Genetic predisposition to obesity is associated with insulin secretion in Chinese adults: The Cardiometabolic Risk in Chinese (CRC) study

Global, regional, and national trends in metabolic risk factor-associated mortality among the working-age population from 1990-2019: An age-period-cohort analysis of the Global Burden of Disease 2019 study

BACKGROUND

Metabolic diseases contribute significantly to premature mortality worldwide, with increasing burdens observed among the working-age population (WAP). This study assessed global, regional, and national trends in metabolic disorders and associated mortality over three decades in WAP.

METHODS

Data from the Global Burden of Disease 2019 study were leveraged to assess global metabolism-associated mortality and six key metabolic risk factors in WAP from 1990-2019. An age-period-cohort model was employed to determine the overall percentage change in mortality.

RESULTS

The 2019 global metabolic risk-related mortality rate in WAP rose significantly by 50.73%, while the age-standardized mortality rate declined by 21.5%. India, China, Indonesia, the USA, and the Russian Federation were the top contributing countries to mortality in WAP, accounting for 51.01% of the total. High systolic blood pressure (HSBP), high body mass index (HBMI), and high fasting plasma glucose (HFPG) were the top metabolic risk factors for the highest mortality rates. Adverse trends in HBMI-associated mortality were observed, particularly in lower sociodemographic index (SDI) regions. HFPG-related mortality declined globally but increased in older age groups in lower SDI countries.

CONCLUSIONS

Despite a general decline in metabolic risk-related deaths in WAP, increasing HBMI- and HFPG-related mortality in lower SDI areas poses ongoing public health challenges. Developing nations should prioritize interventions addressing HBMI and HFPG to mitigate mortality risks in WAP.

Health burden of unbalanced fatty acids intake from 1990 to 2019: A global analysis

BACKGROUND

Unbalanced fatty acids intake is associated with a range of health outcomes; however, the impact on human health remains unclear globally. We aim to provide a comprehensive assessment of the health effect of unbalanced fatty acids intake on a global scale.

METHODS

We analyzed the trends of summary exposure value (SEV) and the attributable burden of unbalanced fatty acids intake, including diet low in polyunsaturated fatty acids (low PUFAs), diet low in seafood omega-3 fatty acids (low seafood-(ω-3)-PUFAs), and diet high in trans fatty acids (high TFAs) from 1990 to 2019 using data from Global Burden of Disease Study 2019.

FINDINGS

The global fatty acids intake was far from the optimal level. High-income North America had the highest SEV of diet of high TFAs, while less-developed regions located in Saharan Africa had the highest SEVs of low PUFAs and low seafood-(ω-3)-PUFAs. The attributable burden was unequally distributed to less-developed regions. Males had lower SEVs but higher attributable burden than females and this gender gap was particularly pronounced before the age of 59. The young population had a higher SEV of diet of low PUFAs, comparable SEV of low seafood-(ω-3)-PUFAs but lower SEV of high TFAs than the elderly population.

CONCLUSIONS

This study underpinned the high prevalence of unbalanced fatty acids intake worldwide and provided evidence-based guidance for identifying at-risk populations and developing effective strategies to improve fatty acids intake in the future.

FUNDING

The study was funded by Shanxi Province "136" Revitalization Medical Project Construction Funds and the Fundamental Research Funds for the Central Universities.

Birth weight is associated with obesity and T2DM in adulthood among Chinese women

BACKGROUND

Previous studies have indicated an association between birth weight (BW) and type 2 diabetes mellitus (T2DM), but few studies have explored this relationship under different conditions of obesity in adulthood.

METHODS

A total of 4,005 individuals from ten provinces of China were randomly selected to participate in this study. We used a questionnaire to collect age, BW, current weight, height, T2DM history, age at T2DM diagnosis, and other variables. The participants were divided into three groups were according to BW trisection (BW ≤ 2500 g for the lower BW group, 2500 g < BW ≤ 3500 g for the normal BW group, and BW > 3500 g for the higher BW group). The cutoff of overweight and obesity were 25 kg/m² and 28 kg/m², respectively.

RESULTS

The prevalence rates of T2DM among women with lower BW, normal BW and higher BW were 5.2%, 3.6% and 2.0%, respectively. The obesity prevalence rates in the lower BW, normal BW and higher BW groups were 8.1%, 6.7% and 9.0%, respectively. In the obese population, we did not find a relationship between BW and T2DM, but in the nonobese population, we found that with increasing BW, the risk of developing T2DM was reduced. Obese status in adulthood modified the association between BW and the risk of T2DM.

CONCLUSION

There is a "U" shape association between BW and risk of adulthood obesity in Chinese women, but this trend is not existed between BW and risk of developing T2DM. In non-overweight females, the risk of developing T2DM decreased with increasing BW, but this trend was not observed in overweight females.

Development of a genetic risk score for obesity predisposition evaluation

Obesity is a major public health issue resulting from an interaction between genetic and environmental factors. Genetic risk scores (GRSs) are useful to summarize the effects of many genetic variants on obesity risk. In this study, we aimed to assess the association of previously well-studied genetic variants with obesity and develop a genetic risk score to anticipate the risk of obesity development in the Iranian population. Among 968 participants, 599 (61.88%) were obese, and 369 (38.12%) were considered control samples. After genotyping, an initial screening of 16 variants associated with body mass index (BMI) was performed utilizing a general linear model (p < 0.25), and seven genetic variants were selected. The association of these variants with obesity was examined using a multivariate logistic regression model (p < 0.05), and finally, five variants were found to be significantly associated with obesity. Two gene score models (weighted and unweighted), including these five loci, were constructed. To compare the discriminative power of the models, the area under the curve was calculated using tenfold internal cross-validation. Among the studied variants, ADRB3 rs4994, FTO rs9939609, ADRB2 rs1042714, IL6 rs1800795, and MTHFR rs1801133 polymorphisms were significantly associated with obesity in the Iranian population. Both of the constructed models were significantly associated with BMI (p < 0.05) and the area under the mean curve of the weighted GRS and unweighted GRS were 70.22% ± 0.05 and 70.19% ± 0.05, respectively. Both GRSs proved to predict obesity and could potentially be utilized as genetic tools to assess the obesity predisposition in the Iranian population. Also, among the studied variants, ADRB3 rs4994 and FTO rs9939609 polymorphisms have the highest impacts on the risk of obesity.

