Impact of ENPP1 K121Q on Change of Insulin Resistance after Web-Based Intervention in Korean Men with Diabetes and Impaired Fasting Glucose

Ectoenzyme nucleotide pyrophosphate phosphodiesterase 1 (ENPP1) gene has been studied in relation to type 2 diabetes mellitus (T2DM) and insulin resistance (IR). We hypothesized that the difference in genotype may be one of the factors that affect the outcome of intervention. We genotyped 448 men with fasting glucose≥5.6 mM/L, including 371 in subjects with K allele (KK) (69 control group [CG]; and 302 intervention group [IG]) and 77 in subjects with Q allele (KQ+QQ) (13 CG and 64 IG). The web-based intervention based on a lifestyle modification was delivered by e-mail once a month for 10 months. In the KK, IG demonstrated significantly decreased levels of fasting serum insulin (FSI) as compared to CG and homeostasis model of assessment of insulin resistance (HOMA-IR). In the KQ+QQ IG group, hemoglobin A1c (HbA1c), FSI and HOMA-IR were significantly decreased, and showed further reduction in the HOMA-IR than KQ+QQ CG. After analysis of covariance, K121Q did significantly influence the change of HbA1c in CG after appropriate adjustment. In a multivariate model, BMI change predicted HOMA-IR change (adjusted β=0.801; P=0.022) in KK IG subjects with T2DM. ENPP1 K121Q did not influence the change in IR. However, individuals with T2DM carrying the K121 variant are very responsive to the effect of BMI reduction on HOMA-IR.

Graphical Abstract

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No evidence for association of the ENPP1 (PC-1) K121Q variant with risk of type 2 diabetes in a Japanese population

Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1, also known as PC-1) inhibits insulin signal transduction pathway(s). Previous studies have demonstrated the K121Q variant of the ENPP1 gene to have a significant functional role in determining susceptibility to insulin resistance and type 2 diabetes (T2D). To assess whether the K121Q variant has any impact on T2D in Japanese, we undertook an extensive case-control association study using a total of 911 unrelated Japanese T2D patients and 876 control subjects. No significant difference was observed in either genotype distribution (P=0.95) or allele frequency (P=0.83) between T2D and control groups. Notably, the frequency of the ancestral Q121 allele, which is also present in other primates, was quite high in African-Americans, and showed a marked ethnic variation (77.3% in African-Americans, 16.7% in European Americans, 10.5% in Japanese and 4.2% in Han Chinese). Consequently, the pairwise F_ST value (a classic measure of genetic distance between pairs of population) showed highly significant differentiations between African-American and non-African-American populations (F_ST>0.3). Our results indicated that the K121Q variant of the ENPP1 gene has very little, if any, impact on T2D susceptibility in Japanese, but may play a role in the inter-ethnic variability in insulin resistance and T2D.An erratum to this article can be found at     

深圳地区人群2型糖尿病相关基因多态性的研究

目的研究分析深圳地区2型糖尿病（DM）相关基因浆细胞膜糖蛋白（PC-1）基因K121Q多态性，探讨其于2型DM的关系。方法选择214例2型DM患者和295例非DM对照人群作病例对照研究。聚合酶链反应-限制性酶切片段长度多态性（PCR-RFLP）检测PC-1基因K121Q多态性。并分析其与2型DM的相关性。结果PC-1基因PCR扩增片段大小为240bp，与预期的扩增片段大小相符。扩增片段经限制性内切酶AvaⅡ酶切后，产生Q与K两个等位基因，出现2种基因型条带，分别为KK型和QK型。509例研究对象中，KK基因型者433例，所占比例最高，为85．07％；KQ基因型者次之，有76例，占14．93％；未见QQ基因型。K等位基因频率为92．53％，Q等位基因频率为7．47％。各组基因型频率及等位基因频率比较，差异均有统计学意义（P〈0．05）。以是否患2型糖尿病为因变量，PC．1基因K121Q基因型为自变量，进行Logistic回归分析。单因素分析结果表明，与KK基因型者相比，KQ基因型与2型DM存在显著相关性，其P=0．034，OR=1．84，OR95％CI为（1．05-3．24）。结论PC-1基因K121Q多态性与2型糖尿病存在相关性，KQ基因型可能是2型糖尿病的危险因素之一。     

The ENPP1 K121Q polymorphism is not associated with type 2 diabetes or obesity in the Chinese Han population

