Serum apolipoprotein A1, B, CII, CIII, E, and lipoprotein (a) levels in children

Decreased Serum Apolipoprotein CIII in the Acute Phase of Kawasaki Disease

Plasma exchange is an effective treatment for Kawasaki disease (KD), suggesting that plasma from patients with KD bears its causative agents. The aim of this study was to use mass spectrometry to identify candidate agents in patient sera. Serum samples were obtained from 17 KD patients. In six patients, samples were collected in each of three phases: the acute phase prior to acetylsalicylic acid (ASA) and intravenous immunoglobulin administration (Phase A1), the remission phase with ASA (Phase A2), and the remission phase without any medication (Phase A3). Sera from the remaining 11 patients were collected during Phases A1 and A2. The study also included two age- and gender-matched control groups, one with eight afebrile children and one with eight febrile children diagnosed with infectious disease. Patients in Phase A1 and febrile controls did not differ in body temperature, white blood cell counts, or C-reactive protein levels. Mass spectrometry analysis revealed that the intensity levels of m/z 9416, identified as apolipoprotein CIII (Apo CIII), were lower in Phase A1 samples compared with samples from patients in Phases A2 and A3, and from febrile controls (all comparisons, p < 0.01). Serum Apo CIII levels were also lower in Phase A1 samples compared with samples from Phase A2 patients and afebrile controls (both p < 0.01), but samples from patients in Phase A2 did not differ significantly from those of the afebrile controls (p = 0.55). This study demonstrated that serum Apo CIII level was decreased in the acute phase of KD.

Lipoprotein(a) concentration does not differ between sexes in healthy offspring of patients with premature myocardial infarction

AIMS

Although a family history of coronary artery disease (CAD) is an established factor influencing lipoprotein(a) [Lp(a)] levels, the effect of sex on Lp(a) concentration remains unclear. A potential cause of the conflicting findings regarding the effect of sex on this novel CAD risk factor is the limited ability of the studies, to date, to adequately control for the potential confounding effect of CAD familial predisposition. Our purpose was to evaluate the influence of sex on Lp(a) concentration in healthy young individuals by controlling for family history of CAD. In order to achieve our goal, we compared Lp(a) levels in pairs of brothers and sisters with a positive parental history of premature myocardial infarction (PHPMI).

METHODS

We measured Lp(a) concentration in 77 healthy brother-sister pairs with PHPMI (mean age: brothers: 18.4 ± 6.2 years and sisters: 18.1 ± 5.8 years). Total cholesterol, low-density lipoprotein (LDL)-cholesterol and high-density lipoprotein (HDL)-cholesterol, triglycerides, apolipoprotein (Apo) A-I and B were also measured.

RESULTS

Lp(a) levels did not differ between siblings of different sex (male vs. female sex: 0.994 ± 1.29 vs. 0.860 ± 0.82 μmol/l, P = 0.940); moreover, the prevalence of elevated (>1.071 μmol/l) Lp(a) concentrations between sexes was the same (29.9%). As expected, compared to female sex, male sex showed higher total/HDL-cholesterol ratio (3.642 ± 0.99 vs. 3.329 ± 0.89, P = 0.017) and lower HDL-cholesterol (1.221 ± 0.24 vs. 1.343 ± 0.28 mmol/l, P = 0.001), Apo A-I (1.390 ± 0.20 vs. 1.474 ± 0.23 g/l, P = 0.003) concentrations and Apo A-I/Apo B ratio (1.632 ± 0.49 vs. 1.830 ± 0.66, P = 0.016).

CONCLUSION

Our results show that healthy young men with PHPMI have a similar Lp(a) levels but worse lipid profile than women.

Metabolic alterations and systemic inflammation in obstructive sleep apnea among nonobese and obese prepubertal children

RATIONALE

Obstructive sleep apnea (OSA) has been associated with a higher prevalence and severity of the metabolic syndrome in adult patients, even after controlling for obesity. In contrast, OSA in prepubertal children does not appear to correlate with the magnitude of such metabolic derangements.

OBJECTIVES

To further establish the potential mechanistic role of OSA in metabolic regulation in prepubertal children.

METHODS

Fasting glucose, insulin, C-reactive protein, apolipoprotein B, and serum lipid concentrations were determined during the initial polysomnographic diagnosis of OSA and 6-12 months after adenotonsillectomy in both obese and nonobese children.

MEASUREMENTS AND MAIN RESULTS

Sixty-two children with OSA (37 obese and 25 nonobese), age 7.40 +/- 2.6 years (mean +/- SD) completed the study. After adenotonsillectomy, significant improvements in apnea-hypopnea index and sleep fragmentation occurred, particularly among nonobese children. In nonobese children, adenotonsillectomy was associated with mild increases in body mass index z scores, no changes in either fasting glucose or insulin, significant increases in high-density lipoprotein and reciprocal decreases in low-density lipoprotein, and reductions in plasma C-reactive protein and apolipoprotein B levels. In obese children, adenotonsillectomy did not result in body mass index or glucose changes, but was associated with marked improvements in all other measures.

