Evaluation and management of dyslipoproteinemia in children

Prevention of non-communicable disease in a population in nutrition transition: Tehran Lipid and Glucose Study phase II

BACKGROUND

The Tehran Lipid and Glucose Study (TLGS) is a long term integrated community-based program for prevention of non-communicable disorders (NCD) by development of a healthy lifestyle and reduction of NCD risk factors. The study begun in 1999, is ongoing, to be continued for at least 20 years. A primary survey was done to collect baseline data in 15005 individuals, over 3 years of age, selected from cohorts of three medical heath centers. A questionnaire for past medical history and data was completed during interviews; blood pressure, pulse rate, and anthropometrical measurements and a limited physical examination were performed and lipid profiles, fasting blood sugar and 2-hours-postload-glucose challenge were measured. A DNA bank was also collected. For those subjects aged over 30 years, Rose questionnaire was completed and an electrocardiogram was taken. Data collected were directly stored in computers as database software- computer assisted system. The aim of this study is to evaluate the feasibility and effectiveness of lifestyle modification in preventing or postponing the development of NCD risk factors and outcomes in the TLGS population.

DESIGN AND METHODS

In phase II of the TLGS, lifestyle interventions were implemented in 5630 people and 9375 individuals served as controls. Primary, secondary and tertiary interventions were designed based on specific target groups including schoolchildren, housewives, and high-risk persons. Officials of various sectors such as health, education, municipality, police, media, traders and community leaders were actively engaged as decision makers and collaborators. Interventional strategies were based on lifestyle modifications in diet, smoking and physical activity through face-to-face education, leaflets & brochures, school program alterations, training volunteers as health team and treating patients with NCD risk factors. Collection of demographic, clinical and laboratory data will be repeated every 3 years to assess the effects of different interventions in the intervention group as compared to control group.

CONCLUSION

This controlled community intervention will test the possibility of preventing or delaying the onset of non-communicable risk factors and disorders in a population in nutrition transition.

TRIAL REGISTRATION

ISRCTN52588395.

Obesity induced during sexual maturation is linked to LDL-triacylglycerols in Yucatan miniature swine

The incidence of childhood obesity is rising dramatically throughout industrialised countries. To evaluate and study the impact of childhood obesity on lipoprotein metabolism, we developed a new animal model of premature obesity. Yucatan mini-pigs aged 4 months were studied over a 12-month period from childhood to adulthood. Animals were divided into two groups: the first group were overfed a Western misbalanced diet; the second group were normally fed a recommended human-type diet. Cholesterol and triacylglycerol concentrations in VLDL-, LDL- and HDL-lipoproteins were followed from baseline to adulthood by fast protein liquid chromatography. At 10 (the end of sexual maturation) and 16 months old (adulthood), liver, visceral and subcutaneous adipose tissues were sampled. Real-time RT-PCR was performed in order to compare apo AI, apo B, apo C-III, PPAR-α, insulin receptor and lipoprotein lipase gene expression between groups and ages. Differences between groups were observed only after sexual maturity. Adult overfed mini-pigs had a higher LDL-cholesterol:HDL-cholesterol ratio (P<0·05; 0·55 (SE 0·06) for overfedv. 0·42 (SE 0·04) for normally fed pigs at the tenth month of the study). In both groups, VLDL-triacylglycerol decreased (P<0·05). VLDL-triacylglycerol evolution in the overfed group was associated with an increase in LDL-triacylglycerol plasma concentrations (P<0·05) after sexual maturation. LDL-triacylglycerol concentration in overfed mini-pigs went from an average of 0·28 mmol/l before sexual maturation to reach an average concentration of 0·56 mmol/l afterwards. This phenomenon has never been observed in similar studies when obesity is induced in adult mini-pigs and may represent a specific hallmark of an obesity induced during sexual maturity.

Childhood obesity and insulin resistance in a Yucatan mini-piglet model: putative roles of IGF-1 and muscle PPARs in adipose tissue activity and development

OBJECTIVE

To explore metabolic and cellular modifications induced during childhood obesity, in a novel animal model of obese mini-piglets.

DESIGN

A total of 10 four-month old Yucatan mini-pigs were followed from prepuberty to adulthood. Animals were divided into two groups. The first one had been overfed (OF) a western-type diet and the second one had been normally fed a control recommended human-type diet (NF).

MEASUREMENTS

Plasma insulin-like growth factor 1 (IGF-1), insulin, leptin, nonesterified fatty acids, triglycerides (TGs) and glucose were determined at sexual maturity and at young adulthood. Quantitative gene expressions of peroxysome-proliferator-activated receptors (PPARs), glucose transporter 4, insulin receptor, IGF-1, leptin and interleukin-6 (IL-6) in skeletal muscle, adipose tissue and liver were also measured at both stages. Adult insulin sensitivity was measured via euglycaemic-hyperinsulinaemic clamps.

RESULTS

Increased body weight in adult OF pigs was associated with increased body size and low insulin sensitivity. Sexually mature OF pigs had higher IGF-1 plasma concentrations than their lean littermates (P < 0.05). In the OF group, TGs and glucose were both decreased (P < 0.05). Muscle PPARgamma and alpha in OF pubescent pigs as compared to NF pigs were 11 times higher and 20 times lower, respectively (P < 0.01).