Type 2 diabetes (T2D) mellitus is a metabolic disorder characterized by chronic hyperglycemia and insulin resistance. It has been a worldwide public health problem, which is increasing rapidly, especially in developing countries such as China. The ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) gene, also known as plasma cell membrane glycoprotein 1, has been reported by genetic association studies as being associated with T2D and obesity in various populations, such as Caucasian and African American. However, there are also some controversial results in Asian populations. Our study tried to examine the associations between ENPP1 and T2D and obesity. Rs1044498 (K121Q) and rs7754561 were genotyped in 1912 patients and 2041 control subjects through TaqMan technology on the ABI7900 system. They showed no statistical association with T2D, obesity or any metabolic quantitative traits. Our meta-analysis result was consistent with it. Our study did not replicate the positive association found previously and suggested that K121Q of ENPP1 might not have a major role in the susceptibility to T2D or obesity in the Chinese Han population.     

Diseases Concomitant With Asthma in Middle-Aged and Elderly Subjects in Korea: A Population-Based Study

Purpose

Asthma is prevalent in many countries. Few studies have investigated the association between asthma and concomitant diseases. We retrospectively analyzed the fourth Korean National Health and Nutrition Survey database, performed in 2008 using nationwide stratified random sampling to obtain a representative cohort of the Korean population.

Methods

We evaluated the association between both self-reported ever-asthmatics and wheezers and concomitant diseases such as arthritis, hypertension, gastrointestinal (GI) ulcers, dyslipidemia, diabetes mellitus, rhinitis, depression, stroke, and obesity in subjects aged ≥40 years. A multivariate analysis was performed to identify concomitant diseases independently associated with asthma, after adjustment for age, gender, income, cigarette smoking, and other chronic diseases.

Results

Of the total of 4,445 subjects, 2,596 (58.4%) were female and the mean age was 58.3 years. Of the 4,445 subjects, 195 (4.4%) had been diagnosed with asthma at some point, and 444 (10%) were wheezers. Multivariate analysis showed that arthritis (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.26-2.42), rhinitis (OR 1.78, 95% CI 1.14-2.78), depression (OR 1.45, 95% CI 1.05-2.07), and obesity (OR 1.61, 95% CI 1.08-2.40) were significantly associated with self-reported ever-asthma, and arthritis (OR 1.50, 95% CI 1.19-1.909), hypertension (OR 1.34, 95% CI 1.07-1.67), GI ulcers (OR 1.48, 95% CI 1.05-2.08), rhinitis (OR 1.60, 95% CI 1.16-2.19), depression (OR 1.94, 95% CI 1.51-2.48), and obesity (OR 1.56, 95% CI 1.17-2.09) were significantly associated with wheezers.

Conclusions

These findings indicate that arthritis, rhinitis, depression, and obesity may be associated with both self-reported ever asthma and wheezers in the Korean population.     

Molecular scanning of the human sorbin and SH3-domain-containing-1 (SORBS1) gene: positive association of the T228A polymorphism with obesity and type 2 diabetes

In the mouse, the SH3P12 or the c-Cbl-associated protein (CAP) has been shown as an important signaling molecule in insulin-stimulated glucose uptake. The human homolog for the sorbin and SH3-domain-containing-1 gene, termed SORBS1, might play a role in human disorders with insulin resistance. To explore the genetic role of SORBS1 in human obesity and type 2 diabetes, we investigated the nucleotide polymorphisms in the SORBS1 gene with molecular scanning. After scanning for a total of 13,136 bp in each of 40 chromosomes, we have identified 14 single nucleotide polymorphisms (SNPs) in the human SORBS1 gene. Among them, two SNPs affected amino acid coding (R74W and T228A), four occurred within exons but did not affect amino acid coding, and the remaining eight occurred within introns, which were located outside of the consensus region of the splicing mechanism. Further studies in 202 non-obese, 113 obese and 455 subjects with type 2 diabetes revealed that the A-allele of the T228A polymorphism in exon 7 exerted a protective role for both obesity [relative risk 0.466; 95% confidence interval (95% CI) 0.265-0.821] and diabetes (relative risk 0.668; 95% CI 0.472-0.945). Neither allele of the R74W polymorphism was associated with either obesity or diabetes. In conclusion, our results suggest that the A228 allele of the T228A polymorphism of the SORBS1 gene is a protective factor for both obesity and diabetes, and also imply that the SORBS1 gene plays an important role in the pathogenesis of human disorders with insulin resistance.     

