Determinants of serum 25(OH)D concentration in young and middle-aged adults. The Cardiovascular Risk in Young Finns Study

INTRODUCTION

We studied prevalence of hypovitaminosis D, its determinants, and whether achievement of recommended dietary vitamin D intake (10 μg/d) is associated with absence of hypovitaminosis D in adults.

METHODS

The study is part of the Cardiovascular Risk in Young Finns Study. We collected serum samples of 25-hydroxyvitamin D as part of the 27-year follow-up (994 men and 1,210 women aged 30-45 years). Hypovitaminosis was defined as vitamin D concentration ≤ 50 nmol/L.

RESULTS

Hypovitaminosis D was found in 38% of men and 34% of women. Dietary vitamin D intake (OR 0.90, 95% CI 0.86-0.93), use of vitamin-mineral supplements (0.66, 0.51-0.85), sunny holiday (0.55, 0.41-0.75), and oral contraceptive use in women (0.45, 0.27-0.75) were independently associated with reduced odds of hypovitaminosis. Increase in body mass index (1.06, 1.03-1.09), being a smoker (1.36, 0.97-1.92), investigation month (December versus other) (1.35, 1.12-1.61), and risk alleles in genotypes rs12785878 (1.31, 1.00-1.70) and rs2282679 (2.08, 1.66-2.60) increased odds of hypovitaminosis. Hypovitaminosis D was common also when recommended dietary intake was obtained (men 29%, women 24%).

CONCLUSION

Several factors were associated with hypovitaminosis D. The condition was common even when recommended vitamin D intake was reported. The results support the importance of vitamin D fortification and nutrient supplement use.

Childhood 25-OH vitamin D levels and carotid intima-media thickness in adulthood: the cardiovascular risk in young Finns study

CONTEXT

Low vitamin D levels in adulthood have been associated with cardiovascular disease.

OBJECTIVE

To investigate if low vitamin D levels in childhood are related with increased carotid artery intima-media thickness (IMT) in adulthood.

DESIGN, SETTING, AND PARTICIPANTS

The analyses included 2148 subjects from the Cardiovascular Risk in Young Finns Study, aged 3-18 years at baseline (in 1980). Subjects were re-examined at age 30-45 years (in 2007). Childhood levels of 25-hydroxy-vitamin D were measured from stored serum in 2010.

MAIN OUTCOME MEASURE

The carotid artery IMT from 2007 was used.

RESULTS

When adjusted for age, sex, and childhood risk factors, continuous data of childhood 25-OH vitamin was inversely associated with adulthood carotid IMT levels among females (β ± SE -0.006 ± 0.003, P = 0.03), but not among males (0.001 ± 0.004, P = 0.88). Children with 25-OH vitamin D levels in the lowest quartile (<40 nmol/L) had significantly increased odds of having high-risk IMT (highest decile of common carotid or carotid bulb IMT or carotid plaque) as adults, in analyses adjusted for age, sex and either childhood risk factors (odds ratio 1.70 [95 % CI 1.15-2.31], P = 0.0007) or adult risk factors, including adult vitamin D levels (odds ratio 1.80 [1.30-2.48], P = 0.0004). In sex-specific analyses, these associations were significant both in females and males (P always <0.05). In sensitivity analyses, those with childhood vitamin D levels in the lowest quintile (<37 nmol/L), gave similar results to those using a quartile cut-point.

CONCLUSIONS

Low 25-OH vitamin D levels in childhood were associated with increased carotid IMT in adulthood.

Serum 25-hydroxyvitamin D and the risk of knee and hip osteoarthritis leading to hospitalization: a cohort study of 5274 Finns

OBJECTIVE

The aim of this study was to investigate whether low levels of serum 25-hydroxyvitamin D [25(OH)D] predicts the development of knee or hip OA.

METHODS

The cohort consisted of 5274 participants in a national health examination survey who had no knee or hip OA at baseline. Information about the incidence of OA was drawn from the National Health Care Register. During the follow-up of 10 years (50 134 person-years), 127 subjects developed incident, physician-diagnosed OA in the knee and 45 in the hip joint. The information on covariates, including age, sex, education, BMI, work load, leisure time physical activity, smoking history, knee or hip complaint during the past month and previous injuries, was gathered at baseline. Serum 25(OH)D concentrations were determined from baseline serum samples.

RESULTS

After adjustment for age and gender, serum 25(OH)D showed statistically significant associations with known risk factors for OA except injuries. In the fully adjusted model, low serum 25(OH)D concentration did not predict increased incidence of knee and hip OA.

CONCLUSION

The results do not support the hypothesis that low levels of serum 25(OH)D contribute to the development of knee or hip OA.

Fish consumption, omega-3 fatty acids, and environmental contaminants in relation to low-grade inflammation and early atherosclerosis

BACKGROUND

Fish consumption and omega-3 polyunsaturated fatty acid (PUFA) intake are shown to protect from cardiovascular diseases (CVD). However, most fish contain environmental contaminants such as dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), and methylmercury (MeHg) that may have adverse effects on cardiovascular health.

OBJECTIVE

Our aim was to elucidate the associations of fish consumption, omega-3 PUFAs, environmental contaminants with low-grade inflammation, early atherosclerosis, and traditional CVD risk factors.

METHODS

The Health 2000 survey participants (n=1173) represented the general Finnish population and the Fishermen study participants (n=255) represented a population with high fish consumption and high exposure to environmental contaminants. Model-adjusted geometric means and tests for linear trend were calculated for CVD risk factors by tertiles of fish consumption and serum omega-3 PUFAs, and additionally in the Fishermen study only, by tertiles of serum PCDD/F+PCB, and blood MeHg.

RESULTS

Serum triglyceride decreased across omega-3 PUFA tertiles in both sexes and studies. Insulin resistance, C-reactive protein, tumour necrosis factor α, and interleukin 6 decreased across omega-3 PUFA tertiles among the Health 2000 survey participants. Among the Fishermen study men, insulin resistance and arterial stiffness indicated by β-stiffness index tended to increase and the RR estimate for carotid artery plaque tended to decrease across tertiles of PCDD/F+PCB and MeHg.

CONCLUSION

Previously established hypotriglyceridemic and anti-inflammatory effects of omega-3 PUFAs were seen also in this study. The hypothesised favourable effect on insulin sensitivity and arterial elasticity was suggested to be counteracted by high exposure to environmental contaminants but the effect on plaque prevalence appeared not to be harmful.

Cross-sectional associations between physical activity and selected coronary heart disease risk factors in young adults. The Cardiovascular Risk in Young Finns Study

OBJECTIVE

Physical activity (PA) may reduce the risk of coronary heart disease (CHD) by inducing beneficial changes in several risk factors. We studied the associations between PA and a range of risk markers of CHD in young adults.

METHODS AND RESULTS

We measured serum lipoproteins, oxidized LDL, adipokines, inflammatory markers, metabolic markers, and arginine metabolites in 2,268 individuals (age 24-39 y). Participants were asked frequency, duration, and intensity of PA in leisure time. In addition, commuting to work was assessed. In both sexes, PA was inversely associated with waist circumference (all P < 0.0001). After controlling for sex, age, and waist circumference, PA was directly associated with HDL-cholesterol and apolipoprotein A1, and inversely with heart rate, smoking, oxidized LDL, apolipoprotein B, insulin, glucose, C-reactive protein, leptin, L-arginine, and phospholipase A2 activity (all P < 0.05).

CONCLUSION

These population-based data are consistent with the idea that the beneficial effects of PA on CHD risk are mediated by favorable influences on several risk factors, as judged by independent relations to markers of lipoprotein metabolism, glucose metabolism, and inflammation. These associations reflect beneficial effects on cardiovascular health in both sexes and may offer mechanistic insights for the inverse association between PA and CHD.

Association of liver enzymes with metabolic syndrome and carotid atherosclerosis in young adults. The Cardiovascular Risk in Young Finns Study

OBJECTIVE

We examined whether metabolic syndrome (MetS) predicts increased alanine aminotransferase (ALT) and gamma-glutamyltransferase (GGT) levels in young adults, whether spontaneous recovery from MetS has a favorable effect on liver enzyme activities, and whether these enzymes contribute to the atherogenicity of MetS (assessed by carotid intima-media thickness (IMT)).

