Perchlorate, nitrate, and thiocyanate are three well-known sodium iodine symporter inhibitors, however, associations of their individual and concurrent exposure with central thyroid hormones sensitivity remain unclear. To investigate the associations of urinary perchlorate, nitrate, thiocyanate, and their co-occurrence with central thyroid hormones sensitivity among US general adults. A total of 7598 non-pregnant adults (weighted mean age 45.9 years and 52.9% men) from National Health and Nutritional Examination Survey 2007-2012 were included in this cross-sectional study. Central sensitivity to thyroid hormones was estimated with the Parametric Thyroid Feedback Quantile-based Index (PTFQI). Ordinary least-squares regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models were performed to examine the associations of three anions and their co-occurrence with PTFQI. The weighted mean values of urinary perchlorate, nitrate, thiocyanate, and perchlorate equivalent concentration (PEC) were 5.48 μg/L, 57.59 mg/L, 2.65 mg/L, and 539.8 μg/L, respectively. Compared with the lowest quartile, the least-square means difference (LSMD) of PTFQI was -0.0516 (LSMD ± SE: -0.0516 ± 0.0185, P < 0.01) in the highest perchlorate quartile. On average, PTFQI decreased by 0.0793 (LSMD ± SE: -0.0793 ± 0.0205, P < 0.001) between the highest and lowest thiocyanate quartile. Compared with those in the lowest quartile, participants in the highest PEC quartile had significantly decreased PTFQI levels (LSMD ± SE: -0.0862 ± 0.0188, P < 0.001). The WQS of three goitrogens, was inversely associated with PTFQI (β: -0.051, 95% CI: -0.068, -0.034). In BKMR model, PTFQI significantly decreased when the levels of three anions were at or above their 60th percentiles compared to the median values. Higher levels of urinary perchlorate, thiocyanate, and co-occurrence of three goitrogens were associated with increased central thyroid hormones sensitivity among US general adults. Further studies are warranted to replicate our results and elucidate the underlying causative mechanistic links.

Molybdenum has been found to be associated with metabolic disorders. However, the relationship between molybdenum and metabolic syndrome (MetS) is still unclear. A large case-control study was conducted in a Chinese population from the baseline of Ezhou-Shenzhen cohort. A total of 5356 subjects were included with 2678 MetS and 2678 controls matched by sex and age (±2 years). Medians (IQRs) of plasma molybdenum concentrations were 1.24 μg/L for MetS cases and 1.46 μg/L for controls. After adjustment for multiple covariates, the odds ratio (OR) and 95% confidence intervals (CIs) for MetS were 1.00 (reference), 0.71 (0.59–0.84), 0.56 (0.46–0.68), and 0.47 (0.39–0.58) across quartiles of plasma molybdenum, and per SD increment of log-transformed molybdenum was associated with a 23% lower risk of MetS. In the spline analysis, the risk of MetS and its components decreased steeply with increasing molybdenum and followed by a plateau when the cutoff point was observed around 2.0 μg/L. The dose-dependent relationship of molybdenum with MetS remained consistent when considering other essential elements in the Bayesian kernel machine regression (BKMR) model. In our study, higher plasma molybdenum was significantly associated with a lower risk of MetS, as well as its components, in a dose-response manner.

Background: The prevalence of central obesity is constantly increasing, and visceral fat is associated with increased production of inflammatory factors and metabolic risk factors. Lutein might retard the development of metabolic disease through its antioxidant and anti-inflammatory properties. Furthermore, epidemiological studies have associated higher dietary intake and serum levels of lutein with decreased adiposity. However, few randomised controlled trials have shown the effects of lutein supplementation on inflammatory biomarkers and metabolic risk factors, especially in adults with central obesity. Methods: This study will be conducted as a double-blind, parallel placebo-controlled clinical trial in which 120 people who have central obesity, are 18 to 60 years old and are willing to provide informed consent will be randomly assigned to the intervention or placebo group in a 1:1 ratio according to sex, age and waist circumference. The intervention group will receive 10 mg daily lutein supplementation for 12 weeks to explore the effect of lutein supplementation on serum lutein, glycaemic and lipid profiles, inflammatory factors and body composition. Two populations (intention-to-treat population and per-protocol population) will be used in the data analyses. Discussion: Our findings from this trial will contribute to the knowledge of the association between lutein supplementation and inflammatory biomarkers and metabolic risk factors in people with central obesity and will offer a possibility for the prevention of inflammatory diseases. Trial registration: Chinese Clinical Trial Registry: ChiCTR1800018098. Registered on 30 August 2018.

