1 2149 118 EPIGENETIC MARKERS TO PREDICT CONVERSION FROM GESTATIONAL DIABETES TO TYPE 2 DIABETES. CONTEXT: LIFESTYLE FACTORS MEDIATE EPIGENETIC CHANGES THAT CAN CAUSE CHRONIC DISEASES. ALTHOUGH ANIMAL AND LABORATORY STUDIES LINK EPIGENETIC CHANGES TO DIABETES, EPIGENETIC INFORMATION IN WOMEN WITH GESTATIONAL DIABETES (GDM) AND TYPE 2 DIABETES IS LACKING. OBJECTIVE: THIS STUDY SOUGHT TO MEASURE EPIGENETIC MARKERS ACROSS PREGNANCY AND EARLY POSTPARTUM AND IDENTIFY MARKERS THAT COULD BE USED AS PREDICTORS FOR CONVERSION FROM GDM TO TYPE 2 DIABETES. DESIGN: GLOBAL HISTONE H3 DIMETHYLATION WAS MEASURED IN WHITE BLOOD CELLS AT THREE TIME POINTS: 30 WK GESTATION, 8-10 WK POSTPARTUM, AND 20 WK POSTPARTUM, FROM FOUR GROUPS OF WOMEN WITH AND WITHOUT DIABETES. SETTING AND PARTICIPANTS: A TOTAL OF 39 PARTICIPANTS (SIX TO NINE IN EACH GROUP) WERE RECRUITED INCLUDING: NONDIABETIC WOMEN; WOMEN WITH GDM WHO DEVELOPED POSTPARTUM TYPE 2 DIABETES; WOMEN WITH GDM WITHOUT POSTPARTUM TYPE 2 DIABETES; AND WOMEN WITH TYPE 2 DIABETES. MAIN OUTCOME MEASURE: PERCENTAGES OF DIMETHYLATION OF H3 HISTONES RELATIVE TO TOTAL H3 HISTONE METHYLATION WERE COMPARED BETWEEN DIABETIC/NONDIABETIC GROUPS USING APPROPRIATE COMPARATIVE STATISTICS. RESULTS: H3K27 DIMETHYLATION WAS 50-60% LOWER AT 8-10 AND 20 WK POSTPARTUM IN WOMEN WITH GDM WHO DEVELOPED TYPE 2 DIABETES, COMPARED WITH NONDIABETIC WOMEN. H3K4 DIMETHYLATION WAS 75% LOWER AT 8-10 WK POSTPARTUM IN WOMEN WITH GDM WHO SUBSEQUENTLY DEVELOPED TYPE 2 DIABETES COMPARED WITH WOMEN WHO HAD GDM WHO DID NOT. CONCLUSIONS: THE PERCENTAGE OF DIMETHYLATION OF HISTONES H3K27 AND H3K4 VARIED WITH DIABETIC STATE AND HAS THE POTENTIAL AS A PREDICTIVE TOOL TO IDENTIFY WOMEN WHO WILL CONVERT FROM GDM TO TYPE 2 DIABETES. 2016 2 649 37 BIRTHWEIGHT, MATERNAL WEIGHT TRAJECTORIES AND GLOBAL DNA METHYLATION OF LINE-1 REPETITIVE ELEMENTS. LOW BIRTHWEIGHT, PREMATURE BIRTH, INTRAUTERINE GROWTH RETARDATION, AND MATERNAL MALNUTRITION HAVE BEEN RELATED TO AN INCREASED RISK OF CARDIOVASCULAR DISEASE, TYPE 2 DIABETES MELLITUS, OBESITY, AND NEUROPSYCHIATRIC DISORDERS LATER IN LIFE. CONVERSELY, HIGH BIRTHWEIGHT HAS BEEN LINKED TO FUTURE RISK OF CANCER. GLOBAL DNA METHYLATION ESTIMATED BY THE METHYLATION OF REPETITIVE SEQUENCES IN THE GENOME IS AN INDICATOR OF SUSCEPTIBILITY TO CHRONIC DISEASES. WE USED DATA AND BIOSPECIMENS FROM AN EPIGENETIC BIRTH COHORT TO EXPLORE THE ASSOCIATION BETWEEN TRAJECTORIES OF FETAL AND MATERNAL WEIGHT AND LINE-1 METHYLATION IN 319 MOTHER-CHILD DYADS. NEWBORNS