Global Burden of Disease Study 2019 suggests that metabolic risk factors are the leading drivers of the burden of ischemic heart disease

Metabolic dysfunction is becoming a predominant risk for the development of many comorbidities. Ischemic heart disease (IHD) still imposes the highest disease burden among all cardiovascular diseases worldwide. However, the contributions of metabolic risk factors to IHD over time have not been fully characterized. Here, we analyzed the global disease burden of IHD and 15 associated general risk factors from 1990 to 2019 by applying the methodology framework of the Global Burden of Disease Study. We found that the global death cases due to IHD increased steadily during that time frame, while the mortality rate gradually declined. Notably, metabolic risk factors have become the leading driver of IHD, which also largely contributed to the majority of IHD-related deaths shifting from developed countries to developing countries. These findings suggest an urgent need to implement effective measures to control metabolic risk factors to prevent further increases in IHD-related deaths.

Genetics of obesity: what genetic association studies have taught us about the biology of obesity and its complications

Genome-wide association studies (GWAS) for BMI, waist-to-hip ratio, and other adiposity traits have identified more than 300 single-nucleotide polymorphisms (SNPs). Although there is reason to hope that these discoveries will eventually lead to new preventive and therapeutic agents for obesity, this will take time because such developments require detailed mechanistic understanding of how an SNP influences phenotype (and this information is largely unavailable). Fortunately, absence of functional information has not prevented GWAS findings from providing insights into the biology of obesity. Genes near loci regulating total body mass are enriched for expression in the CNS, whereas genes for fat distribution are enriched in adipose tissue itself. Gene by environment and lifestyle interaction analyses have revealed that our increasingly obesogenic environment might be amplifying genetic risk for obesity, yet those at highest risk could mitigate this risk by increasing physical activity and possibly by avoiding specific dietary components. GWAS findings have also been used in mendelian randomisation analyses probing the causal association between obesity and its many putative complications. In supporting a causal association of obesity with diabetes, coronary heart disease, specific cancers, and other conditions, these analyses have clinical relevance in identifying which outcomes could be preventable through weight loss interventions.

Differential response of rat strains to obesogenic diets underlines the importance of genetic makeup of an individual towards obesity

Obesity, a multifactorial disorder, results from a chronic imbalance of energy intake vs. expenditure. Apart from excessive consumption of high calorie diet, genetic predisposition also seems to be equally important for the development of obesity. However, the role of genetic predisposition in the etiology of obesity has not been clearly delineated. The present study addresses this problem by selecting three rat strains (WNIN, F-344, SD) with different genetic backgrounds and exposing them to high calorie diets. Rat strains were fed HF, HS, and HFS diets and assessed for physical, metabolic, biochemical, inflammatory responses, and mRNA expression. Under these conditions: significant increase in body weight, visceral adiposity, oxidative stress and systemic pro-inflammatory status; the hallmarks of central obesity were noticed only in WNIN. Further, they developed altered glucose and lipid homeostasis by exhibiting insulin resistance, impaired glucose tolerance, dyslipidemia and fatty liver condition. The present study demonstrates that WNIN is more prone to develop obesity and associated co-morbidities under high calorie environment. It thus underlines the cumulative role of genetics (nature) and diet (nurture) towards the development of obesity, which is critical for understanding this epidemic and devising new strategies to control and manage this modern malady.

An investigation of obesity susceptibility genes in Northern Han Chinese by targeted resequencing

Our earlier genome-wide linkage study of body mass index (BMI) showed strong signals from 7q36.3 and 8q21.13. This case-control study set to investigate 2 genomic regions which may harbor variants contributed to development of obesity.We employed targeted resequencing technology to detect single nucleotide polymorphisms (SNPs) in 7q36.3 and 8q21.13 from 16 individuals with obesity. These were compared with 504 East Asians in the 1000 Genomes Project as a reference panel. Linkage disequilibrium (LD) block analysis was performed for the significant SNPs located near the same gene. Genes involved in statistically significant loci were then subject to gene set enrichment analysis (GSEA).The 16 individuals aged between 30 and 60 years with BMI = 33.25 ± 2.22 kg/m. A total of 12,131 genetic variants across all of samples were found. After correcting for multiple testing, 65 SNPs from 25 nearest genes (INSIG1, FABP5, PTPRN2, VIPR2, WDR60, SHH, UBE3C, LMBR1, PAG1, IMPA1, CHMP4, SNX16, BLACE, EN2, CNPY1, LOC100506302, RBM33, LOC389602, LOC285889, LINC01006, NOM1, DNAJB6, LOC101927914, ESYT2, LINC00689) were associated with obesity at significant level q-value ≤ 0.05. LD block analysis showed there were 10 pairs of loci with D' ≥ 0.8 and r ≥ 0.8. GSEA further identified 2 major related gene sets, involving lipid raft and lipid metabolic process, with FDR values <0.12 and <0.4, respectively.Our data are the first documentation of genetic variants in 7q36.3 and 8q21.13 associated with obesity using target capture sequencing and Northern Han Chinese samples. Additional replication and functional studies are merited to validate our findings.