METHODS

The study included 1,553 subjects (base-line age 31.5 ± 5.0 years). ALT and GGT were measured in 2007. MetS was diagnosed by the new Joint Interim Societies definition.

RESULTS

ALT and GGT levels were higher in subjects with MetS compared to those without in 2007. The association was independent of alcohol intake and BMI. In multivariable models adjusted for base-line age, LDL cholesterol, CRP, alcohol intake, and adiponectin, MetS in 2001 predicted increased ALT (β ± SEM = 0.320 ± 0.062, P < 0.0001 in men; 0.134 ± 0.059, P = 0.02 in women) and GGT (β ± SEM = 0.222 ± 0.067, P < 0.0001 in men; 0.236 ± 0.060, P < 0.0001 in women) levels after 6 years. Subjects with MetS only at base-line (2001) had lower ALT levels after 6 years compared to subjects with persistent and incident MetS. No statistically significant interaction for MetS*ALT (P = 0.81) or MetS*GGT (P = 0.92) on IMT was observed.

CONCLUSION

In young adults MetS may induce liver enzyme changes that indicate increased risk of non-alcoholic fatty liver disease, but we found no evidence that increased enzyme levels would amplify the atherogenicity of MetS.

Association of 25-hydroxyvitamin D with the incidence of knee and hip osteoarthritis: a 22-year follow-up study

OBJECTIVE

In the light of conflicting results from previous studies on the role of vitamin D, we studied serum 25-hydroxyvitamin D [25(OH)D] with regard to its prediction of incident knee and hip osteoarthritis (OA).

METHODS

The study population (n = 805) consisted of participants of a national health examination survey who had undergone baseline and follow-up clinical examinations at intervals of 20-23 years. Knee and hip OA were diagnosed on the basis of a standardized clinical examination by physicians with the same diagnostic criteria at baseline and follow-up. Information on covariates, including age, sex, season of blood draw, education, body mass index (BMI), physical workload, leisure time physical activity, smoking history, and previous injuries, was collected at baseline. Serum 25(OH)D concentrations were determined from baseline serum samples kept frozen at -20°C.

RESULTS

We found no significant association between serum 25(OH)D level and the risk of incident knee or hip OA. However, a statistically significant interaction between season of blood draw and serum 25(OH)D emerged when predicting the development of definite knee OA (p = 0.004). After adjusting for all the covariates, the relative odds (95% confidence interval) of developing definite knee OA per increment of 1 SD (20.7 ng/mL) in winter season 25(OH)D was 1.57 (1.10-2.27), whereas for summer season sera the corresponding rate was 0.53 (0.28-1.00).

CONCLUSION

The results do not support the hypothesis that a low level of serum 25(OH)D contributes to the development of OA. Instead, our study suggests that season is a potent effect modifier of 25(OH)D, which merits attention in future research.

Physical activity, high-sensitivity C-reactive protein, and total and cardiovascular disease mortality in type 2 diabetes

OBJECTIVE

Physical activity reduces high-sensitivity C-reactive protein (hs-CRP), cardiovascular disease (CVD), and total mortality in type 2 diabetic patients. However, it is not known whether the effects of physical activity on mortality depend on the levels of hs-CRP in patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

We prospectively followed-up on 569 type 2 diabetic patients, aged 45-64 years, who were free of CVD at baseline. Participants were stratified according to the level of hs-CRP (<1.0, 1.0-3.0, or >3.0 mg/L) and the degree of physical activity (0-4 metabolic equivalent tasks [METs] or >4 METs). The Cox proportional hazards model was used to estimate the joint association between physical activity and hs-CRP levels and the risk of mortality.

RESULTS

During an 18-year follow-up, 356 patients died, 217 of whom died of CVD. Those who were physically more active had significantly reduced total, CVD and coronary heart disease (CHD) mortality among patients with elevated hs-CRP levels (>3 mg/L). These findings persisted in multivariable analyses. However, in patients with an hs-CRP level<1 mg/L or between 1 and 3 mg/L, there was no statistically significant relationship between physical activity and CVD or CHD mortality.

CONCLUSIONS

Physical activity reduces total, CVD, and CHD mortality in type 2 diabetic patients with elevated hs-CRP levels. This suggests that the anti-inflammatory effect of physical activity may counteract increased CVD and CHD morbidity and mortality associated with high CRP levels.

Serum cotinine predicts bronchial obstruction regardless of self-reported smoking history

BACKGROUND

We studied ability of serum cotinine and detailed history of smoking to predict bronchial obstruction.

METHODS

The baseline study was done during the Mini-Finland Health Survey in 1980 and the follow-up study during the Health 2000 Survey in 2000 for a total of 662 persons free from bronchial obstruction at baseline. Spirometric values of the ratio of forced expiratory volume in one second to forced vital capacity (FEV%) <80% were defined as moderate and <70% as severe bronchial obstruction at follow-up. Cotinine was determined from frozen serum samples collected at baseline.

RESULTS

For those who reported at baseline not to smoke currently but whose serum cotinine (≥100 μg/l) indicated active smoking, the age- and sex-adjusted odds ratio of bronchial obstruction at follow-up was 2.55 (95% CI 1.26-5.19) compared with the ''true non-smokers'' (<100 μg/l). Among current smokers, after adjustment for age, sex, pack years, daily consumption of cigarettes, and inhalation of smoke, the odds ratio of moderate and severe bronchial obstruction was 1.61 (95% CI 1.12- 2.32) and 1.97 (95% CI 1.10-3.54) per an increment of one standard deviation (367 μg/l) in serum cotinine. The predictive value of all the interview measures of past or current smoking was clearly lower.

CONCLUSIONS

Serum cotinine concentration is a useful predictor for development of obstruction. Smoking history alone may be insufficient in risk factor studies focusing on smoking-related diseases.

Evaluation of multiplex immunoassays, used for determination of adiponectin, resistin, leptin, and ghrelin from human blood samples, in comparison to ELISA assays

BACKGROUND

Many different multiplex biomarker immunoassays based on Luminex®-technology have been developed during recent years. We have evaluated the performance of two multiplex immunoassays for determination of adiponectin, resistin, ghrelin and leptin in comparison to corresponding, conventional ELISA assays.

METHODS

Human serum or plasma samples were analysed by commercially available multiplex and ELISA immunoassays manufactured by Millipore Corp.

RESULTS

The correlation between tested multiplex and ELISA immunoassays was good, r > 0.9 for all analytes. The agreement between the methods was acceptable but there were differences in analytical levels. Intra- and inter-assay variation was comparable between both assays. The coefficient of variation for all analytes, independent of method, was ≤15% and for most of them <10%.

CONCLUSION

The performance of the tested multiplex assays was reasonable and they can be considered as valid options to the conventional ELISA assays. However, results obtained with the two different techniques are not necessarily interchangeable due to differences in the concentration levels.

Adiponectin is related with carotid artery intima-media thickness and brachial flow-mediated dilatation in young adults--the Cardiovascular Risk in Young Finns Study

AIMS

Adiponectin may be involved in the pathogenesis of atherosclerosis. We investigated the relation of adiponectin on early functional and structural markers of subclinical atherosclerosis in a large population-based cohort of young men and women.

METHODS AND RESULTS

We measured serum adiponectin using radioimmunoassay in 2,147 young adults (ages 24-39 years) participating in the Cardiovascular Risk in Young Finns Study. The subjects had ultrasound data on carotid intima-media thickness (IMT), carotid artery elasticity (n = 2,139) and brachial flow-mediated dilatation (FMD) (n = 1,996). In univariate analysis, adiponectin was inversely associated with IMT (r = -0.16, P < 0.0001) and directly with FMD (r = 0.12, P < 0.0001) and carotid elasticity (r = 0.20, P < 0.0001). The associations for IMT and FMD remained significant in multivariable models adjusted for age, sex, obesity indices, serum lipids, blood pressure, leptin, glucose, and C-reactive protein: IMT (β = -0.018 ± 0.005, P = 0.0002) and FMD (β = 0.72 ± 0.25, P = 0.004). The relation between adiponectin and carotid elasticity attenuated to non-significant after adjusting for waist circumference and systolic blood pressure.