WITH LOW OR HIGH BIRTHWEIGHT HAD SIGNIFICANTLY LOWER LINE-1 METHYLATION LEVELS IN THEIR CORD BLOOD COMPARED TO NORMAL WEIGHT INFANTS AFTER ADJUSTING FOR GESTATIONAL AGE, SEX OF THE CHILD, MATERNAL AGE AT DELIVERY, AND MATERNAL SMOKING DURING PREGNANCY (P = 0.007 AND P = 0.036, RESPECTIVELY), BUT THE MAGNITUDE OF THE DIFFERENCE WAS SMALL. INFANTS BORN PREMATURELY ALSO HAD LOWER LINE-1 METHYLATION LEVELS IN CORD BLOOD COMPARED TO TERM INFANTS, AND THIS DIFFERENCE, THOUGH SMALL, WAS STATISTICALLY SIGNIFICANT (P = 0.004). WE DID NOT FIND IMPORTANT ASSOCIATIONS BETWEEN MATERNAL PREPREGNANCY BMI OR GESTATIONAL WEIGHT GAIN AND GLOBAL METHYLATION OF THE CORD BLOOD OR FETAL PLACENTAL TISSUE. IN CONCLUSION, WE FOUND SIGNIFICANT DIFFERENCES IN CORD BLOOD LINE-1 METHYLATION AMONG NEWBORNS WITH LOW AND HIGH BIRTHWEIGHT AS WELL AS AMONG PREMATURELY BORN INFANTS. FUTURE STUDIES MAY ELUCIDATE WHETHER CHROMOSOMAL INSTABILITIES OR OTHER FUNCTIONAL CONSEQUENCES OF THESE CHANGES CONTRIBUTE TO THE INCREASED RISK OF CHRONIC DISEASES AMONG INDIVIDUALS WITH THESE CHARACTERISTICS. 2011 3 4085 38 MATERNAL OBESITY AND GESTATIONAL DIABETES REPROGRAM THE METHYLOME OF OFFSPRING BEYOND BIRTH BY INDUCING EPIGENETIC SIGNATURES IN METABOLIC AND DEVELOPMENTAL PATHWAYS. BACKGROUND: OBESITY IS A NEGATIVE CHRONIC METABOLIC HEALTH CONDITION THAT REPRESENTS AN ADDITIONAL RISK FOR THE DEVELOPMENT OF MULTIPLE PATHOLOGIES. EPIDEMIOLOGICAL STUDIES HAVE SHOWN HOW MATERNAL OBESITY OR GESTATIONAL DIABETES MELLITUS DURING PREGNANCY CONSTITUTE SERIOUS RISK FACTORS IN RELATION TO THE APPEARANCE OF CARDIOMETABOLIC DISEASES IN THE OFFSPRING. FURTHERMORE, EPIGENETIC REMODELLING MAY HELP EXPLAIN THE MOLECULAR MECHANISMS THAT UNDERLIE THESE EPIDEMIOLOGICAL FINDINGS. THUS, IN THIS STUDY WE EXPLORED THE DNA METHYLATION LANDSCAPE OF CHILDREN BORN TO MOTHERS WITH OBESITY AND GESTATIONAL DIABETES DURING THEIR FIRST YEAR OF LIFE. METHODS: WE USED ILLUMINA INFINIUM METHYLATIONEPIC BEADCHIP ARRAYS TO PROFILE MORE THAN 770,000 GENOME-WIDE CPG SITES IN BLOOD SAMPLES FROM A PAEDIATRIC LONGITUDINAL COHORT CONSISTING OF 26 CHILDREN BORN TO MOTHERS WHO SUFFERED FROM OBESITY OR OBESITY WITH GESTATIONAL DIABETES MELLITUS DURING PREGNANCY AND 13 HEALTHY CONTROLS (MEASUREMENTS TAKEN AT 0, 6 AND 12 MONTH; TOTAL N = 90). WE CARRIED OUT CROSS-SECTIONAL AND LONGITUDINAL ANALYSES TO DERIVE DNA METHYLATION ALTERATIONS ASSOCIATED WITH DEVELOPMENTAL AND PATHOLOGY-RELATED EPIGENOMICS. RESULTS: WE IDENTIFIED ABUNDANT DNA METHYLATION CHANGES DURING