Myopia and Early-Onset Type 2 Diabetes: A Nationwide Cohort Study

Greater risk of type 2 diabetes progression in multifetal gestations with gestational diabetes: the impact of obesity

BACKGROUND

The relationship between gestational diabetes mellitus and adverse outcomes in multifetal pregnancies is complex and controversial. Moreover, limited research has focused on the risk of gestational diabetes mellitus progression to type 2 diabetes mellitus specifically in multifetal pregnancies, resulting in conflicting results from existing studies.

OBJECTIVE

This study aimed to assess the risk of gestational diabetes mellitus progression to type 2 diabetes mellitus between singleton and multifetal pregnancies in a large cohort of parturients with a 5-year follow-up.

STUDY DESIGN

A retrospective study was conducted on a prospective cohort of pregnant individuals with pregnancies between January 1, 2017, and December 31, 2020, followed up to 5 years after delivery. Glucose levels during pregnancy were obtained from the Meuhedet Health Maintenance Organization laboratory system and cross-linked with the Israeli National Diabetes Registry. The cohort was divided into 4 groups: singleton pregnancy without gestational diabetes mellitus, singleton pregnancy with gestational diabetes mellitus, multifetal pregnancy without gestational diabetes mellitus, and multifetal pregnancy with gestational diabetes mellitus. Gestational diabetes mellitus was defined according to the American Diabetes Association criteria using the 2-step strategy. Univariate analyses, followed by survival analysis that included Kaplan-Meier hazard curves and Cox proportional-hazards models, were used to assess differences between groups and calculate the adjusted hazard ratios with 95% confidence intervals for progression to type 2 diabetes mellitus.

RESULTS

Among 88,611 parturients, 61,891 cases met the inclusion criteria. The prevalence of type 2 diabetes mellitus was 6.5% in the singleton pregnancy with gestational diabetes mellitus group and 9.4% in the multifetal pregnancy with gestational diabetes mellitus group. Parturients with gestational diabetes mellitus, regardless of plurality, were older and had higher fasting plasma glucose levels in the first trimester of pregnancy. The rates of increased body mass index, hypertension, and earlier gestational age at delivery were significantly higher in the gestational diabetes mellitus group among patients with singleton pregnancies but not among patients with multifetal pregnancies. Survival analysis demonstrated that gestational diabetes mellitus was associated with adjusted hazard ratios of type 2 diabetes mellitus of 4.62 (95% confidence interval, 3.69-5.78) in singleton pregnancies and 9.26 (95% confidence interval, 2.67-32.01) in multifetal pregnancies (P<.001 for both). Stratified analysis based on obesity status revealed that, in parturients without obesity, gestational diabetes mellitus in singleton pregnancies increased the risk of type 2 diabetes mellitus by 10.24 (95% confidence interval, 6.79-15.44; P<.001) compared with a nonsignificant risk in multifetal pregnancies (adjusted hazard ratio, 9.15; 95% confidence interval, 0.92-90.22; P=.059). Among parturients with obesity, gestational diabetes mellitus was associated with an increased risk of type 2 diabetes mellitus for both singleton and multifetal pregnancies (adjusted hazard ratio, 3.66; [95% confidence interval, 2.81-4.67; P<.001] and 9.31 [95% confidence interval, 2.12-40.76; P=.003], respectively).

CONCLUSION

Compared with gestational diabetes mellitus in singleton pregnancies, gestational diabetes mellitus in multifetal pregnancies doubles the risk of progression to type 2 diabetes mellitus. This effect is primarily observed in patients with obesity. Our findings underscore the importance of providing special attention and postpartum follow-up for patients with multifetal pregnancies and gestational diabetes mellitus, especially those with obesity, to enable early diagnosis and intervention for type 2 diabetes mellitus.

CircRNA expression profiles and regulatory networks in the vitreous humor of people with high myopia

Myopia is a global health and economic issue. Circular RNAs (circRNAs) have been shown to play an important role in the pathogenesis of many ocular diseases. We first evaluated the circRNA profiles and possible roles in vitreous humor samples of individuals with high myopia by a competitive endogenous RNA (ceRNA) array. Vitreous humor samples were collected from 15 high myopic (5 for ceRNA array, and 10 for qPCR) and 15 control eyes (5 for ceRNA array, and 10 for qPCR) with idiopathic epiretinal membrane (ERM) and macular hole (MH). 486 circRNAs (339 upregulated and 147 downregulated) and 264 mRNAs (202 upregulated and 62 downregulated) were differentially expressed between the high myopia and control groups. The expression of hsa_circ_0033079 (hsa-circDicer1), hsa_circ_0029989 (hsa-circNbea), hsa_circ_0019072 (hsa-circPank1) and hsa_circ_0089716 (hsa-circEhmt1) were validated by qPCR. Pearson analysis and multivariate regression analysis showed positive and significant correlations for axial length with hsa-circNbea and hsa-circPank1. KEGG analysis showed that the target genes of circRNAs were enriched in the mTOR, insulin, cAMP, and VEGF signaling pathways. GO analysis indicated that circRNAs mainly targeted transcription, cytoplasm, and protein binding. CircRNA-associated ceRNA network analysis and PPI network analysis identified several critical genes for myopia. The expression of circNbea, circPank1, miR-145-5p, miR-204-5p, Nras, Itpr1 were validated by qPCR in the sclera of form-deprivation myopia (FDM) mice model. CircPank1/miR-145-5p/NRAS and circNbea/miR-204-5p/ITPR1 were identified and may be important in the progression of myopia. Our findings suggest that circRNAs may contribute to the pathogenesis of myopia and may serve as potential biomarkers.

Myopia and BMI: a nationwide study of 1.3 million adolescents

OBJECTIVE

This study analyzed the association between adolescent BMI and myopia severity.

METHODS

This cross-sectional study comprised 1,359,153 adolescents who were medically examined before mandatory military service. Mild-to-moderate and high myopia were defined based on right-eye refractive data. BMI was categorized based on the US age- and sex-matched percentiles. Logistic regression models were applied separately for women and men to estimate odds ratios (ORs) for myopia per BMI category.

RESULTS

A total of 318,712 adolescents had mild-to-moderate myopia and 23,569 had high myopia. Compared with low-normal BMI (reference group), adjusted ORs for mild-to-moderate and high myopia increased with increasing BMI status, reaching 1.39 (95% CI: 1.23-1.57) and 1.73 (95% CI: 1.19-2.51) for men with severe obesity, respectively, and 1.19 (95% CI: 1.12-1.27) and 1.38 (95% CI: 1.14-1.65) for women with mild obesity, respectively. ORs for mild-to-moderate and high myopia were also higher in men with underweight (OR = 1.20; 95% CI: 1.18-1.23 and OR = 1.39; 95% CI: 1.30-1.47) and women with underweight (OR = 1.06; 95% CI: 1.03-1.09 and OR = 1.12; 95% CI: 1.04-1.22). The overall size effect was greater for men than women (p_interaction  < 0.001), in whom the group with severe obesity did not reach statistical significance.

CONCLUSIONS

BMI was associated with myopia in a J-shaped pattern, with the size effect being greater for adolescent men than women. This study indicates that both low BMI and high BMI are associated with mild-to-moderate and severe myopia.