Serum lipid values in adolescents are related to family history, infant feeding, and physical growth

Breastfeeding and ApoB in late adolescence: a Hong Kong birth cohort study

Breastfeeding is widely promoted. Experimental evidence concerning long-term benefits is limited. Observational studies are open to bias from confounding by socio-economic position. We assessed the association of breastfeeding with late adolescent lipid sub-fractions, particularly apolipoprotein B (ApoB) and non-high-density lipoprotein cholesterol (non-HDL-c), overall and by sex. We took advantage of a setting where breastfeeding has little association with higher socio-economic position and where several results from randomized controlled trials of breastfeeding promotion have been replicated. We used the population-representative "Children of 1997" birth cohort comprising 88% of births in Hong Kong in April and May 1997. Associations of breastfeeding in the first 3 months of life (never, mixed, exclusive) with lipid sub-fractions were obtained using linear regression adjusted for potential confounders including parental socio-economic position, maternal place of birth, type of delivery, gestational age, and birth weight. Differences by sex were assessed. Multiple imputation and inverse probability weighting were used to recover the original sample. Of the 3462 participants included, mean age was 17.6 years and 48.8% were girls. Mean ApoB was 0.74 g/L (standard deviation 0.15). Exclusive versus never breastfeeding was associated with lower ApoB (-0.027 g/L, 95% confidence interval (CI)-0.046 to-0.007, p = 0.007) and lower non-HDL-c (-0.143 mmol/L, 95% CI-0.237 to-0.048) with similar estimates by sex.

CONCLUSION

Breastfeeding may provide some population-level lifelong protection against cardiovascular disease. This study supports policies promoting breastfeeding as a modifiable exposure that contributes to a healthy start in life as an investment for lifelong cardiovascular disease prevention.

WHAT IS KNOWN

• Apolipoprotein B (ApoB) is a recognized risk factor for cardiovascular disease, but whether breastfeeding affects ApoB in later life overall and by sex is unknown.

WHAT IS NEW

• Exclusive breastfeeding in the first 3 months of life was associated with lower ApoB in late adolescence, with similar estimates for both sexes. • The inverse association of breastfeeding with ApoB suggests that breastfeeding could reduce cardiovascular disease and overall mortality over the lifespan.

Relationship between early growth and CVD risk factors in adolescents

Low birth weight and a rapid weight gain in early childhood may lead to an increased risk for developing cardiovascular disease later in life, such as hypertension and dyslipidaemia. In this study, we examined the associations between size at birth, relative weight gain in infancy and childhood with specific cardiovascular disease risk factors in early adulthood. Adolescents (n=1935) from the Birth to Twenty plus (BT20+) cohort were included in the analysis. The following were treated as exposure variables: weight at birth, and relative conditional weight gain (CW), independent of height, between ages 0-24 months and 24-48 months. Outcomes were serum lipids and body composition variables at age 18 years. After adjusting for sex and other confounders, early life exposures were not associated with adolescent lipid profile. Following adjustment for sex and height (body size), birth weight [β=0.704 (0.40, 1.01)], CW 0-24 [β=1.918 (1.56, 2.28)] and CW24-48 [β=1.485 (1.14, 1.82)] accounted for 48% of the variance in fat mass. However, birth weight [β=0.773 (0.54, 1.01)], CW 0-24 [β=1.523 (1.24, 1.80)] and CW24-48 [β=1.226 (0.97, 1.49)] were also positively predicted and accounted for 71% of the variance in fat mass in adolescence (P<0.05). Our data suggests that birth weight and weight gain during infancy and early childhood independent of linear growth are related to adolescent body composition but not blood lipid profiles in an urban African population.

Evalution of Serum Lipid Profiles in Turkish Children Aged Two to Eighteen Years

OBJECTIVE

The purpose of this study was to evaluate dyslipidaemia in children according to age, gender, percentiles, mother's education level, breastfeeding duration and areas of residence.

METHODS

A total of 285 children (137 girls; 148 boys), aged between two and 18 years, were enrolled in this cross-sectional, epidemiologic study. Lipid profiles were assessed and its relation with sociodemographic features was evaluated.

RESULTS

Dyslipidaemia prevalence was 37.4% (n = 107). High very low-density lipoprotein cholesterol (VLDL-C) and low high-density lipoprotein cholesterol (HDL-C) levels are related with percentiles of the children (p = 0.006, p = 0.03, respectively). Gender was a significant factor for VLDL-C, which was higher in girls than boys (p = 0.04). Total cholesterol levels were high in 14 children (4.9%); 72 of the study group (25.3%) had high triglyceride levels; HDL-C levels were low in 52 children (18.2%).

CONCLUSION

All the parameters of dyslipidaemia are not so high in our region. However, as early detection of dyslipidaemia should begin in childhood, we should perform periodic checks to prevent cardiovascular risks.

Anthropometric and Iron Status of Adolescents From Selected Secondary Schools in Ogun State, Nigeria

Purpose. We assessed the anthropometric and iron status of adolescents from selected secondary schools in Ogun State, Nigeria. Methods. In this cross-sectional study, anthropometric data, nutrient data, and blood samples were collected from 127 adolescents in Nigeria. Demographic information of the adolescents was obtained in the language of choice using validated questionnaires. Anthropometric indices (weight and height), multiple iron status indicator (hemoglobin, serum ferritin, and transferrin receptor) and inflammation marker (C-reactive protein) were measured using standard procedures. Subjects were classified by body mass index (BMI) categories as underweight, normal weight, at risk of overweight, and overweight according to the World Health Organization standard. Results. The mean age of the subjects was 16.0 ± 2.3 years. Majority of the subjects (55.1%) had normal BMI values, 21.3% were underweight, and 14.2% were overweight. Boys had significantly (<0.05) higher mean intake for energy and most nutrients than girls. The dietary iron intake of the adolescents was unsatisfactory, with approximately 80% of the subjects failing to meet RNI level. Using multiple criteria of iron indicators, the prevalence of iron depletion and iron deficiency in the adolescents were 7.9% and 15.0%, respectively. The prevalence of anemia was high (24.4%), with iron deficiency anemia being the most (71%) prevalent. In both boys and girls, ferritin correlated positively with BMI, waist circumference, and waist–hip ratio. Conclusions. This study documented a high prevalence of iron deficiency and poor nutritional status among Nigeria adolescents, which can be used as basic for dietary support and nutritional education to improve their iron status.

Adult lipids associated with early life growth in traditional Melanesian societies undergoing rapid modernization: a longitudinal study of the mid-20th century

Both poor fetal development and accelerated post-natal growth have been linked to adult dyslipidemias in many studies conducted in developed societies. It is not known, however, whether these relationships only characterize populations with typical Western diets or if they also may develop in groups at the early stages of a dietary transition. Our longitudinal study of traditional rural populations in the Southwest Pacific during a period of extremely rapid modernization in diet and life-styles shows a nascent association between child growth retardation, subsequent growth acceleration, and adult lipid values in spite of a continuing prevalence of very low lipid levels. However, our results do not entirely conform to results from populations with "modern" diets. Outcome (i.e., young adult) cholesterol and triglyceride levels are more consistently related to initial measures of body fat and growth in body fat measures than with stature, while outcome apo A-1 is more consistently related to initial stature or stature growth than to measures of body fat. We suggest this may reflect a pattern characteristic of the initial stages of "modernization" associated with dietary change, with stronger and more pervasive relationships emerging only later as populations complete the dietary transition.

