Association of IGF1 polymorphism rs6214 with high myopia: A systematic review and meta-analysis

Association Between Physical Indicators and Myopia in American Adolescents: National Health and Nutrition Examination Survey 1999-2008

PURPOSE

Myopia is the most prevalent refractive error, imposing a substantial economic burden. Physical indicators constitute significant influencing factors for myopia. The National Health and Nutrition Examination Survey (NHANES) investigates the health and nutritional status of both children and adults in the United States. This study leveraged NHANES to explore the association between physical indicators and myopia among American adolescents.

DESIGN

Retrospective case-control study.

METHODS

The final study cohort consisted of 9008 adolescents. Demographic data, physical indicators, and vision data were extracted. The association between myopia and demographic factors, as well as physical indicators, employed weighted methods. Regression models were utilized to identify the associations between physical indicators and myopia. Cumulative odds logistic regression analysis was employed to investigate the association between physical indicators and the degree of myopia. Restricted cubic spline analysis was employed to examine the potential nonlinear relationship between physical indicators and the risk of myopia.

RESULTS

The occurrence of myopia was significantly correlated with age (P < .001) and race (P = .019). Adolescents in the fourth percentile for weight (odds ratio [OR] 1.38, 95% confidence interval [CI] 1.13-1.70) and body mass index (BMI) (OR 1.26, 95% CI 1.05-1.51) exhibited an increased possibility of myopia. The highest risk of myopia was observed when the BMI approached 30. Height emerged as a risk factor for the degree of myopia (OR 1.02, 95% CI 1.01-1.03).

CONCLUSIONS

A certain association existed between physical indicators and myopia. Weight and BMI were related to the occurrence of myopia, while height and race were associated with the degree of myopia.

A variant rs6214 within IGF-1 confers risk for ulcerative colitis in Chinese Han populations

Insulin growth factor-1 (IGF-1) has been found to correlate with various diseases such as cancer and cardiovascular diseases including ulcerative colitis (UC). The present study aimed to investigate the plausible association of rs6214 (C > T) within IGF-1 and UC susceptibility in Chinese Han populations. A total of 977 UC patients and 1029 healthy controls were enrolled, and rs6214 was genotyped with PCR and direct sequencing on the ABI 3730XL DNA analyzer platform. Logistic regression analysis was applied for the correlation of rs6214 and UC susceptibility via calculation of odds ratio (OR) with a 95% confidence interval (95% CI) adjusted for age and sex under different genetic models. The difference of clinical parameters between genotypes was measured by one-way analysis of variance (ANOVA). Additional functional assays were conducted to establish the probable relationship. The results indicated that the T allele of rs6214 showed roughly 37% greater risk for UC risk in the additive model (OR = 1.37, 95% CI = 1.21-1.55, P < 0.000001) when compared with C allele carriers, and the pattern was similar in other three genetic models. Further stratified analysis suggested that the association was particularly noteworthy in UC patients with extensive colitis and severe condition. Moreover, the blood level of IGF-1 was downregulated in UC patients, and the mRNA level was lower in T allele carriers in rectal tissues of UC cases. Additional luciferase assay demonstrated that rs6214 regulates IGF-1 expression via promoting miR-2053. Collectively, rs6214 increased UC susceptibility and suppresses IGF-1 expression by enhancing miR-2053 binding. The current findings provided evidence that rs6214 is a promising biomarker for UC prediction and prognosis.

Genetic Association Study Revealed Three Loci Were Associated Risk of Myopia Among Minors

Background

Myopia has raised a predominant public concern among minors. A recent genome-wide association study (GWAS) identified six novel loci in Asian adults. Whether these genetic loci works for myopia in minors remains unknown and worthy of exploration.

Methods

In order to validate the findings, here we performed a case-control study (600 myopia minors, 110 high myopia (HM) minors, and 800 non-myopia minors as controls) utilizing the TaqMan single nucleotide polymorphism (SNP) genotyping assays. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) was adopted.

Results

The median ages in controls, myopia, and HM were 15.1, 15.0, and 15.1, respectively, while the means ± standard deviations for them were 0.32±0.41, - 3.2 ±1.6, and −9.8±2.2, respectively. We found rs2246661 (allelic OR: 1.29; 95% CI: 1.09–1.52; P =0.003), rs74633073 (allelic OR: 1.41; 95% CI: 1.12–1.78; P =0.004), and rs76903431 (allelic OR: 1.42; 95% CI: 1.11–1.81; P =0.005) were significantly associated with increased risk of myopia. Rs2246661 was also significantly associated with increased risk of HM in minors (OR: 1.37; 95% CI: 1.02–1.84; P =0.035).

Conclusion

We identified three loci contributed to myopia in minors and these findings gave new insight into the genetic susceptibility mechanisms of myopia at the molecular level.

Association of IGF1 single-nucleotide polymorphisms with myopia in Chinese children

Purpose

To investigate the association between insulin-like growth factor 1 (IGF1) single-nucleotide polymorphisms (SNPs) and myopia in a young Chinese population.

Methods

A total of 654 Chinese children aged 6–13 years from one primary school participated in our study and underwent a series of comprehensive ocular examinations, including cycloplegic refraction and measurements of axial length. Myopia was defined as a spherical equivalence (SE) ≤ −0.5 D in the worse eye. In total, six tagging SNPs of IGF1 were genotyped using the PCR-LDR (Polymerase Chain Reaction-Ligation Detection Reaction) method. We tested four different genetic modes (the allele, dominant, recessive, and additive models) of these SNPs and used multivariate logistic regression to calculate the effect of SNPs on myopia. In addition, we conducted a haplotype analysis with a variable-sized slide-window strategy.

