👤 K Ohnaka

Chronic kidney disease (CKD) is known to be one of the causes of cardiovascular disease and end-stage renal disease. Among the several treatable risk factors of CKD, that of dyslipidemia is relatively controversial. To clarify the association of polymorphisms in genes involved in lipid metabolism with the risk of CKD in the Japanese population, we used cross-sectional data from the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study. A total of 3,268 men and women, aged 35-69 years, were selected from J-MICC Study participants for inclusion in this study. Twenty-eight candidate single nucleotide polymorphisms (SNPs) were selected in 17 genes associated with the risk of lipid metabolism disorders, and genotyping of the subjects was conducted using the multiplex PCR-based invader assay. The prevalence of CKD was determined for stages 3-5 (defined as estimated glomerular filtration rate <60 ml/min/1.73 m2). Logistic regression analysis revealed that SNPs APOA5 T - 1131C (rs662799), APOA5 T1259C (rs2266788), TOMM40 A/G (rs157580), and CETP TaqIB (rs708272) were significantly associated with CKD risk in those individuals genotyped, with age- and sex-adjusted odds ratios (ORs) per minor allele (and 95% confidence intervals (CIs)) of OR 1.22 (95% CI: 1.06-1.39), 1.19 (1.03-1.37), 1.27 (1.12-1.45), and 0.81 (0.71-0.92), respectively. Analysis of the gene-environment interaction revealed that body mass index (BMI) was a significant effect modifier for APOA5 T - 1131C (rs662799) and a marginally significant effect modifier for APOA5 T/C (rs2266788), with the interaction between BMI ≥30 and individuals with at least one minor allele of each genotype of OR 10.43 (95% CI: 1.29-84.19) and 3.36 (0.87-13.01), respectively. Four polymorphisms in APOA5, TOMM40, and CETP were shown to be significantly associated with CKD risk, and a significant interaction between the two APOA5 SNPs and BMI on CKD risk was also demonstrated. This suggests the future possibility of personalized risk estimation for this life-limiting disease. Show less

This study examined the associations of the APOA5 T-1131C (rs662799), G553T (Cys185Gly, rs2075291), GCK G-30A (rs1799884), GCKR A/G at intron 16 (rs780094) and T1403C (Leu446Pro, rs1260326) polymorphisms with serum lipid and glucose levels in Japanese, considering lifestyle factors. Study subjects were 2,191 participants (aged 35-69 years, 1,159 males) enrolled in the Japan Multi-Institutional Collaborative Cohort (J-MICC) Study. Dyslipidemia was defined as fasting serum triglycerides (FTG) ≥ 150 mg/dL and/or HDL-cholesterol (HDL-C) < 40 mg/dL, while dysglycemia was as fasting blood sugar (FBS) ≥ 110 mg/dL. When those with APOA5 -1131 T/T or 553 G/G were defined as references, those with APOA5 -1131 T/C, C/C or 553 G/T, T/T demonstrated significantly elevated risk of dyslipidemia (age- and sex-adjusted odds ratio: 1.77 [95% confidence interval:1.39-2.27], 3.35 [2.41-4.65], 2.23 [1.64-3.02] and 13.78 [3.44-55.18], respectively). Evaluation of FTG, HDL-C or FBS levels according to the genotype revealed that FTG and HDL-C levels were significantly associated with the APOA5 T-1131C and G553T polymorphisms, FTG with the GCKR rs780094 and rs1260326 polymorphisms, and FBS with the GCKR rs780094 and rs1260326 polymorphisms. Moreover, a significant positive interaction between APOA5 553 G/T+T/T genotypes and fat intake ≥ 25% of total energy for the risk of dyslipidemia was observed. Our cross-sectional study confirmed the essential roles of the polymorphisms of the APOA5, GCK and GCKR in the lipid or glucose metabolism disorders, and suggested the importance of fat intake control in the individualized prevention of dyslipidemia. Show less

In populations of East Asian descent, we performed a replication study of loci previously identified in populations of European descent as being associated with obesity measures such as BMI and type 2 diabetes. We genotyped 14 single nucleotide polymorphisms (SNPs) from 13 candidate loci that had previously been identified by genome-wide association meta-analyses for obesity measures in Europeans. Genotyping was done in 18,264 participants from two general Japanese populations. For SNPs showing an obesity association in Japanese individuals, we further examined diabetes associations in up to 6,781 cases and 7,307 controls from a subset of the original, as well as from additional populations. Significant obesity associations (p < 0.1 two-tailed, concordant direction with previous reports) were replicated for 11 SNPs from the following ten loci in Japanese participants: SEC16B, TMEM18, GNPDA2, BDNF, MTCH2, BCDIN3D-FAIM2, SH2B1-ATP2A1, FTO, MC4R and KCTD15. The strongest effect was observed at TMEM18 rs4854344 (p = 7.1 × 10(-7) for BMI). Among the 11 SNPs showing significant obesity association, six were also associated with diabetes (OR 1.05-1.17; p = 0.04-2.4 × 10(-7)) after adjustment for BMI in the Japanese. When meta-analysed with data from the previous reports, the BMI-adjusted diabetes association was found to be highly significant for the FTO locus in East Asians (OR 1.13; 95% CI 1.09-1.18; p = 7.8 × 10(-10)) with substantial inter-ethnic heterogeneity (p = 0.003). We confirmed that ten candidate loci are associated with obesity measures in the general Japanese populations. Six (of ten) loci exert diabetogenic effects in the Japanese, although relatively modest in size, and independently of increased adiposity. Show less