men (Lemieux et al, 2000), men with glucose intolerance (Suehiro et al, 1995) and obese children (Kang et al, 2002). The mechanisms of the linkage between fat accumulation and sdLDL were investigated in previous studies.…”

“…In adults, abdominal adiposity in particular has a close relationship with LDL particle size (Lemieux et al, 2000). In obese youths, sdLDL is a common feature, and is associated with insulin resistance (Kang et al, 2002).…”

Anthropometric Indices and Their Relationship With Coronary Artery Diseases

“…Since the central body fat distribution is more atherogenic properties than peripheral obesity, much attention has been focused on methods to measure central obesity. Fat deposits in the abdomen and central body releases free fatty acids into the peripheral blood flow and portal blood which can lead to insulin resistance in liver and muscle cells and increase release of triglyceride-rich lipoproteins and very low density from the liver and thus produce dense low-density lipoproteins (10,11). Therefore, the Waist Circumference (WC) and Waist-to-Height Ratio (WHtR) are clinical tools that can be used for diagnosis of abdominal obesity (12).…”