Socioeconomic position in childhood and adult cardiovascular risk factors, vascular structure, and function: cardiovascular risk in young Finns study

OBJECTIVE

To examine the association of childhood socioeconomic position (SEP) with adult cardiovascular risk factors, vascular structure, and vascular function in a contemporary population of young adults.

DESIGN

Population based prospective cohort study with baseline assessment in 1980.

SETTING

Finland.

PARTICIPANTS

856 men and 1066 women whose childhood SEP was determined by parental occupational status (manual, lower non-manual, upper non-manual) at age 3-18 years.

MAIN OUTCOME MEASURES

Cardiovascular risk factors, carotid artery intima-media thickness, and brachial artery flow mediated vasodilatation, assessed at age 24-39 years.

RESULTS

After adjustment for age and adult SEP, systolic pressure was 2.3 mm Hg higher (p = 0.0002), high density lipoprotein (HDL) cholesterol 0.03 mmol/l lower (p = 0.02), and insulin resistance score (homeostasis model assessment index) 0.12 units greater (p = 0.05) among men; and systolic pressure was 1.3 mm Hg higher (p = 0.02), diastolic pressure 1.1 mm Hg higher (p = 0.01), and height 1.1 cm lower (p < 0.0001) among women for each step down the childhood SEP hierarchy. Lower childhood SEP was associated with a 20% increase in the odds of having a waist circumference > 102 cm in men and > 88 cm in women (overall p = 0.05). Childhood SEP was not associated with intima-media thickness, flow mediated vasodilatation, the metabolic syndrome, low density lipoprotein cholesterol, triglycerides, body mass index, alcohol consumption, or smoking.

CONCLUSIONS

Among adults under 40, low childhood SEP predicted higher blood pressure and central obesity and, among men, unfavourable HDL cholesterol and insulin resistance, independent of current SEP. No independent effects were found on adult vascular structure, vascular function, or health related behaviours at this life stage.

Risk factors identified in childhood and decreased carotid artery elasticity in adulthood: the Cardiovascular Risk in Young Finns Study

BACKGROUND

Exposure to risk factors in childhood may have long-term influences on vascular function. We examined the relationship between risk factors identified in childhood and arterial elasticity assessed in adulthood.

METHODS AND RESULTS

Carotid artery compliance (CAC), Young's elastic modulus (YEM), and stiffness index (SI), 3 measures of large-artery elasticity, were assessed with noninvasive ultrasound in 2255 healthy white adults aged 24 to 39 years participating in a population-based cohort study and who had risk factor data available since childhood. In multivariate models, childhood obesity (skinfold thickness) predicted decreased CAC (P<0.001), increased YEM (P<0.01), and increased SI (P<0.01) in adulthood. Childhood blood pressure was inversely associated with CAC (P<0.001) and directly associated with YEM (P<0.001). The number of risk factors identified in childhood, which included high LDL cholesterol (at or above 80th percentile), elevated blood pressure, skinfold thickness, low HDL cholesterol (at or below 20th percentile), and smoking, was related inversely with CAC (P<0.001) and directly with YEM (P<0.001). These associations remained highly significant after adjustment for the number of risk factors identified in adulthood (P=0.005 for CAC and P<0.001 for YEM).

CONCLUSIONS

Cardiovascular risk factors identified in childhood and adolescence predict decreased carotid artery elasticity in adulthood. These data suggest that risk factors operating in early life may have sustained deleterious effects on arterial elasticity.

Lifecourse socioeconomic position, C-reactive protein, and carotid intima-media thickness in young adults: the cardiovascular risk in Young Finns Study

OBJECTIVE

It has been suggested that confounding by socioeconomic position from across the lifecourse together with adult risk factors explain the association between C-reactive protein (CRP) and coronary heart disease, but the evidence for this is limited to elderly subjects. We examined associations between socioeconomic position in childhood and adulthood, adult CRP, and carotid intima-media thickness (IMT), a presymptomatic predictor of coronary heart disease, in a population of young adults.

