The prevalence and correlates of vision impairment and glasses ownership among ethnic minority and Han schoolchildren in rural China

The association between visual impairment, educational outcomes, and mental health: insights from eyeglasses usage among junior high school students in rural China

This study examined the association between visual impairment, visual impairment corrected by wearing eyeglasses, academic performance, and mental health among junior high school students in rural China. Visual acuity assessments were conducted on 19,425 junior high school students by trained medical and research professionals to determine the presence of visual impairment. All sample students were surveyed with a questionnaire that asked about individual and family characteristics, eyeglasses ownership, and educational aspirations and included a standardized math test. Students then completed an official Chinese simplified version of the Strengths and Difficulties Questionnaire (SDQ) to assess their mental health multidimensionally. Among our sample, 37.2% of them suffered from visual impairment, but only 43.4% of the visually impaired students wore proper eyeglasses. Approximately 9.3% of students were categorized as high risk for mental health problems based on their SDQ score. A significant positive association existed between impaired vision and poorer mental health, and eyeglasses usage was associated with better mental health among visually impaired students. For students with better academic performance, eyeglasses usage associated with better mental health. Eyeglasses usage shows a positive association with higher education aspiration both for students with better and worse academic performance. The significant positive relationship between eyeglasses usage and mental health may guide future interventions and policies designed to improve student mental health by supplying them with eyeglasses.

Identification of a Novel Mitochondrial tRNA Mutation in Chinese Family with Type 2 Diabetes Mellitus

Background

Mutations in mitochondrial tRNA (mt-tRNA) could be the origin of some type 2 diabetes mellitus (T2DM) cases, but the mechanism remained largely unknown.

Aim

The aim of this study was to assess the impact of a novel mitochondrial tRNACys/tRNATyr A5826G mutation on the development and progression of T2DM.

Methods

A four-generation Han Chinese family with maternally inherited diabetes underwent clinical, genetic and biochemical analyses. The mitochondrial DNA (mtDNA) mutations of three matrilineal relatives were screened by PCR-Sanger sequencing. Furthermore, to see whether m.A5826G mutations affected mitochondrial functions, the cybrid cell lines were derived from three subjects with m.A5826G mutation and three controls without this mutation. ATP was evaluated by luminescent cell viability assay, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were determined by flow cytometry. The student's two-tailed, unpaired t-test was used to assess the statistical significance between the control and mutant results.

Results

The age at onset of diabetes in this pedigree varied from 40 to 63 years, with an average of 54 years. Mutational analysis of mitochondrial genomes revealed the presence of a novel m.A5826G mutation. Interestingly, the m.A5826G mutation occurred at the conjunction between tRNACys and tRNATyr, a very conserved position that was critical for tRNAs processing and functions. Using trans-mitochondrial cybrid cells, we found that mutant cells carrying the m.A5826G showed approximately 36.5% and 22.4% reductions in ATP and MMP, respectively. By contrast, mitochondrial ROS levels increased approximately 33.3%, as compared with the wild type cells.

Conclusion

A novel m.A5826G mutation was identified in a pedigree with T2DM, and this mutation would lead to mitochondrial dysfunction. Thus, the genetic spectrum of mitochondrial diabetes was expanded by including m.A5826G mutation in tRNACys/tRNATyr, our study provided novel insight into the molecular pathogenesis, early diagnosis, prevention and clinical treatment for mitochondrial diabetes.

Depression, anxiety, stress symptoms and their determinants among secondary students with vision impairment in rural Northwestern China during the COVID-19 pandemic

Objective

The measures implemented to control the spread of Coronavirus disease 2019 (COVID-19) could affect children's mental and vision health. Youth particularly from minority and socioeconomically disadvantaged backgrounds were more likely to be impacted by these measures. This study aimed to examine the mental health of children with vision impairment and associated factors in North-western China during the COVID-19 pandemic.

