Association of Thyroid-Stimulating Hormone with Resting Energy Expenditure in Euthyroid Elderly Subjects: A Cross-Sectional Study.

BACKGROUND: Several studies have reported positive correlations between thyroid-stimulating hormone (TSH) and body mass index (BMI) in euthyroid subjects. As impaired thyroid function is known to affect the metabolic rate, this study investigated whether TSH is associated with resting energy expenditure (REE) in euthyroid elderly subjects, independent of age, anthropometric data and body composition. METHODS: Cross-sectional data of 77 women (66-96 years, BMI 18-36 kg/m²) and 55 men (66-86 years, BMI 20-39 kg/m²) were analyzed. REE was measured using indirect calorimetry, body composition by bioelectrical impedance analysis and serum TSH using an electrochemiluminescence immunoassay. RESULTS: REE, fat-free mass (FFM) and waist circumference (WC) were significantly lower, whereas TSH and fat mass (FM) were significantly higher in women than in men. In multiple stepwise regression analysis, with age-adjusted REE (REE(adj)) as the dependent variable and FFM, FM and WC as independent variables, FFM and WC explained 40.7% in women and FFM 32.8% in men of the variability in REE(adj). Including TSH in the model led to a significant rise of the adjusted R-squared value in women only, and explained an additional 2.8% of the variability in REE(adj). CONCLUSIONS: TSH is independently and negatively associated with REE in euthyroid elderly women.

Dietary intake and main food sources of vitamin D as a function of age, sex, vitamin D status, body composition, and income in an elderly German cohort.

BACKGROUND: Elderly subjects are at risk of insufficient vitamin D status mainly because of diminished capacity for cutaneous vitamin D synthesis. In cases of insufficient endogenous production, vitamin D status depends on vitamin D intake. OBJECTIVE: The purpose of this study is to identify the main food sources of vitamin D in elderly subjects and to analyse whether contributing food sources differ by sex, age, vitamin D status, body mass index (BMI), or household income. In addition, we analysed the factors that influence dietary vitamin D intake in the elderly. DESIGN AND SUBJECTS: This is a cross-sectional study in 235 independently living German elderly aged 66-96 years (BMI=27±4 kg/m(2)). Vitamin D intake was assessed by a 3-day estimated dietary record. RESULTS: The main sources of dietary vitamin D were fish/fish products followed by eggs, fats/oils, bread/bakery products, and milk/dairy products. Differences in contributing food groups by sex, age, vitamin D status, and BMI were not found. Fish contributed more to vitamin D intake in subjects with a household income of <1,500 €/month compared to subjects with higher income. In multiple regression analysis, fat intake and frequency of fish consumption were positive determinants of dietary vitamin D intake, whereas household income and percentage total body fat negatively affected vitamin D intake. Other parameters, including age, sex, physical activity, smoking, intake of energy, milk, eggs and alcohol, showed no significant association with vitamin D intake. CONCLUSION: Low habitual dietary vitamin D intake does not affect vitamin D status in summer, and fish is the major contributor to vitamin D intake independent of sex, age, vitamin D status, BMI, and the income of subjects.

Dietary lipid intake only partially influences variance in serum phospholipid fatty acid composition in adolescents: impact of other dietary factors.

The present study aimed to assess the correlation between food and fatty acid (FA) intake and the serum phospholipid (PL) FA status in European adolescents and explored the percentage of variation in serum PL FA that could be attributed to dietary habits. Participants included 528 adolescents recruited in the HELENA Study. Dietary intake was assessed by two, self-administered, non-consecutive 24-h recalls. PL FA concentrations were measured in fasting venous serum samples. Reduced rank regressions were applied to examine the combined effect of food intakes. Results indicated that the variance in serum PL FA in adolescents, that could be explained by diet varied from 7.0% for MUFA to 14.2% for n-3FA. The variance in the long-chain n-3FA was mainly explained by fish intake but also by coffee and tea consumption. In conclusion this study indicated that dietary intake influences the serum PL FA status to a limited amount but that also other factors interfere. However, dietary intake is important as it is among those factors that could be modified. Furthermore, the results suggest that the overall dietary habits should be considered instead of only the consumption of single foods or nutrients, as the medium of the food or concomitant intake of foods and nutrients might interact and as such influence absorption or metabolism.