Early-life determinants of total and HDL cholesterol concentrations in 8-year-old children; the PIAMA birth cohort study

BACKGROUND

Adult cholesterol concentrations might be influenced by early-life factors, such as breastfeeding and birth weight, referred to as "early programming". How such early factors exert their influence over the life course is still poorly understood. Evidence from studies in children and adolescents is scarce and conflicting. We investigated the influence of 6 different perinatal risk factors on childhood total and HDL cholesterol concentrations and total-to-HDL cholesterol ratio measured at 8 years of age, and additionally we studied the role of the child's current Body Mass Index (BMI).

METHODS

Anthropometric measures and blood plasma samples were collected during a medical examination in 751 8-year-old children participating in the prospective Prevention and Incidence of Asthma and Mite Allergy (PIAMA) birth cohort study. Linear and logistic regression were performed to estimate associations of total and HDL cholesterol concentrations with breastfeeding, birth weight, infant weight gain, maternal overweight before pregnancy, gestational diabetes and maternal smoking during pregnancy, taking into account the child's current BMI.

RESULTS

Linear regressions showed an association between total-to-HDL cholesterol ratio and maternal pre-pregnancy overweight (β = 0.15, Confidence Interval 95% (CI): 0.02, 0.28), rapid infant weight gain (β = 0.13, 95%CI: 0.01, 0.26), and maternal smoking during pregnancy (β = 0.14, 95%CI: 0.00, 0.29). These associations were partly mediated by the child's BMI.

CONCLUSION

Total-to-HDL cholesterol ratio in 8-year-old children was positively associated with maternal pre-pregnancy overweight, maternal smoking during pregnancy and rapid infant weight gain.

Lipoprotein(a) and family history of cardiovascular disease in children with familial dyslipidemias

OBJECTIVE

To investigate in children and adolescents with familial dyslipidemias the association between lipoprotein(a) [Lp(a)] level and family history of cardiovascular disease (CVD), and whether this association is independent of the disturbed lipid profile.

STUDY DESIGN

Lp(a) level, lipid profile, and a 2-generation genealogic tree to detect cardiovascular events were evaluated in 231 patients with familial dyslipidemias. Lp(a) levels were stratified according to presence, age of occurrence, and number and type of cardiovascular events in the patient's kindreds.

RESULTS

Lp(a) and other plasma lipid fractions did not differ between patients with and those without a family history of cardiovascular events. However, the percentage of patients with elevated Lp(a) level (≥85th percentile) was higher in those with a positive family history for early cardiovascular events (P = .01). Lp(a) level was a significant independent predictor of the number of premature cardiovascular events (β = 0.17; P = .01) and of cerebrovascular events in kindreds (OR, 2.5; 95% CI, 1.05-6.03; P = .039), independent of plasma lipid fractions and other cardiovascular risk factors.

CONCLUSIONS

In children and adolescents with familial dyslipidemias, the overall association between Lp(a) level and family history of early CVD may be due to a threshold effect in those with the highest Lp(a) levels. However, multiple cardiovascular events and cerebrovascular events are predicted by any increase in plasma Lp(a) level, independent of other cardiovascular risk factors.

Long-term health outcomes and mechanisms associated with breastfeeding

Breastfeeding is superior to formula feeding because it has factors that have long term consequences for early metabolism and disease later in life. In this paper, the scientific evidence in support of why breast milk is beneficial for infants is summarized and the mechanisms in which breastfeeding impacts on disease are explored. Human milk may show a reduced occurrence of disease because mammalian evolution promotes survival, and because of specific factors in milk that promote active stimulation of the infant's immune system and gastrointestinal mucosal maturation decrease the incidence of infection and alter the gut microflora. Bioactive factors, including: hormones, growth factors, colony-stimulating factors and specific nutrients, may have such far-reaching effects on the infant's immune response that normal development depends heavily on its provision. All mothers should be encouraged and supported to continue breastfeeding for 6 months and beyond in order to promote the good health of their infants.

Impact of early parental child-rearing behavior on young adults' cardiometabolic risk profile: a prospective study

OBJECTIVE

To examine prospectively whether early parental child-rearing behavior is a predictor of cardiometabolic outcome in young adulthood when other potential risk factors are controlled. Metabolic factors associated with increased risk for cardiovascular disease have been found to vary, depending on lifestyle as well as genetic predisposition. Moreover, there is evidence suggesting that environmental conditions, such as stress in pre- and postnatal life, may have a sustained impact on an individual's metabolic risk profile.

METHODS

Participants were drawn from a prospective, epidemiological, cohort study followed up from birth into young adulthood. Parent interviews and behavioral observations at the age of 3 months were conducted to assess child-rearing practices and mother-infant interaction in the home setting and in the laboratory. In 279 participants, anthropometric characteristics, low-density lipoprotein and high-density lipoprotein cholesterol, apolipoproteins, and triglycerides were recorded at age 19 years. In addition, structured interviews were administered to the young adults to assess indicators of current lifestyle and education.

RESULTS

Adverse early-life interaction experiences were significantly associated with lower levels of high-density lipoprotein cholesterol and apolipoprotein A1 in young adulthood. Current lifestyle variables and level of education did not account for this effect, although habitual smoking and alcohol consumption also contributed significantly to cardiometabolic outcomes.

CONCLUSIONS

These findings suggest that early parental child-rearing behavior may predict health outcome in later life through its impact on metabolic parameters in adulthood.

Does initial breastfeeding lead to lower blood cholesterol in adult life? A quantitative review of the evidence

BACKGROUND

Earlier studies have suggested that infant feeding may program long-term changes in cholesterol metabolism.

OBJECTIVE

We aimed to examine whether breastfeeding is associated with lower blood cholesterol concentrations in adulthood.

DESIGN

The study consisted of a systematic review of published observational studies relating initial infant feeding status to blood cholesterol concentrations in adulthood (ie, aged >16 y). Data were available from 17 studies (17 498 subjects; 12 890 breastfed, 4608 formula-fed). Mean differences in total cholesterol concentrations (breastfed minus formula-fed) were pooled by using fixed-effect models. Effects of adjustment (for age at outcome, socioeconomic position, body mass index, and smoking status) and exclusion (of nonexclusive breast feeders) were examined.

RESULTS

Mean total blood cholesterol was lower (P = 0.037) among those ever breastfed than among those fed formula milk (mean difference: -0.04 mmol/L; 95% CI: -0.08, 0.00 mmol/L). The difference in cholesterol between infant feeding groups was larger (P = 0.005) and more consistent in 7 studies that analyzed "exclusive" feeding patterns (-0.15 mmol/L; -0.23, -0.06 mmol/L) than in 10 studies that analyzed nonexclusive feeding patterns (-0.01 mmol/L; -0.06, 0.03 mmol/L). Adjustment for potential confounders including socioeconomic position, body mass index, and smoking status in adult life had minimal effect on these estimates.

CONCLUSIONS

Initial breastfeeding (particularly when exclusive) may be associated with lower blood cholesterol concentrations in later life. Moves to reduce the cholesterol content of formula feeds below those of breast milk should be treated with caution.

Lipoprotein(a) levels in girls with premature adrenarche

AIM

Elevated lipoprotein(a) (Lp(a)) level is a risk factor for cardiovascular disease (CVD). Women with polycystic ovary syndrome (PCOS) have higher Lp(a) and risk for CVD than controls. The girls with premature adrenarche (PA) were shown to share similar hormonal/metabolic properties with PCOS. We compared Lp(a) levels in PA, with healthy and PCOS girls.