Methods

A cross-sectional study was conducted among 2,036 secondary school children living in Ningxia Hui Autonomous Region. Participants completed a survey on sociodemographic and lifestyle information and answered the Chinese version of the 21-item Depression Anxiety Stress Scales (DASS-21) questionnaire. Presenting visual acuity was measured by a trained enumerator. Multivariate logistic regression analysis was used to identify potential risk factors for mental health problems.

Results

Responses from 1,992 (97.8%) children were included in the analysis after excluding those with incomplete mental health outcome data. The prevalence of depression, anxiety and stress symptoms within the dataset were 28.9, 46.4, and 22.3%, respectively. The distribution of children with different stress levels differed significantly between those with and without vision impairment (p = 0.03). Multivariable logistic regression analyses revealed that depression symptoms decreased with higher parental education (OR, 0.76, 95% confidence intervals (CI):0.63-0.96), longer sleep duration (OR, 0.90, 95% CI: 0.81-0.97) and longer study time (OR, 0.82, 95% CI: 0.74-0.91), whereas they increased with higher recreational screen time (OR, 1.19, 95% CI: 1.08-1.32). Anxiety symptoms decreased with higher parental education (OR, 0.80, 95% CI: 0.66-0.96) and increased with higher recreational screen time (OR, 1.15, 95% CI: 1.04-1.27) and being a left-behind child (OR, 1.26, 95% CI: 1.04-1.54). In addition, stress symptoms decreased with longer sleep duration (OR, 0.92, 95%CI: 0.85-0.99) and increased with higher number of siblings (OR, 1.10, 95% CI: 1.01-1.19), higher recreational screen time (OR, 1.15, 95% CI: 1.04-1.28) and older age (OR,1.12, 95% CI: 1.004-1.24).

Conclusion

A considerable proportion of our sample experienced mental health problems during the pandemic. Healthcare planners in China should consider interventions such as reducing recreational screen time, ensuring sufficient sleep, and timely detection of mental health symptoms among socioeconomically disadvantaged groups.

Mitochondrial Diabetes is Associated with tRNALeu(UUR) A3243G and ND6 T14502C Mutations

BACKGROUND

Mutations in mitochondrial DNA (mtDNA) are associated with type 2 diabetes mellitus (T2DM). In particular, m.A3243G is the most common T2DM-related mtDNA mutation in many families worldwide. However, the clinical features and pathophysiology of m.A3243G-induced T2DM are largely undefined.

METHODS

Two pedigrees with maternally inherited T2DM were underwent clinical, molecular and biochemical assessments. The mtDNA genes were PCR amplified and sequenced. Mitochondrial adenosine triphosphate (ATP) and reactive oxygen species (ROS) were measured in polymononuclear leukocytes derived from three patients with both the m.A3243G and m.T14502C mutations, three patients with only the m.A3243G mutation and three controls without these mutations. Moreover, GJB2, GJB3 and GJB6 mutations were screened by PCR-Sanger sequencing.

RESULTS

Members of the two pedigrees manifestated variable clinical phenotypes including diabetes and hearing and vision impairments. The age at onset of T2DM varied from 31 to 66 years, with an average of 41 years. Mutational analysis of mitochondrial genomes indicated the presence of the m.A3243G mutation in both pedigrees. Matrilineal relatives in one of the pedigrees harbored the coexisting of m.A3243G and m.T14502C mutations. Remarkably, the m.T14502C mutation, which causes the substitution of a conserved isoleucine for valine at position 58 in ND6 mRNA, may affect the mitochondrial respiratory chain functions. Biochemical analysis revealed that cell lines bearing both the m.A3243G and m.T14502C mutations exhibited greater reductions in ATP levels and increased ROS production compared with those carrying only the m.A3243G mutation. However, we did not find any mutations in the GJB2, GJB3 and GJB6 genes.

CONCLUSION

Our study indicated that mitochondrial diabetes is associated with the tRNA^Leu(UUR) A3243G and ND6 T14502C mutations.