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Biomedical subjects

J Viikari

Publications and source records attributed to J Viikari.

At least 145 records · Page 8Linked to original sources
PubMed1991

Serum insulin and other cardiovascular risk indicators in children, adolescents and young adults.

We wanted to determine the levels of fasting serum insulin during growth, the tracking of serum insulin, and the correlation of serum insulin with other coronary heart disease risk indicators in children and young adults. In 1986 2433 subjects, aged nine to 24 were studied, and insulin data were available from the same population in 1980 and 1983. Serum insulin levels showed a peak during puberty in both sexes and the decline in insulin continued after the age of 21. Tracking of serum insulin was only moderate, especially in females and young boys. Serum insulin correlated positively with body mass index, concentrations of serum triglycerides, and blood pressure, and inversely with the concentration of high density lipoprotein cholesterol. High triglycerides, high systolic blood pressure, and low level of high density lipoprotein cholesterol clustered among subjects within the highest insulin quartile. Our results suggest that the insulin resistance phenomenon, caused mainly by obesity and leading to unfavourable levels of other coronary heart disease risk indicators, is already developing in children and young adults. This suggests that preventing obesity in early life is important.

Adolescent↗
PubMed1991

Composition of the diet of young Finns in 1986.

The aim was to describe the energy intake and composition of the diet of 1200 9-, 12-, 15-, 18-, 21- and 24-year-old Finns in 1986 and changes in their diet from 1980 to 1986. Data on food consumption were collected using the 48 h recall method. In 1980 protein accounted for 14%, fat for 38% and carbohydrates for 48% of total energy intake, and in 1986 for 15%, 38% and 47%, respectively. The mean P/S ratio increased from 0.24 to 0.31 while the regional differences in the intakes of fatty acids remained unchanged, the P/S ratio being higher in urban than in rural areas and higher in western than in eastern Finland. In 1986 the diet of 15-, 18- and 24-year-old males contained more fat, saturated fatty acids and monounsaturated fatty acids but less sucrose than that of females. The difference in the diet between young men and women, if continued, might increase the male/female ratio at risk for coronary heart disease, which is already pronounced in Finland.

Adolescent↗
PubMed1991

Predictive validity of preadolescent type A determinants for type A dimensions in young adulthood--a 6-year follow-up.

This study examined the predictive validity of preadolescent Type A determinants for Type A dimensions in young adulthood (n = 375). Predictive variables, i.e. hyperactivity, aggression, social maladjustment and self-esteem were measured when the subjects were aged 12. Type A dimensions, i.e. hard-driving, competitiveness plus aggression and impatience were measured in the same subjects when they were aged 18. "Impatience" was predicted by means of preadolescent hyperactivity, and "competitiveness-aggression" by social maladjustment. "Hard-driving", which was most strongly related to CHD risk factor levels in young adulthood, was anteceded by the subject's feeling that he or she could not cope with life. This supports the hypothesis that Type A behaviour is a coping mechanism: a person tries to cope with stress by increasing his or her level of achievement.

Adaptation, Psychological↗
PubMed1991

Dimensions of the coronary arteries in children.

The extent of narrowing of the coronary arteries was measured in a series of 106 children who died accidentally. The outer radius of left main stem coronary artery increases from 1.06 mm at the age of 1 to 1.67 mm at 15. The left anterior descending branch increased with age from 0.70 to 1.35 mm and the inner radius from 0.55 to 1.10 mm. The mean thickness of the media and intima also increased with age; the correlation between thickness and weight was less pronounced. The coronary arteries thickened concomitantly with the size of the artery but that was due mainly to thickening of the intima. Substantial narrowing was found in the youngest age groups and the extent did not correlate with age but with the size of the vessel. The greatest narrowing was 57% of the arterial lumen. The measured dimensions will serve as normal values for the coronary arteries in Finnish children at autopsy.

Adolescent↗
PubMed1991

Association of apolipoprotein E and B polymorphisms with serum lipids.

Genetic polymorphism of apolipoprotein E (apoE) and the Xbal restriction-fragment-length polymorphisms (RFLP) of the gene for apolipoprotein B (apoB) have both been shown to be associated with plasma lipid concentration. We studied the combined effect of these gene polymorphisms on serum cholesterol concentrations in 300 subjects aged nine to 18 years. In three way ANOVA, there was a statistically significant interaction between the effects of apoE phenotype and gender on serum cholesterol (P = 0.009). Therefore, males and females were analysed separately by two way ANOVA: there was no interaction between the effects of apoE phenotype and apoB Xbal polymorphism in either gender. In females, there were independent effects of both the apoE phenotype (P = 0.020) and the apoB Xbal genotype (P = 0.037) on serum cholesterol, but in males these effects were not statistically significant. These data suggest that variations at the apolipoprotein B and E gene locus play a role in the determination of serum cholesterol concentration in young female Finns.

