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MOTIVATION: statistics from genome-wide association studies enable many valuable downstream analyses that are more efficient than individual-level data analysis while also reducing privacy concerns. As growing sample sizes enable better-powered analysis of gene-environment interactions, there is a need for gene-environment interaction-specific methods that manipulate and use summary statistics. RESULTS: We introduce two tools to facilitate such analysis, with a focus on statistical models containing multiple gene-exposure and/or gene-covariate interaction terms. REGEM (RE-analysis of GEM summary statistics) uses summary statistics from a single, multi-exposure genome-wide interaction study to derive analogous sets of summary statistics with arbitrary sets of exposures and interaction covariate adjustments. METAGEM (META-analysis of GEM summary statistics) extends current fixed-effects meta-analysis models to incorporate multiple exposures from multiple studies. We demonstrate the value and efficiency of these tools by exploring alternative methods of accounting for ancestry-related population stratification in genome-wide interaction study in the UK Biobank as well as by conducting a multi-exposure genome-wide interaction study meta-analysis in cohorts from the diabetes-focused ProDiGY consortium. These programs help to maximize the value of summary statistics from diverse and complex gene-environment interaction studies. AVAILABILITY AND IMPLEMENTATION: REGEM and METAGEM are open-source projects freely available at https://github.com/large-scale-gxe-methods/REGEM and https://github.com/large-scale-gxe-methods/METAGEM.
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Interacción Gen-Ambiente , Estudio de Asociación del Genoma Completo , Modelos Estadísticos , Tamaño de la Muestra , Interpretación Estadística de Datos , Polimorfismo de Nucleótido Simple , FenotipoRESUMEN
BACKGROUND: Variability in pediatric dosing of desmopressin (ddAVP) in AVP-deficiency (AVP-D) is well-documented but dosing recommendations are limited. This study evaluates and optimizes ddAVP dosing regimens in children with AVP-D using pharmacokinetic and pharmacodynamic (PK/PD) simulations. METHODS: Retrospective electronic health record review was done to identify children (<18 years) with AVP-D on ddAVP evaluated in the outpatient setting using ICD 9 and 10 codes. A previously developed PK/PD model from Michelet et al was used to simulate ddAVP concentrations and urine rates based on a child's age and ddAVP dose. The effects of demographic characteristics (age, weight, etc.) on dose and urine rate were investigated through simulations to optimize doses of ddAVP for children who were wet overnight. RESULT: A total of 276 dosing records were identified among 53 children with AVP-D. Simulations indicated that in children under 5 years of age who were wet overnight, increasing the outpatient dose to 50 mcg was predicted to decrease urine rate to a pattern similar to those who remained dry. CONCLUSION: An initial outpatient dose of at least 50 mcg for children between 1 and 5 years of age would improve efficacy of ddAVP. IMPACT: 50 mcg is likely a safe initial outpatient dose of oral desmopressin tablet for young children 1-5 yrs of age with central Diabetes Insipidus/AVP-Deficiency. We confirmed that desmopressin doses vary greatly in children with central Diabetes Insipidus/AVP-deficiency. Real-world clinical data can be leveraged to improve medication dosing in rare diseases.
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AIMS/HYPOTHESIS: The Latino population has been systematically underrepresented in large-scale genetic analyses, and previous studies have relied on the imputation of ungenotyped variants based on the 1000 Genomes (1000G) imputation panel, which results in suboptimal capture of low-frequency or Latino-enriched variants. The National Heart, Lung, and Blood Institute (NHLBI) Trans-Omics for Precision Medicine (TOPMed) released the largest multi-ancestry genotype reference panel representing a unique opportunity to analyse rare genetic variations in the Latino population. We hypothesise that a more comprehensive analysis of low/rare variation using the TOPMed panel would improve our knowledge of the genetics of type 2 diabetes in the Latino population. METHODS: We evaluated the TOPMed imputation performance using genotyping array and whole-exome sequence data in six Latino cohorts. To evaluate the ability of TOPMed imputation to increase the number of identified loci, we performed a Latino type 2 diabetes genome-wide association study (GWAS) meta-analysis in 8150 individuals with type 2 diabetes and 10,735 control individuals and replicated the results in six additional cohorts including whole-genome sequence data from the All of Us cohort. RESULTS: Compared with imputation with 1000G, the TOPMed panel improved the identification of rare and low-frequency variants. We identified 26 genome-wide significant signals including a novel variant (minor allele frequency 1.7%; OR 1.37, p=3.4 × 10-9). A Latino-tailored polygenic score constructed from our data and GWAS data from East Asian and European populations improved the prediction accuracy in a Latino target dataset, explaining up to 7.6% of the type 2 diabetes risk variance. CONCLUSIONS/INTERPRETATION: Our results demonstrate the utility of TOPMed imputation for identifying low-frequency variants in understudied populations, leading to the discovery of novel disease associations and the improvement of polygenic scores. DATA AVAILABILITY: Full summary statistics are available through the Common Metabolic Diseases Knowledge Portal ( https://t2d.hugeamp.org/downloads.html ) and through the GWAS catalog ( https://www.ebi.ac.uk/gwas/ , accession ID: GCST90255648). Polygenic score (PS) weights for each ancestry are available via the PGS catalog ( https://www.pgscatalog.org , publication ID: PGP000445, scores IDs: PGS003443, PGS003444 and PGS003445).
