The association between vitamin D receptor polymorphisms and tissue-specific insulin resistance in human obesity.

BACKGROUND/OBJECTIVES: To investigate (1) the association of four VDR polymorphisms (TaqI/rs731236, ApaI/rs7975232, FokI/rs10735810, and Bsml/rs1544410) with markers of adiposity and tissue-specific insulin resistance at baseline, after weight loss and weight maintenance; (2) the effect of the VDR polymorphisms in the SAT transcriptome in overweight/obese Caucasians of the DiOGenes cohort. METHODS: We included 553 adult obese individuals (mean BMI 34.8 kg/m2), men (n = 197) and women (n = 356) at baseline, following an 8-week weight loss intervention and 26 weeks weight maintenance. Genotyping was performed using an Illumina 660W-Quad SNP chip on the Illumina iScan Genotyping System. Tissue-specific IR was determined using Hepatic Insulin Resistance Index (HIRI), Muscle Insulin Sensitivity Index (MISI), and Adipose Tissue Insulin Resistance Index (Adipo-IR). Expression quantitative trait loci (eQTL) analysis was performed to determine the effect of SNPs on SAT gene expression. RESULTS: None of the VDR polymorphisms were associated with HIRI or MISI. Interestingly, carriers of the G allele of VDR FokI showed higher Adipo-IR (GG + GA 7.8 ± 0.4 vs. AA 5.6 ± 0.5, P = 0.010) and higher systemic FFA (GG + GA: 637.8 ± 13.4 vs. AA: 547.9 ± 24.7 µmol/L, P = 0.011), even after adjustment with age, sex, center, and FM. However, eQTL analysis showed minor to no effect of these genotypes on the transcriptional level in SAT. Also, VDR polymorphisms were not related to changes in body weight and IR as result of dietary intervention (P > 0.05 for all parameters). CONCLUSIONS: The VDR Fokl variant is associated with elevated circulating FFA and Adipo-IR at baseline. Nevertheless, minor to no effect of VDR SNPs on the transcriptional level in SAT, indicating that putative mechanisms of action remain to be determined. Finally, VDR SNPs did not affect dietary intervention outcome in the present cohort.

Knowledge, attitudes and practices of sweet food and beverage consumption and its association with dental caries among schoolchildren in Jazan, Saudi Arabia.

The prevalence of dental decay is expected to rise in many developing countries due to the growing consumption of sugars. This study aimed to assess knowledge, attitudes and practices of sweet food and beverage consumption among schoolchildren in Jazan, Saudi Arabia and to determine the relationship with dental caries. In a cross-sectional, descriptive study 853 children aged 6-15 years (520 boys and 333 girls) were assessed by questionnaire and clinical examinations. Caries prevalence (≥ 1 dft/DMFT) was high (91.3%). While knowledge was generally good, 83.5% boys and 85.8% girls had poor attitudes to sweet foods and > 90% frequently consumed sweet foods/beverages. Multiple regression analysis showed that children whose mothers were less educated (OR 2.46; 95% CI: 1.15-5.28) and children with poor dietary attitudes and practices (OR 4.05; 95% CI: 2.33-7.03 and OR 7.80; 95% CI: 4.50-13.52 respectively) were more likely to have dental caries. Well-directed health promotion programmes are needed in Jazan.