CHILD DEVELOPMENT FROM BIRTH TO 6 MONTHS AND, TO A LESSER EXTENT, UP TO 12 MONTHS OF AGE. USING CROSS-SECTIONAL ANALYSES, WE DISCOVERED DNA METHYLATION BIOMARKERS MAINTAINED ACROSS THE FIRST YEAR OF LIFE THAT COULD DISCRIMINATE CHILDREN BORN TO MOTHERS WHO SUFFERED FROM OBESITY OR OBESITY WITH GESTATIONAL DIABETES. IMPORTANTLY, ENRICHMENT ANALYSES SUGGESTED THAT THESE ALTERATIONS CONSTITUTE EPIGENETIC SIGNATURES THAT AFFECT GENES AND PATHWAYS INVOLVED IN THE METABOLISM OF FATTY ACIDS, POSTNATAL DEVELOPMENTAL PROCESSES AND MITOCHONDRIAL BIOENERGETICS, SUCH AS CPT1B, SLC38A4, SLC35F3 AND FN3K. FINALLY, WE OBSERVED EVIDENCE OF AN INTERACTION BETWEEN DEVELOPMENTAL DNA METHYLATION CHANGES AND MATERNAL METABOLIC CONDITION ALTERATIONS. CONCLUSIONS: OUR OBSERVATIONS HIGHLIGHT THE FIRST SIX MONTHS OF DEVELOPMENT AS BEING THE MOST CRUCIAL FOR EPIGENETIC REMODELLING. FURTHERMORE, OUR RESULTS SUPPORT THE EXISTENCE OF SYSTEMIC INTRAUTERINE FOETAL PROGRAMMING LINKED TO OBESITY AND GESTATIONAL DIABETES THAT AFFECTS THE CHILDHOOD METHYLOME BEYOND BIRTH, WHICH INVOLVES ALTERATIONS RELATED TO METABOLIC PATHWAYS, AND WHICH MAY INTERACT WITH ORDINARY POSTNATAL DEVELOPMENT PROGRAMMES. 2023 4 6270 38 THE OBESOGENIC ENVIRONMENT: EPIGENETIC MODIFICATIONS IN PLACENTAL MELANOCORTIN 4 RECEPTOR GENE CONNECTED TO GESTATIONAL DIABETES AND SMOKING. BACKGROUND: MATERNAL METABOLIC INSULTS AS WELL AS GESTATIONAL DIABETES MELLITUS (GDM) INFLUENCE THE FETAL HEALTH AND MAY AFFECT 'OFFSPRING'S SUSCEPTIBILITY TO CHRONIC DISEASES VIA EPIGENETIC MODIFICATIONS. GDM, THE MOST COMMON METABOLIC DISORDER IN PREGNANCY, CAN BE CONSIDERED THE RESULT OF COMPLEX INTERACTIONS BETWEEN GENETIC AND ENVIRONMENTAL FACTORS. A CRITICAL POINT IN THIS VIEW IS THE IDENTIFICATION OF GENES WHICH ARE EPIGENETICALLY MODIFIED UNDER THE INFLUENCE OF GDM. THE MELANOCORTIN 4 RECEPTOR (MC4R) GENE PLAYS A CRUCIAL ROLE IN NUTRITIONAL HEALTH BY SUPPRESSING APPETITE AND PARTICIPATING IN ENERGY CONTROL REGULATION. THE CORRELATIONS BETWEEN PREGNANT 'WOMEN'S METABOLIC PROFILES AND PLACENTAL EPIGENETIC MODIFICATIONS OF THIS GENE HAVE BEEN POORLY INVESTIGATED. OBJECTIVE: THE AIM OF THIS STUDY WAS TO EVALUATE THE EFFECT OF GDM AND MATERNAL CLINICAL PARAMETERS AT THE THIRD TRIMESTER OF PREGNANCY TO DNA METHYLATION LEVELS IN THE PLACENTA AT CPG SITES OF MC4R GENE. DESIGN AND METHODS: SOCIO-DEMOGRAPHIC AND CLINICAL CHARACTERISTICS, MEDITERRANEAN DIET ADHERENCE, SMOKING HABITS, AND PHYSICAL ACTIVITY WERE ASSESSED AT THE THIRD TRIMESTER OF PREGNANCY