Results

Overall, 281 myopic children and 373 non-myopic controls were included in the analysis. The SNP rs2162679 showed a statistical difference between the two groups in both the allele (p = 0.0474) and additive (p = 0.0497) models. After adjusting for age and gender, children with the genotype AA in the SNP rs2162679 had a higher risk of myopia than those with the genotype GG (OR = 2.219, 95% CI [1.218–4.039], p = 0.009). All haplotypes that varied significantly between the two groups contained the SNP rs2162679, and the four-SNP window rs5742653–rs2162679 had the lowest p value (Chi square = 5.768, p = 0.0163). However, after permutation tests, none of the associations remained statistically significant.

Conclusion

The SNP rs2162679 in IGF1 was associated with myopia in a young Chinese population. The G allele in the SNP rs2162679 may protect against myopia.

Ethnic disparity in prevalence and associated risk factors of myopia in adolescents

BACKGROUND/PURPOSE

To examine ethnic disparity in prevalence and associated factors of myopia in adolescents using the Unites States National Health and Nutrition Examination Survey (NHANES) dataset.

METHODS

Participants who were aged 12-19 years were included from NHANES (1999-2008). Logistic regression analyses were applied to identify risk factors associated with myopia after stratification by race.

RESULTS

A total of 9,960 participants were included in the prevalence analysis, and 6,571 in the risk factor analysis. Other race (excluded Mexican American, other Hispanic, non-Hispanic white, non-Hispanic black) participants had the highest frequency of myopia (42.77%). Multivariate analyses of the whole population suggested that the odds of myopia were significantly lower in participants with household smokers (odds ratio [OR] = 0.79, 95% confidence interval [CI]: 0.66-0.97), and significantly greater in Mexican American race (OR = 1.28, 95% CI: 1.01-1.62), other Hispanic (OR = 1.79, 95% CI: 1.10-2.92) and in participants with senior high school graduate education (OR = 1.79, 95% CI: 1.01-3.18), watched 2 hours of television daily (OR = 1.27, 95% CI: 1.02-1.59), used the computer for 1 hour daily (OR = 1.276, 95% CI: 1.02-1.57). When examined by race/ethnicity, 1 hour of computer use increased the odds of myopia in the non-Hispanic White group, in Mexican Americans a higher family poverty income ratio and 2 hours of television time was associated with myopia, and in the Other Hispanic group, a higher family poverty income ratio was associated with myopia, while males and those with a higher sugar had a lower risk of myopia.

CONCLUSION

Risk factors for myopia vary with race/ethnicity.

IMI - Myopia Genetics Report

The knowledge on the genetic background of refractive error and myopia has expanded dramatically in the past few years. This white paper aims to provide a concise summary of current genetic findings and defines the direction where development is needed. We performed an extensive literature search and conducted informal discussions with key stakeholders. Specific topics reviewed included common refractive error, any and high myopia, and myopia related to syndromes. To date, almost 200 genetic loci have been identified for refractive error and myopia, and risk variants mostly carry low risk but are highly prevalent in the general population. Several genes for secondary syndromic myopia overlap with those for common myopia. Polygenic risk scores show overrepresentation of high myopia in the higher deciles of risk. Annotated genes have a wide variety of functions, and all retinal layers appear to be sites of expression. The current genetic findings offer a world of new molecules involved in myopiagenesis. As the missing heritability is still large, further genetic advances are needed. This Committee recommends expanding large-scale, in-depth genetic studies using complementary big data analytics, consideration of gene-environment effects by thorough measurement of environmental exposures, and focus on subgroups with extreme phenotypes and high familial occurrence. Functional characterization of associated variants is simultaneously needed to bridge the knowledge gap between sequence variance and consequence for eye growth.

The high prevalence of myopia in Korean children with influence of parental refractive errors: The 2008-2012 Korean National Health and Nutrition Examination Survey

The present study was conducted to investigate the effect of parental refractive errors on myopic children in Korean families using a nationally representative survey. We used the ophthalmologic examination dataset of the Korean National Health and Nutrition Examination Surveys IV and V, a nationwide population-based cross-sectional study using a complex, stratified, multistage, probability cluster survey, which were performed from 2008–2012. We included 3,862 children from 5–18 years of age from 2,344 families without any ocular trauma, surgical history, or cataract affecting refractive errors. The generalized estimating equation was conducted to assess the association of refractive errors among children and their parents. Among 3,862 children, 2,495 had myopia, which was 64.6% prevalence. There were 208 children with high myopia (5.4%). The prevalence rate ratio (PRR) for pediatric myopia and high myopia with myopic parents was 1.34 (95% confidence intervals [CI] 1.24–1.45) and 3.11 (95% CI 1.93–5.01), respectively. The PRR of myopia and high myopia in children significantly increased to 1.37 (95% CI 1.04–1.81) and 11.41 (95% CI 6.24–20.88), as the degree of parental myopia increased (P < 0.001, respectively). Children with two myopic parents were more myopic than those with only one myopic parent (P < 0.001, respectively). In addition to parental myopia, the age of the child and household income were also significant risk factors for all degrees of pediatric myopia in a family (P ≤ 0.005, respectively). In conclusion, Korean children showed high prevalence of myopia. Children with myopic parents showed a significantly greater risk for myopia and high myopia.