Gender and age influence blood folate, vitamin B12, vitamin B6, and homocysteine levels in European adolescents: the Helena Study.

It is important to be able to evaluate vitamin status correctly at any age, but this is especially vital during adolescence since there are higher requirements for healthy growth and development. However, there are no currently available B-vitamin reference values for healthy adolescents. The aim of the present study is to assess the vitamin B status in European adolescents in order to contribute to the development of reference values for selected B-vitamins and total homocysteine (tHcy). Within the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) cross-sectional study, a sub sample of 1051 (499 males, 552 females) adolescents from ten European cities aged 12.5 to 17.49 were analyzed for fasting plasma folate (PF), red blood cell (RBC) folate, serum cobalamin (Cbl), holo-transcobalamin (Holo-TC), Vitamin B(6) (PLP), and tHcy. The level of significance was set at P < .05. Following the current cut-off for adults, 2% had low Cbl and 5% had low holo-TC concentrations. Low concentrations of both PF and RBC folate were identified in 10%. Five percent had PLP concentrations <20 nmol/L and 20% <30 nmol/L. Moreover, 5% had high tHcy; median values for the whole sample were: PF 16.0 nmol/L, RBC folate 721.9 nmol/L, Cbl 319 pmol/L, Holo-TC 57.8 pmol/L, and tHcy 6.7 µmol/L. Females had significantly higher median Cbl but lower PLP and tHcy concentrations (P < .01). THcy increased (P < .001) and PF (P < .001) concentrations decreased across age categories. Subjects showed significantly higher tHcy values at the fifth percentile of PF, corresponding with 7.5 nmol/L. Sex and age had an influence on most of the studied biomarkers and should be taken into account. The HELENA percentile distribution is consistent with data from smaller studies and could be used as reference value to characterize B-vitamin status of European adolescents.

FADS1 genetic variability interacts with dietary α-linolenic acid intake to affect serum non-HDL-cholesterol concentrations in European adolescents.

Two rate-limiting enzymes in PUFA biosynthesis, Δ5- and Δ6-desaturases, are encoded by the FADS1 and FADS2 genes, respectively. Genetic variants in the FADS1-FADS2 gene cluster are associated with changes in plasma concentrations of PUFA, HDL- and LDL-cholesterol, and TG. However, little is known about whether dietary PUFA intake modulates these associations, especially in adolescents. We assessed whether dietary linoleic acid (LA) or α-linolenic acid (ALA) modulate the association between the FADS1 rs174546 polymorphism and concentrations of PUFA, other lipids, and lipoproteins in adolescents. Dietary intakes of LA and ALA, FADS1 rs174546 genotypes, PUFA levels in serum phospholipids, and serum concentrations of TG, cholesterol, and lipoproteins were determined in 573 European adolescents from the HELENA study. The sample was stratified according to the median dietary LA (≤9.4 and >9.4 g/d) and ALA (≤1.4 and >1.4 g/d) intakes. The associations between FADS1 rs174546 and concentrations of PUFA, TG, cholesterol, and lipoproteins were not affected by dietary LA intake (all P-interaction > 0.05). Similarly, the association between the FADS1 rs174546 polymorphism and serum phospholipid concentrations of ALA or EPA was not modified by dietary ALA intake (all P-interaction > 0.05). In contrast, the rs174546 minor allele was associated with lower total cholesterol concentrations (P = 0.01 under the dominant model) and non-HDL-cholesterol concentrations (P = 0.02 under the dominant model) in the high-ALA-intake group but not in the low-ALA-intake group (P-interaction = 0.01). These results suggest that dietary ALA intake modulates the association between FADS1 rs174546 and serum total and non-HDL-cholesterol concentrations at a young age.

