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.

Interactions between genetic variants and dietary lipid composition: effects on circulating LDL cholesterol in children.

BACKGROUND: Elevated serum low-density lipoprotein (LDL) cholesterol is a predictor of cardiovascular disease events, and the quality of dietary fat is known to influence serum concentrations of LDL cholesterol in children. Interindividual differences in response to diet exist, but the underlying genetic factors remain largely unknown. OBJECTIVE: We aimed to identify genetic variants that modify the variation in serum lipid response to dietary fat quality. DESIGN: We used data from 2 longitudinal Finnish cohorts designed to study risk factors for cardiovascular diseases. Large-scale genotyping was performed with Metabochip in a long-term randomized controlled dietary intervention trial, the Special Turku Coronary Risk Factor Intervention Project (STRIP), for discovery of genetic polymorphisms. The observational Cardiovascular Risk in Young Finns Study (YFS) with genome-wide genetic data was used as a replication sample for the initial findings. Dietary records were used to calculate the ratio of unsaturated to saturated fats. Interaction models and multiple follow-ups were used in the analysis. RESULTS: In the STRIP cohort, a variant within the PARK2 locus, rs9364628, showed moderate interaction with dietary fat quality and a consistent direction of effect in both scans on serum LDL-cholesterol concentration in children aged 5 and 7 y (P < 0.0084 and P < 0.0057, respectively). In the YFS cohort, we were unable to replicate the initial discovery signal, but rs12207186 within the PARK2 locus and dietary lipid quality had a stronger interaction effect on serum LDL-cholesterol concentration (P < 9.44 × 10(-5)) than did rs9364628 in children aged 6 y. CONCLUSION: This genotyping study involving 2 cohorts of healthy Finnish children indicates a possible interaction between PARK2 variants and dietary fat quality on serum LDL-cholesterol concentration. This trial was registered at clinicaltrials.gov as NCT00223600.

Fetal growth, omega-3 (n-3) fatty acids, and progression of subclinical atherosclerosis: preventing fetal origins of disease? The Cardiovascular Risk in Young Finns Study.

BACKGROUND: Impaired fetal growth is independently associated with an increased risk of cardiovascular events in adulthood. Prevention strategies that can be implemented during adulthood have not been identified. OBJECTIVE: The objective was to determine whether habitual omega-3 (n-3) fatty acid intake is associated with the rate of increase of carotid intima-media thickness during adulthood in individuals with impaired fetal growth. DESIGN: This was a population-based, prospective cohort study of 1573 adults in Finland. Carotid intima-media thickness was assessed in 2001 (at ages 24-39 y) and in 2007. Participants were categorized as having had impaired fetal growth (term birth with birth weight <10th percentile for sex or preterm birth with birth weight <25th percentile for gestational age and sex; n = 193) or normal fetal growth (all other participants; n = 1380). Omega-3 fatty acid intake was assessed by using a food-frequency questionnaire and on the basis of serum fatty acid concentrations. RESULTS: In multivariable models, the 6-y progression of carotid intima-media thickness was inversely associated with dietary omega-3 fatty acids in those with impaired fetal growth (P = 0.04). Similarly, serum omega-3 fatty acid concentrations were inversely associated with the 6-y progression of carotid intima-media thickness in those with impaired fetal growth (P = 0.04) but were not noted in those with normal fetal growth (P = 0.94 and P = 0.26, respectively). CONCLUSION: Dietary intake of omega-3 fatty acids is associated with a slower rate of increase in carotid intima-media thickness in those with impaired fetal growth.

Childhood serum cholesterol ester fatty acids are associated with blood pressure 27 y later in the Cardiovascular Risk in Young Finns Study.

BACKGROUND: In adults, dietary fatty acids (FAs) modify blood pressure (BP), but it is not known whether childhood FA quality is associated with adulthood BP. OBJECTIVE: The purpose of the study was to investigate links between childhood serum cholesterol ester fatty acid (CEFA) proportions and adulthood systolic blood pressure (SBP) and diastolic blood pressure (DBP). DESIGN: We examined a cohort of 803 boys and girls (aged 3-18 y at baseline in 1980 and followed for 27 y) by using regression models adjusted for the known risk factors of BP. CEFAs were analyzed as markers of dietary FA intake. RESULTS: In men, serum SFA (B = 2.97, P < 0.001 for SBP; B = 1.48, P = 0.015 for DBP), MUFA (B = 0.61, P = 0.001 for SBP; B = 0.27, P = 0.078 for DBP), and omega-3 (n-3) PUFA (B = 5.50, P < 0.001 for SBP; B = 2.47, P = 0.015 for DBP) proportions, which were derived mainly from animal fats in this population, were positively associated with BP, whereas the omega-6 (n-6) PUFA proportion, which was derived mainly from vegetable oils and margarines, was negatively associated with BP (B = -0.56, P < 0.001 for SBP; B = -0.27, P < 0.018 for DBP). Serum cholesterol ester SFA and PUFA associations were supported by dietary intake data. In women, the associations between CEFA proportions and BP were weaker [for SBP: B = 0.36, P = 0.638 (NS) for SFA; B = 0.44, P = 0.019 for MUFA; B = 1.18, P = 0.376 (NS) for n-3 PUFA; and B = -0.33, P = 0.023 for n-6 PUFA]. CONCLUSION: Our findings suggest that fat quality as reflected in the serum cholesterol ester fraction in childhood is independently associated with adulthood BP particularly in men but also, to some extent, in women.