A meta-analysis of pregnancy outcomes in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common reproductive disorder associated with many characteristic features, including hyperandrogenaemia, insulin resistance and obesity which may have significant implications for pregnancy outcomes and long-term health of the woman. This meta-analysis was conducted to evaluate the risk of pregnancy and neonatal complications in women with PCOS. Electronic databases were searched for the following MeSH headings: PCOS, hyperandrogenism, pregnancy outcome, pregnancy complications, diabetes mellitus, type II. A handsearch of human reproduction and fertility and sterility was also conducted. Studies in which pregnancy outcomes in women with PCOS were compared with controls were considered for inclusion in this meta-analysis. Fifteen of 525 identified studies were included, involving 720 women presenting with PCOS and 4505 controls. Women with PCOS demonstrated a significantly higher risk of developing gestational diabetes [odds ratio (OR) 2.94; 95% confidence interval (CI): 1.70-5.08], pregnancy-induced hypertension (OR 3.67; 95% CI: 1.98-6.81), pre-eclampsia (OR 3.47; 95% CI: 1.95-6.17) and preterm birth (OR 1.75; 95% CI: 1.16-2.62). Their babies had a significantly higher risk of admission to a neonatal intensive care unit (OR 2.31; 95% CI: 1.25-4.26) and a higher perinatal mortality (OR 3.07; 95% CI: 1.03-9.21), unrelated to multiple births. In conclusion, women with PCOS are at increased risk of pregnancy and neonatal complications. Pre-pregnancy, antenatal and intrapartum care should be aimed at reducing these risks.     

A common functional variant in the interleukin-6 gene is associated with increased body mass index in subjects with type 2 diabetes mellitus

Circulating levels of interleukin-6 (IL-6) are raised in insulin resistant states such as obesity, impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM). Growing evidence suggests that IL-6 is not only produced by fat cells but is also capable of inducing insulin resistance in these cells. The expected result of this in vivo, would be to increase adipose mass and subsequently body mass index (BMI). The IL-6 -174G > C common functional gene variant has consistently been associated with increased plasma IL-6, insulin resistance, and increased cardiovascular risk. We looked at the association between genotype and BMI in 571 Caucasian subjects with T2DM. There was a significant linear association between genotype and BMI: Median (interquartile range) GG 28.8 kg/m2 (26.0-31.6) vs GC; 29.4 kg/m2 (26.3-32.5) vs CC; 30.4 kg/m2 (26.1-33.0), p=0.05. When the group was divided by the median BMI (29.1 kg/m2), 62% of -174CC subjects were in the higher group compared to 38% in the lower group (p=0.008). By contrast, in 2,652 non-diabetic Caucasian men with a median BMI of 26.1 kg/m2, there was no difference in genotype distribution (p=0.288). The frequency of the -174C allele was lower in type 2 diabetes compared to the non-diabetic men (-174C allele frequency: 0.35[0.33-0.38] vs 0.43[0.42-0.45], p <0.00001; -174CC homozygotes: 12.3 vs 18.3%, respectively). The -174C allele is associated with higher BMI in type 2 diabetes, but not amongst healthy subjects. The increased cardiovascular risk associated with the -174C allele may account for the lower frequency of this allele in those with type 2 diabetes.     

Association between polymorphisms in SLC30A8, HHEX, CDKN2A/B, IGF2BP2, FTO, WFS1, CDKAL1, KCNQ1 and type 2 diabetes in the Korean population