METHODS AND RESULTS

The association of socioeconomic indicators at age 3 to 18 and in adulthood with CRP and IMT at age 24 to 39 were examined in a prospective cohort study of 2290 (1030 men and 1260 women) participants in the Young Finns Study. After adjustment for age and sex, both childhood and adulthood socioeconomic position were inversely associated with CRP (ps< or =0.02). There was also a direct correlation between CRP and IMT (P<0.008). However, both the association between socioeconomic position and CRP and that between CRP and IMT attenuated to the null with adjustment for BMI and waist-to-hip ratio. Controlling for other risk factors had little effect on these associations.

CONCLUSIONS

In young adults, the interrelations between socioeconomic position, CRP, and carotid atherosclerosis are accounted for by adiposity.

Depressive symptoms and carotid artery intima-media thickness in young adults: the Cardiovascular Risk in Young Finns Study

OBJECTIVE

Depression and coronary heart disease are often comorbid conditions, but the mechanism behind this link is largely unknown. We tested the hypothesis that a high level of depressive symptoms in healthy young adults would be related to more prevalent preclinical atherosclerosis.

METHODS

We studied the association between depressive symptoms and carotid atherosclerosis in 1126 young adults (410 men and 716 women) as part of the ongoing population-based Cardiovascular Risk in Young Finns Study. The participants responded to a revised version of Beck's Depression Inventory in 1992, 1997, and 2001. Carotid atherosclerosis was assessed by measuring the thickness of the common carotid artery intima-media complex with ultrasound in 2001. Cardiovascular risk factors were measured in childhood/adolescence (1980) and in adulthood (2001).

RESULTS

In men, high scorers of depressive symptoms in 2001 had higher carotid artery intima-media thickness (0.63 mm) compared with those with low or moderate scores on depressive symptoms (0.57 mm). This relationship (B = 0.08, F[1, 405] = 9.24, p = .003) persisted after adjustment for age and cardiovascular risk factors in adolescence and adulthood. Depression scores in 1992 and 1997 were not predictive of intima-media thickness. In women, no association was found between depressive symptoms and intima-media thickness.

CONCLUSIONS

Depressive symptoms during early adulthood seem to be associated with higher levels of carotid intima-media thickness in men, but not in women.

Geographic Origin as a Determinant of Carotid Artery Intima-Media Thickness and Brachial Artery Flow-Mediated Dilation

Objective— People living in eastern Finland have ≈40% higher coronary heart disease mortality rates than western Finns. Whether this is because of genetic or environmental factors is unknown. We examined the effect of geographic family origin on subclinical atherosclerosis among young Finns.

Methods and Results— As part of a longitudinal follow-up study, we measured carotid intima-media thickness (IMT) in 2264 and brachial flow-mediated dilation (FMD) in 2109 white adults, aged 24 to 39 years. Subjects from eastern Finland had greater IMT and lower FMD compared with western subjects. These differences accentuated when the subjects’ family origin (grandparents’ birthplace) was taken into account and remained significant after adjusting for several environmental factors. Among subjects with all grandparents born in eastern or western Finland, IMTs were (mean±SEM) 0.592±0.003 versus 0.565±0.005 mm ( P <0.0001), respectively. The corresponding FMD values were 7.61±0.15% versus 8.75±0.26%; P <0.01. The number of grandparents born in eastern Finland was directly related to IMT ( P <0.0001) and inversely to FMD ( P <0.05).

Conclusions— Young adults originating from eastern Finland have greater carotid IMT and lower brachial FMD than western Finns. Consistent with a hereditable component predisposing to or protecting from atherosclerosis, these differences accentuated when subjects’ family origin was taken into account.