Associations of birth weight with serum long chain polyunsaturated fatty acids in adolescents; the HELENA study.

OBJECTIVES: Nutritional factors in early life may have long-term physiologic effects in humans. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) play important roles in protecting against cardiovascular disease (CVD) risk. Our aim was to examine the association of birth weight (BW) with serum long chain polyunsaturated fatty acids (LCPUFA) profile in adolescents. SUBJECTS AND METHODS: A total of 772 European adolescents (56.3% females) aged 14.7 ± 1.2 years were included in this study. Information on BW and gestational age was obtained from parental records. DHA, EPA and arachidonic acid (AA) concentrations were measured in serum phospholipids. Alfa-linolenic (ALA), linoleic (LA), AA, EPA and DHA intakes assessed by a computer based 24h dietary recall. Gender, gestational age, pubertal status, body mass index, center and total energy and LCPUFA intakes were used as confounders in all the analyses. RESULTS: BW was significantly associated with serum DHA and EPA (both adjusted P<0.05) independently of potential confounders including their main dietetic source. We did not observe any significant relationship between BW and serum AA levels. CONCLUSIONS: Our findings suggest that early metabolic changes, as a result from prenatal environmental influences, could affect long chain polyunsaturated fatty acid metabolism later in life. These results may contribute to explain the relationship between early nutrition and growth and later metabolic disorders as CVD.

Polymorphisms in the CD36/FAT gene are associated with plasma vitamin E concentrations in humans.

BACKGROUND: Blood vitamin E concentrations are modulated by dietary, metabolic, and genetic factors. CD36 (cluster of differentiation 36), a class B scavenger receptor, might be involved in tissue vitamin E uptake and thus would influence blood vitamin E concentrations. OBJECTIVE: The goal of the study was to assess the association between CD36 single nucleotide polymorphisms (SNPs) and plasma α-tocopherol concentrations in humans. DESIGN: A subsample from the adult SU.VI.MAX (SUpplementation en VItamines et Minéraux AntioXydants) cohort (n = 621) and the adolescent cross-sectional HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study (n = 993) were genotyped for CD36 SNPs (4 and 10 SNPs, respectively). Fasting plasma α-tocopherol concentrations were assayed by using HPLC. Associations were determined by haplotype analyses and by general linear regression models. RESULTS: In the SU.VI.MAX subsample, haplotype analyses showed that some haplotypes of SNPs rs1984112, rs1527479, rs7755, and rs1527483 tended to be associated with plasma α-tocopherol concentrations (P = 0.08 and P = 0.09 for haplotypes 1222 and 1122, respectively). We then investigated the whole known common genetic variability (10 SNPs) of CD36 in the HELENA Study. Three SNPs were associated with lower plasma α-tocopherol concentrations (rs1984112: -3.2%, P = 0.053; rs1761667: -2.9%, P = 0.046; rs1527479: -3.7%, P = 0.0061). After correction for multiple testing, the association between rs1527479 and α-tocopherol concentrations remained significant. This association was modulated by concentrations of fasting serum triglycerides (P for interaction = 0.006) and long-chain polyunsaturated fatty acids (P for interaction = 0.005). CONCLUSION: Our results suggest that CD36 can modulate blood α-tocopherol concentrations and may therefore be involved in the intestinal absorption or tissue uptake of vitamin E.

Antioxidant vitamin status (A, E, C, and beta-carotene) in European adolescents - the HELENA Study.