CONCLUSION

Obesity and insulin resistance induced by overfeeding mini-pigs during development and puberty were not associated with the cluster of metabolic modifications frequently observed in their adult littermates. Increased IGF-1 concentrations and modifications of skeletal muscle PPAR (alpha and gamma) expressions may help the young obese pig to partially regulate its glycaemia and triglyceridaemia through an increase of fat mass, which maintains its high insulin sensitivity.

Lipoprotein profile in long term theophylline administration in children with asthma

Atherosclerosis in childhood has a slowly progressive course and its clinical features usually become prominent in middle ages. Hypercholesterolemia is one of the major risk factors for the development of atherosclerosis. A clear correlation exists between hypercholesterolemia in childhood and atherosclerotic lesions extending into adulthood.In this study, we evaluated the effect of slow release theophylline (SRT) treatment on plasma lipid profile and assessed the risk for atherosclerotic coronary heart disease in children with bronchial asthma. Group 1 consisted of 15 children with a mean age of 10.8 3.19 years who received SRT for bronchial asthma for a mean period of 9.13 2.17 months. Group 2 was composed of 15 children with a mean age of 11.40 3.78 years and followed up for bronchial asthma, who received no SRT treatment. Group 3 comprised 15 children with a mean age of 9.00 3.76 years and no history of asthma or wheezing. In all patients lipid profiles were assessed by measuring levels of plasma triglyceride, total cholesterol, high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C) apolipoprotein A (Apo-A) and apolipoprotein B (Apo-B). In group 1, the mean total cholesterol level was 175.53 24.36 mg/dl, LDL-C level was 91.00 24.07 mg/dl and Apo-B level was 87.27 12.74 mg/dl after SRT treatment. In group 1, group 2 (control group with asthma) and group 3 (the non-asthmatic control group), the mean plasma lipid level after SRT treatment was significantly higher than that before SRT treatment. In conclusion, long-term SRT treatment in children with bronchial asthma may alter lipid profile and may increase the risk for developing atherosclerotic coronary heart disease.

Lipid profile in congenital adrenal hyperplasia

Glucocorticoids have been reported to exert a marked effect on lipoprotein metabolism. Several studies have shown a potential risk of hyperlipidemia in patients under long-term glucocorticoid therapy. Current management of patients with congenital adrenal hyperplasia (CAH) includes the use of glucocorticoids to attenuate the increased production of undesirable adrenal hormones. A case-control study was designed to compare the serum lipid profiles of 14 patients with CAH under glucocorticoid therapy and 14 normal controls and to determine the characteristics of the profiles. A total of 9 patients (64.3%) had serum total cholesterol (TC) greater than 4.4 mmol/L (170 mg/dL), compared with 6 individuals in the control group (42.3%). Nine patients with CAH (64.3%) had serum triglycerides (TGs) more than 1.0 mmol/L (90 mg/dL), compared with only 2 in the control group (14.3%). Similarly, the mean serum TG was higher in the CAH group versus the controls, 1.33 mmol/L (118 mg/dL) versus 0.75 mmol/L (67 mg/dL), respectively. Serum low-density lipoprotein, (LDL-C) and high-density, lipoprotein (HDL-C) cholesterol were determined in 13 children with CAH and in the 14 controls. Nine CAH patients (69.2%) and 8 controls (57%) had LDL-C greater than 2.8 mmol/L (<110 mg/dL). For HDL-C, 2 children with CAH (15.4%) and 4 controls (28.6%) had levels less than 0.9 mmol/L (35 mg/dL). There were no significant differences for the cholesterol index, 0.24 for the controls and 0.22 for the CAH group. In the CAH group, the mean serum TG level and the percentage of individuals with TGs greater than 1.0 mmol/L were statistically significant compared with the controls. The mean serum TC and LDL-C, as well as the percentage of subjects with levels over the cutoff point, although slightly higher in the CAH group, were of no statistical significance. The results of this pilot study suggest that long-term glucocorticoid therapy in patients with CAH may induce abnormalities in the serum lipid profile characterized mainly by an increment in serum TGs.

A public health vs a risk-based intervention to improve cardiovascular health in elementary school children: the Cardiovascular Health in Children Study

OBJECTIVES

This study sought to determine the population effects of both classroom-based and risk-based interventions designed to reduce cardiovascular disease risk factors in children.

METHODS

Elementary school children (n = 2109; age range: 7-12 years) were randomized by school to a classroom-based intervention for all third and fourth graders, a risk-based intervention only for those with 1 or more cardiovascular disease risk factors, or a control group. The 8-week interventions involved both knowledge--attitude and physical activity components.

RESULTS

School-level analyses showed that physical activity in the risk-based group and posttest knowledge in the classroom-based group were significantly higher than in the control group. With regard to trends shown by individual-level analyses, cholesterol dropped more in the classroom-based than in the control group, and skinfold thickness decreased 2.9% in the classroom-based group and 3.2% in the risk-based group (as compared with a 1.1% increase in the control group).

CONCLUSIONS

Both classroom-based and risk-based interventions had positive effects on physical activity and knowledge, with trends toward reduced body fat and cholesterol. However, the classroom-based approach was easier to implement and evidenced stronger results than the risk-based intervention.