Apolipoprotein A-I/C-III/A-IV SstI and apolipoprotein B XbaI polymorphisms and their association with carotid artery intima-media thickness in the Finnish population. The Cardiovascular Risk in Young Finns Study

Apolipoprotein A-I/C-III/A-IV (apoA-I/C-III/A-IV) SstI and apolipoprotein B (apoB) XbaI polymorphisms have been shown to affect serum low-density lipoprotein (LDL) cholesterol concentrations in a sample of Finnish children. We studied whether these polymorphism are associated with carotid artery intima-media thickness (IMT), a marker of pre-clinical atherosclerosis, measured in the same subjects during their adulthood. A random sub-sample of 214 individuals from the "Cardiovascular Risk in Young Finns" study, for whom genotypes, cardiovascular risk factor data and carotid artery IMT measured in 2001 were available, were studied. Mean carotid IMT values increased according to the apoA-I/C-III/A-IV SstI genotype groups in the order of S1S1 (0.58+/-0.08 mm), S1S2 (0.61+/-0.08 mm), and S2S2 (0.70+/-0.16 mm, p=0.02, ANOVA). In multiple linear regression analysis after adjusting for age, sex and body mass index the mean IMT thickness among the S2 allele carriers was higher (p=0.02) compared to non-carriers. In logistic regression analysis the frequency of S2 allele carriers was higher among the high IMT group compared to the low IMT group (OR=4.02, CI: 1.68-9.61, p=0.002). No significant association between apoB XbaI polymorphism and carotid IMT was found. However, serum total and LDL cholesterol and apoB concentrations were significantly different among apoB genotype groups (p<0.001 for all traits). The apoA-I/C-III/A-IV SstI polymorphism is associated with carotid IMT in young Finns.

Risk factors for coronary heart disease in children and young adults

This review covers two ongoing studies in Finland: the Cardiovascular Risk in Young Finns study, which started in 1978, and the Special Turku Coronary Risk Factor Intervention Project for Children (STRIP), which started in 1989. In the cross-sectional Cardiovascular Risk in Young Finns study, cardiovascular risk factors were first assessed in 1980 in 3596 children and adolescents covering ages between 3 and 18 y at 3-y intervals. The latest follow-up examination was performed in 2001, when risk factors and early markers of atherosclerosis in carotid and brachial arteries were examined in 2264 subjects from the original cohorts, now covering ages from 24 to 39 y. The results clearly show that an individual's coronary heart disease (CHD) risk factor profile is regulated by early lifestyle-related factors and that exposure to risk factors in childhood induces changes in arteries that contribute to the development of atherosclerosis in adulthood. In the STRIP study, 1062 infants were randomized into an intervention group (n = 540; low-saturated-fat, low-cholesterol diet) or a control group (n = 522) at 7 mo of age. Fat, saturated fat and cholesterol intakes have been lower, while the polyunsaturated to saturated fat ratio has been higher in the intervention children than in the control children throughout the ongoing trial. During the first 7 y of life, serum cholesterol concentration was 0.2-0.3 mmol/l lower in the intervention boys than in the control boys, but the difference was negligible in girls. Neurological development of the intervention children at age 5 y was at least as good as that of the control children. Counselling had no effect on children's growth.

Interrelations between brachial endothelial function and carotid intima-media thickness in young adults: the cardiovascular risk in young Finns study

BACKGROUND

Endothelial vasodilator dysfunction and carotid intima-media thickening (IMT) are 2 indicators of subclinical cardiovascular disease. We examined their correlation and interaction with risk factors in a large, community-based cohort of young adults.

METHODS AND RESULTS

As part of the longitudinal Cardiovascular Risk in Young Finns Study, we measured endothelium-dependent brachial artery flow-mediated dilatation (FMD) and carotid artery IMT by ultrasound in 2109 healthy adults aged 24 to 39 years. FMD was inversely associated with IMT (P< or =0.001) in a multivariate model adjusted for age, sex, brachial vessel size, and several risk variables. The subjects with age- and sex-specific FMD values in the extreme deciles were classified into groups of impaired (n=204, FMD=1.1+/-1.4%, mean+/-SD) and enhanced (n=204, FMD=16.3+/-2.9%) FMD response. The number of risk factors was correlated with increased IMT in subjects with an impaired FMD response (P<0.05) but not in subjects with an enhanced FMD response (P>0.2).

CONCLUSIONS

Brachial FMD is inversely associated with carotid IMT. The number of risk factors in young adults is correlated with increased IMT in subjects with evidence of endothelial dysfunction, but not in subjects with preserved endothelial function. These observations suggest that endothelial dysfunction is an early event in atherosclerosis and that the status of systemic endothelial function may modify the association between risk factors and atherosclerosis.