According to recent genome-wide association studies, a number of single nucleotide polymorphisms (SNPs) are reported to be associated with type 2 diabetes mellitus (T2DM). The aim of the present study was to investigate the association among the polymorphisms of SLC30A8, HHEX, CDKN2A/B, IGF2BP2, FTO, WFS1, CDKAL1 and KCNQ1 and the risk of T2DM in the Korean population. This study was based on a multicenter case-control study, including 908 patients with T2DM and 502 non-diabetic controls. We genotyped rs13266634, rs1111875, rs10811661, rs4402960, rs8050136, rs734312, rs7754840 and rs2237892 and measured the body weight, body mass index and fasting plasma glucose in all patients and controls. The strongest association was found in a variant of CDKAL1 [rs7754840, odds ratio (OR) = 1.77, 95% CI = 1.50-2.10, p = 5.0 x 10(-11)]. The G allele of rs1111875 (OR = 1.43, 95% CI = 1.18-1.72, p = 1.8 x 10(-4)) in HHEX), the T allele of rs10811661 (OR = 1.47, 95% CI = 1.23-1.75, p = 2.1 x 10(-5)) in CDKN2A/B) and the C allele of rs2237892 (OR = 1.31, 95% CI = 1.10-1.56, p = 0.003) in KCNQ1 showed significant associations with T2DM. Rs13266634 (OR = 1.19, 95% CI = 1.00-1.42, p = 0.045) in SLC30A8 showed a nominal association with the risk of T2DM, whereas SNPs in IGF2BP2, FTO and WFS1 were not associated. In conclusion, we have shown that SNPs in HHEX, CDKN2A/B, CDKAL1, KCNQ1 and SLC30A8 confer a risk of T2DM in the Korean population.     

Relationships of mental disorders and weight status in the Korean adult population

The purpose of this study was to evaluate the associations between weight status and mental disorders, including depressive disorder, anxiety disorder and alcohol use disorder. A total of nationally representative 6,510 subjects aged 18-64 yr was interviewed in face-to-face household survey. Response rate was 81.7%. Mental disorders were diagnosed using the Korean version of the Composite International Diagnostic Interview (K-CIDI). The subjects reported their heights and weights. After adjusting for age and gender, the lifetime diagnosis of depressive disorder had a significant association with only the underweight group (odds ratio [OR], 1.68, 95% confidence interval [CI], 1.19-2.38). The association between underweight and depressive disorder was the strongest for subjects with a high education level (OR, 1.75, 95% CI, 1.2-2.56), subjects with a married/cohabiting status (OR, 1.94, 95% CI, 1.17-3.22) and smokers (OR, 2.58, 95% CI, 1.33-4.98). There was no significant association between obesity and depressive disorder in Korea. But there was a significant association between the underweight group and depressive disorder. The relationship between obesity and mental disorder in a Korean population was different from that in a Western population. These results suggest that the differences of traditional cultures and races might have an important effect on the associations between the weight status and mental disorders.     

Intron 4 a/b polymorphism of the endothelial nitric oxide synthase gene is associated with both type 1 and type 2 diabetes in a genetically homogeneous population

Current classifications of diabetes distinguish between type 1 diabetes (T1D) and type 2 diabetes (T2D), however recent evidence highlights overlap between T1D and T2D. Earlier studies have suggested altered nitric oxide (NO) metabolism in both T1D and T2D. In the present case-control study, we investigated whether the endothelial NO synthase gene intron 4 a/b polymorphism is associated with T1D and T2D in the island of Crete, a well-defined area with genetically homogeneous population. Mutated allele "a" was more common in individuals with both T1D and T2D than in controls (odds ratio [OR] = 1.71, 95% confidence interval [CI] = 1.06-2.77, p = 0.013; and OR = 1.50, 95% CI = 0.930-2.42, p = 0.047, respectively). Mutated genotype (a/a or a/b) was more common in individuals with T1D than in nondiabetic individuals (OR = 1.93, 95% CI = 1.12-3.32, p = 0.008); this increased frequency was also observed for T2D, although not at a significant level (OR = 1.38, 95% CI = 0.802-2.37). No difference was found in the frequency of mutated allele a or mutated genotype (a/a or a/b) between T1D and T2D populations. In conclusion, our results indicate that allele a of the intron 4 endothelial NO synthase gene is associated with susceptibility to both T1D and T2D and may represent a common genetic factor for diabetes.     

The factors relevant to partial remission in children with type 1 diabetes mellitus after measles vaccination: A retrospective study

