Plasma cholesterol and other cardiac risk factors in adolescent girls

High protein diets do not affect anthropometric indexes and cardiometabolic risk factors among children with excess weight: A randomized controlled trial

Introduction: Limited information exists regarding the effects of high protein (HP) diets on cardiovascular disease (CVD) risk factors among overweight and obese children. Our aim was to determine the effects of an HP diet on anthropometric indexes and CVD risk factors among overweight and obese children. Methods: In a parallel randomized controlled trial, we recruited 50 overweight and obese children, aged 6-11 years, for a 10 week HP or control diet (protein, carbohydrate, fat: 25%, 45%, 30% in the HP diet vs. 15%, 55%, 30% in the control diet, respectively). Fasting blood glucose (FBG) serum insulin levels, lipid profiles, systolic and diastolic blood pressure (SBP and DBP), and anthropometric measurements were assessed using standard guidelines. Results: 86% of children completed the trial. Percent changes (PC) for anthropometric and biochemical variables were not significantly different between the two groups. The PC of serum triglyceride (TG) level was significantly decreased in the HP group compared to in the control group (PC: -10.16±4.30% vs.12.11±7.80%; P = 0.01) in the crude model, but not in the adjusted model. For other variables, we did not find any significant differences between the HP group and the controls. Conclusion: In the present study, we did not find any significant effect of adherence to an HP diet in improving anthropometric measurements or other CVD risk factors among obese and overweight children.

Smoking, Adolescents and Health: Isfahan Healthy Heart Programme-Heart Health Promotion from Childhood

To evaluate the effect of some environmental factors on smoking, and to assess some health hazards of smoking in adolescents, this cross-sectional study was performed among 1950 students, ages11-18, selected by multi-stage random sampling from three cities in Iran. According to self-administered questionnaires, 12.9% of boys and 4% of girls reported to be smoker (OR=3.34, 95%CI: 2.33, 4.77, p<0.001). The mean values of total-and LDL-cholesterol were higher in smokers and their HDL-C was lower than non-smokers (163.33± 33.83, 90.73± 31 and 46.7± 12.24 vs.156± 29.53, 85±26.5 and 49.4±13.7 mg/dl, respectively, p<0.05). The mean systolic and diastolic blood pressures were higher in smokers than non-smokers (110.7± 14.5, 67.6± 11.55 vs. 104.9± 14.3, 63.2± 10.8 mmHg, respectively, p<0.05). The smokers had higher BMI than non-smokers (20.34 ±3.84 vs.19.55 ± 3.66, p<0.05). The mean food consumption frequency was lower for fruits and vegetables and higher for fat/salty snacks and fast foods in smokers than non-smokers. Logistic regression analysis showed significant association between sex, age, the number of family members and number of smokers in the family and smoking in students. The findings of this study have implications for future tobacco prevention strategies through community-based interventions. Asia Pac JPublic Health 2004; 16(1): 15-22.

Relationship between serum cholesterol and body mass index in Nigeria schoolchildren aged 2-15 years

BACKGROUND

Non-communicable disease is becoming a public health problem that it is already present in more affluent countries. The aim of this study was to determine the relationship between body mass index (BMI) and total serum cholesterol with its lipoprotein fractions in children aged 2-15 years.

METHODS

Serum cholesterol was estimated using the enzymatic spectrophotometer cholesterol oxidase/peroxidase method. BMI was calculated as weight (kg)/height (m(2)).

RESULTS

Total cholesterol and low-density lipoprotein were positively co-related with BMI (p < 0.05). Using linear regression, equations that can be used to predict serum total cholesterol from known BMI values were developed.

CONCLUSION

There is a positive correlation between BMI and serum cholesterol. BMI which is non-invasive is recommended as a screening tool for cardiovascular risk in settings where serum cholesterol cannot be routinely estimated.