CONCLUSION

In young healthy adults, low serum adiponectin concentration is independently related with increased carotid IMT and attenuated brachial FMD, supporting the role of adiponectin in the pathogenesis of early atherosclerosis.

Serum vitamin D and the risk of Parkinson disease

OBJECTIVE

To investigate whether serum vitamin D level predicts the risk of Parkinson disease.

DESIGN

Cohort study.

SETTING

The study was based on the Mini-Finland Health Survey, which was conducted from 1978 to 1980, with Parkinson disease occurrence follow-up through the end of 2007. During the 29-year follow-up period, 50 incident Parkinson disease cases occurred. Serum 25-hydroxyvitamin D level was determined from frozen samples stored at baseline. Estimates of the relationship between serum vitamin D concentration and Parkinson disease incidence were calculated using the Cox model.

PARTICIPANTS

Three thousand one hundred seventy-three men and women, aged 50 to 79 years and free of Parkinson disease at baseline. Main Outcome Measure Parkinson disease incidence.

RESULTS

Individuals with higher serum vitamin D concentrations showed a reduced risk of Parkinson disease. The relative risk between the highest and lowest quartiles was 0.33 (95% confidence interval, 0.14-0.80) after adjustment for sex, age, marital status, education, alcohol consumption, leisure-time physical activity, smoking, body mass index, and month of blood draw.

CONCLUSIONS

The results are consistent with the suggestion that high vitamin D status provides protection against Parkinson disease. It cannot, however, be excluded that the finding is due to residual confounding and further studies are thus needed.

Bioavailability of various polyphenols from a diet containing moderate amounts of berries

Berries are a rich source of various polyphenols. The objective of this study was to investigate the bioavailability of polyphenols from berries. Middle-aged subjects (n = 72) consumed moderate amounts of berry or control products for 8 weeks in a randomized, placebo-controlled dietary intervention trial. Average intake of berries was 160 g/day (bilberries, lingonberries, black currants, and chokeberries). Plasma and urine polyphenols were analyzed by GC-MS and HPLC and berry polyphenols by HPLC. The total intake of polyphenols was 837 mg/day. Plasma quercetin, p-coumaric acid, 3-hydroxyphenylacetic acid, caffeic acid, protocatechuic acid, vanillic acid, homovanillic acid, and 3-(3-hydroxyphenyl)propionic acid increased significantly from the baseline in the berry group compared to the control group (p < 0.05). The urinary excretion of quercetin, p-coumaric acid, and 3-hydroxyphenylacetic acid increased significantly in the berry group compared to the control group (p < 0.05). In conclusion, a number of polyphenols are bioavailable from a diet containing moderate amounts of blue and red berries.

Follow-ups of the Cardiovascular Risk in Young Finns Study in 2001 and 2007: levels and 6-year changes in risk factors

OBJECTIVES

To examine cardiovascular risk factor levels in 2007 and their 6-year changes between 2001 and 2007 using the data collected in the follow-ups of the Cardiovascular Risk in Young Finns Study.

DESIGN

Population-based follow-up study.

SUBJECTS

A total of 2204 healthy Finnish adults aged 30-45 years (1210 women; 994 men).

MAIN OUTCOME MEASURES

Levels in 2007 and changes between 2001 and 2007 of lipids, insulin, glucose, blood pressure, smoking, body mass index, alcohol consumption, waist and hip circumferences.

RESULTS

The mean serum total cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol and triglyceride concentrations in 30- to 45-year-old adults were 5.05, 3.09, 1.34 and 1.40 mmol L(-1), respectively. Significant changes (P < 0.05) between 2001 and 2007 in 30- to 39-year-old subjects included a decrease in total cholesterol (-6.6% in men, -5.8% in women), LDL-cholesterol (-10.2% and -11.6%) and an increase in diastolic blood pressure (3.5% and 3.9%). Waist circumference (1.8% and 5.5%) and systolic blood pressure increased in 36-39 year olds (2.3% and 2.3%). HDL-cholesterol increased in 30- to 33-year-old women (5.8%) Glucose levels increased in 30- to 39-year-old women (3.7%) and 36- to 39-year-old men (3.6%). Smoking prevalence decreased in 36- to 39-year-old men from 29.8% to 22.2%.

CONCLUSIONS

The 6-year changes in total cholesterol, LDL-cholesterol and HDL-cholesterol in young Finns were favourable between 2001 and 2007. However, waist circumference, glucose and blood pressure levels increased. Therefore, continuous efforts are still needed in fighting against cardiovascular risk factors.

Interleukin-18 gene polymorphism and markers of subclinical atherosclerosis. The Cardiovascular Risk in Young Finns Study

BACKGROUND AND AIM

Interleukin-18 (IL-18) is a pro-atherosclerotic cytokine. We wanted to evaluate whether IL-18 gene polymorphism associates independently of risk factors, with early subclinical markers of atherosclerosis (intima-media thickness (IMT), coronary artery compliance (CAC), and flow-mediated dilatation (FMD)) in a population of young healthy Caucasian adults.

METHODS

This study was based on the on-going Cardiovascular Risk in Young Finns Study consisting of 2260 young adults, mean age being 31.7 (range 24-39 years) (1247 women and 1013 men).

RESULTS

Five studied tagSNPs formed six major haplotypes, which accounted for 99.9% of all variation of the IL-18 gene. According to adjusted analysis of variance, the IL-18 gene polymorphism did not associate with subclinical atherosclerosis in the whole study population. However, one major haplotype associated differently among men and women with IMT (P = 0.011). Male carriers of a major CCTgT haplotype (n = 441) seemed to have a lower IMT when compared to the non-carriers (-0.016 mm, 95% confidence interval (CI) -0.028 to -0.004, P = 0.014). Among women no significant associations were observed.

CONCLUSIONS

Among all study subjects, the polymorphism of the IL-18 gene is not associated with subclinical markers of atherosclerosis. However, among men one major IL-18 haplotype seemed to associate with substantially lower IMT values.

The relative importance of modifiable potential risk factors of type 2 diabetes: a meta-analysis of two cohorts

Lifestyle factors predict type 2 diabetes occurrence, but their effect in high- and low-risk populations is poorly known. This study determines the prediction of low-risk lifestyle on type 2 diabetes in those with and without metabolic syndrome in a pooled sample of two representative Finnish cohorts, collected in 1978-1980 and 2000-2001. Altogether 8,627 individuals, aged 40-79 years, and free of diabetes and cardiovascular disease at baseline were included in this study. A low-risk lifestyle was defined based on body mass index, exercise, alcohol consumption, smoking, and serum vitamin D concentration. The metabolic syndrome was defined according to the International Diabetes Federation including obesity, blood pressure, serum HDL cholesterol, serum triglycerides, and fasting glucose. During a 10-year follow-up, altogether 226 type 2 diabetes cases occurred. Overweight was the strongest predictor of type 2 diabetes (population attributable fraction (PAF) = 77%, 95% confidence interval (CI): 53, 88%). Together with lack of exercise, unsatisfactory alcohol consumption, smoking, and low vitamin D concentration it explained 82% of the cases. Altogether 62% (CI: 47, 73%) of the cases were attributable to the metabolic syndrome and 92% (CI: 67, 98%) to the most unfavourable combination of its components. The metabolic syndrome did not modify the prediction of lifestyle factors but persons with normal blood pressure benefited more from positive changes in exercise, alcohol consumption, and smoking than those with elevated blood pressure (P for interaction = 0.01). In conclusion, modification of lifestyle factors apparently reduces type 2 diabetes risk, especially in persons with normal blood pressure.