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Diabetes Mellitus Tipo 2 , Salud Poblacional , Humanos , Estudio de Asociación del Genoma Completo , Diabetes Mellitus Tipo 2/genética , Medicina de Precisión , Genotipo , Hispánicos o Latinos/genética , Polimorfismo de Nucleótido Simple/genéticaRESUMEN
Metformin is the first-line treatment for type 2 diabetes (T2D) in youth but with limited sustained glycemic response. To identify common variants associated with metformin response, we used a genome-wide approach in 506 youth from the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) study and examined the relationship between T2D partitioned polygenic scores (pPS), glycemic traits, and metformin response in these youth. Several variants met a suggestive threshold (P < 1 × 10-6), though none including published adult variants reached genome-wide significance. We pursued replication of top nine variants in three cohorts, and rs76195229 in ATRNL1 was associated with worse metformin response in the Metformin Genetics Consortium (n = 7,812), though statistically not being significant after Bonferroni correction (P = 0.06). A higher ß-cell pPS was associated with a lower insulinogenic index (P = 0.02) and C-peptide (P = 0.047) at baseline and higher pPS related to two insulin resistance processes were associated with increased C-peptide at baseline (P = 0.04,0.02). Although pPS were not associated with changes in glycemic traits or metformin response, our results indicate a trend in the association of the ß-cell pPS with reduced ß-cell function over time. Our data show initial evidence for genetic variation associated with metformin response in youth with T2D.
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Diabetes Mellitus Tipo 2 , Metformina , Adulto , Humanos , Adolescente , Metformina/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/complicaciones , Péptido C , Insuficiencia del Tratamiento , Variación Genética , Glucemia , Hipoglucemiantes/uso terapéuticoRESUMEN
OBJECTIVES: To evaluate the frequency and severity of new cases of youth-onset type 2 diabetes in the US during the first year of the pandemic compared with the mean of the previous 2 years. STUDY DESIGN: Multicenter (n = 24 centers), hospital-based, retrospective chart review. Youth aged ≤21 years with newly diagnosed type 2 diabetes between March 2018 and February 2021, body mass index ≥85th percentile, and negative pancreatic autoantibodies were included. Demographic and clinical data, including case numbers and frequency of metabolic decompensation, were compared between groups. RESULTS: A total of 3113 youth (mean [SD] 14.4 [2.4] years, 50.5% female, 40.4% Hispanic, 32.7% Black, 14.5% non-Hispanic White) were assessed. New cases of type 2 diabetes increased by 77.2% in the year during the pandemic (n = 1463) compared with the mean of the previous 2 years, 2019 (n = 886) and 2018 (n = 765). The likelihood of presenting with metabolic decompensation and severe diabetic ketoacidosis also increased significantly during the pandemic. CONCLUSIONS: The burden of newly diagnosed youth-onset type 2 diabetes increased significantly during the coronavirus disease 2019 pandemic, resulting in enormous strain on pediatric diabetes health care providers, patients, and families. Whether the increase was caused by coronavirus disease 2019 infection, or just associated with environmental changes and stressors during the pandemic is unclear. Further studies are needed to determine whether this rise is limited to the US and whether it will persist over time.