METHODS

In total, 25 PA, 20 controls and 10 girls with PCOS were evaluated. Lp(a), lipid profiles and insulin, glucose, free testosterone, dehydroepiandrosterone sulfate (DHEAS) and androstenedione levels were measured. A family history about CVD was obtained.

RESULTS

The mean age of girls with PA, at time of the study, was 10.04 +/- 1.53, control 9.83 +/- 1.58 and PCOS was 16.58 +/- 1.46 years. The median (range) of Lp(a) levels were 22.5 (3.50-99.90), 9.6 (3.33-32.40) and 21.2 (5.89-85.65) mg/dL in PA, control and PCOS groups, respectively (P > 0.05). The median Lp(a)'s were 14.5 (3.50-87.00) and 24.30 (6.20-99.90) mg/dL, in prepubertal (Tanner 1) and pubertal PA girls (Tanner 2-5), respectively (P > 0.05). The median Lp(a) of prepubertal peers was 8.7 (3.33-21.17), while that of pubertal ones was 15.4 (4.72-32.40) mg/dL (P > 0.05). There was no difference between Lp(a) levels of pre-pubertal PA girls and their peers; however, significant difference was found in Lp(a) levels in pubertal stages of PA and healthy peers (P < 0.05). The positive family history of CVD was 60% in PA; 55% and 80% in the control and PCOS groups, respectively, with no statistical difference. Lp(a) level was correlated with DHEAS (r = 0.386, P = 0.008) and free testosterone (r = 0.337, P = 0.022) levels positively. There was no significant correlation between Lp(a) and body mass index, fasting insulin and fasting glucose/insulin ratio.

CONCLUSIONS

Lipoprotein(a) levels in pubertal girls with PA differ significantly from healthy peers. However, to clarify whether the girls with PA have an additional risk for CVD with respect to Lp(a), further follow-up studies with larger number of patients are necessary.

Maternal smoking in pregnancy is associated with cholesterol development in the offspring: A 27-years follow-up study

OBJECTIVE

To examine the associations of maternal smoking in pregnancy with development of cholesterol levels from childhood to adulthood.

METHODS

Total cholesterol, high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol were measured annually from 1975 to 1993 and in 2002 in 350 subjects aged 5-19 years at baseline who participate in a prospective cohort study. Pregnancy and birth data were obtained through questionnaires sent to the parents.

RESULTS

Children of mothers who smoked in pregnancy showed a higher annual change in total cholesterol of 0.12 mmol/l per 10 years (95% confidence interval (CI): 0, 0.23) compared to children whose mothers did not smoke in pregnancy. Larger effect estimates were found in children with moderate overweight (0.39 mmol/l per 10 years (95% CI: 0.14, 0.63). HDL-cholesterol and LDL-cholesterol showed tendencies towards a decrease and increase, respectively, in children of mothers who smoked in pregnancy compared to children whose mothers did not smoke in pregnancy. Adjustment for potential confounders did not materially change the effect estimates.

CONCLUSION

This study suggests for the first time that maternal smoking in pregnancy is associated with an increased rise in total cholesterol levels and a tendency towards an adverse lipoprotein profile in the offspring.

Dietary fat in infancy should be more focused on quality than on quantity

OBJECTIVE

The primary aim was to assess, the association of the quantity and quality of dietary fat intake from 6 to 12 months of age and serum lipids at 12 months.

SUBJECTS/METHODS

Three hundred healthy term Swedish infants were recruited in a longitudinal prospective study at the age of 6 months; 276 remained in the study at 12 months. Food records and anthropometric data were collected monthly from 6 to 12 months; serum lipids were analysed at 6 and 12 months.

RESULTS

Swedish infants had a total fat intake within the Nordic recommendations, but intake of polyunsaturated fatty acids (PUFA) was low (5.6 percent of total energy (E%)) and intake of saturated fatty acids (SAFA) was high (15.1 E%). Higher PUFA intake was associated with lower total serum cholesterol (TC, B=-0.13, P=0.003), lower low-density-lipoprotein cholesterol (LDL-C, B=-0.12, P=0.004) and apolipoprotein B (B=-0.03) (P=0.034) in girls but not in boys. When data from the present study were compared to data from similar studies in Finland and Iceland, it appears that the quality of the dietary fat has greater impact on serum lipid levels than the quantity of fat in the diet.

CONCLUSIONS

Higher PUFA and lower SAFA intakes may reduce TC and LDL-C early in life, particularly in girls. Further, with respect to lowering serum lipid concentrations in early childhood it seems appropriate to set focus on fat quality rather than the quantity.

SPONSORSHIPS

Swedish Research Council for Environment, Agricultural Sciences and Spatial Planning (Formas), Swedish Research Council, Medicine, Stiftelsen Oskar Foundation, Sven Jerring Foundation, Samariten Foundation, Stiftelsen Goljes minne and Semper AB.

Life course body size and lipid levels at 53 years in a British birth cohort

OBJECTIVES

To investigate the association between growth in height and change in body mass index (BMI) during the life course on lipid levels at 53 years.

METHODS

2311 men and women from a British cohort study were included in analyses. Non-fasting total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol levels were measured at 53 years. Height and BMI at 2, 4, 7, 11, 15 and 36 years in relation to the lipid outcomes at 53 years were assessed using multiple regression models. The effects of z scores of height and BMI at 2 years and yearly rates of change (velocities) in height and BMI between 2-7, 7-15 and 15-36 years were also considered.

RESULTS

Total cholesterol level decreased by 0.119 mmol/l (95% CI -0.194 to -0.045) per SD increase in height at 2 years and by 0.073 mmol/l (95% CI -0.145 to -0.001) for every SD increase in height velocity between 15 years and adulthood. Similar, but weaker associations were seen for LDL cholesterol. The relationships between leg length and total and LDL cholesterol were stronger than the relationship with trunk length. Higher BMI at 36 and 53 years and greater BMI increases between 15-36 and 36-53 years were associated with higher total and LDL cholesterol and lower HDL cholesterol levels. The effects of growth could not be explained by birth weight or lifetime socioeconomic status.

CONCLUSIONS

Early life exposures, which restrict height growth in infancy, resulting in shorter adult leg length, may influence lipid levels in adult life.

Menstruation does not cause anemia: endometrial thickness correlates positively with erythrocyte count and hemoglobin concentration in premenopausal women

Menstruation has often been cited as a risk factor for iron-deficiency anemia. This study tested whether normal, premenopausal women's luteal endometrial thickness (ET) was associated with their red blood cell count (RBC) and hemoglobin concentrations (Hg), and therefore whether a high ET put women at risk for anemia. Endometrial thickness can be considered a reasonable proxy for menstrual blood loss in normal women. Twenty-six healthy women from the Mogielica Human Ecology Study Site in Poland, aged 20-40 years (29 +/- 5.3 years, mean +/- SD), were selected. Subjects' ET was measured by transvaginal ultrasound in the luteal phase of the menstrual cycle, and their red blood cell count and hemoglobin concentrations were measured by fasting morning blood samples. Controlling for day of ET measurement, RBC and Hg were positively correlated with ET (r(2) = 0.24, P = 0.05; r(2) = 0.25, P = 0.04, respectively). We propose that, contrary to popular understanding, a thicker endometrium suggests greater iron reserves, rather than greater risk for anemia, in healthy women.