Vitamin D status and the risk of cardiovascular disease death

Accumulating evidence suggests that inadequate vitamin D levels may predispose people to chronic diseases. The authors aimed to investigate whether serum 25-hydroxyvitamin D (25(OH)D) level predicts mortality from cardiovascular disease (CVD). The study was based on the Mini-Finland Health Survey and included 6,219 men and women aged > or =30 years who were free from CVD at baseline (1978-1980). During follow-up through 2006, 640 coronary disease deaths and 293 cerebrovascular disease deaths were identified. Levels of 25(OH)D were determined from serum collected at baseline. Cox's proportional hazards model was used to assess the association between 25(OH)D and risk of CVD death. After adjustment for potential confounders, the hazard ratio for total CVD death was 0.76 (95% confidence interval (95% CI): 0.60, 0.95) for the highest quintile of 25(OH)D level versus the lowest. The association was evident for cerebrovascular death (hazard ratio = 0.48, 95% CI: 0.31, 0.75) but not coronary death (hazard ratio = 0.91, 95% CI: 0.70, 1.18). A low vitamin D level may be associated with higher risk of a fatal CVD event, particularly cerebrovascular death. These findings need to be replicated in other populations. To demonstrate a causal link between vitamin D and CVD, randomized controlled trials are required.

Vitamin D status and common risk factors for bone fragility as determinants of quantitative ultrasound variables in a nationally representative population sample

Calcaneal quantitative ultrasound (QUS) can predict bone strength and fracture risk. Bone fragility has no single cause but results from a complex interplay of several etiologic or contributing factors. Vitamin D is essential for bone health even though it is still unclear how much of this vitamin is required to maintain bone strength and prevent fractures. Measurements of serum 25-hydroxyvitamin D [S-25(OH)D] have indicated a high prevalence of inadequate vitamin D status in a number of studies mostly based on selected study populations. The objective of this study was to examine the associations between S-25(OH)D, common risk factors for bone fragility, and QUS variables in a large unselected population sample. The study population consisted of 2736 men and 3299 women from a nationally representative population sample, aged 30 years or over. Information on lifestyle was elicited by means of interviews and questionnaires. Body fat mass was estimated using an impedance-meter. S-25(OH)D was measured by radioimmunoassay. Calcaneal QUS was performed on the Hologic Sahara apparatus recording broadband ultrasound attenuation (BUA) and speed of sound (SOS). The potential determinants of BUA and SOS were analysed using separate multiple linear regression models for men and women. S-25(OH)D proved to be an independent determinant of BUA (P<0.0001 for men, P<0.001 for women) and SOS (P<0.0001 for men, P<0.05 for women). BUA was also independently associated with age, height, weight, alcohol consumption, and postmenopausal status in women, and with weight, alcohol consumption, smoking and physical activity in men. All of the above variables, except for weight in women, were also found to be independent determinants of SOS in both men and women. A reverse association was found between S-25(OH)D and adiposity in spite of higher intakes of vitamin D in those with higher fat mass. In this unselected sample of men and women, vitamin D status, several lifestyle factors and physical characteristics proved to be significant determinants of BUA and SOS. Inadequate vitamin D status was common, and measures ensuring adequate intakes of vitamin D in the population thus deserve continued attention. Obesity should be taken into account in future assessments of vitamin D status in Finland as in other countries.

Hepatic lipase promoter C-480T polymorphism is associated with serum lipids levels, but not subclinical atherosclerosis: the Cardiovascular Risk in Young Finns Study

The common C-480T polymorphism (rs1800588) of the hepatic lipase gene (LIPC) has been associated with high-density lipoprotein (HDL) cholesterol, atherosclerosis, and coronary artery disease. In this study, we examined whether the polymorphism is associated with serum lipid and lipoprotein concentrations, as well as with subclinical atherosclerosis in Young Finns. The participants comprised 2041 men and women (aged 24-39 years) enrolled in the Cardiovascular Risk in Young Finns Study with complete data concerning the rs1800588 polymorphism and serum lipids concentration. All participants underwent an ultrasound examination for brachial artery flow-mediated vasodilatation (FMD) and carotid artery intima-media thickness (IMT) measurement. The marker of arterial elasticity, carotid artery compliance (CAC), was also calculated by means of ultrasound and concomitant brachial blood pressure measurements. In all subjects, serum total cholesterol (p < 0.001), HDL cholesterol (p = 0.006), apolipoprotein AI (apoAI, p < 0.001), and triglyceride (p = 0.009) concentrations increased according to rs1800588 genotype in the order CC, CT, and TT. The same order applied only to apoAI after adjustment for age, body mass index, systolic and diastolic blood pressure, smoking, alcohol consumption, physical activity, diabetes, hypertension, contraceptive hormone use in women, and concentrations of glucose, insulin and C-reactive protein in men and women separately (p = 0.007 and p = 0.003, respectively). The polymorphism was also associated with HDL cholesterol, total cholesterol, and triglyceride levels in women (adjusted p = 0.004, p = 0.007 and 0.02, respectively), but not in men (p was not significant for all). No significant association between the rs1800588 and brachial FMD, carotid IMT, or CAC was found among the entire study population or among women or men separately, with or without adjustment for the above-mentioned factors. The rs1800588 is associated with serum lipid and apolipoprotein concentrations, especially in women, but does not seem to be a determinant of brachial artery FMD, carotid IMT, or CAC in young healthy adults.

Migration at early age from a high to a lower coronary heart disease risk country lowers the risk of subclinical atherosclerosis in middle-aged men

BACKGROUND

Study of migrants offers a natural model to assess environmental risk of coronary heart disease (CHD) in countries differing in CHD occurrence. In Sweden, CHD risk has been markedly lower than in Finland from where a large migration occurred in the 1970s.

OBJECTIVES

To study the structural and functional markers of subclinical atherosclerosis in twin pairs discordant for migration with the main focus on age at migration, length of residence and integration into Swedish society after migration from a high to a lower CHD risk country.

METHODS

Carotid intima-media thickness (IMT) and brachial artery endothelial function (EF) were assessed with high-resolution ultrasound and a set of cardiovascular, socio-economic and psychosocial risk factors were estimated in 76 middle-aged male twin pairs discordant for migration from Finland to Sweden.

RESULTS

Men who had migrated in adolescence had lower IMT values compared with their co-twins living in Finland (0.665 +/- 0.114 vs. 0.802 +/- 0.167 mm, P = 0.009). Also men who integrated well to Swedish society had lower (0.720 +/- 0.154 vs. 0.799 +/- 0.207 mm, P = 0.013) IMT values than their twin brothers living in Finland. Associations between IMT and migration age and between IMT and integration remained significant in multivariate analyses of several CHD risk factors. The intrapair difference in IMT was significantly associated with immigration age and integration (ANOVA, P = 0.0082), the difference being greatest among pairs where the brother living in Sweden had migrated at early age and integrated well to Swedish society. EF was better in men who had migrated to Sweden before the age of 21 years, but not later, compared with their co-twins in Finland (6.4 +/- 4.6% vs. 3.8 +/- 3.6%, P = 0.025).

CONCLUSIONS

Migration at an early age and good integration are beneficial to vascular health associated with moving from a high to a lower CHD risk country, suggesting that an environment-sensitive period influences atherogenesis before adulthood.

Depressive symptoms and the metabolic syndrome in childhood and adulthood: a prospective cohort study

OBJECTIVE

To examine the reciprocal associations between depressive symptoms and clinical definitions of the metabolic syndrome in childhood and adulthood.

DESIGN

Population-based prospective cohort study of 921 participants (538 women and 383 men) in Finland. The components of the metabolic syndrome were measured in childhood (mean age 12 years) and again in adulthood (mean age 33 years). A revised version of the Beck Depression Inventory was used to assess depressive symptoms at the mean ages of 24 and 33.

MAIN OUTCOME MEASURES

Metabolic syndrome defined by the National Cholesterol Education Program Adult Treatment Panel III (NCEP), the European Group for the Study of Insulin Resistance, and the International Diabetes Federation criteria.

RESULTS

In women, depressive symptoms were associated with increased risk of the metabolic syndrome in adulthood (odds ratio for NCEP metabolic syndrome per 1 SD increase in depressive symptoms 1.40, 95% confidence interval 1.05-1.85). The metabolic syndrome in childhood, in turn, predicted higher levels of depressive symptoms in adulthood (p = .03). In men, no associations were found between depressive symptoms and the clinical definitions of the metabolic syndrome.

CONCLUSION

The process linking depressive symptoms with the metabolic syndrome may go into both directions and may begin early in life.

