Improvement in lipid profile after vitamin D supplementation in indigenous argentine school children.

OBJECTIVE: To determine whether vitamin D supplementation of indigenous school children living at high altitude who are vitamin D insufficient improves lipid profile. METHODS: A prospective two-year study evaluated 60 children (29 males) from Hogar School who received 100,000 units of vitamin D and 36 children (16 males) from Sosa School who received 50,000 units. Anthropometric measures, Triglycerides (TG), HDL-C, TG/HDL-C, and vitamin D levels were measured in November 2011 and in November 2013. RESULTS: Children aged 8.8 ± 2 years with mean z-BMI (-0.43) were evaluated. After vitamin D supplementation, mean vitamin D levels increased from 14.7 to 32.1 ng/mL (p < 0.01) in Hogar and from 14.6 to 25.1 ng/mL (p < 0.01) in Sosa School. Furthermore, mean HDL-C increased significantly in Hogar (39.8 to 43.9 mg/dL); while no significant changes were found in Sosa School (44.4 to 45.1 mg/dL). Though no significant changes were found in median TG (117 to 111 mg/dL) and TG/HDL (3.0 to 2.7 mg/dL) in Hogar; TG (95 to 111 mg/dL) and TG/HDL-C (2.2 to 2.4 mg/dL) increased significantly in Sosa School. Several multiple linear regression analyses showed that children from Hogar School decreased TG/HDL-C by 1.3 mg/dL (R(2): 0.14), HDL-c by 3.6 mg/dL (R(2): 0.13), and TG by 31 mg/dL (R(2): 0.11), adjusted for confounding factors. CONCLUSIONS: Indigenous children who received 100,000 U of vitamin D significantly improved vitamin D and lipid levels compared to children who received 50,000 U, suggesting that optimal vitamin D levels are associated with a healthier lipid profile.

Association between vitamin D and Apo B concentrations in Argentinean Indian children.

OBJECTIVE: The objective of the study was to determine the prevalence of vitamin D insufficiency and its association with non-traditional cardiovascular disease (CVD) risk factors such as Apo B in South American Indian school children. METHODS: A cross-sectional study of 355 children (166 Males) aged 9.6±2.3 y was performed. Anthropometric measures, glucose, lipids, insulin, Apo B, Apo A, and vitamin D concentrations were measured. RESULTS: The prevalence of overweight and obesity was 10.7% (38) per CDC. One child (0.3%) had optimal vitamin D concentrations [25(OH)D[>30 ng/ml. Univariate analysis showed significant associations between vitamin D and HDL-C (r=0.12 p<0.05), age (r=-0.11 p<0.05) BMI (r=-0.22 p<0.05), LDL-C (r=-0.22 p<0.01), triglycerides (r=-0.16 p<0.01), non HDL-C (r=-0.21 p<0.01), Apo B (r=-0.23 p<0.01), Apo B/Apo A (r=-0.21 p<0.01), insulin (r=-0.17 p<0.05), and HOMA-IR (r=-0.16 p<0.05). Multiple linear regression analysis showed that female gender and Apo B were significantly associated with vitamin D adjusted for confounding factors (R(2) 0.12). CONCLUSION: Vitamin D deficiency was associated with increased Apo B among Indian children, suggesting that it could be used as a risk marker of CVD.

N-6-adenine-specific DNA methyltransferase 1 (N6AMT1) polymorphisms and arsenic methylation in Andean women.

BACKGROUND: In humans, inorganic arsenic is metabolized to methylated metabolites mainly by arsenic (+3 oxidation state) methyltransferase (AS3MT). AS3MT polymorphisms are associated with arsenic metabolism efficiency. Recently, a putative N-6-adenine-specific DNA methyltransferase 1 (N6AMT1) was found to methylate arsenic in vitro. OBJECTIVE: We evaluated the role of N6AMT1 polymorphisms in arsenic methylation efficiency in humans. METHODS: We assessed arsenic methylation efficiency in 188 women exposed to arsenic via drinking water (~ 200 µg/L) in the Argentinean Andes by measuring the relative concentrations of arsenic metabolites in urine [inorganic arsenic, methylarsonic acid (MMA), and dimethylarsinic acid] by high-performance liquid chromatography coupled with hydride generation and inductively coupled plasma mass spectrometry. We performed genotyping for N6AMT1 and AS3MT polymorphisms by Taqman assays, and gene expression (in blood; n = 63) with Illumina HumanHT-12 v4.0. RESULTS: Five N6AMT1 single nucleotide polymorphisms (SNPs; rs1997605, rs2205449, rs2705671, rs16983411, and rs1048546) and two N6AMT1 haplotypes were significantly associated with the percentage of MMA (%MMA) in urine, even after adjusting for AS3MT haplotype. %MMA increased monotonically according to the number of alleles for each SNP (e.g., for rs1048546, mean %MMA was 7.5% for GG, 8.8% for GT, and 9.7% for TT carriers). Three SNPs were in linkage disequilibrium (R2 > 0.8). Estimated associations for joint effects of N6AMT1 (haplotype 1) and AS3MT (haplotype 2) were generally consistent with expectations for additive effects of each haplotype on %MMA. Carriers of N6AMT1 genotypes associated with lower %MMA showed the lowest N6AMT1 expression, but associations were monotonic according to copy number for only one genotype and one haplotype. CONCLUSIONS: N6AMT1 polymorphisms were associated with arsenic methylation in Andean women, independent of AS3MT. N6AMT1 polymorphisms may be susceptibility markers for arsenic-related toxic effects.