Is family history of premature cardiovascular diseases appropriate for detection of dyslipidemic children in population-based preventive medicine programs? CASPIAN study

The objectives of this study were to determine the prevalence of dyslipidemia and the usefulness of self-report family history (FH) of premature cardiovascular disease (CVD) for identifying children with lipid disorders. This study was conducted on a representative, population-based sample of 4811 Iranian children and adolescents (2248 boys and 2563 girls) aged 6-18 years. We compared the obtained serum lipid profile with that of the Lipid Research Clinic (LRC) and calculated the predictive value of FH for detecting those children with dyslipidemia.Overall, for both genders and for age groups, the mean serum triglycerides (TG) and its percentiles were significantly higher, and the mean and percentiles of total, low-density, and high-density cholesterol (TC, LDL-C, and HDL-C respectively) were significantly lower than the LRC values. In total, 45.7% of participants had dyslipidemia; the most frequent ones were low HDL-C (24.8%) and hypertriglyceridemia (24.5%), followed by hypercholesterolemia (6.4%) and high LDL-C (6.3%), respectively. The mean serum lipid levels and the anthropometric measures were not significantly different among those with or without positive FH. The sensitivity, and specificity, positive and negative predictive values for FH in detecting those children with dyslipidemia were 28.4, 70.3. 44.7, and 53.8%, respectively. The usefulness of FH in identifying dyslipidemic children was relatively low. The common lipid disorders in our community were the components of the metabolic syndrome. We suggest that the current guidelines for screening lipid disorders in youths, which are based on cholesterol, should consider such ethnic differences.

Associations of anthropometric characteristics with blood cholesterol fractions among adults. The Greek EPIC study

OBJECTIVE

To explore the independent associations of body height, body mass index (BMI), waist circumference and hip circumference with high-density lipoprotein-cholesterol (HDL-cholesterol) and non-high-density lipoprotein-cholesterol (non-HDL-cholesterol), in a large general population sample.

DESIGN

Cross sectional.

SETTING

Urban and rural areas throughout Greece.

SUBJECTS

In total,10 837 volunteers, 2034 men and 8803 women, aged 25-82 years, participants in the European Prospective Investigation into Cancer and Nutrition study (EPIC), who have never smoked and never been treated for dyslipidemia.

INTERVENTIONS

None.

RESULTS

The effect of height on non-HDL-cholesterol was opposite but in absolute terms almost as important as that of BMI with no gender interaction. Among women, hip circumference was inversely associated with non-HDL-cholesterol (standardized coefficient bst = -1.11, with standard error (s.e.)=0.42) and positively with HDL-cholesterol (bst = 0.85, s.e.= 0.12) whereas, waist circumference was inversely associated with HDL-cholesterol (bst = -1.16, s.e.=0.13) and strongly positively with non-HDL-cholesterol (bst = 8.83, s.e.= 0.45). Among men, associations were generally weaker (in absolute terms by about 50%) and for hip circumference the association with non-HDL-cholesterol was actually non significantly positive.

CONCLUSIONS

Height was inversely associated with HDL and non-HDL-cholesterol implicating early life phenomena in the regulation of these variables. Larger hip circumference among women had beneficial effects on blood cholesterol fractions by increasing HDL-cholesterol and reducing non-HDL-cholesterol, whereas among men the relevant effects were less clear cut. The detrimental consequences of large waist circumference on both HDL (reduction) and non-HDL-cholesterol (increase) were also particularly marked among women.

SPONSORSHIP

The European Prospective Investigation into Cancer and Nutrition (EPIC) is coordinated by the International Agency for Research on Cancer (World Health Organization) and supported by the Europe Against Cancer Program of the European Commission. The Greek segment of the EPIC study is also supported by the Greek Ministry of Health and the Greek Ministry of Education. This study was additionally supported by the fellowship 'Vassilios and Nafsika Tricha'.

Sex differences in the association between birth weight and total cholesterol. A meta-analysis

PURPOSE

Determine whether a sex difference exists in the association between birth weight and total cholesterol later in life.

METHODS

Meta-analysis of within-study differences in regression coefficients of cholesterol on birth weight.

RESULTS

A total of 34 regression coefficients from 30 studies were included in the analyses; these provided data on 33,650 males and 23,129 females. There was evidence that the inverse association between birth weight and total cholesterol was stronger in males compared to females. The pooled within-study difference in age-adjusted regression coefficients was -0.03 mmol/l (-0.06, -0.01), p = 0.02 and the pooled within-study difference in age and body mass index adjusted regression coefficients was -0.04 mmol/l (-0.07, -0.02), p = 0.002. There was no evidence of heterogeneity in these meta-analyses (both p values > 0.6).

CONCLUSIONS

These results provide some evidence for a sex difference in the birth weight-total cholesterol association. This is consistent with studies of fetal growth which suggest that birth size reflects different biological processes for females and males. However, other very large studies are required to confirm this finding.

Breastfeeding during infancy and the risk of cardiovascular disease in adulthood

BACKGROUND

Numerous studies have reported associations between the type of feeding during infancy and subsequent cardiovascular risk factors. Only 2 studies have evaluated the relation between having been breastfed and the risk of adult cardiovascular events.

METHODS

We examined this association among 87,252 female participants of the longitudinal Nurses' Health Study. Participants (all born between 1921 and 1946) reported in 1992 whether and for how long they were breastfed. During 8 years of follow up, there were 1099 cases of coronary heart disease and 940 strokes among women who knew whether they had been breastfed. We used proportional hazards models to estimate hazard ratios for cardiovascular events, adjusting for changing adult risk factors.

RESULTS

Compared with women who were never breastfed, women who were breastfed had hazard ratios of 0.92 (95% confidence interval = 0.80-1.05) for coronary heart disease and 0.91 (0.79-1.06) for stroke, after adjustment for age, birthweight, and smoking. When body mass index was also included in the model, the results were similar. Looking within subgroups of stroke, hazard ratios were 0.86 (0.70-1.07) for ischemic stroke and 1.01 (0.70-1.46) for hemorrhagic stroke. Comparing women who were breastfed at least 9 months with those who were not breastfed, the hazard ratios were 0.84 (0.69-1.03) for coronary heart disease and 1.00 (0.81-1.23) for stroke. Breastfeeding history was not associated with high blood pressure in adulthood.

CONCLUSIONS

These data suggest, but cannot establish, that breastfeeding in infancy may be associated with a small reduction in risk of ischemic cardiovascular disease in adulthood.

The relationship between physical activity and cholesterol levels in children and adolescents

OBJECTIVES: to describe total cholesterol (TC) plasma levels according to age and sex; to determine the contribution of sex, age, body mass index and physical activity (PA) to TC variation; to determine the odds ratio for high total cholesterol (HTC) plasma levels of the subjects in the first PA quartile (lower PA) in comparison to the fourth PA quartile. METHODS: the sample comprised 799 white children and adolescents, 353 males and 446 females. Body height and body weight were determined by standard anthropometric methods. Subject's capillary blood samples were taken from the earlobe after at least 12 hours fasting in order to obtain values of plasmatic TC. To calculate physical activity index (PAI) a PA questionnaire was used. RESULTS: the logistic regression of HTC for males and females showed that girls in the lower quartile of PAI, are 3.0 times (p <0.05; 95%CI: 1.3-6.8) as likely to belong at HTC group in relation to girls in the fourth PAI quartile. No significant influence was found in boys. CONCLUSIONS: the results of the present study suggested that the higher TC values could be found even in early ages.

Breastmilk feeding and lipoprotein profile in adolescents born preterm: follow-up of a prospective randomised study

BACKGROUND

Breastfeeding is associated with reduced cholesterol concentration later in life, but previous studies have not used random assignment of infant diet with prospective follow-up. We tested the hypothesis that breastmilk feeding benefits the lipoprotein profile in adolescents born preterm, in whom randomisation to different diets at birth is feasible.