Alcohol consumption is directly associated with carotid intima-media thickness in Finnish young adults: the Cardiovascular Risk in Young Finns Study

OBJECTIVES

There is substantial epidemiological data suggesting a J- or U-shaped association between alcohol consumption and coronary events. However, some studies in experimental animals suggest that alcohol may increase atherosclerosis. Therefore, our aim was to study whether alcohol consumption is associated with carotid intima-media thickness (IMT), marker of subclinical atherosclerosis, in young, healthy adults.

METHODS

Alcohol consumption, carotid IMT and conventional cardiovascular risk factors were investigated in 2074 subjects, aged 24-39 years.

RESULTS

In subjects consuming none, >0 to <2, 2 to <4 or >or=4 units of alcohol per day, the respective carotid IMT values were 0.57+/-0.004, 0.59+/-0.003, 0.59+/-0.006, and 0.60+/-0.012 mm (mean+/-S.E.M., P<0.0001 for increasing IMT trend across alcohol consumption categories). This direct association between alcohol consumption and IMT was independent of age, sex and several cardiovascular risk factors, e.g. blood pressure, LDL-cholesterol, HDL-cholesterol, BMI, smoking, CRP and insulin (P=0.008 in multivariable regression model). The frequencies of drinking wine or strong alcohol beverages (respective P-values 0.03 and 0.01 for increasing IMT trend across beverage consuming frequency) were directly correlated with carotid IMT in models adjusted for age, sex and risk factors.

CONCLUSIONS

We found a direct relationship between alcohol consumption and carotid IMT in young adults. This association was independent of cardiovascular risk factors suggesting that in young healthy adults alcohol consumption may have pro-atherogenic effects.

Allelic variants of upstream transcription factor 1 associate with carotid artery intima-media thickness: the Cardiovascular Risk in Young Finns study

BACKGROUND

Polymorphisms of the upstream transcription factor 1 (USF1) have been associated with familial combined hyperlipidemia and coronary heart disease. The impact of this gene on subclinical atherosclerosis is unknown. Associations of 3 allelic variants of the USF1 gene and their haplotypes with carotid artery intima - media thickness (IMT), carotid artery compliance (CAC) and brachial artery flow mediated dilatation (FMD) were studied in a population of Finnish healthy young adults.

METHODS AND RESULTS

The study population comprised 2,281 individuals participating in the Cardiovascular Risk in Young Finns study. IMT, CAC and FMD values were measured by ultrasound examination. Genotypes were analysed using the 5' nuclease assay. A significant difference in IMT was found for usf1s1 (rs3737787) and usf1s8 (rs2516838) genotypes (p-values 0.046 and 0.021, respectively). Moreover, there was a significant difference between groups in haplotype 1 and haplotype 2 for IMT (p-values 0.011 and 0.028 respectively). In multivariate stepwise linear regression models adjusted by age, sex, body mass index, systolic and diastolic blood pressures, smoking, C-reactive protein, glucose, high- and low-density lipoprotein-cholesterols and triglycerides there were significant associations for the usf1s1 minor genotype AA to predict low IMT (p=0.038) and usf1s8 minor genotype GG to predict high IMT (p=0.003). There was also a significant association for haplotype 2 to predict low IMT in the otherwise similar multivariate model (p=0.006). No associations were found for polymorphisms and CAC, FMD or serum lipids.

CONCLUSIONS

The rs2516838 and rs3737787 polymorphisms of USF1 influence the carotid artery IMT, which is a new finding.

Arterial intima-media thickness in 13-year-old adolescents and previous antichlamydial antimicrobial use: a retrospective follow-up study

BACKGROUND

Children with persistent Chlamydia pneumoniae infection may be at increased risk for atherosclerosis. The impact of antimicrobial therapy for primary prevention of atherosclerotic cardiovascular disease is unsolved.

OBJECTIVE

The purpose of this study was to determine whether treatment with antimicrobial agents effective against C pneumoniae during childhood, regardless of indication, has a favorable influence on the arterial wall-thickness in children by the time they reach adolescence.

SUBJECTS AND METHODS

The association of macrolide, tetracycline, quinolone, and rifamycin use (number of exposure events) between ages 5 and 13 years with carotid and aortic intima-media thickness at age 13 years was investigated among 508 healthy children. Information about the use of medications was obtained from the Finnish prescription register. Arterial intima-media thickness was measured with a high-resolution ultrasound.

RESULTS

Mean aortic intima-media thickness showed a significant direct association with the number of antichlamydial antimicrobial exposure events also after controlling for established atherosclerotic risk factors. Elevated C-reactive protein level had an additional effect on aortic intima-media thickness in a multivariable model. Carotid intima-media thickness was not associated with the number of preceding antichlamydial treatments.

CONCLUSIONS

Recurrent antichlamydial treatments in childhood have no favorable influence on early vascular changes but are associated with increased intima-media thickness in the abdominal aorta. These findings suggest that the use of antimicrobial agents does not offer protection against the potential atherogenicity of repeated infectious insults.

Polymorphism in the IL6 promoter region is associated with the risk factors and markers of subclinical atherosclerosis in men: The Cardiovascular Risk in Young Finns Study

OBJECTIVE

Inflammatory factors modify the risk of coronary heart disease. Promoter region genetic polymorphism of inflammatory cytokine interleukin-6 (IL6 -174 G>C) is associated with the variation of IL-6 production. We investigated whether IL6 -174 G>C associates with the risk factors of atherosclerosis and carotid artery compliance (CAC) in young subjects.

METHODS AND RESULTS

As part of the Cardiovascular Risk in Young Finns Study, we performed carotid artery ultrasound examinations, IL6 -174 G>C genotyping and coronary heart disease risk factor determination for 2228 subjects aged 24-39 years. In men CAC was higher for IL6 -174 GG (2.10+/-0.65) than for GC (2.00+/-0.68) or CC (1.95+/-0.63, %/10mmHg, mean+/-S.D., p=0.0221). A similar association was observed for HDL cholesterol (GG 1.22+/-0.29, GC 1.15+/-0.27 and CC 1.14+/-0.28mmol/L, p=0.0015) and apolipoprotein A1 (apoA1) (GG 1.44+/-0.21, GC 1.40+/-0.20, CC 1.38+/-0.21mmol/L, p=0.0118). The opposite genotype effect was present in systolic (GG 127+/-13.1, GC 129+/-13.1, CC 130+/-14.3mmHg, p=0.0382) and diastolic blood pressure (GG 73.8+/-9.14, GC 75.1+/-8.68, CC 75.9+/-9.70mmHg, p=0.0374). The genetic effect size for these parameters was not significant in women.

CONCLUSIONS

IL6 -174 allele G homozygozity associates with beneficial profile of early predictors of atherosclerosis such as high CAC, HDL-C and apoA1 as well as low systolic and diastolic blood pressure in men.

Mortality in a cohort with high fish consumption

BACKGROUND

Our aim was to assess the mortality of fishermen and fishermen's wives in Finland, presuming that the mortality reflects their high consumption of contaminated fish.

METHODS

All Finnish fishermen, registered since 1980, were identified from the Professional Fishermen Register (N = 6410), and the fishermen's wives from the national population register (N = 4260). The cohorts were individually linked with cause-of-death data until 2005 at Statistics Finland. The follow-up started in the year after the first registration as a fisherman and at marriage (if later) for the wives. The standardized mortality ratios (SMRs) were calculated based on the national mortality rates. In addition, blood samples and food frequency questionnaire data were collected from a volunteer sample.

RESULTS

The average fish consumption and serum concentrations of fish-derived fatty acids and environmental contaminants were higher among the fishermen and their wives than among the general population from the same region. The fishermen and their wives had lower mortality from all causes (SMR 0.78, 95% confidence interval (CI) 0.73-0.82, and 0.84, 0.76-0.93, respectively), and ischaemic heart diseases (0.73, 0.65-0.81, and 0.65, 0.50-0.83) than the general population. Mortality from cerebrovascular diseases and malignant neoplasms was decreased among the fishermen (0.67, 0.52-0.85, and 0.90, 0.80-1.01), but not among the wives. In addition, the fishermen's mortality from water transport accidents was extremely high (8.31, 5.65-11.79).