The 21-year follow-up of the Cardiovascular Risk in Young Finns Study: risk factor levels, secular trends and east-west difference

OBJECTIVES

The Cardiovascular Risk in Young Finns Study is an on-going multicentre study of atherosclerosis precursors in Finnish children and young adults. We have collected risk factor data in the 21-year follow-up performed in 2001. The aims of this analysis were to examine the levels, secular trends and east-west difference in risk factors amongst young adults.

DESIGN

Population based follow-up study.

SUBJECTS

A total of 2283 participants aged 24-39 years in 2001 (63.5% of the original cohort).

MAIN OUTCOME MEASURES

Levels of serum lipids, apolipoproteins, blood pressure and smoking.

RESULTS

The mean serum total cholesterol, low density lipoprotein cholesterol, high density lipoprotein (HDL) cholesterol and triglyceride concentrations in 24-39-year-old adults were 5.16, 3.27, 1.29 and 1.34 mmol L(-1), respectively. Total cholesterol (5.21 vs. 5.12 mmol L(-1), P = 0.046), HDL cholesterol (1.31 vs. 1.28 mmol L(-1), P = 0.027), systolic blood pressure (118 vs. 115 mmHg, P < 0.0001) and diastolic blood pressure (72 vs. 70 mmHg, P < 0.0001) were higher in subjects originating from eastern Finland compared with those from western Finland. Significant secular trends between 1986 and 2001 in 24-year-old subjects (n = 783) included an increase in serum triglycerides and body mass index (BMI), a decrease in blood pressure and HDL cholesterol and a modest 5% decrease in total cholesterol levels.

CONCLUSIONS

During the past 15 years, BMI and triglyceride levels have increased in young adults in Finland. At the same time, the reduction in cholesterol concentration has been slow. Consistent with persistent regional differences in cardiovascular morbidity within Finland, our data demonstrate significant differences in the levels of cardiovascular risk factors between subjects originating from eastern and western Finland.

Biochemical markers of types I and III collagen and limited joint mobility in type 1 diabetic patients

Limited joint mobility (LJM), a long-term complication of diabetes, has been shown to be associated with microvascular complications of diabetes. Connective tissue alterations may contribute to the development of LJM and other diabetic complications. We tested whether biochemical markers of types I and III collagen metabolism are associated with LJM in type 1 diabetes. We studied 28 male patients of mean age 43.4 years (SD=9.5) and with a duration of diabetes of 25.2 years (SD=9.7) years. LJM assessment included goniometric measurements of the joints and classification by Rosenbloom's method. We measured serum concentrations of aminoterminal propeptide of type III procollagen (PIIINP), carboxyterminal propeptide of type I procollagen (PICP) and carboxyterminal crosslinked telopeptide of type I collagen (ICTP); urinary excretion of crosslinked N-telopeptides of type I collagen (NTX) and deoxypyridinoline crosslinks (DPyr) was also measured. Although average serum PIIINP tended to be higher in subjects with moderate-severe LJM (3.1 +/- 1.3 microg/l) than in subjects with mild LJM (2.5 +/- 0.7 microg/l) or without LJM (2.6 +/- 0.4 microg/l), no significant association was found (p<0.27). Concentrations of the other collagen markers were not different in subjects with or without LJM. We conclude that synthesis and degradation of types I and III collagen in diabetic subjects with LJM did not differ from those without LJM to reflect changes in the biochemical markers of these proteins.

Cardiovascular risk factors in childhood and carotid artery intima-media thickness in adulthood: the Cardiovascular Risk in Young Finns Study

CONTEXT

Exposure to cardiovascular risk factors during childhood and adolescence may be associated with the development of atherosclerosis later in life.

OBJECTIVE

To study the relationship between cardiovascular risk factors measured in childhood and adolescence and common carotid artery intima-media thickness (IMT), a marker of preclinical atherosclerosis, measured in adulthood.

DESIGN, SETTING, AND PARTICIPANTS

Population-based, prospective cohort study conducted at 5 centers in Finland among 2229 white adults aged 24 to 39 years who were examined in childhood and adolescence at ages 3 to 18 years in 1980 and reexamined 21 years later, between September 2001 and January 2002.