OF 60 CAUCASIAN PREGNANT WOMEN, OF WHICH 33 WITH GDM. CLINICAL PARAMETERS OF THE NEWBORNS WERE RECORDED AT BIRTH. MC4R DNA METHYLATION ON MATERNAL AND FETAL SIDES OF THE PLACENTA WAS ANALYZED USING BISULFITE PYROSEQUENCING. RESULTS: MC4R DNA METHYLATION LEVELS AT CPG1 AND CPG2 WERE LOWER ON THE FETAL SIDE OF THE PLACENTA IN GDM-AFFECTED WOMEN THAN IN NON-GDM-AFFECTED RECRUITS (P = 0.033). MOREOVER, DNA METHYLATION LEVELS ON THE MATERNAL SIDE AT CPG1 WERE POSITIVELY RELATED TO GLUCOSE CONCENTRATION AT 2-H ORAL GLUCOSE TOLERANCE TEST (OGTT). ON THE OTHER HAND, CPG2 DNA METHYLATION WAS POSITIVELY RELATED TO BOTH 1-H AND 2-H DURING OGTT. MATERNAL DNA METHYLATION LEVEL AT CPG2 WAS ALSO ASSOCIATED WITH LOW DENSITY LIPOPROTEIN CHOLESTEROL (LDL-C) AT THE THIRD TRIMESTER OF PREGNANCY (RHO = 0.340, P < 0.05), WHILE CPG1 METHYLATION WAS NEGATIVELY RELATED TO MATERNAL WEIGHT VARIATIONS AT DELIVERY (RHO = -0.316, P < 0.05). SIGNIFICANT ASSOCIATIONS BETWEEN MC4R DNA METHYLATION ON THE MATERNAL SIDE AND LIPID PROFILE AT THIRD TRIMESTER OF PREGNANCY IN WOMEN SMOKERS WERE FOUND. CONCLUSION: OUR RESULTS SUGGEST THAT MC4R METHYLATION PROFILE IN THE PLACENTA IS RELATED TO MATERNAL METABOLIC AND NUTRITIONAL CONDITIONS, POTENTIALLY AFFECTING FETAL PROGRAMMING AND THE FUTURE METABOLIC HEALTH OF THE NEWBORN. 2022 5 1599 30 DNA METHYLATION SIGNATURE OF CHILDHOOD CHRONIC PHYSICAL AGGRESSION IN T CELLS OF BOTH MEN AND WOMEN. BACKGROUND: HIGH FREQUENCY OF PHYSICAL AGGRESSION IS THE CENTRAL FEATURE OF SEVERE CONDUCT DISORDER AND IS ASSOCIATED WITH A WIDE RANGE OF SOCIAL, MENTAL AND PHYSICAL HEALTH PROBLEMS. WE HAVE PREVIOUSLY TESTED THE HYPOTHESIS THAT DIFFERENTIAL DNA METHYLATION SIGNATURES IN PERIPHERAL T CELLS ARE ASSOCIATED WITH A CHRONIC AGGRESSION TRAJECTORY IN MALES. DESPITE THE FACT THAT SEX DIFFERENCES APPEAR TO PLAY A PIVOTAL ROLE IN DETERMINING THE DEVELOPMENT, MAGNITUDE AND FREQUENCY OF AGGRESSION, MOST OF PREVIOUS STUDIES FOCUSED ON MALES, SO LITTLE IS KNOWN ABOUT FEMALE CHRONIC PHYSICAL AGGRESSION. WE THEREFORE TESTED HERE WHETHER OR NOT THERE IS A SIGNATURE OF PHYSICAL AGGRESSION IN FEMALE DNA METHYLATION AND, IF THERE IS, HOW IT RELATES TO THE SIGNATURE OBSERVED IN MALES. METHODOLOGY/PRINCIPAL FINDINGS: METHYLATION PROFILES WERE CREATED USING THE METHOD OF METHYLATED DNA IMMUNOPRECIPITATION (MEDIP) FOLLOWED BY MICROARRAY HYBRIDIZATION AND STATISTICAL AND BIOINFORMATIC ANALYSES ON T CELL DNA OBTAINED FROM ADULT WOMEN WHO WERE FOUND TO BE ON A CHRONIC PHYSICAL AGGRESSION TRAJECTORY (CPA) BETWEEN 6 AND 12 YEARS OF AGE COMPARED TO WOMEN WHO FOLLOWED A NORMAL PHYSICAL AGGRESSION TRAJECTORY. WE CONFIRMED THE EXISTENCE OF A WELL-DEFINED, GENOME-WIDE SIGNATURE OF DNA METHYLATION ASSOCIATED WITH CHRONIC PHYSICAL AGGRESSION IN THE PERIPHERAL T CELLS OF ADULT FEMALES THAT INCLUDES MANY OF THE GENES SIMILARLY ASSOCIATED WITH PHYSICAL AGGRESSION IN THE SAME CELL TYPES OF ADULT MALES. CONCLUSIONS: THIS STUDY IN A SMALL NUMBER OF WOMEN PRESENTS PRELIMINARY EVIDENCE FOR A GENOME-WIDE VARIATION IN PROMOTER DNA METHYLATION THAT ASSOCIATES WITH CPA IN WOMEN THAT WARRANT LARGER STUDIES FOR FURTHER VERIFICATION. A SIGNIFICANT PROPORTION OF THESE ASSOCIATIONS WERE PREVIOUSLY OBSERVED IN MEN WITH CPA SUPPORTING THE HYPOTHESIS THAT THE EPIGENETIC SIGNATURE OF EARLY LIFE AGGRESSION IN FEMALES IS COMPOSED OF A COMPONENT SPECIFIC TO FEMALES AND ANOTHER COMMON TO BOTH MALES AND FEMALES. 2014 6 1439 30 DIFFERENTIAL PLACENTAL CPG METHYLATION IS ASSOCIATED WITH CHRONIC LUNG DISEASE OF PREMATURITY. BACKGROUND: CHRONIC LUNG DISEASE (CLD) IS THE MOST COMMON PULMONARY MORBIDITY IN EXTREMELY PRETERM INFANTS. IT IS UNCLEAR TO WHAT EXTENT PRENATAL EXPOSURES INFLUENCE THE RISK OF CLD. EPIGENETIC VARIATION IN PLACENTA DNA METHYLATION MAY BE ASSOCIATED WITH DIFFERENTIAL RISK OF CLD, AND THESE ASSOCIATIONS MAY BE DEPENDENT UPON SEX. METHODS: DATA WERE OBTAINED FROM A MULTI-CENTER COHORT OF INFANTS BORN EXTREMELY PRETERM (<28 WEEKS' GESTATION) AND AN EPIGENOME-WIDE APPROACH WAS USED TO IDENTIFY ASSOCIATIONS BETWEEN PLACENTAL DNA METHYLATION AND CLD (N = 423). ASSOCIATIONS WERE EVALUATED USING ROBUST LINEAR REGRESSION ADJUSTING FOR COVARIATES, WITH A FALSE DISCOVERY RATE OF 0.05. ANALYSES STRATIFIED BY SEX WERE USED TO ASSESS DIFFERENCES IN METHYLATION-CLD ASSOCIATIONS. RESULTS: CLD WAS ASSOCIATED WITH DIFFERENTIAL METHYLATION AT 49 CPG SITES REPRESENTING 46 GENES IN THE PLACENTA. CLD WAS ASSOCIATED WITH DIFFERENTIAL METHYLATION OF PROBES WITHIN GENES RELATED TO PATHWAYS INVOLVED IN FETAL LUNG DEVELOPMENT, SUCH AS P53 SIGNALING AND MYO-INOSITOL BIOSYNTHESIS. ASSOCIATIONS BETWEEN CPG METHYLATION AND CLD DIFFERED BY SEX. CONCLUSIONS: DIFFERENTIAL PLACENTAL METHYLATION WITHIN GENES WITH KEY ROLES IN FETAL LUNG DEVELOPMENT MAY REFLECT COMPLEX CELL SIGNALING BETWEEN THE PLACENTA AND FETUS WHICH MEDIATE CLD RISK. THESE PATHWAYS APPEAR TO BE DISTINCT BASED ON FETAL SEX. IMPACT: IN EXTREMELY PRETERM INFANTS, DIFFERENTIAL METHYLATION OF CPG SITES WITHIN PLACENTAL GENES INVOLVED IN PATHWAYS RELATED