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COVID-19 , Diabetes Mellitus Tipo 1 , Diabetes Mellitus Tipo 2 , Cetoacidosis Diabética , Niño , Adolescente , Humanos , Femenino , Masculino , Pandemias , COVID-19/epidemiología , Diabetes Mellitus Tipo 1/diagnóstico , Diabetes Mellitus Tipo 1/epidemiología , Diabetes Mellitus Tipo 1/complicaciones , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/complicaciones , Estudios Retrospectivos , Cetoacidosis Diabética/complicacionesRESUMEN
PURPOSE OF REVIEW: To provide an update on knowledge the role of genetics in youth-onset type 2 diabetes (T2D). RECENT FINDINGS: The prevalence in youth of T2D, once thought to be exclusively a disease of adults, has increased by over 35% since 2001. Youth with T2D tend to have higher rates of complications, more aggressive disease, with more rapid loss of beta-cell function and a less favorable response to treatment than adults. Obesity is the most important risk factor for T2D, and the rise in childhood overweight and obesity appears responsible for the dramatic increase in T2D in youth. However, some obese children do not develop T2D, consistent with genetic differences in susceptibility to the disease in the setting of obesity and insulin resistance, currently far less well characterized in youth than in adults. Recent studies have begun to show associations of several established adult T2D genetic risk variants with youth-onset T2D and related glycemic quantitative traits, including the strongest known cross-population T2D genetic contributor TCF7L2. Maturity-onset diabetes of the young (MODY), a diabetes subtype distinct from type 1 diabetes (T1D) and T2D, is now known to result from a highly penetrant gene mutation in one of several genes. MODY has been shown to account for or contribute to at least 4.5% of clinically diagnosed T2D, even among those who are overweight or obese, impacting treatment decisions. The recently formed ProDiGY (Progress in Diabetes Genetics in Youth) Consortium is using genome-wide association studies and whole exome sequencing to understand the genetic architecture of T2D in youth, including how it differs from that of adults. The limited amount of research conducted to date on the genetics of youth-onset T2D, which tends to be a more aggressive disease than adult T2D, suggests some overlap with genes involved in adult T2D and a sizeable influence of highly penetrant monogenic diabetes variants. The ProDiGY Consortium is expected to provide a more comprehensive understanding of youth T2D genetics.
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Diabetes Mellitus Tipo 2/genética , Predisposición Genética a la Enfermedad , Adolescente , Edad de Inicio , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/fisiopatología , Estudio de Asociación del Genoma Completo , Humanos , Mutación/genética , Factores de RiesgoRESUMEN
On the basis of strong research evidence, hyperthyroidism is a rare but potentially serious disorder in childhood that, if uncontrolled, can lead to a wide range of complications, including effects on growth and development. ⢠On the basis of strong research evidence, Graves' disease is the most common cause of hyperthyroidism in children, accounting for greater than 95% of cases. It is caused by stimulating antibodies to the thyroid-stimulating hormone receptor. ⢠On the basis of some research evidence and consensus, history, physical examination, and thyroid function tests help diagnose hyperthyroidism. The condition is characterized by suppressed serum thyrotropin and elevated serum triiodothyronine and thyroxine. Radioactive iodine (or technetium-99) uptake and serum thyroid antibody measurements help determine the cause of hyperthyroidism. ⢠On the basis of some research evidence and consensus, treatment options for Graves' disease in children include antithyroid medications, radioactive iodine, and surgery. Antithyroid medications are commonly used as the first-line therapy in children. However, because of the low rates of spontaneous remission, most children eventually require permanent treatment with radioactive iodine or surgery. Of the available antithyroid medications, current guidelines recommend use of methimazole and not propylthiouracil because of the unacceptable risk of hepatotoxicity associated with propylthiouracil. ⢠On the basis of strong research evidence, thyroid storm is a rare life-threatening endocrine emergency that should be suspected in children with hyperthyroidism who demonstrate evidence of systemic decompensation. ⢠On the basis of strong research evidence, neonatal hyperthyroidism can occur in infants born to mothers with a history of Graves' disease due to transplacental passage of TSH receptor stimulating antibodies.