MAIN OUTCOME MEASURES

Association between cardiovascular risk variables (levels of low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], and triglycerides; LDL-C/HDL-C ratio; systolic and diastolic blood pressure; body mass index; smoking) measured in childhood and adulthood and common carotid artery IMT measured in adulthood.

RESULTS

In multivariable models adjusted for age and sex, IMT in adulthood was significantly associated with childhood LDL-C levels (P =.001), systolic blood pressure (P<.001), body mass index (P =.007), and smoking (P =.02), and with adult systolic blood pressure (P<.001), body mass index (P<.001), and smoking (P =.004). The number of risk factors measured in 12- to 18-year-old adolescents, including high levels (ie, extreme age- and sex-specific 80th percentile) of LDL-C, systolic blood pressure, body mass index, and cigarette smoking, were directly related to carotid IMT measured in young adults at ages 33 through 39 years (P<.001 for both men and women), and remained significant after adjustment for contemporaneous risk variables. The number of risk factors measured at ages 3 to 9 years demonstrated a weak direct relationship with carotid IMT at ages 24 to 30 years in men (P =.02) but not in women (P =.63).

CONCLUSIONS

Risk factor profile assessed in 12- to 18-year-old adolescents predicts adult common carotid artery IMT independently of contemporaneous risk factors. These findings suggest that exposure to cardiovascular risk factors early in life may induce changes in arteries that contribute to the development of atherosclerosis.

Decreased large artery distensibility in borderline hypertension is related to increased in vivo low-density lipoprotein oxidation

The present study tested the hypothesis that reduced arterial elasticity seen in hypertension is related to increased oxidation of LDL. Fifteen men with borderline hypertension (BHT), with blood pressure values classified as high normal (systolic blood pressure 130-140 mmHg or diastolic blood pressure 85-89 mmHg) were included. The control group comprised 22 men with normal blood pressure values (<135/80 mmHg) matched for age, body size and LDL-cholesterol level. Distensibility of aorta was measured using magnetic resonance imaging, and distensibility of the common carotid artery using ultrasound. Baseline LDL diene conjugation was used as a marker for ox-LDL. Aortic and carotid distensibilities were lower in the BHT men than in controls (1.4 +/- 0.6 vs. 1.9 +/- 0.6%/10 mmHg, p<0.05 for aortic distensibility; 2.9 +/- 0.9 vs. 3.6 +/- 0.6%/10 mmHg, p<0.05 for carotid distensibility). Ox-LDL was significantly higher in the BHT men than in controls (44 +/-15 vs. 28 +/- 8 micromol/L, p<0.01). In univariate analysis, ox-LDL associated with aortic distensibility (r=-0.43, p<0.05). In multivariate analysis, the differences in distensibilities between the groups disappeared when the values were adjusted for ox-LDL. These data show decreased arterial elasticity and increased LDL oxidation in young men with borderline hypertension, and suggest that oxidative modification of LDL particles may play a pathophysiological role in the development of reduced arterial distensibility in hypertension.

Vitamin D and attainment of peak bone mass among peripubertal Finnish girls: a 3-y prospective study

BACKGROUND

Little is known about the effect of vitamin D status on bone gain in adolescents.

OBJECTIVE

The objective was to examine whether vitamin D status is associated with accrual of bone mineral density (BMD) and bone mineral apparent density (BMAD).

DESIGN

This 3-y prospective study examined the association between changes in BMD or BMAD and serum 25-hydroxyvitamin D [25(OH)D] in 171 healthy Finnish girls aged 9-15 y. Lumbar spine and femoral neck BMDs were measured by dual-energy X-ray absorptiometry.

RESULTS

Baseline 25(OH)D correlated significantly with the unadjusted 3-y change in BMD at the lumbar spine (r = 0.35, P < 0.001) and femoral neck (r = 0.32, P < 0.001) in all participants. The difference from baseline in adjusted 3-y BMD accumulation between those with severe hypovitaminosis D [25(OH)D < 20 nmol/L] and those with a normal vitamin D status [25(OH)D > or = 37.5 nmol/L] was 4% (12.7%, 13.1%, and 16.7% for the lowest, middle, and highest tertiles of 25(OH)D, respectively; P for trend = 0.01) at the lumbar spine in the girls with advanced sexual maturation at baseline (n = 129). Moreover, the adjusted change in lumbar spine BMD was 27% greater in the highest vitamin D intake tertile than in the lowest tertile in the same girls (P for trend = 0.016).