Serum ferritin (SF) and haemoglobin (Hb) are widely used in clinical practice to assess iron status. Studies exploring the relationship of SF and Hb with atherosclerotic cardiovascular disease (ASCVD) risk have yielded conflicting results, and some indicated sex specificity. Hypertensive patients have abnormal iron status. However, research on patients with hypertension is limited. We aim to investigate the sex-specific links of SF and Hb with the predicted 10-year ASCVD risk in hypertensive patients. This cross-sectional study included 718 hypertensive men and 708 hypertensive women. The predicted 10-year ASCVD risk was calculated based on the China-PAR equation. The dose–response curves were illustrated by fitting linear and quadratic models. In hypertensive men, the iron status fits for a quadratic model for ASCVD risk, showing a U-shape. After adjusting for potential confounding factors, the regression coefficients and 95% confidence intervals (95% CI) across tertile of SF were 0.0 (reference), − 0.99 (− 1.65, − 0.33) and − 0.22 (− 0.88, 0.44), and of Hb were 0.0 (reference), − 0.74 (− 1.41, − 0.08) and − 0.77 (− 1.46, − 0.08). In hypertensive women, iron status was linearly and positively associated with ASCVD risk. Per one unit increment of log-transformed SF as well as Hb was associated with a 1.22 (95% CI: 0.97, 1.48) and 0.04 (95% CI: 0.02, 0.07) increased in ASCVD risk score, respectively. A significant interaction between iron status and inflammation on ASCVD risk was observed in hypertensive women. SF and Hb showed a U-shape with ASCVD risk in hypertensive men; however, a positive linear relationship was observed in hypertensive women.

Central obesity poses a significant health threat. Lutein-rich fruits and vegetables may help manage obesity. Limited evidence suggests that lutein exerts health effects by inhibiting advanced glycation end products (AGEs), but data on its effects in centrally obese individuals are sparse. Thus, we aimed to investigate the effects of lutein supplementation in subjects with central obesity. A double-blind, randomized controlled trial was conducted involving patients with central obesity. Anthropometric indices, dietary intake, metabolic parameters, carotenoid and AGEs levels were compared between those receiving a 32-week intervention of 10 mg d⁻¹ lutein and a placebo group. There were 117 patients randomly assigned in the analysis. Twenty-three patients were lost to follow-up. Both intention-to-treat analysis and the per-protocol analysis showed significant reductions in plasma total cholesterol, low-density lipoprotein cholesterol, apolipoprotein B, and malonaldehyde levels in the lutein supplementation group compared with the placebo group. Significant differences were also observed between the groups in plasma lutein, carboxyethyl lysine (CEL), carboxymethyl lysine (CML), methylglyoxal hydroimidazolone (MG-HI) levels and skin carotenoid index (all P < 0.05). The mean difference and 95% confidence interval were 0.12 [0.08 to 0.16] μg ml⁻¹, −8.76 [−16.60 to −0.89] ng ml⁻¹, −72.3 [−134.0 to −10.9] ng ml⁻¹, −233.9 [−429.0 to −36.8] ng ml⁻¹ and 0.94 [0.56 to 1.31] a.u., respectively. Furthermore, changes in plasma lutein concentration were positively correlated with changes in the skin carotenoid index (r = 0.41, P < 0.001), and negatively correlated with changes in plasma CEL (r = −0.24, P = 0.018), (CML) (r = −0.21, P = 0.051, and MG-H1) (r = −0.25, P = 0.017). In conclusion, regular lutein intake can improve metabolic health in adults with central obesity by increasing plasma lutein concentrations, reducing oxidative stress, lowering plasma TC, LDL-C, and ApoB levels, and downregulating AGEs.