M. Dahl

Atherosclerosis precursors in Finnish children and adolescents. I. General description of the cross-sectional study of 1980, and an account of the children's and families' state of health.

ABSTRACT. The paper describes the general outline of a multicentre study on the risk factors of coronary heart disease (CHD) and their determinants in children of various ages in different parts of Finland. The study was a cross‐sectional one, and was carried out in 1980 in five university cities of Finland with medical schools and in 12 rural communities in their vicinity. The randomized sample included an equal number of boys and girls, aged 3, 6, 9, 12, 15, and 18 years, and an equal number of urban and rural population in each area. The total sample size was 4,320 subjects, and of these 3,596 participated (83.1 %). The families received before the medical examination of the child, questionnaires on the Socioeconomic background, the childs general health and development, the parents’and grandparents’health status, and the childs food and exercise habits. At the physical examination also a fasting blood sample (lipids, insulin, trace elements) was taken, a bundle of hair was cut for trace element analysis, and a 48‐hour recall on food intake was obtained from every second subject.

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.

Serum Lipids and Lipoproteins in Children, Adolescents and Young Adults in 1980–1986

A multicentre study on atherosclerosis precursors in young Finns aged three to 18 years was started in 1980 (3596 subjects) serum lipid concentrations (cholesterol, HDL (high density lipoprotein) cholesterol and triglycerides) were determined (n = 3554) and the apolipoproteins A-I and B measured (n = 1355). Two follow-up studies were carried out in 1983 (n = 2851) and 1986 (n = 2489), when HDL-subfractions (HDL-2-cholesterol and HDL-3-cholesterol) were also determined. Apolipoproteins A-I and B were measured again in 1986 (n = 1202). Serum total cholesterol concentration has fallen by about 1% annually during the 1980s from 5.07 mmol/l (1980) to 4.79 mmol/l (1986) in 9- to 18-year old children and adolescents. Mean values of serum triglycerides have slightly increased during the follow-up from 0.79 mmol/l to 0.84 mmol/l, respectively. In children and young adults (3-24 years) the mean cholesterol concentration was highest at the age of six and lowest during puberty. Concentrations of serum cholesterol, LDL (low density lipoprotein) cholesterol apoprotein B and triglycerides were higher in eastern than in western Finland in 1980 and 1983, but these differences were smaller in 1986, with the exception of serum triglycerides. Both in 1983 and in 1986 HDL-2-cholesterol was lower in the west than in the east, whereas HDL-3-cholesterol was higher in the former. The favourable changes in lipid levels should be reflected in future morbidity and mortality rates from coronary heart disease in Finland.

Atherosclerosis precursors in Finnish children and adolescents. IV. Serum lipids in newborns, children and adolescents

ABSTRACT. A multicentre study on atherosclerosis precursors in Finnish children and adolescents was carried out in five urban and 12 rural areas in the autumn of 1980 and spring of 1981. Serum lipids, i.e. cholesterol (TC), HDL‐cholesterol (HDL‐C) and triglyceride (TG) concentrations were determined and LDL‐cholesterol (LDL‐C) was calculated in 630 newborns and 3,596 children aged 3, 6, 9, 12, 15 and 18 years. In the newborns the mean serum TC concentration was 1.50 mmol/l, and the ratio of HDL‐C to TC was 0.44. Newborn boys had lower mean TC, HDL‐C and LDL‐C values than the girls. In 3 to 18‐year‐old children the mean TC, LDL‐C and HDL‐C concentrations were 4.83 mmol/l, 3.09 mmol/l and 1.38 mmol/l, respectively. During puberty, TC mean values decreased, more so in boys. The serum levels of HDL‐C also decreased, especially in boys, and after passing puberty boys had lower mean HDL‐C levels than girls (1.26 vs. 1.39 mmol/l, p

Atherosclerosis precursors in Finnish children and adolescents. X. Leisure‐time physical activity

ABSTRACT. As part of the more extensive project concerned with atherosclerosis precursors in Finnish children, this article aims at 1) describing the method developed for epidemiological estimation of habitual physical activity, 2) discussing the reliability and validity of the method and 3) reporting the results of the application of this strategy in the measurement of habitual physical activity among 3 to 18‐year‐old Finnish boys and girls. The questionnaire for the measurement of physical activity was addressed to the parents of 3‐ and 6‐year‐old subjects (younger group) and to the subjects themselves in 9‐ to 18‐year‐olds (older group). Using four variables in the younger group and nine variables in the older group, sum indices of physical activity were made. Internal consistency coefficients (Kuder—Richardson) varied in the younger group from .57 to .63 and in the older group from .56 to .79. Most Finnish children and adolescents were physically active during their leisure‐time. For comparison of passive and active children, screening for passive ones was difficult. Differences between East and West Finland associated with many risk factors, were not detected in the physical activity patterns of children and adolescents. On the other hand, the physical activity pattern was significantly determined by the local environment. In sparsely populated areas, young people were more inactive than in densely populated areas.