CONCLUSIONS

Pubertal girls with hypovitaminosis D seem to be at risk of not reaching maximum peak bone mass, particularly at the lumbar spine. Dietary enrichment or supplementation with vitamin D should be considered to ensure an adequate vitamin D status.

Genetic influences contributing to LDL particle size in familial combined hyperlipidaemia

The nature of the genetic and environmental factors influencing low density lipoprotein (LDL) particle size in patients with familial combined hyperlipidaemia (FCHL) is under debate. We measured LDL peak particle size in 553 subjects belonging to 48 Finnish FCHL families. Individuals with high triglyceride (TG) concentrations (phenotype IV) or combined hyperlipidaemia (phenotype IIB) had significantly smaller LDL particles than those with hypercholesterolaemia (phenotype IIA) or unaffected subjects (P<0.001). In stepwise regression analyses, serum TGs (r(2)=43%, P<0.001) and high density lipoprotein cholesterol (HDL-C) (r(2)=4.5%, P<0.001) were the only significant predictors of LDL peak particle size. Familial correlations support the conclusion that LDL peak particle size is familial, and most probably influenced by genes in these families. Segregation analysis of LDL peak particle size, a quantitative trait, was performed to model this genetic influence. Our results suggest a polygenic background for LDL size with a recessive major gene that may contribute to large LDL peak particle size in women. Serum TG and HDL-C concentrations predict the majority of variations in LDL particle size.

A candidate gene study in low HDL-cholesterol families provides evidence for the involvement of the APOA2 gene and the APOA1C3A4 gene cluster

In patients with premature coronary heart disease, the most common lipoprotein abnormality is high-density lipoprotein (HDL) deficiency. To assess the genetic background of the low HDL-cholesterol trait, we performed a candidate gene study in 25 families with low HDL, collected from the genetically isolated population of Finland. We studied 21 genes encoding essential proteins involved in the HDL metabolism by genotyping intragenic and flanking markers for these genes. We found suggestive evidence for linkage in two candidate regions: Marker D1S2844, in the apolipoprotein A-II (APOA2) region, yielded a LOD score of 2.14 and marker D11S939 flanking the apolipoprotein A-I/C-III/A-IV gene cluster (APOA1C3A4) produced a LOD score of 1.69. Interestingly, we identified potential shared haplotypes in these two regions in a subset of low HDL families. These families also contributed to the obtained positive LOD scores, whereas the rest of the families produced negative LOD scores. None of the remaining candidate regions provided any evidence for linkage. Since only a limited number of loci were tested in this candidate gene study, these LOD scores suggest significant involvement of the APOA2 gene and the APOA1C3A4 gene cluster, or loci in their immediate vicinity, in the pathogenesis of low HDL.

Genome scans provide evidence for low-HDL-C loci on chromosomes 8q23, 16q24.1-24.2, and 20q13.11 in Finnish families

We performed a genomewide scan for genes that predispose to low serum HDL cholesterol (HDL-C) in 25 well-defined Finnish families that were ascertained for familial low HDL-C and premature coronary heart disease. The potential loci for low HDL-C that were identified initially were tested in an independent sample group of 29 Finnish families that were ascertained for familial combined hyperlipidemia (FCHL), expressing low HDL-C as one component trait. The data from the previous genome scan were also reanalyzed for this trait. We found evidence for linkage between the low-HDL-C trait and three loci, in a pooled data analysis of families with low HDL-C and FCHL. The strongest statistical evidence was obtained at a locus on chromosome 8q23, with a two-point LOD score of 4.7 under a recessive mode of inheritance and a multipoint LOD score of 3.3. Evidence for linkage also emerged for loci on chromosomes 16q24.1-24.2 and 20q13.11, the latter representing a recently characterized region for type 2 diabetes. Besides these three loci, loci on chromosomes 2p and 3p showed linkage in the families with low HDL-C and a locus on 2ptel in the families with FCHL.