CONCLUSIONS

The fishermen and their wives had lower mortality from many natural causes. The high intakes of environmental contaminants in fish were not seen as excess mortality.

Association of high sensitive C-reactive protein with apolipoprotein E polymorphism in children and young adults: the Cardiovascular Risk in Young Finns Study

BACKGROUND

A relation between apolipoprotein E (APOE) genotypes and high sensitive C-reactive protein (hsCRP) has been observed in some studies with elderly subjects and different patient groups. We studied whether serum hsCRP levels are linked with common APOE (epsilon 2, epsilon 3, epsilon 4) polymorphism already in children and young adults.

METHODS

The study cohort included 1221 subjects participating in the Cardiovascular Risk in Young Finns Study at age 3-18 years at baseline in 1980. These subjects were reexamined at the 21-year follow-up at age 24-39 years in 2001. APOE phenotypes were examined in 1986, serum hsCRP was measured from fresh samples in 2001 and baseline hsCRP (in 1980) was measured from frozen samples in 2005.

RESULTS

Serum hsCRP was significantly associated with APOE phenotypes in children and young adults using multivariate analysis adjusted for age, body mass index, smoking, total cholesterol and low-density lipoprotein cholesterol. Male epsilon 4 carriers had significantly lower hsCRP levels both in childhood (p=0.003) and in adulthood (p=0.013). hsCRP increased in both phenotype classes (epsilon 4+ and epsilon 4-) during the 21-year follow-up. Female epsilon 4 carriers had lower hsCRP levels in childhood (p=0.032) but not in adulthood (p=0.995). An interaction effect between time and APOE phenotype (p=0.045) in relation to hsCRP was observed in females during the 21-year follow-up.

CONCLUSIONS

Common APOE polymorphism affects the level of circulating hsCRP already in children and young adults. Male APOE epsilon 4 carriers have consistently lower hsCRP levels. In females, APOE epsilon 4 carriers had lower hsCRP levels in childhood but not in adulthood.

Exercise training with dietary counselling increases mitochondrial chaperone expression in middle-aged subjects with impaired glucose tolerance

BACKGROUND

Insulin resistance and diabetes are associated with increased oxidative stress and impairment of cellular defence systems. Our purpose was to investigate the interaction between glucose metabolism, antioxidative capacity and heat shock protein (HSP) defence in different skeletal muscle phenotypes among middle-aged obese subjects during a long-term exercise and dietary intervention. As a sub-study of the Finnish Diabetes Prevention Study (DPS), 22 persons with impaired glucose tolerance (IGT) taking part in the intervention volunteered to give samples from the vastus lateralis muscle. Subjects were divided into two sub-groups (IGTslow and IGTfast) on the basis of their baseline myosin heavy chain profile. Glucose metabolism, oxidative stress and HSP expressions were measured before and after the 2-year intervention.

RESULTS

Exercise training, combined with dietary counselling, increased the expression of mitochondrial chaperones HSP60 and glucose-regulated protein 75 (GRP75) in the vastus lateralis muscle in the IGTslow group and that of HSP60 in the IGTfast group. In cytoplasmic chaperones HSP72 or HSP90 no changes took place. In the IGTslow group, a significant positive correlation between the increased muscle content of HSP60 and the oxygen radical absorbing capacity values and, in the IGTfast group, between the improved VO2max value and the increased protein expression of GRP75 were found. Serum uric acid concentrations decreased in both sub-groups and serum protein carbonyl concentrations decreased in the IGTfast group.

CONCLUSION

The 2-year intervention up-regulated mitochondrial HSP expressions in middle-aged subjects with impaired glucose tolerance. These improvements, however, were not correlated directly with enhanced glucose tolerance.

Relation of apolipoprotein E polymorphism to markers of early atherosclerotic changes in young adults--the Cardiovascular Risk in Young Finns Study

BACKGROUND

Carotid artery intima-media thickness (IMT), which is measured by ultrasound, is used in the assessment of early atherosclerotic changes, and has been associated with apolipoprotein E (APOE) polymorphism in many studies comprising elderly subjects. However, results are still inconclusive and data relating to young adults are missing. Whether common APOE polymorphism is related to carotid IMT was studied in a population of young adults. Also brachial flow-mediated dilatation (FMD) and carotid artery compliance (CAC) were determined to clarify their relation to this genetic factor.

METHODS AND RESULTS

A total of 1,188 young adults (aged 24-39 years) participating in the Cardiovascular Risk in Young Finns Study with complete data of common APOE polymorphism underwent a carotid and brachial ultrasound. Patients' lipid levels and blood pressure were also examined. There was no significant association between the APOE phenotypes and carotid IMT, brachial FMD or CAC either in young men or in young women. The results were similar for systolic and diastolic blood pressure. In the same population, the well-known association between APOE phenotypes and lipids was seen.

CONCLUSIONS

Common APOE polymorphism does not seem to be an independent genetic determinant of carotid IMT, brachial FMD or CAC.

Associations of dyslipidemias from childhood to adulthood with carotid intima-media thickness, elasticity, and brachial flow-mediated dilatation in adulthood: the Cardiovascular Risk in Young Finns Study

BACKGROUND

Dyslipidemias are the major cause for atherosclerosis. They may act synergistically with nonlipid risk factors to increase atherogenesis. In the present study, we examined the effects of dyslipidemias from childhood to adulthood and their interaction with nonlipid risk factors on markers of subclinical atherosclerosis.

METHODS AND RESULTS

Study subjects were participants of the longitudinal Cardiovascular Risk in Young Finns Study started in 1980 (n=2265, age 3 to 18 years). To phenotype type IIa, IIb, and IV dyslipidemias and hypoHDL-cholesterolemia, we calculated age and sex-specific z scores for lipid values for each subject in 1980, 1983, 1986, and 2001. Subjects with mean z score over 90th percentile for LDL-cholesterol or triglycerides were considered having type IIa or IV dyslipidemia. Subjects with mean z score over 90th percentile for LDL-cholesterol and triglycerides had type IIb dyslipidemia, and those with mean z score below 10th percentile for HDL-cholesterol had hypoHDL-cholesterolemia. Compared to controls, subjects with type IIb dyslipidemia had increased carotid IMT (P<0.01). This difference remained significant when adjusted with other risk factors (P<0.05). Carotid IMT also increased significantly more with increasing number of nonlipid risk factors (P<0.001) or presence of the metabolic syndrome (P<0.05) in subjects with type IIb than in controls. Subjects with type IIb or type IV dyslipidemia had decreased carotid elasticity (P<0.05), but these differences became nonsignificant (P>0.3) when adjusted with blood pressure.

CONCLUSIONS

Our findings suggest that type IIb dyslipidemia has deleterious effects on vasculature already since childhood. Subjects with type IIb dyslipidemia are more vulnerable to the effects of cardiovascular risk factors and metabolic syndrome.

Favorable effects of berry consumption on platelet function, blood pressure, and HDL cholesterol

BACKGROUND

Berries are a particularly rich source of polyphenols. They also contain other bioactive substances, such as vitamin C. Previous studies indicated that the consumption of polyphenol-rich foods (eg, cocoa, tea, and red wine) may induce beneficial changes in pathways related to cardiovascular health. Whether the consumption of berries has similar effects is unknown.

OBJECTIVE

We aimed to investigate the effects of berry consumption on hemostatic function, serum lipids, and blood pressure (BP).

DESIGN

Middle-aged unmedicated subjects (n = 72) with cardiovascular risk factors consumed moderate amounts of berry or control products for 8 wk in a single-blind, randomized, placebo-controlled intervention trial.

RESULTS

Berry consumption inhibited platelet function as measured with a platelet function analyzer (using collagen and ADP as platelet activator) [changes: 11% and -1.4% in the berry and control groups, respectively; P = 0.018, analysis of covariance (ANCOVA)]. Plasma biomarkers of platelet activation, coagulation, and fibrinolysis did not change during the intervention. Serum HDL-cholesterol concentrations increased significantly more (P = 0.006, ANCOVA) in the berry than in the control group (5.2% and 0.6%, respectively), but total cholesterol and triacylglycerol remained unchanged. Systolic BP decreased significantly (P = 0.050, ANCOVA); the decrease mostly occurred in subjects with high baseline BP (7.3 mm Hg in highest tertile; P = 0.024, ANCOVA). Polyphenol and vitamin C concentrations in plasma increased, whereas other nutritional biomarkers (ie, folate, tocopherols, sodium, and potassium) were unaffected.