We aimed to identify the determinants of partial remission in patients with type 1 diabetes mellitus (DM), and whether there is an influence of vaccination against measles on partial remission. This was a retrospective study consisting of consecutive patients diagnosed with type 1 DM followed-up from 1 September 2010, through 30 November 2011. The study included children vaccinated within 3 months after diagnosis, and children unvaccinated during the first 12 months of the disease. The daily insulin dose, hemoglobin A1c, and C-peptide levels, and whether children are in partial remission based on the insulin dose-adjusted HbA1c were recorded at diagnosis and 3, 6, 9, 12, 24, and 36 months. A total of 55 children with type 1 DM were analyzed. Thirty-one patients (56.4%) reached partial remission during the follow-up period, whereas 24 of them did not. Patients with diabetic ketoacidosis (DKA) at diagnosis were less likely to reach partial remission than patients without DKA (odds ratio [OR], 0.24; 95% confidence interval [CI], 0.062-0.946; P = .038). Patients vaccinated against measles were more likely to be in partial remission than patients unvaccinated (OR, 4.2; 95% CI, 1.35-13; P = .011). Partial remission was significantly associated with the C-peptide level and insulin dosage at diagnosis P = .002; P = .013, respectively). The lack of DKA, higher C-peptide level, and lower insulin dosage at diagnosis, and vaccination against measles after diagnosis may have an influence on partial clinical remission in patients with new-onset type 1 DM.     

Serum insulin-like growth factor-1, asthma,and lung function among British adults

BackgroundInsulin-like growth factor-1 (IGF-1) plays a key role in the pathogenesis of metabolic syndrome, which is in turn associated with asthma. Whether IGF-1 contributes to asthma causation or asthma severity is largely unknown.ObjectiveTo evaluate the relation between serum IGF-1 and asthma, asthma outcomes, and lung function in adults.MethodsCross-sectional study of 297,590 adults (aged 40-69 years) who participated in the United Kingdom Biobank, had no diagnosis of diabetes, and were not on insulin. Multivariable logistic or linear regression was used to analyze serum IGF-1 and physician-diagnosed asthma, current wheezing, asthma hospitalizations, and lung function measures (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], and FEV1 to FVC ratio).ResultsSerum IGF-1 levels above the lowest quartile (Q1) were significantly associated with lower odds of asthma (adjusted odds ratio for fourth quartile [Q4] vs Q1 = 0.88; 95% confidence interval [CI], 0.85-0.91). Among the participants with asthma, IGF-1 levels above Q1 were significantly associated with lower odds of current wheezing (adjusted odds ratio for Q4 vs Q1 = 0.89; 95% CI, 0.83-0.96), but not with asthma hospitalizations. Serum IGF-1 was significantly and positively associated with FEV1 (b = 20.9 mL; 95% CI, 19.1-22.7) and FVC (b = 25.6 mL; 95% CI, 23.4-27.7), regardless of an asthma diagnosis; these associations were significant in men and women, with larger estimated effects in men.ConclusionIn a large study of British adults, higher serum IGF-1 levels were associated with lower odds of asthma and current wheezing and higher FEV1 and FVC. Our findings suggest potential beneficial effects of circulating IGF-1 on asthma and asthma outcomes in adults.     

Diisocyanate asthma and gene-environment interactions with IL4RA, CD-14, and IL-13 genes.

BACKGROUND: Diisocyanate asthma (DA) affects 2% to 10% of exposed workers, yet the pathogenetic mechanisms underlying this disorder remain ill defined. OBJECTIVE: To determine if specific single nucleotide polymorphisms (SNPs) of interleukin 4 receptor alpha (IL4RA), IL-13, and CD14 promoter genes are associated with DA. METHODS: Sixty-two workers with DA confirmed by specific inhalation challenge (SIC) and 75 diisocyanate-exposed, SIC-negative workers were analyzed for SNPs associated with IL4RA, IL-13, and CD14 promoter genes. RESULTS: No associations were found with individual SNPs and DA. When stratified according to specific diisocyanate exposure, a significant association was found between IL4RA (I50V) II and DA among individuals exposed to hexamethylene diisocyanate (HDI) (odds ratio [OR], 3.29; 95% confidence interval [CI], 1.33-8.14; P = .01) only. Similarly, the IL4RA (I50V) II and IL-13 (R110Q) RR combination was significantly associated with DA in HDI-exposed workers (OR, 4.13; 95% CI, 1.35-12.68; P = .01), as was the IL4RA (I50V) II and CD14 (C159T) CT genotype combination (OR, 5.2; 95% CI, 1.82-14.88; P = .002) and the triple genotype combination IL4RA (I50V) II, IL-13 (R110Q) RR, and CD14 (C159T) CT (OR, 6.4; 95% CI, 1.57-26.12; P = .01). CONCLUSIONS: Gene-environmental interactions may contribute to the pathogenesis of DA, and gene-gene interactions may modulate this relationship.     