Adolescent↗
PubMed1991

DNA polymorphisms of the apolipoprotein B and A-I/C-III genes are associated with variations of serum low density lipoprotein cholesterol level in childhood.

A number of restriction fragment length polymorphisms (RFLPs) of the apolipoprotein B (apoB) and apolipoprotein A-I/C-III(apoA-I/C-III) genes have been found to be associated with serum lipoprotein levels in many adult populations. In order to examine whether these genetic polymorphisms influence serum lipoprotein levels in childhood and adolescence, we determined the apoB XbaI and apoA-I/C-III SstI genotypes and serum lipoprotein concentrations in 307 healthy Finns aged 9 to 21 years. In the age groups of 9, 12, and 15 years, subjects homozygous for the X2 allele (the XbaI site present) of the apoB gene had mean serum low-density lipoprotein (LDL) cholesterol levels (3.69, 3.43, and 3.15 mmol/l, respectively) that were 12-20% higher than those in subjects homozygous for the absence of this allele (3.08, 3.02, and 2.80 mmol/l, respectively). This association was more significant in males than in females. At the age of 9 to 18 years, subjects carrying the S2 allele (SstI site present) of the apoA-I/C-III gene complex had an approximately 6-15% higher mean serum LDL-cholesterol level than those homozygous for its absence. The combined genotype X2+S2+ (the simultaneous presence of the X2 allele and the S2 allele) was associated with an even more marked elevation of serum LDL-cholesterol level than either allele alone. As an example, the serum LDL cholesterol concentration was 20% higher in 9-year-old subjects with at least one X2 and one S2 allele than in those without either allele (3.55 vs. 2.97 mmol/l, P less than 0.005). The S2 allele was found to be significantly more frequent in eastern than in western Finland, whereas no significant areal differences were seen in the occurrence of the X2 allele. In conclusion, genetic variations of the apoB and apoA-I/C-III gene loci influence serum lipoprotein concentrations already in childhood.

Adolescent↗
PubMed1990

Intimal thickening in the coronary arteries of infants and children as an indicator of risk factors for coronary heart disease.

Narrowings of the coronary arteries were measured in 94 infants aged less than 1 year who died in hospital and 102 1- to 16-year-old children who died accidentally. The arteries were transformed mathematically to circles. The degree of narrowing caused by intimal thickening was determined as the ratio of intimal area to the original luminal area. This ratio was further transformed to percentage. The degree of narrowing varied between 0 and 58% (mean 20%). The mean degree of narrowing in the left coronary artery during the first year of life was 17% and, between 12 and 15 years, 34%. Narrowing was greater in males (P = 0.02), when all the 333 coronary samples were included in the analysis. The birthplaces of the subjects' grandparents were traced from population registers and it was found that narrowing in the left coronary artery of infants was greater in those descended from grandparents from eastern Finland, an area of high mortality from coronary heart disease (CHD). Intimal thickening in infants and children seems to be a morphological manifestation of hereditary predisposition to CHD.

Adolescent↗
PubMed1990

Cardiovascular risk in young Finns. Experiences from the Finnish Multicentre Study regarding the prevention of coronary heart disease.

A large multicentre study of coronary heart disease risk factors and their determinants in children and adolescents was planned in the late 1970s. The main cross-sectional study with 3,596 subjects was made in 1980, and two follow-up studies have been carried out, in 1983 and 1986, respectively. In addition, a study with 630 newborns was carried out in 1981, and a series of children aged 1 to 36 months was collected in 1981-1982. Cord blood, serum cholesterol was about 1.5 mmol/l, which is no different from the level found in other studies. The diet of mothers had no effect on the cholesterol values of the newborns. The cholesterol level of infants and small children was correlated with the amount and quality of fat eaten. The dietary habits of the family were correlated with the family's standard of education, which calls for intervention measures already in early childhood. Serum cholesterol levels have decreased in Finnish children during the 1980s by about 1% per year, which should be reflected in coronary heart disease morbidity and mortality in the future.

Adolescent↗
PubMed1990

Debrisoquine hydroxylation polymorphism in diabetic patients.