CONCLUSIONS

OSA does not appear to induce insulin resistance in nonobese pediatric patients but seems to play a significant role in obese patients. The significant improvements in lipid profiles, C-reactive protein, and apolipoprotein B after adenotonsillectomy in the two groups suggest a pathogenic role for OSA in lipid homeostasis and systemic inflammation independent of the degree of adiposity.

Pediatric reference intervals for lipids and apolipoproteins on the VITROS 5,1 FS Chemistry System

OBJECTIVES

Lipid biomarkers are integral in the assessment of dyslipidemia and cardiovascular risk, conditions that have become increasingly prevalent in pediatric populations. A comprehensive set of pediatric reference intervals for traditional or recently established lipid analytes is not currently available.

DESIGN AND METHODS

525 outpatient samples from a pediatric population were categorized into five age groups ranging from 0 to 20 years of age. Groups were further partitioned by gender. Serum or plasma samples were analyzed on the VITROS 5,1 FS Chemistry System for cholesterol and triglycerides by dry-film methods, direct HDL-C and LDL-C by selective detergent elimination, and apolipoproteins AI and B by immunoturbidimetry. Reference intervals were established by non-parametric methods at the 2.5th and 97.5th percentiles.

RESULTS

Lipid levels show age- and gender-related differences, particularly during the first year of life and in young adults following puberty. Concentrations of total cholesterol, LDL-C, and apo B were lowest in the 12 months after birth and remained relatively constant throughout childhood, but decreased for males in early adulthood. Triglyceride levels increased gradually throughout childhood and adolescence, and along with cholesterol, the upper limits of these intervals exceeded the recommended concentrations of lipid levels in children. For HDL-C and apo AI, no age- or sex-related differences were found until after puberty when values for males decreased slightly.

CONCLUSIONS

Our current reference intervals in children and adolescents provide an important update for lipid markers and suggest earlier incidence of hypercholesterolemia when compared to previous ranges. Increased profiling of lipids is anticipated, and these will aid in the early assessment of cardiovascular risk in pediatric populations.

Gap analysis of pediatric reference intervals for risk biomarkers of cardiovascular disease and the metabolic syndrome

The childhood obesity epidemic has begun to compromise the health of the pediatric population by promoting premature development of atherosclerosis and the metabolic syndrome (MS), both of which significantly increase the risk of cardiovascular disease (CVD) early in life. As a result, recently, there has been increased recognition of the need to assess and closely monitor children and adolescents for risk factors of CVD and components of the MS. Serum/Plasma biomarkers including total cholesterol, triglycerides, HDL-C, LDL-C, insulin and C-peptide have been used for this purpose for many years. Recently, emerging biomarkers such as apolipoprotein AI, apolipoprotein B, leptin, adiponectin, free fatty acids, and ghrelin have been proposed as tools that provide valuable complementary information to that obtained from traditional biomarkers, if not more powerful predictions of risk. In order for biomarkers to be clinically useful in accurately diagnosing and treating disorders, age-specific reference intervals that account for differences in gender, pubertal stage, and ethnic origin are a necessity. Unfortunately, to date, many critical gaps exist in the reference interval database of most of the biomarkers that have been identified. This review contains a comprehensive gap analysis of the reference intervals for emerging and traditional risk biomarkers of CVD and the MS and discusses the clinical significance and analytical considerations of each biomarker.

Correlates of serum lipoprotein (A) in children and adolescents in the United States. The third National Health Nutrition and Examination Survey (NHANES-III)

Objective

To determine the correlates of serum lipoprotein (a) (Lp(a)) in children and adolescents in the United States.

Methods

Cross-sectional study using representative data from a US national sample for persons aged 4–19 years participating in The Third National Health Nutrition and Examination Survey (NHANES-III).

Results

We observed ethnicity-related differences in levels of Lp(a) > 30 mg/dl, with values being markedly higher in African American (black) than nonhispanic white (white) and Mexican American children in multivariate model (P < 0.001). Higher levels of Lp(a) > 30 mg/dl associated with parental history of body mass index and residence in metro compared to nonmetro in Blacks, and high birth weight in Mexican American children in the NHANES-III. In the entire group, total cholesterol (which included Lp(a)) and parental history of premature heart attack/angina before age 50 (P < 0.02) showed consistent, independent, positive association with Lp(a). In subgroup analysis, this association was only evident in white (P = 0.04) and black (P = 0.05) children. However, no such collective consistent associations of Lp(a) were found with age, gender, or birth weight.

Conclusion

Ethnicity-related differences in mean Lp(a) exist among children and adolescents in the United States and parental history of premature heart attack/angina significantly associated with levels of Lp(a) in children. Further research on the associations of Lp(a) levels in childhood with subsequent risk of atherosclerosis is needed.