TO CELL SIGNALING, OXIDATIVE STRESS, AND TROPHOBLAST INVASION IS ASSOCIATED WITH CHRONIC LUNG DISEASE OF PREMATURITY. DNA METHYLATION PATTERNS ASSOCIATED WITH CHRONIC LUNG DISEASE WERE DISTINCTLY BASED ON FETAL SEX, SUGGESTING A POTENTIAL MECHANISM UNDERLYING DIMORPHIC PHENOTYPES. MECHANISMS RELATED TO FETAL HYPOXIA AND PLACENTAL MYO-INOSITOL SIGNALING MAY PLAY A ROLE IN FETAL LUNG PROGRAMMING AND THE DEVELOPMENTAL ORIGINS OF CHRONIC LUNG DISEASE. CONTINUED RESEARCH OF THE RELATIONSHIP BETWEEN THE PLACENTAL EPIGENOME AND CHRONIC LUNG DISEASE COULD INFORM EFFORTS TO AMELIORATE OR PREVENT THIS CONDITION. 2022 7 1503 29 DNA METHYLATION AND GENE EXPRESSION DIFFERENCES IN CHILDREN CONCEIVED IN VITRO OR IN VIVO. EPIDEMIOLOGICAL DATA INDICATE THAT CHILDREN CONCEIVED IN VITRO HAVE A GREATER RELATIVE RISK OF LOW BIRTH-WEIGHT, MAJOR AND MINOR BIRTH DEFECTS, AND RARE DISORDERS INVOLVING IMPRINTED GENES, SUGGESTING THAT EPIGENETIC CHANGES MAY BE ASSOCIATED WITH ASSISTED REPRODUCTION. WE EXAMINED DNA METHYLATION AT MORE THAN 700 GENES (1536 CPG SITES) IN PLACENTA AND CORD BLOOD AND MEASURED GENE EXPRESSION LEVELS OF A SUBSET OF GENES THAT DIFFERED IN METHYLATION LEVELS BETWEEN CHILDREN CONCEIVED IN VITRO VERSUS IN VIVO. OUR RESULTS SUGGEST THAT IN VITRO CONCEPTION IS ASSOCIATED WITH LOWER MEAN METHYLATION AT CPG SITES IN PLACENTA AND HIGHER MEAN METHYLATION AT CPG SITES IN CORD BLOOD. WE ALSO FIND THAT IN VITRO CONCEPTION-ASSOCIATED DNA METHYLATION DIFFERENCES ARE ASSOCIATED WITH GENE EXPRESSION DIFFERENCES AT BOTH IMPRINTED AND NON-IMPRINTED GENES. THE RANGE OF INTER-INDIVIDUAL VARIATION IN GENE EXPRESSION OF THE IN VITRO AND IN VIVO GROUPS OVERLAPS SUBSTANTIALLY BUT SOME INDIVIDUALS FROM THE IN VITRO GROUP DIFFER FROM THE IN VIVO GROUP MEAN BY MORE THAN TWO STANDARD DEVIATIONS. SEVERAL OF THE GENES WHOSE EXPRESSION DIFFERS BETWEEN THE TWO GROUPS HAVE BEEN IMPLICATED IN CHRONIC METABOLIC DISORDERS, SUCH AS OBESITY AND TYPE II DIABETES. THESE FINDINGS SUGGEST THAT THERE MAY BE EPIGENETIC DIFFERENCES IN THE GAMETES OR EARLY EMBRYOS DERIVED FROM COUPLES UNDERGOING TREATMENT FOR INFERTILITY. ALTERNATIVELY, ASSISTED REPRODUCTION TECHNOLOGY MAY HAVE AN EFFECT ON GLOBAL PATTERNS OF DNA METHYLATION AND GENE EXPRESSION. IN EITHER CASE, THESE DIFFERENCES OR CHANGES MAY AFFECT LONG-TERM PATTERNS OF GENE EXPRESSION. 