METHODS

926 infants born preterm were randomly assigned in two parallel trials to receive (trial 1) donated banked breastmilk or preterm formula, or (trial 2) standard term formula or preterm formula, as sole diet or as supplements to mother's milk in both trials. We followed up 216 participants at age 13-16 years and measured ratio of low-density to high-density lipoprotein cholesterol (LDL to HDL), ratio of apolipoprotein B to apolipoprotein A-1 (apoB to apoA-1), and concentration of C-reactive protein (CRP; a measure of the inflammatory process associated with atherosclerosis).

RESULTS

Adolescents who had been randomised to banked breastmilk had a lower CRP concentration (p=0.006) and LDL to HDL ratio (mean difference 0.34 [14% lower], 95% CI -0.67 to -0.01; p=0.04) than those given preterm formula. A greater proportion of human milk intake in infancy was associated with lower ratios of LDL to HDL (p=0.03) and apoB to apoA-1 (p=0.004)--independent of gestation and potential confounding factors--and with lower CRP concentration (p=0.03). CRP concentration correlated with the two lipoprotein ratios (p<0.0001 and p=0.003, respectively).

INTERPRETATION

Our data provide experimental evidence for the long-term benefits of breastmilk feeding on the risk of atherosclerosis.

Birth weight, growth and feeding in infancy: relation to serum lipid concentration in 12-month-old infants

OBJECTIVE

To assess the effects of birth size, growth and feeding in infancy on serum lipids in 12-month-old infants.

DESIGN

A longitudinal observation study on infants' consumption and growth. Food and growth records were made every month. At 6, 9 and 12 months, food records were weighed to calculate intake. Serum total cholesterol (TC), high-density lipoprotein-cholesterol (HDL), low-density lipoprotein (LDL) -cholesterol and triglyceride concentrations were analysed at 12 months.

SETTINGS

Birth and growth information was gathered from maternity wards and healthcare centres in Iceland and food consumption data at home.

SUBJECTS

Randomly selected newborns (n=180) according to the mother's domicile and 77% (n=138) participated, of them 75% (n=103), came in for blood sampling.

RESULTS

Among boys, a 1 kg higher birth weight resulted in a 0.79 mmol/l higher TC (P=0.005), but nonsignificant after adjustment for growth. Duration of breastfeeding was related to LDL-cholesterol (B=0.06 +/-0.02, P=0.020, adj. R(2)=0.039), adjusting for gender. Independent of size at birth and breastfeeding, increase in length from 6 to 12 months and in weight from birth to 12 months were negatively related to TC (B=-0.455+/-0.156, P=0.008 and B=-1.086+/-0.474, P=0.032, respecitvely) in boys. PUFA was the strongest nutrient variable predicting TC (B=0.332, adj. R(2)=0.24, P>0.001). Cod liver oil consumption increased both TC and LDL-cholesterol in girls (B=0.141+/-0.051, P=0.008 and B=0.112+/-0.047, P=0.021, respectively).

CONCLUSION

Slower growth of high birth weight infants and breastfeeding contributes to higher TC concentration at the age of 12 months. Nutrient intake in infancy also affects lipid profile. The effect of birth weight, growth and nutrient intake in infancy on lipid profile is different for boys and girls.

Association of birth weight and breast-feeding with coronary heart disease risk factors at the age of 6 years

BACKGROUND AND AIM

It has been shown that early growth and nutrition affect health in childhood and later life. The aim of this study was to assess the association of birth weight and breast-feeding in infancy with body mass index (BMI) and serum lipids at the age of six years. The contributions of current macronutrient intake, maternal age and BMI were assessed.

METHODS AND RESULTS

This was a longitudinal observational study of 120 randomly chosen children whose birth weight and duration of breast-feeding had been recorded. At the age of six years, their weight and height, and serum cholesterol (total, LDL and HDL) and triglyceride levels were measured at healthcare centres in Iceland. Dietary intake at six years was estimated using 3-day weighed food records. The duration of breast-feeding negatively correlated with BMI in 6-year-old boys (B = -0.19 +/- 0.07, p = 0.011) but not in girls; after adjusting for maternal BMI, the relationship in boys was of borderline significance (p = 0.087). The 6-year-old boys who had been breast-fed for < 6 months had a significantly higher BMI (18.0 +/- 2.5 kg/m2) than those breast-fed for 8-9 months (15.8 +/- 1.2 kg/m2, p = 0.006) or > or = 10 months (15.7 +/- 1.2 kg/m2, p = 0.005). A longer duration of breast-feeding was related to higher HDL-cholesterol levels in 6-year-old girls (B = 0.03 +/- 0.01, p = 0.032), but not boys. Birth weight was not related to BMI or serum lipid levels at the age of 6 years.

CONCLUSION

In this high birth weight population, a longer duration of breast-feeding may be effective in preventing childhood overweight, at least among boys. Breast-feeding also seems to be related to an improved lipid profile in girls.

Relationship between birthweight and blood lipid concentrations in later life: evidence from the existing literature

BACKGROUND

It has been suggested that there is a link between fetal growth and chronic diseases later in life. Several studies have shown a negative association between birthweight and cardiovascular diseases, as well as cardiovascular disease risk factors, such as blood pressure and type 2 diabetes. Far fewer studies have focused on the association between size at birth and blood lipid concentrations. We have conducted a qualitative assessment of the direction and consistency of the relationship between size at birth and blood lipid concentrations to see whether the suggested relationship between intrauterine growth and cardiovascular diseases is mediated by lipid metabolism.

METHODS

A literature search covering the period January 1966 to January 2003 was performed using Medline, Embase, and Web of Science. All papers written in English and reporting the relationship between size at birth and lipid levels in humans were assessed. Bibliographies were searched for further publications.

RESULTS

From an initial screen of 1198 references, 39 papers were included involving 28 578 individuals. There was no consistent relationship between size at birth and blood lipid levels; the one exception being triglyceride concentration, which showed statistically significant negative or U-shaped, but not positive, relationships with birthweight.

CONCLUSION

This review does not strongly support a link between birthweight and blood lipid levels in later life. However, the research in this area is limited and in order to make any definitive conclusions, longitudinal studies with sufficient power, data, and prospective follow-up are needed.

Family study of the relationship between height and cardiovascular risk factors in the STANISLAS cohort

BACKGROUND

Short stature is a risk factor for coronary heart disease and is associated with an adverse cardiovascular profile. Mechanisms responsible for this association remain unknown. A genetic contribution to this association would imply a familial clustering between height and cardiovascular risk factors.

METHODS

This study investigated whether lipids and blood pressure (BP) levels shared a common familial component with height. The sample included 865 nuclear families from the French STANISLAS cohort volunteering for a free health examination between 1993 and 1994. Within-individual correlations and familial intra-trait and cross-trait correlations were estimated using the Estimating Equation technique extended to a bivariate phenotype.

RESULTS

Height negatively correlated to total and low density lipoprotein cholesterol (LDL-C) and triglycerides in both parents and offspring, and positively correlated to high density lipoprotein cholesterol (HDL-C) in parents only. In offspring, the correlation between height and HDL-C markedly increased with sexual maturation to reach after puberty the same value as in parents. The correlation of height with systolic BP was negative in fathers and positive in sons, whereas it was non-significant in mothers and daughters. The pattern of cross-trait familial correlations between height and LDL-C was compatible with the existence of a weak transmissible component explaining the relationship between these two traits. By contrast, the pattern observed for HDL-C and triglycerides was rather compatible with the influence of shared environmental factors. No familial clustering between height and BP levels was detected.