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Enfermedad de Graves , Niño , Medicina Basada en la Evidencia , Femenino , Enfermedad de Graves/complicaciones , Enfermedad de Graves/diagnóstico , Enfermedad de Graves/epidemiología , Enfermedad de Graves/terapia , Humanos , IncidenciaRESUMEN
Background: Weight and waist gain are significant concerns in adulthood. Both weight and waist gain are particularly important among South Asians, a high-risk group known to develop chronic cardiometabolic complications at any body mass index compared to other racial and ethnic groups. Objective: The aim of this study was to investigate factors predicting weight and waist gain in a longitudinal cohort of US South Asians, a high-risk group for developing obesity-related complications. Methods: We used data from Mediators of Atherosclerosis in South Asians Living in America study (MASALA) exam 1 (2010-2013) and exam 2 (2015-2018), with a mean 4.8 years of follow-up. Results: Of 634 participants studied (42.7% women, mean age 55 years, BMI 25.7 kg/m2, weight 70.4 kg at exam 1), 34.7% had gained ≥5% weight and 32.3% gained ≥5% waist at exam 2. In the adjusted models, older age, higher number of years of US residence, and having diabetes were associated with lower odds of weight gain; being female and having higher adiponectin were associated with higher odds of weight gain. Being female, employed full or part time, or retired were associated with lower odds of waist gain. Being single, separated/divorced, having a higher leptin and a higher C-reactive protein level were associated with higher odds of waist gain. Conclusions: South Asian subgroups with higher risk of weight and/or waist gain may benefit from targeted interventions to improve health outcomes.
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Background: Weight and waist gain are significant concerns in adulthood. Both weight and waist gain are particularly important among South Asians, known to have an increased risk of developing chronic cardiometabolic complications at any body mass index compared to other racial and ethnic groups. The aim of this study was to investigate factors predicting weight and waist gain in a longitudinal cohort of South Asians living in the US (United States). Methods: This was a prospective analysis using data from exam 1 (2010-2013) and exam 2 (2015-2018) of the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study, a prospective cohort study of South Asians (recruited from San Francisco and Chicago), with a mean 4.8 years of follow-up. Results: Of 634 participants studied (42.7 % women, mean age 55 years, BMI 25.7 kg/m2, weight 70.4 kg at exam 1), 34.7 % had gained ≥5 % weight and 32.3 % gained ≥5 % waist at exam 2. In the adjusted models, older age, higher number of years of US residence, and having diabetes were associated with lower odds of weight gain; being female and having higher adiponectin were associated with higher odds of weight gain. Being female and being employed full/part time or being retired predicted lower likelihood of waist gain. Being single, separated/divorced, having a higher leptin and a higher C-reactive protein level predicted higher likelihood of waist gain. Conclusions: The current study identified several social, demographic, and clinical factors that can serve as targets for obesity interventions among US South Asians. In addition, this study also raises hypotheses about associations of adipokine levels with weight and waist gain.
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Importance: Earlier puberty is associated with adverse health outcomes, such as mental health issues in adolescence and cardiometabolic diseases in adulthood. Despite rapid growth of the Asian American, Native Hawaiian, and Pacific Islander populations in the US, limited research exists on their pubertal timing, potentially masking health disparities. Objective: To examine pubertal timing among Asian American, Native Hawaiian, and Pacific Islander children and adolescents by disaggregating ethnic subgroups. Design, Setting, and Participants: This retrospective cohort study included Asian American, Native Hawaiian, and Pacific Islander youths aged 5 to 18 years assessed for pubertal development at Kaiser Permanente Northern California, a large, integrated health care delivery system. Follow-up occurred from March 2005, through December 31, 2019. Data were analyzed in October 2023. Exposure: Race and ethnicity, categorized into 11 ethnic subgroups: Asian Indian, Chinese, Filipino, Japanese, Korean, Native Hawaiian and Pacific Islander, Other South Asian, Other Southeast Asian, Vietnamese, multiethnic, and multiracial. Main Outcomes and Measures: Pubertal timing was determined using physician-assessed sexual maturity ratings (SMRs). Outcomes included the median age at transition from SMR 1 (prepubertal) to SMR 2 or higher (pubertal) for onset of genital development (gonadarche) in boys, breast development (thelarche) in girls, and pubic hair development (pubarche) in both boys and girls. Results: In this cohort of 107â¯325 Asian American, Native Hawaiian, and Pacific Islander children and adolescents (54.61% boys; 12.96% Asian Indian, 