LDL particle size in familial combined hyperlipidemia: effects of serum lipids, lipoprotein-modifying enzymes, and lipid transfer proteins

Small, dense LDL particles are typical for FCHL. Intravascular lipid exchange and net transfer among HDL, LDL, and triglyceride-rich lipoproteins as well as lipolysis in the VLDL-IDL-LDL cascade regulate properties of LDL. We investigated postheparin plasma activities of hepatic lipase (HL) and LPL, and plasma activities of CETP and phospholipid transfer protein (PLTP) in 191 individuals from 37 Finnish FCHL families. LDL peak particle diameter (LDL size) was measured with 2-10% gradient polyacrylamide gel electrophoresis. LDL size was significantly smaller in affected FCHL family members (n = 68) as compared with nonaffected FCHL family members (n = 78) or spouses (n = 45) (25.3 +/- 1.5 nm, 26.8 +/- 1.2 nm, and 26.6 +/- 1.2 nm, respectively, P < 0.001 for both). In affected FCHL family members, serum triglycerides were the strongest correlate for LDL size (r = -0.71, P < 0.001). In univariate correlation analysis LDL size was not associated with HL, LPL, CETP, and PLTP activities. In multivariate stepwise regression analysis, however, serum triglycerides, CETP activity, HL activity, and HDL cholesterol were significant predictors of LDL size in affected FCHL subjects (adjusted r (2) = 0.642). We conclude that serum triglyceride concentration is strongly correlated with LDL size in affected FCHL subjects. After adjustment for serum triglycerides, HL and CETP activities are associated with LDL size in FCHL.

Nutritional influences on lipids and future atherosclerosis beginning prenatally and during childhood

Autopsy findings of pre-atherosclerotic changes in the coronaries and other arteries of young soldiers killed in action in the Korean war stimulated studies on the mechanisms that regulate the development of atherosclerosis. The data confirmed that vascular changes obviously begin developing much earlier than the manifestation of clinical symptoms, and numerous risk factors for atherosclerosis have been firmly identified. The mechanisms consist of the effects of numerous poorly characterized genes and a complex mixture of environmental factors, dominated by factors associated with nutrition. Observational and epidemiological studies also showed that the pathogenesis is not restricted to the postnatal period. The nutrition of the fetus during the 40 weeks of pregnancy may also play an important role both directly and by determining metabolism in the individual more widely than was previously believed. At the same time, several studies suggested that biochemical predictors of atherosclerosis, e.g. a high concentration of serum LDL cholesterol, a low concentration of serum HDL cholesterol and other lipid and lipoprotein abnormalities, may already in early infancy and childhood predict values later in life quite well. We now review recent studies that deal with the effects of fetal and childhood nutrition on serum lipid values, and discuss the likelihood that clinically meaningful changes of atherosclerosis may appear earlier than expected.

Recognition of familial dyslipidemias in 5-year-old children using the lipid phenotypes of parents. The STRIP project

Adult dyslipidemias may reveal familial and, therefore, offspring dyslipidemias. We evaluated the prevalences of the adult-offspring dyslipidemias in 441 general population families composed of both parents and one 5-year-old child. Family members were classified using the 90th or 10th percentiles for hypercholesterolemia (IIA), hypertriglyceridemia (IV), combined hyperlipidemia (IIB), and low high density lipoprotein cholesterol concentration without hyperlipidemia (hypoHDL). In familial combined hyperlipidemia (FCHL), the IIB-phenotype was in one generation and one of the three hyperlipidemias in the other generation. Finally, the parental dyslipidemia phenotypes and elevated lipids (>80th percentile) that reveal offspring dyslipidemia were selected by stepwise logistic regression. Either the IIA-, IV- or hypoHDL phenotype was found in both generations in 2.8, 2.0 and 1.4% of the families, respectively. FCHL was seen in 1.8% of the families, which confirms the earlier views. The predictive values of the elevated parental cholesterol, type IV or hypoHDL parents to find type IIA, IV and hypoHDL children were low for systematic screening: 16, 13 and 15%, respectively. However, 44% of the children of IIB parents expressed hyperlipidemia (odds ratio 4.7, P=0.006). The IIB phenotype of the parent is a good predictor of the child's hyperlipidemia, and when encountered, it indicates that the lipids of the child should be studied. This would be as important as selective screening of familial hypercholesterolemia.