CONCLUSIONS

The association between short stature and increased LDL-C might be partly of familial origin.

Does bile salt-stimulated lipase affect cholesterol uptake when bound to rat intestinal mucosa in vitro?

Bile salt-stimulated lipase (BSSL), or carboxyl ester lipase, is a constituent of exocrine pancreatic secretion and, in some species, including humans, also of milk. BSSL has been suggested to have a direct effect on intestinal uptake of dietary cholesterol besides being the key enzyme in the hydrolysis of fat-soluble vitamins and cholesterol esters. Furthermore, an intestinal heparin-containing receptor for the enzyme has been implicated. If BSSL promotes dietary cholesterol utilization, this might be of particular importance in the neonatal period, which is characterized by a high need of cholesterol for membrane synthesis. We have studied binding of BSSL to intestinal membranes in vitro and if such binding affects the uptake of cholesterol. BSSL bound avidly to rat intestinal microvesicle membranes and the binding was inhibited by addition of free heparin or heparin fragments. In this model system, we could not demonstrate any effect of BSSL on cellular uptake of free cholesterol. However, if esterified rather than free cholesterol was present in the incubation, hydrolysis by BSSL was the rate-limiting step in cellular cholesterol uptake. We therefore conclude that BSSL is important for utilization of dietary cholesterol only by hydrolyzing cholesterol esters and not by acting as a transport protein.

Blood lipids, fatty acids, diet and lifestyle parameters in adolescents from a region in northern Norway with a high mortality from coronary heart disease

INTRODUCTION

Students aged 13 and 14 y, in a region in northern Norway with high blood cholesterol levels and high mortality from coronary heart disease (CHD) in the adult population, were studied with respect to lifestyle, dietary habits, nutritional intake and blood lipids including fatty acids in serum. The students came from a coastal community with seawater fish as an important part of the traditional diet, and an inland community with meat from reindeer as a major constituent of the diet.

OBJECTIVE

To investigate whether the traditional diet was maintained among the adolescents and to evaluate the lifestyle and blood lipids. The study was followed up after 1 y.

RESULTS

The adolescents from the coastal region did not maintain the traditional diet. In the inland region the students had a high intake of meat, probably reflecting the traditional food culture. The inland boys had higher mean body mass index (BMI) than the coastal boys, and 12% had BMI>28, as compared to none of the coastal boys. Other findings showed that the students had higher levels of blood cholesterol than in the south of Norway and several other countries (about 25% had total cholesterol >5.2 mmol/l), higher intake of dietary sugar and fat than the national recommendations and little intake of seawater fish with corresponding low levels of n-3 fatty acids. This did not change after 1 y of follow up. Some 10-20% reported daily smoking and 8-13% reported that they rarely or never did physical exercise. About 30% of the students presented no factors negatively related to development of cardiovascular disease.

CONCLUSION

The findings demonstrate, in the majority of students at the age of 13 and 14 y, the appearance of factors contributing to development of cardiovascular disease (CHD).

SPONSORSHIP

This study was supported by the program 'Medisinsk forskning i Finnmark, University of Tromsø'.

[Study of overweight and obesity in a population of urban school children in Sousse, Tunisia]

AIM

The aim of this study was to assess the prevalence of obesity and overweight and their relationship with cardiovascular disease risk factors.

METHODS

Epidemiological survey based on a representative sample of 1569 urban school children of Sousse, Tunisia.

RESULTS

Overweight (BMI > or = 25) was significantly higher in girls (16.1%) than in boys (11.6%); (chi 2 = 8.2; p = 0.004). Obesity (BMI > or = 30) was slightly higher in girls (3.7%) than in boys (2.7%); (chi 2 = 0.89; p = 0.34). Girls had significantly higher BMI, diastolic blood pressure, cholesterol and HDL cholesterol levels than boys who had however significantly higher levels of systolic blood pressure. Overweight was significantly higher in children who did not practice sport at school: 22 versus 13.1% (p < 0.002), in groups of youngsters who were not affiliated to school sport or city associations. Overweight children had a significantly higher levels of cholesterol, HDL cholesterol and means of systolic and diastolic blood pressures.

CONCLUSION

These results will serve to set up a regional program of health promotion at schools.

Dietary fat intake in healthy adolescents: inverse relationships between the estimated intake of saturated fatty acids and serum cholesterol

The objective of the present study was to describe the intake of dietary fatty acids among healthy 15-year-old boys and girls and to relate the intake of specific fatty acids and the fatty acid composition of the serum cholesterol esters to serum lipid, apolipoprotein (Apo) and insulin concentrations respectively. Fifty-two girls and forty-two boys were randomly selected from the official population register. Unexpectedly, significant inverse associations were found between the dietary content of saturated fatty acids with a chain length of four to fifteen C atoms, mainly derived from milk fat, as well as the corresponding fatty acids in the serum cholesterol esters, on the one hand and the serum concentrations of cholesterol and ApoB on the other. The estimated dietary intake of 4:0-10:0, 12:0 and 14:0 respectively, were all significantly inversely related to the serum cholesterol (r -0.32, r -0.31, r -0.30, all and ApoB (r -0.42, r -0.42, and r -0.40, all concentrations in girls and 12:0 to the ApoB concentration (r -0.55, in boys. The proportions of 12:0 and 15:0 in the serum cholesterol esters were negatively correlated with the serum cholesterol concentrations in both girls (r -0.34, r -0.32, and boys (r -0.53, r -0.32, and with the ApoB concentrations among boys (r -0.61, r -0.43, It is conceivable that milk fat contains or is associated with some component in the diet, or some other characteristics of the food intake, which counterbalances the expected positive relationships between saturated fat intake and lipid levels.

A comparison of perspectives on breastfeeding between two generations of black American women

PURPOSE

To determine differences in breastfeeding perspectives between two generations of black American women with and without access to governmental food assistance programs (i.e., WIC).

DATA SOURCES

Descriptive, comparative study of a convenience sample of 118 black American women in their childbearing years and beyond conducted in a primary rural health care clinic serving an indigent population.

CONCLUSIONS

A significant difference was found between breastfeeding perceptions and rate among younger black American women on WIC program and their mothers without access to these programs. The availability of free formula through WIC programs has partially influenced the rate of breastfeeding among the young black American women. The other significant influencing factor was public embarrassment at breastfeeding.

IMPLICATIONS FOR PRACTICE

An extensive educational campaign is needed in order to influence the public's perceptions of breastfeeding as an embarrassment. The success of programs such as WIC must be measured beyond the first six months of an infant's life.

Inverse association between birth weight, birth length and serum total cholesterol in adulthood

OBJECTIVES

To investigate whether impaired fetal growth, measured by low birth weight and short birth length, is linked with raised levels of serum lipids and increased risk and mortality of coronary heart disease.

DESIGN

The association between birth length, birth weight, Ponderal Index and total serum cholesterol was examined in 545 Danish men and women aged 31 to 51 years who participated in the Ebeltoft Health Promotion Project in Denmark.

RESULTS

No associations were found in women. For men, a negative association was found between birth weight and serum total cholesterol, with a fall in mean serum total cholesterol from 6.03 mmol/l at birth weight below 3300 g to 5.64 mmol/l at birth weight above 4000. A similar association was found between birth length and serum cholesterol, with a mean value of 6.23 mmol/l at birth length below 51 cm and a mean value of 5.56 mmol/l at birth length above 54 cm. No associations were found for Ponderal Index. Between 3% and 8% of the variance in serum total cholesterol could be explained by the statistical models used in this study.