The effects of polyunsaturated:saturated fatty acids ratios and peroxidisability index values of dietary fats on serum lipid profiles and hepatic enzyme activities in rats

Raising the dietary PUFA:saturated fatty acids (SFA) ratio has been recommended for the prevention of CVD. However, a high PUFA:SFA (P:S) ratio diet enhances oxidative stress because PUFA are highly susceptible to lipid peroxidation. Thus, we focused on the role of the dietary P:S ratio and peroxidisability index (PI) value on serum and liver tissue and investigated the effects of dietary P:S ratios (0.4, 1.0, and 4.8) with a fixed PI value (81) on serum lipid parameters and hepatic enzyme activities (experiment 1). To elucidate whether those phenomena were unique to the P:S ratio, we examined the effects of dietary PI values (36, 81, 126, and 217) with a constant P:S ratio (1.0) (experiment 2). Female Sprague-Dawley rats weighing 240-280 g were fed experimental diets for 4 weeks. When dietary PI value was maintained at 81, serum HDL-cholesterol (HDL-C) increased with increasing dietary P:S ratio. When the P:S ratio was fixed at 1.0, HDL-C was the lowest with mid-low PI (MLPI) (PI value of 81). In both experiments, serum LDL-cholesterol:HDL-C ratio kept in the range of 0-2. The hepatic superoxide dismutase, catalase, and glutathione peroxidase (GSH-Px) activities and thiobarbituric acid reactive substance (TBARS) concentrations were the highest in the lowest dietary P:S ratio group (experiment 1). GSH-Px, glutathione-S-transferase, and TBARS were the lowest in rats fed the MLPI diet (experiment 2). In conclusion, these results indicate that a P:S ratio of 1.0-1.5 and a PI value of 80-90 in the diet are within a favourable range to reduce the risk of CVD.

Effects of two P/S ratios with same peroxidizability index value and antioxidants supplementation on serum lipid concentration and hepatic enzyme activities of rats

BACKGROUND

High polyunsaturated/saturated fatty acid (P/S) ratio of diet decreases the risk of cardiovascular disease (CVD) with improvement of serum lipid profiles and inhibition of lipid peroxidation. This study was to investigate the effects of P/S ratio and antioxidants supplementation on lipid and peroxidation when dietary peroxidizability index (PI) value was the same.

METHODS

Female Sprague-Dawley rats weighing 100-120 g were fed four different experimental diets for 4 weeks. The P/S ratios were 0.38 (LP) and 4.81 (HP) when the PI value of diet was 81.22. These diets were supplemented with vitamin E 1000 mg/kg diet and selenium 2.5 mg/kg diet (LPS and HPS).

RESULTS

The total-cholesterol (T-C) and HDL-cholesterol concentrations of serum were higher in HP and HPS (p<0.001). The cardiac index and atherogenic index were lower in HP and HPS (p<0.001). Hepatic thiobarbituric acid reactive substance concentrations were higher in LP and LPS (p<0.001). However, P/S ratio and antioxidants had no effect on antioxidant enzyme activities in the liver.

CONCLUSION

A high P/S ratio diet has a beneficial effect on CVD risk even without antioxidant when the PI value is the same. We suggest that P/S ratio as well as PI value should be considered for reducing the risk of CVD.

Plasma cholesterol and endogenous cholesterol synthesis during refeeding in anorexia nervosa

Normal or high levels of cholesterol have been measured in patients with anorexia nervosa (AN). Given that cholesterol intake in AN is usually very low, the reasons for this anomaly are not clearly understood. We studied lipid and lipoprotein profiles and endogenous cholesterol synthesis, estimated by serum lathosterol, in a population of 14 girls with AN, before and during a period of 30 days refeeding. The initial body mass index (BMI) of the patients was 13.41+/-1.62 kg/m(2). No changes were observed during refeeding in endocrine parameters (ACTH, cortisol and estradiol). At Day 0 the lipids data measured here showed normal levels of triglycerides, and total cholesterol at the upper limits of the normal range (5.44+/-1 mmol/l). At this time, total and LDL cholesterol were negatively correlated with transthyretin and BMI. Serum lathosterol (a precursor in cholesterol synthesis pathway) increased significantly (5.99+/-1.75 (Day 0) vs. 8.39+/-2.96 (Day 30); P=0.02) while there was a significant decrease in apo B (0.79+/-0.33 (Day 0) vs. 0. 60+/-0.17 g/l (Day 30), P=0.02) with refeeding. Thus, patients with initial high cholesterol levels have the worst nutritional status and high cholesterol levels are not related to a de novo synthesis. This profile returns to normal with refeeding. An increase of cellular cholesterol uptake may be responsible for this apparently paradoxical evolution with increase of cholesterol synthesis and decrease of apo B during renutrition.