Debrisoquine hydroxylation was assessed in 54 type I and in 42 type II diabetic patients. The distribution of metabolic ratio debrisoquine/4-hydroxydebrisoquine (MR) in urine of the patients was compared with a MR-distribution of 176 healthy subjects, and the correlation of glucose balance parameters with the MR was investigated. One poor metabolizer of debrisoquine was found among type I diabetics but no poor metabolizers were found among type II diabetics. Despite the low frequency of the poor metabolizers, the prevalences of debrisoquine hydroxylation phenotypes did not differ from that in healthy volunteers in either diabetic group. No correlation was found between MR and fasting blood glucose or blood glycosylated hemoglobin A1c, whereas a negative correlation was evident between age and the excretion of 4-hydroxydebrisoquine in urine. In summary, debrisoquine hydroxylation is essentially unaltered in type I and type II diabetes mellitus, and no relationship exists between debrisoquine hydroxylation and glucose balance.

Adult↗
PubMed1990

Two new two-step immunoassays for free thyroxin evaluated: solid-phase radioimmunoassay and time-resolved fluoroimmunoassay.

We measured concentrations of free thyroxin (FT4) in serum by using two new two-step FT4 assays--a solid-phase two-step radioimmunoassay. Spectria, and a time-resolved fluoroimmunoassay. Delfia--and compared the results with those by a two-step FT4 assay (RIA-gnost), a one-step FT4 analog assay (Amerlex-M), and FT4 measured after equilibrium dialysis. The new FT4 assays classified 30 hypothyroid and 43 hyperthyroid patients (untreated) well. In 138 patients with nonthyroidal illness (NTI) and in late pregnancy (n = 36), fewer subnormal FT4 values were reported by Spectria (P less than 0.001), Delfia (P less than 0.001), and RIA-gnost (P less than 0.01) than by Amerlex-M. The results of the Spectria and Delfia methods correlated with the results of the dialysis method (r = 0.76) in NTI patients and pregnancy, and were in better agreement with the clinical state than was FT4 by Amerlex-M. The FT4 values by Amerlex-M, but not by other methods, correlated with albumin concentration. We conclude that these new two-step methods present good alternatives for FT4 analysis.

Adult↗
PubMed1990

Apolipoprotein E phenotypes in Finnish youths: a cross-sectional and 6-year follow-up study.

Apolipoprotein E (apoE) polymorphism is a genetic determinant of plasma lipid levels and of coronary heart disease (CHD) risk. We determined the apoE phenotypes and plasma lipid levels in 1577 youths aged 3 to 18 years in 1980. The subjects were randomly selected from five areas of Finland. ApoE phenotyping was performed directly from plasma by isoelectric focusing and immunoblotting. The apoE allele frequencies in the population sample were epsilon 2 = 0.039, epsilon 3 = 0.767, and epsilon 4 = 0.194. There were no differences in the apoE phenotype distribution between East and West Finland or between sexes. The concentrations of serum total cholesterol, low density lipoprotein cholesterol, and apolipoprotein B increased with apoE phenotype in the order of E2/2, E3/2, E4/2, E3/3, E4/3, and E4/4. This increase was already seen in 3-year-old children; it was observed in both sexes, but was clearer in males than in females. The mean levels of high density lipoprotein (HDL) cholesterol, apolipoprotein A-I, triglyceride, Lp[a] lipoprotein, and the activity of lecithin:cholesterol acyltransferase did not differ between the apoE phenotypes. The observed differences in serum cholesterol remained fairly stable during the 6-year follow-up from 1980 to 1986, while the mean serum cholesterol concentration in the whole study population decreased by 6.3%. This study confirms the reported higher frequency of the epsilon 4 allele in Finns as compared to most other populations; this may contribute to the high rates of CHD in Finland as compared to most other populations. The results do not, however, explain the higher rate of CHD in East Finland in comparison to the western part of the country.

Adolescent↗
PubMed1989

Lecithin: cholesterol acyltransferase activity in children and young adults.

The association between serum lecithin: cholesterol acyltransferase (LCAT) activity and demographic and environmental factors, and the correlation of LCAT activity with serum lipids and lipoproteins were studied in a representative series of 1071 9-24-year-old subjects from East and West Finland. LCAT activity was determined by a method involving the use of exogenous substrate. Males had higher LCAT activity than females and subjects from East Finland had significantly higher activity than those from West Finland. LCAT activity tended to be lowest shortly after puberty. Women using oral contraceptives had significantly lower LCAT activity than women not using them. Serum LCAT activity was not associated with body mass index, physical activity index or smoking. Serum LCAT activity correlated positively with most serum lipid and lipoprotein variables. The highest correlation coefficients were found between LCAT activity and total cholesterol. LCAT activity correlated positively with the change in serum total cholesterol which had occurred during the preceding 3 and 6 years in men. Our results suggest that sex hormonal factors are associated with serum LCAT activity. The results are also in accordance with the idea that activity of LCAT increases in response to enhanced demands for cholesterol esterification in plasma.