CONCLUSION

Our findings support the hypothesis of a negative association between birth weight, birth length and elevated serum cholesterol in adult life, but only in men.

Familial aggregation of serum total cholesterol: a population-based family study in eastern Finland

BACKGROUND

The Finnish population has a high risk of coronary heart disease, which is associated to a high population level of serum total cholesterol (CHOL) already evident at early ages. The study investigated the familial aggregation of CHOL in a sample of families with young offspring from eastern Finland.

METHODS

Fifteen-year-old offspring were examined during 1996-1997 and their biological parents were examined during 1993-1994. A total of 224 children were invited and 184 families participated, of which 123 were included in the analysis with complete data. The main outcome measure was the CHOL (millimoles per liter).

RESULTS

Significant positive familial correlations of CHOL were found for the pairs of mother/offspring (r = 0.35, P < 0.001, n = 111), father/offspring (r = 0.29, P = 0.007, n = 82), mother/daughter (r = 0.46, P = 0.001, n = 49), mother/son (r = 0.27, P = 0.036, n = 62), and father/daughter (r = 0.35, P = 0.035, n = 36). The adjustments for the offspring's gender and body mass index (BMI) and the parent's age, BMI, education, and family history of acute myocardial infarction did not alter these results. There was a higher proportion of the offspring in the highest quartile of CHOL when the mother had CHOL > or =5 mmol/L (OR = 3.26, 95% CI = 1.2-8.9, n = 111).

CONCLUSIONS

The study confirmed the familial aggregation of CHOL. The consistent CHOL association between the mother and the offspring may indicate the key role of the mother for the primary prevention of hypercholesterolemia.

Rapid westernization of children's blood cholesterol in 3 countries: evidence for nutrient-gene interactions?

The aim of this study was to examine potential factors that modify blood cholesterol among children in countries in which dietary and lifestyle habits are becoming westernized. Population data on serum total and lipoprotein cholesterol, anthropometric indexes, and dietary intake were reviewed and compared for children aged 1-18 y from Japan, Spain, and the United States. The data show that total serum cholesterol in Japanese and Spanish children recently exceeded the 75th percentile for US children, primarily reflecting LDL cholesterol, although both LDL and HDL cholesterol contributed. Adiposity indexes do not explain the trends observed. Total and saturated fat intakes increased substantially in both Japan and Spain but in Japan are still lower than intakes in the United States. The Hegsted equation was used to relate differences in serum cholesterol to dietary fat intake. Changes in total serum cholesterol followed established dietary correlations among children in Spain, but not in Japan. Serum cholesterol in Japanese children was predicted to be 0.20-0.32 mmol/L lower than in US children; actual concentrations were considerably higher. These results suggest that a rapid westernization of children's blood cholesterol concentrations has occurred in Japan and Spain. Changes in fat intake predict changes in blood cholesterol in Spain, but not in Japan. Differences in genetic response to diet in certain populations, such as the Japanese, may explain higher blood cholesterol concentrations with lower fat intakes compared with the United States.

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.

Restricted fetal growth and the response to dietary cholesterol in the guinea pig

Epidemiological studies suggest that retarded growth before birth is associated with increased plasma total and low-density lipoprotein (LDL) cholesterol concentrations in adult life. Thus perturbations of prenatal growth may permanently alter cholesterol metabolism. To determine directly whether restriction of prenatal nutrition and growth alters postnatal cholesterol homeostasis, the plasma cholesterol response to cholesterol feeding (0.25% cholesterol) was examined in adult guinea pig offspring of ad libitum-fed or moderately undernourished mothers. Maternal undernutrition (85% ad libitum intake throughout pregnancy) reduced birth weight (-13%). Plasma total cholesterol was higher prior to and following 6 wk cholesterol feeding in male offspring of undernourished mothers compared with male offspring of ad libitum-fed mothers (P < 0.05). The influence of birth weight on cholesterol metabolism was examined by dividing the offspring into those whose birth weight was above (high) or below (low) the median birth weight. Plasma total cholesterol concentrations prior to cholesterol feeding did not differ with size at birth, but plasma total and LDL cholesterol were 31 and 34% higher, respectively, following cholesterol feeding in low- compared with high-birth weight males (P < 0.02). The response to cholesterol feeding in female offspring was not altered by variable maternal nutrition or size at birth. Covariate analysis showed that the effect of maternal undernutrition on adult cholesterol metabolism could be partly accounted for by alterations in prenatal growth. In conclusion, maternal undernutrition and small size at birth permanently alter postnatal cholesterol homeostasis in the male guinea pig.

Dissecting the genetic architecture of lipids, lipoproteins, and apolipoproteins: lessons from twin studies

We review the ways in which twin studies have been used to investigate the genetic architecture of lipids, lipoproteins, and apolipoproteins. We focus on the age dependency of genetic effects and the importance of pleiotropy for the lipid system. Finally, consequences are discussed of age dependency and pleiotropy for the design and power of twin studies aimed at detecting the actual quantitative trait loci (QTLs) involved. It is concluded that twin studies have played an important role and will remain highly valuable for the elucidation of the genetic architecture of lipids, lipoproteins, and apolipoproteins. Twins can efficiently be used to identify the location and function of QTLs. Taking account of pleiotropy and age-dependent gene expression in study design and data analysis will improve the power and efficiency to find these QTLs for components of the lipid system.

Family history of early cardiovascular disease in children with moderate to severe hypercholesterolemia: relationship to lipoprotein (a) and low-density lipoprotein cholesterol levels

Lipoprotein (a) (Lp(a)) is an established cardiovascular risk factor in adults. We sought to evaluate whether raised Lp(a) levels were predictive of a family history of early cardiovascular disease (CVD) in children already at increased risk for premature atherosclerosis because of elevated low-density lipoprotein (LDL) cholesterol levels. Lp(a) and serum lipid levels were measured in 69 children and offspring with established moderate to severe hypercholesterolemia (serum cholesterol > 170 mg/dL) who were aged 10.7 +/- 4.3 years (range 1.5 to 21 years) and had been referred to a pediatric lipid center. The children represented families with a positive (n = 27) or negative (n = 42) history for premature CVD (<55 years of age in parent or grandparent). In all children, Lp(a) levels ranged from 1 to 140 mg/dL, with a median of 29 mg/dL. Mean total cholesterol, LDL cholesterol, and high-density lipoprotein (HDL) cholesterol levels were 234 mg/dL, 166 mg/dL, and 45 mg/dL, respectively. There was no difference in median Lp(a) levels between the children with a positive family history and those with a negative family history (29.9 mg/dL vs 29.0 mg/dL, respectively). In contrast, children with a positive family history showed significantly higher LDL cholesterol levels (186 +/- 61 mg/dL vs 153 +/- 52 mg/dL, P = .02). Thus, in this group of hypercholesterolemic children, LDL cholesterol but not Lp(a) levels were associated with a family history of premature CVD. Further studies are needed to identify additional specific risk factors associated with the development of CVD in this population.