22.24% Chinese, 26.46% Filipino, 1.80% Japanese, 1.66% Korean, 1.96% Native Hawaiian and Pacific Islander, 0.86% Other South Asian, 3.26% Other Southeast Asian, 5.99% Vietnamese, 0.74% multiethnic, and 22.05% multiracial), the overall median ages for girls' pubarche and thelarche were 10.98 years (95% CI, 10.96-11.01 years) and 10.13 years (95% CI, 10.11-10.15 years), respectively. For boys' pubarche and gonadarche, median ages were 12.08 years (95% CI, 12.06-12.10 years) and 11.54 years (95% CI, 11.52-11.56 years), respectively. Differences between subgroups with earliest and latest median age at onset were 14 months for girls' pubarche, 8 months for thelarche, 8 months for boys' pubarche, and 4 months for gonadarche. In general, Asian Indian, Native Hawaiian and Pacific Islander, and Other South Asian subgroups had the earliest ages at onset across pubertal markers, while East Asian youths exhibited the latest onset. Restricting to those with healthy body mass index did not substantially change the findings. Conclusions and Relevance: In this cohort study of Asian American, Native Hawaiian, and Pacific Islander children and adolescents, pubertal timing varied considerably across ethnic subgroups. Further investigation is warranted to assess whether these differences contribute to observed health disparities in adulthood, such as type 2 diabetes and cardiovascular diseases.
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Asiático , Nativos de Hawái y Otras Islas del Pacífico , Pubertad , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Asiático/etnología , Asiático/estadística & datos numéricos , California , Hawaii , Nativos de Hawái y Otras Islas del Pacífico/estadística & datos numéricos , Pueblos Isleños del Pacífico , Pubertad/fisiología , Estudios Retrospectivos , Maduración Sexual/fisiología , Etnicidad , Personas del Sur de Asia , Grupos Raciales/etnología , Pueblos del Sudeste AsiáticoRESUMEN
Partitioned polygenic scores (pPS) have been developed to capture pathophysiologic processes underlying type 2 diabetes (T2D). We investigated the association of T2D pPS with diabetes-related traits and T2D incidence in the Diabetes Prevention Program. We generated five T2D pPS (ß-cell, proinsulin, liver/lipid, obesity, lipodystrophy) in 2,647 participants randomized to intensive lifestyle, metformin, or placebo arms. Associations were tested with general linear models and Cox regression with adjustment for age, sex, and principal components. Sensitivity analyses included adjustment for BMI. Higher ß-cell pPS was associated with lower insulinogenic index and corrected insulin response at 1-year follow-up with adjustment for baseline measures (effect per pPS SD -0.04, P = 9.6 × 10-7, and -8.45 µU/mg, P = 5.6 × 10-6, respectively) and with increased diabetes incidence with adjustment for BMI at nominal significance (hazard ratio 1.10 per SD, P = 0.035). The liver/lipid pPS was associated with reduced 1-year baseline-adjusted triglyceride levels (effect per SD -4.37, P = 0.001). There was no significant interaction between T2D pPS and randomized groups. The remaining pPS were associated with baseline measures only. We conclude that despite interventions for diabetes prevention, participants with a high genetic burden of the ß-cell cluster pPS had worsening in measures of ß-cell function.
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Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Estado Prediabético , Humanos , Células Secretoras de Insulina/metabolismo , Estado Prediabético/genética , Masculino , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/metabolismo , Femenino , Persona de Mediana Edad , Predisposición Genética a la Enfermedad , Herencia Multifactorial , Adulto , IncidenciaRESUMEN
The prevalence of youth-onset type 2 diabetes (T2D) and childhood obesity has been rising steadily1, producing a growing public health concern1 that disproportionately affects minority groups2. The genetic basis of youth-onset T2D and its relationship to other forms of diabetes are unclear3. Here we report a detailed genetic characterization of youth-onset T2D by analysing exome sequences and common variant associations for 3,005 individuals with youth-onset T2D and 9,777 adult control participants matched for ancestry, including both males and females. We identify monogenic diabetes variants in 2.4% of individuals and three exome-wide significant (P < 2.6 × 10-6) gene-level associations (HNF1A, MC4R, ATXN2L). Furthermore, we report rare variant association enrichments within 25 gene sets related to obesity, monogenic diabetes and ß-cell function. Many youth-onset T2D associations are shared with adult-onset T2D, but genetic risk factors of all frequencies-and rare variants in particular-are enriched within youth-onset T2D cases (5.0-fold increase in the rare variant and 3.4-fold increase in common variant genetic liability relative to adult-onset cases). The clinical presentation of participants with youth-onset T2D is influenced in part by the frequency of genetic risk factors within each individual. These findings portray youth-onset T2D as a heterogeneous disease situated on a spectrum between monogenic diabetes and adult-onset T2D.