BACKGROUND: An adequate nutritional status of antioxidant vitamins (vitamins A, C, E) and b-carotene is essential especially during childhood and adolescence, because of their important roles in cell growth and development. Currently, there are no physiological reference values for blood concentration of these vitamins and b-carotene in apparently healthy European adolescents. The aim of the current study was to obtain reliable and comparable data of antioxidant vitamins and b-carotene in a cross-sectional study, within HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence), which was conducted in a representative sample of adolescents from ten European cities. MATERIAL AND METHODS: From a subsample of 1,054 adolescents (males= 501) of the HELENA Cross Sectional Study with an age range of 12.5 to 17.49 years, fasting blood samples were taken and analyzed for vitamins A, E, C, and b-carotene status. As specific reference values for adolescents are missing, percentile distribution by age and sex is given. RESULTS: Mean concentrations were the following: Retinol: 356.4 ± 107.9 cm/mL; alpha-tocopherol: 9.9 ± 2.1 microg/mL; vitamin C: 10.3 ± 3.3 mg/L; and b-carotene: 245.6 ± 169.6 cm/mL. Females showed higher alpha-tocopherol and vitamin C values compared with males and 17-year-old boys had higher retinol levels than the same-aged girls (p = 0.018). Retinol serum concentrations increased significantly according to age in both gender, but girls had also significantly increasing b-carotene levels by age. CONCLUSIONS: For the first time, concentrations of antioxidant vitamins and pro-vitamin beta-carotene have been obtained in a representative sample of apparently healthy European adolescents. These data can contribute to the establishment of reference ranges in adolescents.

Single nucleotide polymorphisms in the FADS gene cluster are associated with delta-5 and delta-6 desaturase activities estimated by serum fatty acid ratios.

Genetic variability in the FADS1-FADS2 gene cluster [encoding delta-5 (D5D) and delta-6 (D6D) desaturases] has been associated with plasma long-chain PUFA (LCPUFA) and lipid levels in adults. To better understand these relationships, we further characterized the association between FADS1-FADS2 genetic variability and D5D and D6D activities in adolescents. Thirteen single nucleotide polymorphisms (SNPs) were genotyped in 1,144 European adolescents (mean +/- SD age: 14.7 +/- 1.4 y). Serum phospholipid fatty acid levels were analyzed using gas chromatography. D5D and D6D activities were estimated from the C20:4n-6/C20:3n-6 and C20:3n-6/C18:2n-6 ratios, respectively. Minor alleles of nine SNPs were associated with higher 18:2n-6 levels (1.9E-18

Associations between common genetic polymorphisms in angiopoietin-like proteins 3 and 4 and lipid metabolism and adiposity in European adolescents and adults.

CONTEXT: Plasma-borne angiopoietin-like proteins (ANGPTL) act as endocrine factors on their target tissues. Because ANGPTL3 and ANGPTL4 play important roles in lipid metabolism and the regulation of adiposity in mice, we hypothesized that genetic variability at the ANGPTL3 and ANGPTL4 genes loci might influence lipid metabolism and fat deposition in humans. OBJECTIVE: The aim of the study was to examine the association between ANGPTL3 and ANGPTL4 genetic polymorphisms and metabolic phenotypes in adolescent and adult samples. DESIGN AND PARTICIPANTS: Two independent population-based studies, one composed of 1144 adolescents (mean age, 14.8 +/- 1.4 yr) from nine European countries (the HELENA study) and the other composed of 1155 adults (age range, 35-65 yr) from Northern France (the MONICA Lille study), were genotyped for one ANGPTL3 polymorphism and four ANGPTL4 polymorphisms. RESULTS: The ANGPTL3 rs11207997 polymorphism (minor allele frequency, 0.32) was associated with lower plasma HDL-cholesterol and apolipoprotein A-I levels in both adolescents (P = 0.0004, P = 0.00006, respectively) and adults (P = 0.03, P = 0.02, respectively). The ANGPTL4 rs4076317 polymorphism (minor allele frequency, 0.29) was associated with a higher percentage of body fat (P = 0.02) in adolescents and a higher waist-to-hip ratio (in interaction with the peroxisome proliferator-activated receptor gamma Pro12Ala polymorphism) in adults (P = 0.0004). CONCLUSION: The present study underlines the role of ANGPTL3 in HDL-cholesterol metabolism as early as in adolescence. Our data also suggest possible associations between ANGPTL4 polymorphisms and body fat, but these findings require replication.