Plasma lipids and apolipoproteins in breastfed and formula-fed Swedish infants

This study was carried out to compare plasma lipid pattern in breastfed and formula-fed infants and the effects of exchanging breast milk for formula and of introducing weaning foods. Healthy infants, exclusively breastfed at least until 3 mo, were at this age randomly assigned to infant formulas with similar fat composition. Formula was gradually introduced when breastfeeding was discontinued. One group continued to breastfeed beyond 6 mo of age. All infants received the same weaning foods and were studied between 3 and 12 mo of age. Decreased plasma concentrations of total and low-density lipoprotein cholesterol (TC, LDL-C), apolipoprotein B (apo B) and A1 (p < 0.001), and of high-density lipoprotein cholesterol (p < 0.05) were found when breast milk was exchanged for formula before 6 mo. At this age plasma TC, LDL-C and apo B were lower in formula-fed than in breastfed infants (p < 0.001). These plasma lipids then increased (p < 0.01) when the intake of formula decreased and that of weaning foods increased. However, plasma TC and/or LDL-C remained lower at 12 mo in formula-fed than in breastfed infants (p < 0.05). Our results indicate that the plasma lipid profile of infants is highly responsive to the dietary nutrient intake, as indicated by the decrease in plasma lipids and apolipoproteins when breast milk was exchanged for formula and by the increase in these concentrations when the intake of weaning foods gradually increased.

Apoptosis and cell proliferation after porcine coronary angioplasty

BACKGROUND

Angioplasty initiates a number of responses in the vessel wall including cellular migration, proliferation, and matrix accumulation, all of which contribute to neointima formation and restenosis. Cellular homeostasis within a tissue depends on the balance between cell proliferation and apoptosis.

METHODS AND RESULTS

Profiles of apoptosis and proliferation were therefore examined in a porcine PTCA injury model over a 28-day period. Forty-two arteries from 21 pigs, harvested at the site of maximal injury at 1, 6, and 18 hours, and 3, 7, 14, and 28 days after PTCA, were examined (n=3 animals per time point). Uninjured arteries were used as controls. Apoptosis was demonstrated by the terminal uridine nick-end labeling (TUNEL) method, transmission electron microscopy (TEM), and DNA fragmentation. Cells traversing the cell cycle were identified by immunostaining for proliferating cell nuclear antigen (PCNA). Apoptosis was not detected in control vessels at all time points nor at 28 days after PTCA. Apoptotic cells were identified at all early time points with a peak at 6 hours (5.1+/-0.26%; compared to uninjured artery, P<0.001) and confirmed by characteristic DNA ladders and TEM findings. Regional analysis showed apoptosis within the media, adventitia, and neointima peaked at 18 hours, 6 hours, and 7 days after PTCA, respectively. In comparison, PCNA staining peaked at 3 days after PTCA (7.16+/-0.29%; compared to 1.78+/-0.08% PCNA-positive cells in the uninjured artery, P<0.001). Profiles of apoptosis and cell proliferation after PTCA were discordant in all layers of the artery except the neointima. These profiles also differed between traumatized and nontraumatized regions of the arterial wall. Immunostaining with cell-type specific markers and TEM analysis revealed that apoptotic cells included vascular smooth muscle cells (VSMCs), inflammatory cells, and adventitial fibroblasts.

CONCLUSIONS

These results suggest that the profile of apoptosis and proliferation after PTCA is regional and cell specific, and attempts to modulate either of these events for therapeutic benefit requires recognition of these differences.

Worldwide distribution of blood lipids and lipoproteins in childhood and adolescence: a review study

Review and pooled analysis of the relevant worldwide literature was investigated from 1975 to 1996. Eighteen surveys out of 54 were suitable for analysis according to the selection criteria. This represents a total of 60494 observations from 26 countries all over the world. Data suggests differences as great as 76 mg/dl when comparing northern European countries to black African children. The overall curve of cholesterol with age observed in the pooled population indicates a pre-adolescent peak and then a slightly inverse change is observed for both boys and girls, from 3 to 12 years old being almost coincident absolute values. Beyond age 12, values for boys continue to slightly decrease to age 16, while for girls values tend to increase through this age-range. The curve in the late teens (16-18 years) tends to reach pre-teen levels for both sexes, although girls have consistently higher absolute values than boys. There is a great variation in the specific age-sex and race levels of cholesterol among different populations or even in the same populations over a period of time. However, an apparently universal pattern of an early rise, a fall, and a subsequent rise in mean values of total cholesterol by age from the preadolescence to late teens is observed. More data are needed on total cholesterol and lipid fractions between late school age and mid-adulthood.

Serum lipoproteins and apolipoproteins in children during the first five years of diabetes

Serum lipoproteins and apolipoproteins were followed in 34 children during a period of 5 years from the onset of diabetes. The group did not differ in these respects from a healthy control group after 5 years of disease. The variation in serum triglycerides and very-low-density lipoprotein (VLDL) triglycerides was more pronounced, some patients having high values. Serum triglycerides and VLDL lipids were significantly correlated to subcutaneous fat, measured as triceps and subscapular skinfolds. None of the patients had albuminuria, so lipid levels could not be related to renal albumin excretion. There was no significant correlation between any serum lipid and haemoglobin A1c.

Cardiovascular risk indicators cluster in girls from families of low socio-economic status

We evaluated tobacco use, physical activity, dietary intake and cardiovascular risk indicators (s-lipids, s-insulin, s-ferritin, anthropometric measurements, blood pressure, physical fitness) in healthy 14- and 17-year-old Swedish adolescents in relation to socio-economic status (SES) of their parents. Girls reported more smoking than boys (14-year-olds 10 and 3%, 17-year-olds 27 and 18%, girls and boys, respectively). Daily smoking was associated to low SES of the family, but was most strongly associated to smoking in peers (OR = 58.7). Tobacco use was considerably higher among adolescents attending vocational programs at secondary high school as compared with theoretical programs. Daily smokers had a more unfavourable serum lipid profile compared with non-smokers. Adolescents from families with a low educational level of the mother had a higher relative dietary fat intake. Boys and girls from families of low SES had higher body mass index (BMI), and girls, but not boys, also had lower physical fitness. Clustering of high BMI, low physical fitness and daily smoking was more pronounced in girls from families of low SES. In conclusion, our study shows that in both boys and girls low SES and educational level of the parents are related to an unfavourable cardiovascular risk profile in Swedish adolescents. Furthermore, smoking in adolescents is more related to smoking in peers than to smoking in parents, implying that preventive efforts should focus on peer groups.

Insulin resistance syndrome in adolescents

To explore whether the so-called insulin resistance syndrome can be identified in adolescents, serum insulin level was measured in 842 healthy Swedish adolescents (462 boys and 380 girls) and the values were related to current serum lipoprotein and apolipoprotein values (triglyceride [TG], total cholesterol [TC], high-density lipoprotein cholesterol [HDL-C), low-density lipoprotein cholesterol [LDL-C], apolipoprotein [apo] A-I, apo B, and lipoprotein(a)), blood pressure (BP), and anthropometric measurements and previous physical growth. Mean serum insulin values were higher in 14-year-olds as compared with 17-year-olds and were highest in midpuberty. Adolescents with a high serum insulin had a higher attained height and weight during infancy and childhood. Obesity (body mass index [BMI] > 30 kg/m2) was found in 1% of both boys and girls, and hypertensive BP levels were found in 3% of the boys and 1% of the girls. Controlling for age, serum insulin correlated positively with BMI (r = .36 and .25 in boys and girls, respectively), TG (r = .32 and .14), LDL-C (r = .17 and .24), and apoB (r = .23 and .23) and negatively with HDL-C (r = -.13 and -.21). High serum insulin, TG, LDL-C, and BP and low HDL-C clustered in adolescents with high BMI. In conclusion, the findings of this study indicate that features typical of the insulin resistance syndrome are already present in adolescents.