Atherosclerosis precursors in Finnish children and adolescents. II. Height, weight, body mass index, and skinfolds, and their correlation to metabolic variables

ABSTRACT. In a Finnish Multicentre Study, height, weight and skinfold thicknesses were measured in 3‐, 6‐, 9‐, 12‐, 15‐ and 18‐year‐old children (N = 3,596). Height and weight percentiles superimposed on the current Finnish growth charts were above the standards in 6—15‐year‐old boys and 3–12‐year‐old girls. Triceps skinfold thickness percentiles (10 % and 90 %) appeared to be closest to British values and below American values. Weight, body mass index (BMI) and skinfold thicknesses showed good intercorrelations (up to .90) except in young boys. Height had a low positive correlation with BMI (.28 to .36) and with skinfold thickness (23 to .36) in the age groups 6–12 years. BMI and subscapular skinfold seem to be useful obesity indicators. No consistent correlations were seen between physical variables and serum LDL‐ or total cholesterol and apoprotein B concentrations. There was a slight negative correlation between the physical variables and serum HDL‐cholesterol. Apoprotein A1 correlated negatively to all obesity indicators in 12‐year‐old girls. Serum triglycerides showed slight positive correlation to physical variables. BMI and skinfolds had a low to moderate correlation with insulin (.21–.51) mainly in the three oldest age groups. On the ground of BMI and skinfold rneasurements we have reason to believe that the prevalence of obesity at 3–18 years of age is similar in Finland as in other countries in Europe.

Blood Pressure in Children, Adolescents and Young Adults

The question of whether blood pressure is one of the main risk factors for cardiovascular diseases in childhood has been evaluated in a Study of Cardiovascular Risk in Young Finns. In the second follow-up study, carried out in 1986, blood pressure was successfully measured in 2500 individuals aged nine to 24 years using a random zero sphygmomanometer. The mean systolic blood pressure in girls rose from 102 mmHg (95th percentile 119 mmHg) at age nine to 116 mmHg (138 mmHg) at age 24 and that in boys from 102 mmHg (95th percentile 121 mmHg) to 128 mmHg (148 mmHg). Diastolic blood pressure was more often measurable using Korotkoffs 5th than the 4th phase. The values observed were similar to those reported by the Second Task Force on Blood Pressure Control in Children, but owing to differences in the methods used to measure blood pressure it cannot be reliably concluded that the blood pressures were similar in the two series. Even in childhood blood pressure measurement is important, and since it changes wit...

Atherosclerosis precursors in Finnish children and adolescents. VII. Serum immunoreactive insulin

ABSTRACT. In the Finnish Multicentre Study of the risk factors of coronary heart disease serum immunoreactive insulin (IRI) was measured in 3,486 children and adolescents aged 3–18 years. Serum IRI increased with age till the age of 15 years in both sexes. The increase in serum IRI levelled off with the progression of pÜbertal development. Serum IRI levels were higher in girls than in boys from the age of 6 years onwards. Comparison of serum IRI gave identical results from eastern and western parts of the country. Serum IRI correlated positively with skinfold thickness, weight, relative weight and body mass index in all age groups except the 3‐year‐old children.

Atherosclerosis precursors in Finnish children and adolescents. VI. Serum apolipoproteins A‐I and B

ABSTRACT. The concentrations of apolipoproteins A‐I and B were determined in 1,341 3‐ to 18‐year‐old children and adolescents from five urban and 12 rural communities. The analyses were made with radial immunodiffusion. The mean concentrations (± S.D.) of apo A‐I and apo B were 152 ± 25 and 94 ± 22 mg/100 ml. respectively. 3‐year‐old children had the highest apo B levels which then decreased with advancing age in both sexes. Boys tended to have lower levels of apo B than girls. Apo A‐1 concentration was significantly higher in the 9‐ and 12‐year‐old boys than in the other age groups but showed no age‐bound trend in girls. The apo A‐I to apo B ratio increased with age in both sexes. The concentration of apo A‐I was significantly lower, and that of apo B higher, in children living in eastern Finland in comparison with those from the western part of the country. This difference and a higher HDL‐cholesterol to apo A‐I ratio in both sexes in eastern Finland may be asSociated with the regional differences in the prevalence of coronary heart disease in this country. Key words: adolescents, apolipoproteins, apo A‐I, apo B, children, serum lipids.

Atherosclerosis precursors in Finnish children and adolescents. V. Fatty acid composition of serum cholesteryl esters: regional differences in Finland.

ABSTRACT. Fatty acid compositions of serum cholesteryl esters (CE) were analysed with gas chromatography from a total of 1,348 Finnish children. The study was a part of a comprehensive survey of atherosclerosis precursors among children, and included 3‐, 6‐, 9‐, 12‐, 1.5, and 18‐year‐old children and adolescents from five urban and twelve rural communities in Finland. In all age groups and both sexes, the mean percentages of linoleate (CE‐18:2) were lower and those of saturated and monounsaturated fatty acids higher in eastern rural areas than elsewhere. Eastern rural children also had significantly higher proportions of ω3 polyunsaturated fatty acids in their serum CEs. The percentage of serum CE‐18:2 parellels the PIS values obtained by a dietary survey from the same populations. The reason for higher percentages of the ω3 fatty acids in rural communities cannot be explained by diet, and remains unclear.