Coronary heart disease risk factors in male adolescents, with particular reference to smoking and blood lipids

PURPOSE

To examine coronary heart disease (CHD) risk factors, particularly blood lipids and smoking, in adolescent boys in the Sydney Metropolitan area, and to investigate possible differences between boys from English-speaking (ESB) and non-English-speaking backgrounds (NESBs).

METHODS

Male volunteers aged 15-18 years were recruited from the senior years of four secondary schools in different geographical areas of Sydney. Body mass index (BMI), waist-hip ratio (WHR), blood lipids, and percent body fat were measured. Behavioral variables were estimated by questionnaire.

RESULTS

A total of 110 boys were recruited; 74% were from an ESB. Mean WHR (0.836 +/- 0.045), waist circumference (80.6 +/- 9.4 cm), and percent body fat (21.0 +/- 6.3) were similar across age groups. Atherogenicity of the lipid profile, as measured by the ratio of total cholesterol to high-density lipoprotein cholesterol (TC:HDL-C), was lower in boys aged 15 years than in any other age group (p < .05). TC:HDL-C was strongly associated with BMI (r = .57; p < .0001) and WHR (r = .35; p < .01). Smokers had higher BMI, were less active and had lower HDL-C (p < .001) and higher TC:HDL-C (p < .0001) than nonsmokers. Smoking, even of short duration, and quite moderate consumption of cigarettes (6/day) were associated with a deterioration of the lipid profile. Boys from NESBs had a higher degree of risk in all of the factors examined.

CONCLUSIONS

Regular smoking of short duration has an appreciable impact on lipid and lipoprotein concentrations in this sample of Australian adolescent boys. Boys from an NESB appear to be at greater risk of developing CHD in later life.

Relation of circumferences and skinfold thicknesses to lipid and insulin concentrations in children and adolescents: the Bogalusa Heart Study

BACKGROUND

Although body fat patterning has been related to adverse health outcomes in adults, its importance in children and adolescents is less certain.

OBJECTIVE

We examined the relation of circumference (waist and hip) and skinfold-thickness (subscapular and triceps) measurements to lipid and insulin concentrations among 2996 children and adolescents aged 5-17 y.

DESIGN

This was a community-based, cross-sectional study conducted in 1992-1994.

RESULTS

A central or abdominal distribution of body fat was related to adverse concentrations of triacylglycerol, LDL cholesterol, HDL cholesterol, and insulin; these associations were independent of race, sex, age, weight, and height. These associations were observed whether fat patterning was characterized by using 1) waist circumference alone (after adjustment for weight and height), 2) waist-to-hip ratio, or 3) principal components analysis. Compared with a child at the 10th percentile of waist circumference, a child at the 90th percentile was estimated to have, on average, higher concentrations of LDL cholesterol (0.17 mmol/L), triacylglycerol (0.11 mmol/L), and insulin (6 pmol/L) and lower concentrations of HDL cholesterol (-0.07 mmol/L). These differences, which were independent of weight and height, were significant at the 0.001 level and were consistent across race-sex groups.

CONCLUSIONS

These findings emphasize the importance of obtaining information on body fat distribution, waist circumference in particular, in children. Waist circumference, which is relatively easy to measure, may help to identify children likely to have adverse concentrations of lipids and insulin.