CONCLUSION

The consumption of moderate amounts of berries resulted in favorable changes in platelet function, HDL cholesterol, and BP. The results indicate that regular consumption of berries may play a role in the prevention of cardiovascular disease.

The influence of smoking and homocysteine on subclinical atherosclerosis is modified by the connexin37 C1019T polymorphism - The Cardiovascular Risk in Young Finns Study

BACKGROUND

A polymorphism C1019T on the connexin37 (Cx37) gene has been found to associate with coronary artery disease. There are conflicting results on which allele confers risk, and the possibility of interactions between the polymorphism and risk factors has been raised. In this study, we examined interactions between the Cx37 polymorphism and common risk factors and their associations to early vascular parameters of atherosclerosis: carotid artery intima-media thickness (IMT), and carotid artery compliance (CAC) and brachial artery flow mediated dilatation (FMD).

METHODS

A population of 1440 healthy young adults from the Cardiovascular Risk in Young Finns Study was studied. The subjects were genotyped and their cardiovascular risk factor and ultrasound data gathered in 2001 were used for the statistical analyses.

RESULTS

In the whole population, homocysteine in subjects with the TT genotype was found to be associated with higher FMD values (p for interaction 0.038) and remained so in three different adjusted models (p for interaction 0.022-0.038). In women with the CC genotype, smoking was found to be associated with higher FMD values and the smoking-by-genotype interaction remained significant in three adjusted models (p for interaction 0.001-0.041). In women with TT genotype, the effect of smoking was opposite, i.e., FMD values for smokers were lower compared to non-smokers. In men, physical activity interacted with Cx37 on CAC in the CT and TT genotypes (p for interaction 0.011). No significant interactions were found to predict IMT.

CONCLUSIONS

The effect of smoking and homocysteine levels on arterial endothelial functions and elasticity were modified by the allelic variation of the Cx37 gene. These data suggest that variation in the connexin gene may modify effects risk factors have on vascular function.

When do social inequalities in C-reactive protein start? A life course perspective from conception to adulthood in the Cardiovascular Risk in Young Finns Study

BACKGROUND

It is unclear when in the life course do social inequalities in inflammation emerge. We examined whether the association between socioeconomic position (SEP) and C-reactive protein (CRP) is determined at conception, in childhood, adolescence or adulthood in 1484 participants from the population-based Cardiovascular Risk in Young Finns Study.

METHODS

Five variants of the CRP gene were used to investigate whether SEP differences in CRP levels are determined at conception. SEP and serum CRP were assessed in childhood (age 3-9), adolescence (age 12-18) and in adulthood (age 24-39). SEP was measured using parental education and occupational status in childhood and adolescence, and participants' own education and occupational status in adulthood. Participants with CRP > 10 mg/l were excluded.

RESULTS

All CRP gene variants were associated with circulating CRP concentrations in childhood, but there were no differences in the distribution of these variants by SEP. No strong evidence was found of associations between parental SEP and CRP. A graded association between higher SEP and lower CRP was observed in adulthood for education (P = 0.0005) but not for occupational status. Trajectories that led to high educational achievement both in the participants and their parents were associated with lower (P <or= 0.047) CRP levels in adulthood. Excluding participants with infectious diseases, pregnant or lactating women and women using oral contraceptives did not change the findings.

CONCLUSION

In this cohort, SEP differences in CRP concentrations seen in adulthood appear not to be determined at conception or evident in childhood or adolescence.

Relationship between leptin and C-reactive protein in young Finnish adults

CONTEXT

Leptin and C-reactive protein (CRP) concentrations are increased in inflammation, and both have been linked to increased risk for cardiovascular diseases.

OBJECTIVE

The objective of the study was to explore in a population-based sample whether the relation between leptin and CRP is independent of obesity level and whether genetic causes of CRP elevation contribute to leptin levels.

DESIGN

This was a population-based study including 1862 young adults (971 women; 891 men) aged 24-39 yr.

SETTING

The study was conducted at five centers in Finland.

MAIN OUTCOME MEASURES

Associations between leptin and CRP adjusted for obesity indices, risk factors, genetic variables, and lifestyle variables were measured.

RESULTS

Women had 3.0-fold higher median concentrations of leptin (12.5 vs. 4.1 ng/ml) and 1.3-fold higher median concentrations of CRP (0.75 vs. 0.56 mg/liter) than men (P < 0.0001 in both comparisons). In univariate analyses, CRP and leptin were significantly intercorrelated (r = 0.47, P < 0.0001 for women; r = 0.46, P < 0.0001 for men). In multiple regression analysis including age, body mass index, waist circumference, insulin, lipids, systolic and diastolic blood pressures, smoking status, and use of oral contraceptives in women, leptin was the main determinant of CRP in men (P < 0.0001) and the second most important determinant in women (P < 0.0001). A Mendelian randomization test based on genetic variants in the CRP gene (five single nucleotide polymorphisms) provided no support for CRP as a causal agent for leptin.

CONCLUSIONS

Leptin, obesity, and oral contraceptive use in women were the main factors related to CRP. The relation between leptin and CRP was independent of obesity and cardiovascular risk factors.

Associations between connexin37 gene polymorphism and markers of subclinical atherosclerosis: the Cardiovascular Risk in Young Finns study

OBJECTIVE

Connexin37 (cx37) C1019T polymorphism has been shown to associate with coronary artery disease in different populations. We investigated whether this polymorphism associates with carotid artery intima-media thickness (IMT), carotid artery compliance (CAC) and brachial artery flow mediated dilatation (FMD) - i.e., early ultrasound markers of subclinical atherosclerosis - in a clinically healthy population of young Finnish adults.

METHODS AND RESULTS

1440 individuals from the Cardiovascular Risk in Young Finns study were genotyped and studied using cardiovascular risk factor and ultrasound data obtained in 2001. In linear regression models, no significant association between the cx37 polymorphism and carotid IMT, CAC or brachial artery FMD (ANOVA, p=0.159, 0.151 and 0.547), respectively, was found in the whole population or in women and men separately.

CONCLUSIONS

The connexin37 C1019T polymorphism is not related with markers of subclinical atherosclerosis in young adults.

Associations of methylenetetrahydrofolate reductase C677T polymorphism with markers of subclinical atherosclerosis: the Cardiovascular Risk in Young Finns Study

OBJECTIVE

To study whether the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism or serum homocysteine concentration is associated with carotid artery intima media thickness (IMT), carotid artery compliance (CAC) or brachial artery flow mediated dilatation (FMD) in a healthy Finnish adult population.

METHODS

Cross-sectional data obtained in 2001 for the Cardiovascular Risk in Young Finns Study were used. Carotid artery IMT, CAC and brachial FMD were measured by ultrasound and serum homocysteine concentrations using a commercial immunoassay kit. We studied 1,440 subjects (aged 24-39 years). Genotyping was performed using the 5' nuclease TaqMan assay.

RESULTS

Homocysteine values differed between genotypes in women and men (ANOVA, p<0.001 for both sex groups): the genotype raised values in the order of CC, CT, TT. There was a significant difference in CAC values between the MTHFR genotypes in men (ANOVA, p = 0.008), and the CC genotype had the lowest values. In multivariate linear regression analysis adjusted for other major coronary risk factors (e.g. age, smoking, body mass index, systolic blood pressure, C-reactive protein), the association remained significant (R (2) = 25.8 %, beta = 0.091; p = 0.02). Homocysteine level was directly associated with CAC in the whole population (R (2) = 18.0 %, beta = 0.012; p = 0.014) and in women (R (2) = 9.3%, beta = 0.02; p = 0.013), but not in men (R (2) = 15.2 %, beta = 0.004; p = 0.444). We found no association between homocysteine level or the MTHFR polymorphism and carotid IMT or brachial artery FMD.

CONCLUSIONS

The findings suggest that the MTHFR polymorphism does not influence IMT or FMD, but that the T allele may have an effect on CAC in men.