Brachial artery dilatation responses in healthy children and adolescents

To characterize brachial artery flow-mediated dilatation (FMD) in children, we monitored arterial diameter changes with ultrasound between 40 and 180 s after a 4.5-min forearm cuff occlusion-induced hyperemia in 105 healthy children (mean age, 11 yr; range, 9-16 yr). The peak FMD was 7.7 +/- 4.0% and occurred 79 +/- 33 s after cuff release. FMD at 60 s (5.3 +/- 4.0%) was significantly lower than the peak FMD (P < 0.0001). Twenty-three percent of the children (n = 24) reached peak FMD first after 110 s of postocclusion. Compared with others, these late responders weighed less, had smaller vessel size, and were more often girls, but had similar peak FMD. In multivariate analysis, FMD responses were inversely associated with brachial artery baseline diameter and serum cholesterol concentration. We conclude that the time to reach the peak FMD response in children varies considerably. When studying endothelial function in children with the use of the noninvasive ultrasound method, several brachial artery diameter measurements up to 120 s after cuff release are needed to determine the true FMD peak response.

Two loci on chromosomes 2 and X for premature coronary heart disease identified in early- and late-settlement populations of Finland

Coronary heart disease (CHD) is a complex disorder constituting a major health problem in Western societies. To assess the genetic background of CHD, we performed a genomewide linkage scan in two study samples from the genetically isolated population of Finland. An initial study sample consisted of family material from the northeastern part of Finland, settled by a small number of founders approximately 300 years ago. A second study sample originated from the southwestern region of Finland, settled approximately 2,000 years ago. Families were ascertained through probands exhibiting premature CHD, defined as >50% stenosis of at least two coronary arteries at a young age, as verified by coronary angiography. Both study samples and the pooled data set provided evidence for linkage in two chromosomal regions. A region on chromosome 2q21.1-22 yielded two-point LOD scores of 3.2, 1.9, and 3.7, in the affected sib-pair (ASP) analyses of the northeastern, southwestern, and pooled study samples. The corresponding multipoint maximum-likelihood scores (MLSs) for these three study samples were 2.4, 1.3, and 3.0. In addition, a region on chromosome Xq23-26 resulted in two-point LOD scores of 1.9, 3.5, and 2.9 and in multipoint MLSs of 3.4, 3.1, and 2.5, respectively. In conclusion, this study identifies two loci likely to contribute to premature CHD: one on chromosome 2q21.1-22 and another on chromosome Xq23-26.

Characteristics of young men with clustering risk factors for coronary heart disease: The cardiovascular risk in young finns study

The majority of coronary heart disease (CHD) arises from a population with only moderately elevated risk factor levels. This study addressed the issue of whether clustering of moderately adverse levels of serum low density lipoprotein cholesterol (LDL-C), serum high density lipoprotein cholesterol (HDL-C), and diastolic blood pressure (DBP) was detectable in children and young adults. Significant clustering of these factors was observed in young men (ages 18-24 years) (Observed/Expected [O/E] ratio = 1.5, p = 0.014), whereas in young women or children no clustering greater than due to chance was found. In males, clustering tended to increase with age. Compared to young women, young men had a higher relative intake of dietary fat, and smoked and used alcohol more often. Compared to men without risk factors, the men at risk were significantly more obese, consumed more dietary fat, and smoked more often. The highest degree of clustering was seen in the highest quartile for the subscapular skinfold thickness (O/E ratio = 2.4). In conclusion, high LDL-C, low HDL-C, and high DBP cluster in young adult males. The clear sex difference observed in clustering may be one of the causes for the susceptibility of adult men to CHD. Am. J. Hum. Biol. 9:565-571, 1997. © 1997 Wiley-Liss, Inc.