Adolescent↗
PubMed1989

Serum zinc and copper: associations with cholesterol and triglyceride levels in children and adolescents. Cardiovascular risk in young Finns.

Associations among serum lipids (total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides) and levels of serum zinc (S-Zn), serum copper (S-Cu), and their ratio were analyzed in 3373 3-, 6-, 9-, 12-, 15-, and 18-year-old Finnish girls and boys. S-Zn was positively related to total cholesterol, HDL-cholesterol, and LDL-cholesterol; S-Cu related negatively to HDL-cholesterol. Obesity did not affect these relationships. The few exceptionally high lipid levels found were not associated with very low or high S-Zn or S-Cu. S-Zn and S-Cu were related to serum lipids; causality between the variables, however, remains to be studied.

Adolescent↗
PubMed1989

Cardiovascular risk in young Finns, results from the second follow-up study.

A comprehensive study of coronary heart disease (CHD) risk factors and their determinants in children and adolescents in Finland was initiated in the late 1970's. The main cross-sectional study was undertaken in 1980, with 3596 subjects aged from 3 to 18 years participating. The first follow-up study was carried out in 1983, and the second in 1986. The present report describes briefly some findings in 2746 children and young adults, aged 9, 12, 15, 18, 21 and 24 years, participating in 1986. Serum total cholesterol concentrations, mean (SD), ranged between 4.31 (0.73) and 4.91 (0.81) mmol/l in boys, and between 4.73 (0.85) and 5.09 (0.82) mmol/l in girls, respectively. Mean serum cholesterol values had fallen from 1980 to 1986 by 5.4% in such age cohorts, which had been included in all three studies. Fat content in the diet remained unchanged (38 E %), whereas the mean P/S ratio increased from 0.24 in 1980 to 0.31 in 1986. Young Finns from East Finland had a higher somatic risk index than those from West Finland (P greater than 0.001). The clustering of somatic risk factors was stable between 1980 and 1986. Further follow-up of the cohorts will, we hope, provide the tools for implementing primary prevention of CHD in Finland.

Adolescent↗
PubMed1989

Postheparin plasma lipoprotein and hepatic lipase are determinants of hypo- and hyperalphalipoproteinemia.

To study the role of the two postheparin plasma lipolytic enzymes, lipoprotein lipase (LPL) and hepatic lipase (HL) in high density lipoprotein (HDL) metabolism at a population level, we determined serum lipoproteins, apoproteins A-I, A-II, B, and E, and postheparin plasma LPL and HL activities in 65 subjects with a mean HDL-cholesterol of 34 mg/dl and in 62 subjects with a mean HDL-cholesterol of 87 mg/dl. These two groups represented the highest and lowest 1.4 percentile of a random sample consisting 4,970 subjects. The variation in HDL level was due to a 4.1-fold difference in the HDL2 cholesterol (P less than 0.001) whereas the HDL3 cholesterol level was increased only by 32% (P less than 0.001) in the group with high HDL-cholesterol. Serum apoA-levels were 128 +/- 2.2 mg/dl and 210 +/- 2.8 mg/dl (mean +/- SEM) in hypo- and hyper-HDL cholesterolemia, respectively. Serum apoA-II concentration was elevated by 28% (P less than 0.001) in hyperalphalipoproteinemia. The apoA-I/A-II ratio was elevated only in women with high HDL-cholesterol but not in men, suggesting that elevation of apoA-I is involved in hyperalphalipoproteinemia in females, whereas both apoA proteins are elevated in men with high HDL cholesterol. Serum concentration of apoE and its phenotype distribution were similar in the two groups. The HL activity was reduced in the high HDL-cholesterol group (21.2 +/- 1.5 vs. 38.5 +/- 1.8 mumol/h/ml, P less than 0.001), whereas the LPL activity was elevated in the group with high HDL-cholesterol compared to subjects with low HDL-cholesterol (27.8 +/- 1.3 vs. 19.9 +/- 0.8 mumol/h/ml, P less than 0.001). The HL and LPL activities correlated in opposing ways with the HDL2 cholesterol (r = 0.57, P less than 0.001 and r = 0.51, P less than 0.001, respectively), and this appeared to be independent of the relative ponderosity by multiple correlation analysis. The results demonstrate major influence of both HL and LPL on serum HDL cholesterol concentration at a population level.

Adult↗