2009 8 5875 28 SYMPTOMS OF ALLERGIC RHINITIS IN WOMEN DURING EARLY PREGNANCY ARE ASSOCIATED WITH HIGHER PREVALENCE OF ALLERGIC RHINITIS IN THEIR OFFSPRING. BACKGROUND: EPIGENETIC CONTROL OF GENE EXPRESSION PROFILES IS A UBIQUITOUS MECHANISM DURING CELL DIFFERENTIATION, ORGANOGENESIS AND CHRONIC INFLAMMATORY REACTIONS. RECENT STUDIES HAVE SHOWN THAT ALLERGEN EXPOSURE DURING VERY EARLY PREGNANCY INCREASES BRONCHIAL HYPERSENSITIVITY IN OFFSPRING IN A MURINE MODEL OF BRONCHIAL ASTHMA. HOWEVER, NO SUCH PHENOMENA WERE REPORTED IN HUMANS. IN THE PRESENT STUDY, THE ROLE OF EPIGENETIC CONTROL IN THE ONSET OF ALLERGIC DISEASES WAS INVESTIGATED. METHODS: A TOTAL OF 400 PAIRS OF MOTHERS WITH PHYSICIAN-DIAGNOSED ALLERGIC RHINITIS (AR) AND THEIR OFFSPRING (AGE 7-18 MONTHS) WHO PARTICIPATED IN A LARGE-SCALE MEDICAL CHECK-UP WERE ENROLLED IN THIS RETROSPECTIVE COHORT STUDY. FAMILY HISTORY OF ALLERGIC DISEASES AND THE PRESENCE OR ABSENCE OF AR SYMPTOMS DURING PREGNANCY WERE INQUIRED ABOUT USING A SELF-ANSWERED QUESTIONNAIRE. A LOGISTIC REGRESSION MODEL ADJUSTED FOR AGE, GENDER, BIRTH MONTH AND FATHER'S HISTORY OF ALLERGIC DISEASES WAS STATISTICALLY ANALYZED. RESULTS: OFFSPRING WHOSE MOTHERS HAD ANY AR SYMPTOMS DURING EARLY PREGNANCY SHOWED A SIGNIFICANTLY HIGHER ADJUSTED ODDS RATIO FOR THE ONSET OF AR IN OFFSPRING THAN THOSE WHOSE MOTHERS HAD NO SYMPTOMS DURING PREGNANCY (ADJUSTED ODDS RATIO: 6.26, P = 0.036). HOWEVER, THE SYMPTOMS OF AR DURING LATE PREGNANCY SHOWED NO EFFECTS ON THE ODDS RATIO. IN CONTRAST, THE PRESENCE OR ABSENCE OF AR SYMPTOMS DURING EARLY OR LATE PREGNANCY SHOWED NO ASSOCIATION WITH THE PREVALENCE OF FOOD ALLERGY, ATOPIC DERMATITIS OR ASTHMA IN OFFSPRING. CONCLUSIONS: OUR RESULTS SUGGEST THE PRESENCE OF POSSIBLE EPIGENETIC MECHANISMS REGULATING THE ONSET OF AR IN HUMANS PRESUMABLY THROUGH INCREASED ORGAN-SPECIFIC HYPERSENSITIVITY. 2007 9 5090 27 PLACENTAL ADIPONECTIN GENE DNA METHYLATION LEVELS ARE ASSOCIATED WITH MOTHERS' BLOOD GLUCOSE CONCENTRATION. GROWING EVIDENCE SUGGESTS THAT EPIGENETIC PROFILE CHANGES OCCURRING DURING FETAL DEVELOPMENT IN RESPONSE TO IN UTERO ENVIRONMENT VARIATIONS COULD BE ONE OF THE MECHANISMS INVOLVED IN THE EARLY DETERMINANTS OF ADULT CHRONIC DISEASES. IN THIS STUDY, WE TESTED WHETHER MATERNAL GLYCEMIC STATUS IS ASSOCIATED WITH THE ADIPONECTIN GENE (ADIPOQ) DNA METHYLATION PROFILE IN PLACENTA TISSUE, IN MATERNAL CIRCULATING BLOOD CELLS, AND IN CORD BLOOD CELLS. WE FOUND THAT LOWER DNA METHYLATION LEVELS IN THE PROMOTER OF ADIPOQ ON THE FETAL SIDE OF THE PLACENTA WERE CORRELATED WITH HIGHER MATERNAL GLUCOSE LEVELS DURING THE SECOND TRIMESTER OF PREGNANCY (2-H GLUCOSE AFTER THE ORAL GLUCOSE TOLERANCE TEST; R(S)