Risk factors for diabetes,but not for cardiovascular disease,are associated with family history of Type 2 diabetes in subjects from central Mexico

Background: Independent of obesity, family history of type 2 diabetes mellitus (FHT2DM) is another important risk factor for developing diabetes.

Aim: To establish the association among FHT2DM, risk factors for diabetes and cardiovascular disease in subjects from central Mexico.

Subjects and methods: Clinical and biochemical studies were performed in 383 first-degree relatives of patients with type 2 diabetes and 270 subjects unrelated to patients with type 2 diabetes—all subjects were from the city of Puebla in central Mexico. Logistic regressions were used to assess the association between FHT2DM and metabolic parameters. Cardiovascular risk was classified by dyslipidemia and the Framingham Risk Score (FRS).

Results: FHT2DM was associated with risk factors for diabetes, such as increased fasting insulin levels (OR = 1.731, 95% CI = 1.041–2.877), decreased insulin sensitivity (OR = 1.951, 95% CI = 1.236–3.080) and pre-diabetes (OR = 1.63, 95% CI = 1.14–2.33). FHT2DH was not associated with risk factors for cardiovascular disease, such as dyslipidemia (OR = 1.12, 95% CI = 0.70–1.79) and FRS (OR = 0.74, 95% CI = 0.40–1.36) when adjusted for gender, age, smoking and obesity.

Conclusion: Diabetic risk factors, but not cardiovascular disease risk factors, are associated with a positive family history of diabetes in subjects from central Mexico, independent of the presence of obesity.     

Association between Obesity and Cervical Microflora Dominated by Lactobacillus iners in Korean Women

Lactobacillus spp. are associated with the maintenance of reproductive health, but obesity reduces fertility and is a risk factor for obstetric and neonatal complications. We assessed the association between obesity and the cervical Lactobacillus composition, which has not been examined previously. Pyrosequencing was performed using cervical swabs collected from 76 normal participants with negative results for cervical intraepithelial neoplasia (CIN) and 57 participants with CIN, based on histological examinations. Cluster analysis of nine Lactobacillus spp. was performed, and five cluster types were identified. The association between obesity and the Lactobacillus community was assessed by logistic regression analysis after adjustment for confounding factors. The proportion of Lactobacillus iners increased and that of Lactobacillus crispatus decreased according to body mass index (BMI) categories, i.e., underweight (BMI of <18.5 kg m⁻²), normal weight (BMI of 18.5 to 22.9 kg m⁻²), overweight (BMI of 23.0 to 24.9 kg m⁻²), and obese (BMI of ≥25 kg m⁻²). The L. iners-dominant type had a significant association with obesity (odds ratio [OR], 7.55 [95% confidence interval [CI], 1.18 to 48.2]), compared to the L. crispatus-dominant type. The group with high values for the ratio obtained by dividing the relative abundance of L. iners by that of L. crispatus had a significant association with obesity (OR, 6.54 [95% CI, 1.22 to 35.1]), compared to the low-ratio group. Associations between obesity and the L. iners/L. crispatus ratio were observed among young women (OR, 6.26 [95% CI, 1.15 to 33.9]) but not older women and in the normal group (OR, 6.97 [95% CI, 1.20 to 70.4]) but not the CIN group. Obesity was associated with cervical microflora dominated by L. iners in reproductive-age women without dysplasia.     

<Emphasis Type="Italic">APOA5</Emphasis> gene variation modulates the effects of dietary fat intake on body mass index and obesity risk in the Framingham Heart Study

