The impact of thyroid dysfunction in subclinical ranges on metabolic syndrome (MetS) is not well known. The aim of the present study is to evaluate the association of thyroid dysfunction with MetS and its components. In the cross-sectional population-based Tehran Thyroid Study, out of 5 786 randomly selected participants, aged≥20 years, subjects with thyroid nodules and cancer or any severe systemic disease, those who were pregnant and those using thyroid medication were excluded, leaving 5 422 subjects to be investigated. Body weight, waist circumference, and blood pressure were measured. Fasting blood glucose and concentrations of lipids and lipoproteins, free T4, and TSH were assayed. Mean age of the participants was 40.3±14.4 of whom 101 (2%) had overt hypothyroidism, 294 (5%) subclinical hypothyroidism, 82 (2%) overt hyperthyroidism, and 178 (3%) had subclinical hyperthyroidism; 1 704 (32%) had MetS. Clinically hypothyroid subjects had the highest prevalence of MetS (41.6%), abdominal obesity (45%), and hypertriglyceridemia (58%) compared to other groups (p<0.05). Significant odds ratio for prevalent MetS was observed only in clinically hypothyroid men [OR: 2.9, 95% CI: 1.04, 8.4, p=0.04]. In women, the association between overt hypothyroidism and MetS was marginally significant only in the crude model [OR: 0.068, 95% CI (0.97-2.42), p=0.06]. There was higher risk of Mets in subclinically hypothyroid subjects, aged>50. Overt and subclinical hyperthyroidism had significantly higher odds of hyperglycemia in men and women after full adjustment for age, smoking, and BMI. Overt hypothyroidism and subclinical hypothyroidism especially in the elderly could be associated with MetS. Hyperthyroidism may induce hyperglycemia.

A decrease in serum fT4 values is associated with an increased risk for MetS, especially in non-obese adults.

Little is known about whether DNA methylation (DNAm) of cytosine-phosphate-guanine (CpG) sites at birth predicts patterns of lung function development. We used heel prick DNAm from the F1-generation of Isle of Wight birth cohort (IOWBC-F1) for discovery of CpGs associated with lung function trajectories (Forced Expiratory Volume, Forced Vital Capacity, their ratio, and Forced Expiratory Flow at 25–75%) over the first 26 years, stratified by sex. We replicated the findings in the Avon Longitudinal Study of Parents and Children (ALSPAC) using cord blood DNAm.Epigenome-wide screening was applied to identify CpGs associated with lung function trajectories in 396 boys, and 390 girls of IOWBC-F1. Replication in ALSPAC focused on lung function at ages 8, 15 and 24 years. Statistically significantly replicated CpGs were investigated for consistency in direction of association between cohorts, stability of DNAm over time in IOWBC-F1, relevant biological processes, and for association with gene expression (n=161) in IOWBC F2-generation (IOWBC-F2).Differential DNAm of 8 CpGs on genes GLUL, MYCN, HLX, LHX1, COBL, COL18A1, STRA6, and WNT11 involved in developmental processes, were significantly associated with lung function in the same direction in IOWBC-F1 and ALSPAC, and showed stable patterns at birth, age 10 and 18 years between high and low lung function trajectories in IOWBC-F1. CpGs on LHX1 and COL18A1 were linked to gene expression in IOWBC-F2.In two large cohorts, novel DNAm at birth were associated with patterns of lung function in adolescence and early adulthood providing possible targets for preventative interventions against adverse pulmonary function development.