Toll-like receptor 4 gene (Asp299Gly) polymorphism associates with carotid artery elasticity. The cardiovascular risk in young Finns study

OBJECTIVE

Early subclinical markers of atherosclerosis, such as carotid artery intima media thickness (IMT) and elasticity predict future coronary events. The G allele of the Toll-like receptor 4 (TLR-4) gene Asp299Gly polymorphism has been previously associated with decreased development of atherosclerosis and with lower risk of myocardial infractions. We wanted to examine the association of this polymorphism with carotid IMT and compliance in a population of young Finnish Caucasian adults.

METHODS

Carotid artery IMT and elasticity indices of 2201 study subjects who participated in a randomized multicenter study (cardiovascular risk in young Finns study) were measured with ultrasound. The genotyping was performed using the TaqMan 5'-nuclease assay.

RESULTS

According to multivariate linear regression analysis adjusted with potential confounders, the G allele carriers had significantly higher carotid arterial compliance, measured in increase of luminal diameter percentage in response to blood pressure rise of 10 mmHg, than did the AA homozygotes (beta=0.099 with 95% CI 0.029-0.169 and p=0.006). The difference between AA homozygotes and GG homozygotes was even more pronounced (beta=0.382 with 95% CI 0.119-0.644 and p=0.004). Variation in the TLR-4 genotype was not related with IMT. The results of the two independent study cohorts of Eastern and Western Finland were in accordance with the results of the whole combined study population.

CONCLUSION

The G allele of the TLR-4 gene Asp299Gly polymorphism is associated with increased carotid artery compliance in young adults. This beneficial effect of the G allele may reduce the risk of future cardiovascular events.

Influence of apolipoprotein E polymorphism on serum lipid and lipoprotein changes: a 21-year follow-up study from childhood to adulthood. The Cardiovascular Risk in Young Finns Study

BACKGROUND

We examined the influence of apolipoprotein E (apoE) polymorphism on longitudinal changes in serum lipids by following the subjects participating in The Cardiovascular Risk in Young Finns Study over a 21-year period.

METHODS

Serum lipids were determined in randomly selected Finnish children and adolescents in 1980 and the subjects were re-examined in 1983, 1986 and after 21 years in 2001. ApoE polymorphism was determined in 1736 participants, and serum lipid values and apoE phenotypes were available for 1233 subjects.

RESULTS

ApoE phenotype-related differences in serum total and low-density lipoprotein (LDL)-cholesterol were maintained throughout the 21-year follow-up from childhood to adulthood, i.e., the apoE epsilon2 allele was consistently associated with lower and the epsilon4 allele with higher total and LDL-cholesterol (p<0.001 for all). In adulthood, there was also a significant apoE phenotype-related difference in high-density lipoprotein (HDL)-cholesterol (p=0.007), and the epsilon2 allele was associated with higher and the epsilon4 allele with lower apoA-I and HDL-cholesterol. In addition, apoB increased in the phenotype order E3/2<E3/3<E4 (E4/3+E4/4) (p<0.001). The LDL-lowering effect of the epsilon2 allele was greater in adulthood than in childhood, i.e., there was a significant apoE phenotypextime interaction (p=0.039) with longitudinal change in LDL-cholesterol.

CONCLUSIONS

ApoE polymorphism is associated with lipid levels at different ages and affects the longitudinal change in LDL-cholesterol from childhood to adulthood.

Brachial artery flow-mediated dilation and asymmetrical dimethylarginine in the cardiovascular risk in young Finns study

BACKGROUND

Elevated asymmetrical dimethylarginine (ADMA) is a novel risk factor for atherosclerosis that may impair endothelial function by interfering with endothelial nitric oxide synthesis. To gain insight into the effects of ADMA on systemic endothelial function, we examined the association between ADMA and brachial artery flow-mediated dilation (FMD) in a large population of young adults.

METHODS AND RESULTS

Plasma ADMA and brachial FMD, as well as conventional cardiovascular risk factors, were measured in 2096 white adults aged 24 to 39 years. In univariate analysis, ADMA was inversely correlated with FMD (r=-0.07, P=0.003). The inverse association between ADMA and FMD remained significant in a multivariable regression model adjusted for age, sex, conventional cardiovascular risk factors, estimated glomerular filtration rate, and brachial artery baseline diameter (beta+/-SE -1.56+/-0.62%, P=0.01).

CONCLUSIONS

We conclude that elevated plasma ADMA concentrations are associated with decreased brachial FMD responses in healthy adults. These data provide evidence at the population level that ADMA levels are associated with endothelial function.

Impact of repeated dietary counseling between infancy and 14 years of age on dietary intakes and serum lipids and lipoproteins: the STRIP study

BACKGROUND

Atherosclerosis development might be delayed or prevented by dietary measures. The aims of the present study were to evaluate the effect of low-saturated-fat, low-cholesterol dietary counseling on fat intakes, growth, serum cholesterol values, and pubertal development in children and adolescents.

METHODS AND RESULTS

In the randomized prospective Special Turku Coronary Risk Factor Intervention Project (STRIP), a low-saturated-fat, low-cholesterol diet was introduced to intervention infants (n=540) at 7 months of age, and control children (n=522) received an unrestricted diet. Dietary intakes, serum cholesterol values, somatic growth, and development were followed up throughout childhood and adolescence. Saturated fat intakes, serum total cholesterol, and low-density lipoprotein cholesterol values were lower (P<0.001) in the intervention than in control children during the 14 years, whereas high-density lipoprotein cholesterol values in the 2 study groups showed no difference. Boys had lower total and low-density lipoprotein cholesterol concentrations than girls throughout childhood (P<0.001), and the intervention effect on serum cholesterol concentration was larger in boys than girls. The 2 study groups showed no difference in growth, body mass index, pubertal development, or age at menarche (median, 13.0 and 12.8 years in the intervention and control girls, respectively; P=0.52). The cholesterol values decreased as puberty progressed. Mean concentrations of total and high-density lipoprotein cholesterol decreased from approximately 4.5 and approximately 1.4 mmol/L, respectively, in Tanner stage 1 (prepubertal) boys to approximately 3.9 and approximately 1.1 mmol/L in Tanner stage 4 (late pubertal) boys.

CONCLUSIONS

Repeated dietary counseling remains effective in decreasing saturated fat and cholesterol intake and serum cholesterol values at least until 14 years of age. Puberty markedly influences serum cholesterol concentrations.

CYBA C242T gene polymorphism and flow-mediated vasodilation in a population of young adults: the Cardiovascular Risk in Young Finns Study

OBJECTIVE

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase is a major source of the superoxide anion that contributes to decreased nitric oxide bioavailability in the vasculature. The C242T polymorphism of the CYBA gene that encodes p22phox, a component of NADPH oxidase, has been found to modulate superoxide production. We examined the relationship of the C242T polymorphism with endothelial-dependent brachial artery flow-mediated vasodilatation (FMD) in a population-based sample of young healthy adults.

METHODS

FMD, defined as the increased percentage in brachial artery diameter after reactive hyperemia, was assessed by ultrasound and the C242T polymorphism using a 5' nuclease assay in 2058 subjects aged 24-39 years.

RESULTS

The mean values of brachial artery FMD were 8.0 +/- 4.4% in all study subjects (n = 2058), and 7.8 +/- 4.4, 8.2 +/- 4.5, and 8.7 +/- 4.5% in subjects with the CC (n = 1362), CT (n = 616), and TT (n = 80) genotypes of the C242T CYBA polymorphism, respectively (P = 0.02 for trend). The association remained significant (P = 0.019) in multivariate analyses adjusted for age, sex, obesity indices, smoking habits, blood pressure, serum glucose, lipids, and C-reactive protein. The relationship between FMD and the C242T polymorphism was stronger (P = 0.004) in overweight subjects (body mass index > or = 25 kg/m, n = 895) and ever-smokers (P = 0.008, n = 1082), whereas no relationship was found in normal-weight subjects and non-smokers (P = 0.824 and P = 0.438, respectively).

CONCLUSION

The C242T polymorphism of the CYBA gene seems to be related to endothelial function in a population-based sample of young healthy adults. Overweight and smoking status may modify this genetic effect.