Diet is an important environmental factor interacting with our genes to modulate the likelihood of developing lipid disorders and, consequently, cardiovascular disease risk. Our objective was to study whether dietary intake modulates the association between APOA5 gene variation and body weight in a large population-based study. Specifically, we have examined the interaction between the APOA5-1131T>C and 56C>G (S19W) polymorphisms and the macronutrient intake (total fat, carbohydrate, and protein) in their relation to the body mass index (BMI) and obesity risk in 1,073 men and 1,207 women participating in the Framingham Offspring Study. We found a consistent and statistically significant interaction between the -1131T>C single-nucleotide polymorphism (SNP; but not the 56C>G) and total fat intake for BMI. This interaction was dose-dependent, and no statistically significant heterogeneity by gender was detected. In subjects homozygous for the -1131T major allele, BMI increased as total fat intake increased. Conversely, this increase was not present in carriers of the -1131C minor allele. Accordingly, we found significant interactions in determining obesity and overweight risks. APOA5-1131C minor allele carriers had a lower obesity risk (OR, 0.61, 95%; CI, 0.39-0.98; P = 0.032) and overweight risk (OR, 0.63, 95%; CI, 0.41-0.96; P = 0.031) compared with TT subjects in the high fat intake group (>or=30% of energy ) but not when fat intake was low (OR, 1.16, 95%; CI, 0.77-1.74; P = 0.47 and OR = 1.15, 95%; CI, 0.77-1.71; P = 0.48) for obesity and overweight, respectively). When specific fatty acid groups were analyzed, monounsaturated fatty acids showed the highest statistical significance for these interactions. In conclusion, the APOA5-1131T>C SNP, which is present in approximately 13% of this population, modulates the effect of fat intake on BMI and obesity risk in both men and women.     

Association of the calpain-10 gene with type 2 diabetes mellitus in a Mexican population

Variation in the calpain-10 gene (CAPN10) has been associated with risk of type 2 diabetes in the Mexican American population of Starr County, Texas. We typed five polymorphisms in the calpain-10 gene (SNP-43, -43, -63, and -110 and Indel-19) to test for association with type 2 diabetes in 248 individuals representative of the mestizo population of Mexico City and Orizaba, Mexico including 134 patients with type 2 diabetes and 114 subjects with normal fasting blood glucose levels. We found a significant difference in SNP-44 allele and genotype frequencies between type 2 diabetic and non-diabetic subjects. The rare allele at SNP-44 was associated with increased risk of type 2 diabetes (odds ratio (OR)=2.72, 95% confidence interval (CI)=1.16-6.35, P=0.017). SNP-110, which is in perfect linkage disequilibrium with SNP-44, was also associated with type 2 diabetes. The SNP-43, Indel-19, and SNP-63 haplogenotype 112/121 associated with significantly increased risk (OR=2.16, 95% CI=1.31-3.57) of type 2 diabetes in Mexican Americans was not associated with significantly increased in risk in Mexicans (OR=1.15, 95% CI=0.57-2.34). The results suggest that variation in CAPN10 affects risk of type 2 diabetes in the mestizo population of central Mexico (Mexico City and Orizaba) and in Mexican Americans (Starr County, Texas).     

Systematic search for single nucleotide polymorphisms in a lymphoid tyrosine phosphatase gene (PTPN22): association between a promoter polymorphism and type 1 diabetes in Asian populations

The protein tyrosine phosphatase, nonreceptor 22 gene (PTPN22) maps to human chromosome 1p13.3-p13.1 and encodes an important negative regulator of T-cell activation, lymphoid-specific phosphatase (Lyp). Recently, the minor allele of a single-nucleotide polymorphism (SNP) at nucleotide position 1858 (rs2476601, +1858C > T) was found to be associated with type 1 diabetes. However, the degree of the association is variable among ethnic populations, suggesting the presence of other disease-associated variants in PTPN22. To examine this possibility, we carried out a systemic search for PTPN22 using direct sequencing of PCR-amplified products in the Japanese population. Association and linkage studies were also conducted in 1,690 Japanese samples, 180 Korean samples, and 472 Caucasian samples from 95 nuclear families. We identified five novel SNPs, but not the +1858C > T SNP. Of these two frequent SNPs, -1123G > C, and +2740C > T were in strong linkage disequilibrium (LD), and the -1123G > C promoter SNP was associated with acute-onset but not slow-onset type 1 diabetes in the Japanese population (odds ratio [OR] = 1.42, 95% CI = 1.07-1.89, P = 0.015). This association was observed also in Korean patients with type 1 diabetes (Mantel-Haenszel chi2= 6.543, P = 0.0105, combined OR = 1.41 95% CI = 1.09-1.82). Furthermore, the affected family-based control (AFBAC) association test and the transmission disequilibrium analysis of multiplex families of European descent from the British Diabetes Association (BDA) Warren Repository indicated that the association was stronger in -1123G > C compared to +1858C > T. In conclusion, the type 1 diabetes association with PTPN22 is confirmed, but it cannot be attributed solely to the +1858C > T variant. The promoter -1123G > C SNP is a more likely causative variant in PTPN22.