Sex differences in the influence of type 2 diabetes (T2D)-related genes, parental history of T2D, and obesity on T2D development: a case-control study

Environment driven changes in type 2 diabetes, overweight and obesity in an isolated Mixe community in the Valley of Oaxaca, southern Mexico

BACKGROUND

This study focused on type 2 diabetes mellitus (T2DM) in a group of adult Mixe, an Indigenous population from Oaxaca, Mexico. Mixe comprised an estimated 9.4% (n ≅ 90 000) of the Indigenous population in Oaxaca. Mexico.

OBJECTIVE

This study focused on a group of adult Mixe, an Indigenous population from Oaxaca, Mexico. To compare the prevalence of T2DM, overweight (OW), obesity (OB), and hypertension (HTN) between 2007 and 2017 for a small, isolated Mixe community in the Valley of Oaxaca, Mexico. We test whether or not environmental changes have affected T2DM prevalence.

METHODS AND MATERIALS

Demographic and medical record data were collected in the community in 2007 and 2017 from the medical clinic and the mayor's office. T2DM was medically diagnosed among adults (>34 years old), in 2007 (n = 730) and in 2017 (n = 829).

RESULTS

T2DM crude prevalence increased from 6.7% to 12.1% (p < .001) from 2007 to 2017. The mean age of the sample analyzed was 60.6 (SD = 9.7). Age-adjusted T2DM prevalence increased from 6.7% to 10.8% (p < .002). T2DM was 5.7%-5.5% among males (p < .53) and 7.1%-13.6% among females (p < .001). Sex-specific OW and OB simulation studies indicate females had 7% less OW in 2007, and males were unchanged compared with 2017. OB among males and females was significantly higher in 2017 compared with 2007 (increased by 15.2% and 8.3%, males and females, respectively). Sexes combined OW + OB increased 12.7% among males but was unchanged in females (-0.5%). In the sexes combined analysis, OW prevalence increased 12.7% to 27.1% (p < .001) and OB prevalence increased 10.7%-27.9% (p < .001) from 2007 to 2017. HTN did not change significantly from 2007 to 2017 (15.4% and 14.6%, respectively) (p = .63) in adults. Among T2DM individuals, the frequency of HTN was not significantly different in 2007 and 2017 (57.1% and 37%, respectively) (p = .65). Transition to a Western diet consisting of high-carbohydrate foods occurred at the same time as increased T2DM from 2007 to 2017, with a higher prevalence of T2DM noted among females in 2017.

CONCLUSIONS

An increased prevalence of T2DM, OW, and OB but not HTN was observed in the Mixe community from 2007 to 2017 and was associated with the adoption of a high-carbohydrate Western diet.

Sex- and age-specific associations of serum essential elements with diabetes among the Chinese adults: a community-based cross-sectional study

BACKGROUND

Although several studies have found the relationship between essential elements and diabetes, the studies about the association of essential elements with diabetes diagnosed according to an oral glucose tolerance test (OGTT) and glycated hemoglobin (HbA1c) in a sex- and age-specific manner were limited. To investigate the linear and nonlinear relationship of five essential elements including iron (Fe), copper (Cu), Zinc (Zn), magnesium (Mg), and calcium (Ca) with diabetes, fasting plasma glucose (FPG), 2-h postprandial plasma glucose (PPG), and HbA1c and to evaluate the sex- and age-specific heterogeneities in these relationships.

METHODS

A total of 8392 community-dwelling adults were recruited to complete a questionnaire and undergo checkups of anthropometric parameters and serum levels of five metals (Fe, Cu, Zn, Mg, and Ca). The multivariable logistic and linear regression, the restricted cubic spline (RCS) analysis, and subgroup analysis were applied to find the associations between the essential elements and the prevalence of diabetes as well as FPG, PPG, and HbA1c.

RESULTS

In the multivariable logistic regression and multivariable linear regression, serum Cu was positively associated with FPG, PPG, and HbA1c while serum Mg was significantly inversely correlated with FPG, PPG, HbA1c, and diabetes (all P < 0.001). In the RCS analysis, the non-linear relationship of Cu and diabetes (P < 0.001) was found. In the subgroup analysis, stronger positive associations of Cu with diabetes (P for interaction = 0.027) and PPG (P for interaction = 0.002) were found in younger women.

CONCLUSIONS

These findings may lead to more appropriate approaches to essential elements supplementation in people with diabetes of different ages and sexes. However, more prospective cohort and experimental studies are needed to probe the possible mechanism of sex- and age-specific associations between serum essential elements and diabetes.

