ABSTRACT
OBJECTIVE: Youth-onset type 2 diabetes (T2D) is physiologically distinct from adult-onset, but it is not clear how the two diseases differ at a molecular level. In utero exposure to maternal type 2 diabetes (T2D) is known to be a specific risk factor for youth-onset T2D. DNA methylation (DNAm) changes associated with T2D but which differ between youth- and adult-onset might delineate the impacts of T2D development at different ages and could also determine the contribution of exposure to in utero diabetes. METHODS: We performed an epigenome-wide analysis of DNAm on whole blood from 218 youth with T2D and 77 normoglycemic controls from the iCARE (improving renal Complications in Adolescents with type 2 diabetes through REsearch) cohort. Associations were tested using multiple linear regression models while adjusting for maternal diabetes, sex, age, BMI, smoking status, second-hand smoking exposure, cell-type proportions and genetic ancestry. RESULTS: We identified 3830 differentially methylated sites associated with youth T2D onset, of which 3794 were moderately (adjusted p-value < 0.05 and effect size estimate > 0.01) associated and 36 were strongly (adjusted p-value < 0.05 and effect size estimate > 0.05) associated. A total of 3725 of these sites were not previously reported in the EWAS Atlas as associated with T2D, adult obesity or youth obesity. Moreover, three CpGs associated with youth-onset T2D in the PFKFB3 gene were also associated with maternal T2D exposure (FDR < 0.05 and effect size > 0.01). This is the first study to link PFKFB3 and T2D in youth. CONCLUSION: Our findings support that T2D in youth has different impacts on DNAm than adult-onset, and suggests that changes in DNAm could provide an important link between in utero exposure to maternal diabetes and the onset of T2D.
Subject(s)
DNA Methylation , Diabetes Mellitus, Type 2 , Prenatal Exposure Delayed Effects , Humans , Diabetes Mellitus, Type 2/genetics , Female , DNA Methylation/genetics , Pregnancy , Adolescent , Male , Prenatal Exposure Delayed Effects/genetics , Epigenesis, Genetic/genetics , Age of Onset , Child , Case-Control Studies , Diabetes, Gestational/genetics , Adult , Epigenome/geneticsABSTRACT
AIMS: To evaluate associations between 24-h ambulatory blood pressure monitor (ABPM) data vs. single casual blood pressure (BP) and albuminuria in youth with type 2 diabetes. METHODS: A cross-sectional analysis of youth with type 2 diabetes 10-<18 yrs. from the iCARE cohort. MAIN EXPOSURES: daytime HTN (+/- nocturnal), isolated nocturnal HTN and single casual BP. MAIN OUTCOME: non-orthostatic urine albumin: creatinine ratio (ACR) ≥ 3 mg/mmol and log-transformed urine ACR. Regressions evaluated associations between 1. HTN status based on ABPM and log-transformed urine ACR (continuous) and 2. ABPM-derived BP z-scores and casual BPcentiles and albuminuria status (categorical). RESULTS: Of 281 youth included, 19.6 % had daytime HTN (+/- nocturnal), and 28.5 % isolated nocturnal HTN on 24-h ABPM. In multivariate linear regression, HTN (ABPM) (ß = 0.553; p = 0.001), duration of diabetes (ß = 0.857; p = 0.02), HbA1c (ß = 1.172; p ≤0.0001) and ACEI/ARB use (ß = 3.94; p < 0.0001) were positively associated with log-transformed ACR; (R2 = 0.184). In logistic regression analysis, all ABPM LMS z-scores were positively associated with albuminuria; casual BPcentile was not significant. CONCLUSIONS: Youth with type 2 diabetes have high rates of HTN based on 24-ABPM data. ABPM-derived measures of BP are associated with albuminuria. These data support the routine use of ABPM devices to diagnose hypertension in youth with type 2 diabetes.