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Diabetes Mellitus Tipo 2 , Obesidad Infantil , Masculino , Adulto , Femenino , Humanos , Adolescente , Niño , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/genética , Exoma , Estudio de Asociación del Genoma Completo , BiologíaRESUMEN
Background: There is a range of responses among individuals seen for medical management of their obesity. This retrospective analysis of longitudinal data considers the relationship between identified prediabetes and subsequent weight change among children (8-17 years) in a weight management clinic. Methods: Analysis included 733 patients (2687 visits in 2008-2016) with overweight and obesity (but not diabetes) whose referral laboratories included a hemoglobin A1c (HbA1c) within 90 days. Mixed-effects modeling examined the association between baseline prediabetes (serum HbA1c 5.7%-6.4%) and growth curve of percentage of the 95th percentile for BMI (%BMIp95). Random effects (individual growth curves) and fixed effects (prediabetes status, starting age and %BMIp95, sex, race/ethnicity, and linear slope and quadratic term of months since the initial visit) were modeled. Interactions between prediabetes and elapsed time estimated the influence of a recent prediabetic-range HbA1c on weight during the subsequent 12 months. Results: Mean %BMIp95 was 125.5% (SD 22.5), corresponding to severe obesity, and 35% had prediabetes. Adjusted monthly decrease in %BMIp95 was stronger for children with prediabetes compared with the peers in this clinic (slope: -0.62, standard error 0.10, p < 0.001). Conclusion: There was greater weight improvement among children with prediabetes compared with their peers with normal HbA1c.
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Type 2 diabetes diagnosed in childhood or early adulthood is termed early-onset type 2 diabetes. Cases of early-onset type 2 diabetes are increasing rapidly globally, alongside rising obesity. Compared with a diagnosis later in life, an earlier-onset diagnosis carries an unexplained excess risk of microvascular complications, adverse cardiovascular outcomes, and earlier death. Women with early-onset type 2 diabetes also have a higher risk of adverse pregnancy outcomes. The high burden of complications renders individuals with early-onset type 2 diabetes at future risk of multimorbidity and interventions to reverse these concerning trends should be a priority. Within the early-onset cohort, disease pathophysiology and interventions have been better studied in paediatric-onset (<19 years) type 2 diabetes compared to adults; however, young adults aged 19-39 years (a larger number proportionally) are not well characterised and are also invisible in the current evidence base supporting management, which is derived from trials in later-onset type 2 diabetes. Young adults with type 2 diabetes face challenges in self-management that older individuals are less likely to experience (being in education or of working age, higher diabetes distress, and possible obesity-related stigma and diabetes-related stigma). There is a major research gap as to the optimal strategies to deploy in managing type 2 diabetes in adolescents and young adults, given that current models of care appear to not work as well in this age group. In the face of manifold risk factors (obesity, female sex, social deprivation, non-White European ethnicity, and genetic risk factors) prevention strategies with tailored lifestyle interventions, where needed, are likely to have greater success, but more evidence is needed. In this Review, we draw on evidence from both adolescents and young adults to provide a contemporary update on the current insights and emerging trends in early-onset type 2 diabetes.