LDER-GE estimates phenotypic variance component of gene-environment interactions in human complex traits accurately with GE interaction summary statistics and full LD information

Gene-environment (GE) interactions are essential in understanding human complex traits. Identifying these interactions is necessary for deciphering the biological basis of such traits. In this study, we review state-of-art methods for estimating the proportion of phenotypic variance explained by genome-wide GE interactions and introduce a novel statistical method Linkage-Disequilibrium Eigenvalue Regression for Gene-Environment interactions (LDER-GE). LDER-GE improves the accuracy of estimating the phenotypic variance component explained by genome-wide GE interactions using large-scale biobank association summary statistics. LDER-GE leverages the complete Linkage Disequilibrium (LD) matrix, as opposed to only the diagonal squared LD matrix utilized by LDSC (Linkage Disequilibrium Score)-based methods. Our extensive simulation studies demonstrate that LDER-GE performs better than LDSC-based approaches by enhancing statistical efficiency by ~23%. This improvement is equivalent to a sample size increase of around 51%. Additionally, LDER-GE effectively controls type-I error rate and produces unbiased results. We conducted an analysis using UK Biobank data, comprising 307 259 unrelated European-Ancestry subjects and 966 766 variants, across 217 environmental covariate-phenotype (E-Y) pairs. LDER-GE identified 34 significant E-Y pairs while LDSC-based method only identified 23 significant E-Y pairs with 22 overlapped with LDER-GE. Furthermore, we employed LDER-GE to estimate the aggregated variance component attributed to multiple GE interactions, leading to an increase in the explained phenotypic variance with GE interactions compared to considering main genetic effects only. Our results suggest the importance of impacts of GE interactions on human complex traits.

Type 1 and type 2 diabetes mortality burden: Predictions for 2030 based on Bayesian age-period-cohort analysis of China and global mortality burden from 1990 to 2019

AIMS

This study assessed diabetes (type 1 and type 2) mortality in China and globally from 1990 to 2019, predicting the next decade's trends.

MATERIALS AND METHODS

Data came from the Global Burden of Disease (GBD) database. The annual percentage change (AAPC) in age-standardized mortality rates (ASMR) for diabetes (type 1 and type 2) during 1990-2019 was calculated. A Bayesian age-period-cohort (BAPC) model predicted diabetes (type 1 and type 2) mortality from 2020 to 2030.

RESULTS

In China, type 1 diabetes deaths declined from 6,005 to 4,504 cases (AAPC -2.827), while type 2 diabetes deaths rose from 64,084 to 168,388 cases (AAPC -0.763) from 1990 to 2019. Globally, type 1 diabetes deaths increased from 55,417 to 78,236 cases (AAPC 0.223), and type 2 diabetes deaths increased from 606,407 to 1,472,934 cases (AAPC 0.365). Both China and global trends showed declining type 1 diabetes ASMR. However, female type 2 diabetes ASMR in China initially increased and then decreased, while males had a rebound trend. Peak type 1 diabetes deaths were in the 40-44 age group, and type 2 diabetes peaked in those over 70. BAPC predicted declining diabetes (type 1 and type 2) mortality burden in China and globally over the next 10 years.

CONCLUSIONS

Type 2 diabetes mortality remained high in China and globally despite decreasing type 1 diabetes mortality over 30 years. Predictions suggest a gradual decrease in diabetes mortality over the next decade, highlighting the need for continued focus on type 2 diabetes prevention and treatment.

Impact of the trans-ancestry polygenic risk score on type 2 diabetes risk, onset age and progression among population in Taiwan

Type 2 diabetes (T2D) prevalence in adults at a younger age has increased but the disease status may go unnoticed. This study aimed to determine whether the onset age and subsequent diabetic complications can be attributed to the polygenic architecture of T2D in the Taiwan Han population. A total of 9,627 cases with T2D and 85,606 controls from the Taiwan Biobank were enrolled. Three diabetic polygenic risk scores (PRSs), PRS_EAS and PRS_EUR, and a trans-ancestry PRS (PRS_META), calculated using summary statistic from East Asian and European populations. The onset age was identified by linking to the National Taiwan Insurance Research Database, and the incidence of different diabetic complications during follow-up was recorded. PRS_META (7.4%) explained a higher variation for T2D status. And the higher percentile of PRS is also correlated with higher percentage of T2D family history and prediabetes status. More, the PRS was negatively associated with onset age (β = -0.91 yr), and this was more evident among males (β = -1.11 vs. -0.76 for males and females, respectively). The hazard ratio of diabetic retinopathy (DR) and diabetic foot were significantly associated with PRS_EAS and PRS_META, respectively. However, the PRS was not associated with other diabetic complications, including diabetic nephropathy, cardiovascular disease, and hypertension. Our findings indicated that diabetic PRS which combined susceptibility variants from cross-population could be used as a tool for early screening of T2D, especially for high-risk populations, such as individuals with high genetic risk, and may be associated with the risk of complications in subjects with T2D. NEW & NOTEWORTHY Our findings indicated that diabetic polygenic risk score (PRS) which combined susceptibility variants from Asian and European population affect the onset age of type 2 diabetes (T2D) and could be used as a tool for early screening of T2D, especially for individuals with high genetic risk, and may be associated with the risk of diabetic complications among people in Taiwan.