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Diabetes Mellitus Tipo 2 , Adolescente , Adulto , Niño , Femenino , Humanos , Embarazo , Adulto Joven , Diabetes Mellitus Tipo 2/epidemiología , Diabetes Mellitus Tipo 2/terapia , Diabetes Mellitus Tipo 2/complicaciones , Etnicidad , Obesidad/complicaciones , Resultado del Embarazo , Factores de Riesgo , Edad de InicioRESUMEN
Youth-onset type 2 diabetes (T2D) is a growing public health concern. Its genetic basis and relationship to other forms of diabetes are largely unknown. To gain insight into the genetic architecture and biology of youth-onset T2D, we analyzed exome sequences of 3,005 youth-onset T2D cases and 9,777 ancestry matched adult controls. We identified (a) monogenic diabetes variants in 2.1% of individuals; (b) two exome-wide significant (P < 4.3×10-7) common coding variant associations (in WFS1 and SLC30A8); (c) three exome-wide significant (P < 2.5×10-6) rare variant gene-level associations (HNF1A, MC4R, ATX2NL); and (d) rare variant association enrichments within 25 gene sets broadly related to obesity, monogenic diabetes, and ß-cell function. Many association signals were shared between youth-onset and adult-onset T2D but had larger effects for youth-onset T2D risk (1.18-fold increase for common variants and 2.86-fold increase for rare variants). Both common and rare variant associations contributed more to youth-onset T2D liability variance than they did to adult-onset T2D, but the relative increase was larger for rare variant associations (5.0-fold) than for common variant associations (3.4-fold). Youth-onset T2D cases showed phenotypic differences depending on whether their genetic risk was driven by common variants (primarily related to insulin resistance) or rare variants (primarily related to ß-cell dysfunction). These data paint a picture of youth-onset T2D as a disease genetically similar to both monogenic diabetes and adult-onset T2D, in which genetic heterogeneity might be used to sub-classify patients for different treatment strategies.
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Context: Both type 1 diabetes (T1D) and type 2 diabetes (T2D) have significant genetic contributions to risk and understanding their overlap can offer clinical insight. Objective: We examined whether a T1D polygenic score (PS) was associated with a diagnosis of T2D in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium. Methods: We constructed a T1D PS using 79 known single nucleotide polymorphisms associated with T1D risk. We analyzed 13 792 T2D cases and 14 169 controls from CHARGE cohorts to determine the association between the T1D PS and T2D prevalence. We validated findings in an independent sample of 2256 T2D cases and 27 052 controls from the Mass General Brigham Biobank (MGB Biobank). As secondary analyses in 5228 T2D cases from CHARGE, we used multivariable regression models to assess the association of the T1D PS with clinical outcomes associated with T1D. Results: The T1D PS was not associated with T2D both in CHARGE (P = .15) and in the MGB Biobank (P = .87). The partitioned human leukocyte antigens only PS was associated with T2D in CHARGE (OR 1.02 per 1 SD increase in PS, 95% CI 1.01-1.03, P = .006) but not in the MGB Biobank. The T1D PS was weakly associated with insulin use (OR 1.007, 95% CI 1.001-1.012, P = .03) in CHARGE T2D cases but not with other outcomes. Conclusion: In large biobank samples, a common variant PS for T1D was not consistently associated with prevalent T2D. However, possible heterogeneity in T2D cannot be ruled out and future studies are needed do subphenotyping.
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Genome-wide significant loci for metformin response in type 2 diabetes reported elsewhere have not been replicated in the Diabetes Prevention Program (DPP). To assess pharmacogenetic interactions in prediabetes, we conducted a genome-wide association study (GWAS) in the DPP. Cox proportional hazards models tested associations with diabetes incidence in the metformin (MET; n = 876) and placebo (PBO; n = 887) arms. Multiple linear regression assessed association with 1-year change in metformin-related quantitative traits, adjusted for baseline trait, age, sex, and 10 ancestry principal components. We tested for gene-by-treatment interaction. No significant associations emerged for diabetes incidence. We identified four genome-wide significant variants after correcting for correlated traits (P < 9 × 10-9). In the MET arm, rs144322333 near ENOSF1 (minor allele frequency [MAF]AFR = 0.07; MAFEUR = 0.002) was associated with an increase in percentage of glycated hemoglobin (per minor allele, ß = 0.39 [95% CI 0.28, 0.50]; P = 2.8 × 10-12). rs145591055 near OMSR (MAF = 0.10 in American Indians) was associated with weight loss (kilograms) (per G allele, ß = -7.55 [95% CI -9.88, -5.22]; P = 3.2 × 10-10) in the MET arm. Neither variant was significant in PBO; gene-by-treatment interaction was significant for both variants [P(G×T) < 1.0 × 10-4]. Replication in individuals with diabetes did not yield significant findings. A GWAS for metformin response in prediabetes revealed novel ethnic-specific associations that require further investigation but may have implications for tailored therapy.