Study on influential factors and reference values for thyroid volume in Chinese children aged 6-12 years.

The purpose of the current study was to research the factors influencing thyroid volume (TVOL) in 6-12-year-old children and update the reference values. A cross-sectional study was carried out in iodine-sufficient areas of four provinces in China. Urine, edible salt and drinking water samples were collected from children. Children's height, weight and TVOL were measured. Ridge regression was used to screen variables for solving the multicollinearity problem. Quantile regression was used to analyse the relationship between the quantiles of TVOL and other variables. In total, 5653 children aged 6-12 years were enrolled in this study, including 2838 boys and 2815 girls. There was no significant difference in TVOL between boys and girls (P > 0·05). Spearman correlation analysis showed that total TVOL was positively correlated with age, height, weight, body surface area (BSA) and BMI, and the correlation coefficients were 0·616, 0·663, 0·669, 0·685 and 0·479, respectively. Among them, the correlation between TVOL and BSA was the strongest. According to the ridge regression results, age and BSA influenced TVOL, and the ridge regression coefficients were 0·13 and 0·94, respectively. Quantile regression further showed that age and BSA had significant influences on the whole TVOL distribution (P < 0·001). Therefore, the TVOL of children aged 6-12 years in China was mainly influenced by age and BSA, and reference values for TVOL of different genders based on age and BSA were established.

Geographical influences on the iodine status in pregnant women, neonates, and school-age children in China.

BACKGROUND: Pregnant women, neonates, and school-age children are vulnerable to iodine deficiency. The iodine contents in the environment (drinking water and household salt for cooking) vary by geographical location in China. The aim of this study was to assess the iodine status in vulnerable groups from different geographical zones and analyze the iodine content in household salt and drinking water from these zones. METHODS: In coastal and inland regions of Zhejiang Province, China, samples of spot urine, drinking water, and household salt for cooking from both pregnant women and school-age children were determined for iodine concentration between 2017 and 2018. Thyroid-stimulating hormone (TSH) levels from neonates born between 2014 and 2015 were acquired from the Newborns Screening Information System. The iodine status of the vulnerable populations was assessed according to the criteria recommended by the World Health Organization. RESULTS: The median UIC of pregnant women was significantly lower in the coastal region (113.0 µg/L) than the inland region (134.9 µg/L; p < 0.001). The median UICs of pregnant women from these two regions were below the lower optimal iodine cutoff level of 150 µg/L. The percentage of neonates with elevated TSH (> 5 mIU/L) was significantly higher in the coastal region (15.8%) than the inland region (10.5%; p < 0.001). The percentage of neonates with elevated TSH from each region decreased within the range of mild iodine deficiency of 3-19.9%. The median UIC of the coastal school-age children was 156.0 µg/L, and the median UIC of inland children was 181.5 µg/L. Both medians fell within the recommended optimal iodine range of 100-299 µg/L. The iodine concentrations in drinking water varied from 1.0 µg/L in the inland region to 2.0 µg/L in the coastal region. The proportion of households that consumed iodized salt was lower in the coastal region (nearly 65%) than the inland region (approximately 95%). CONCLUSIONS: In these two regions with low iodine contents in drinking water, both pregnant women and neonates were iodine-deficient, although school-age children were iodine-sufficient. Urgent efforts are needed to improve the iodine status of pregnant women and neonates.

Iodine deficiency in pregnant women after the adoption of the new provincial standard for salt iodization in Zhejiang Province, China.

BACKGROUND: Zhejiang has achieved the goal of elimination of iodine deficiency disorders (IDD) via the implementation of universal salt iodization (USI) since 2011. Iodine content in household table salt decreased from the national standard (35 ppm) to the Zhejiang provincial standard (25 ppm) in 2012. It is crucial to periodically monitor iodine status in pregnant women because IDD in pregnancy have adverse effects on fetal neurodevelopment. METHODS: We carried out a cross-sectional study between April 2014 and September 2015 in the eight sentinel surveillance counties across Zhejiang Province, where IDD was previously known to be endemic. A total of 1304 pregnant women participated and provided a random spot urine sample and a household table salt sample. Urinary iodine concentration (UIC) was determined using arsenic-cerium catalytic spectrophotometry. Iodine content in salt was measured using a titration method with sodium thiosulphate. RESULTS: Overall, the median UIC of the total study population of pregnant women was 129.3 µg/L, with a higher UIC in inland (152.54 µg/L) and a lower UIC in coastal counties (107.54 µg/L). Household coverage of iodized salt was 94.6% and the rate of adequately iodized salt was 89.9%. CONCLUSIONS: Our results indicate deficient iodine status in the pregnant population of Zhejiang, according to the lower cut-off value of optimal iodine nutrition (150 µg/L) recommended by the World Health Organization. In addition to sustaining USI, more efforts are urgently needed to improve iodine intake in women during pregnancy, especially those residing in the coastal counties.

[Effect factors of the prevalence of thyroid nodules in Zhejiang Province in 2010].

OBJECTIVE: To assess the prevalence of thyroid nodules and explore the risk factors for thyroid nodules among the community residents in Zhejiang Province. METHODS: The residents of twenty-two communities in Zhejiang Province were selectedwith stratified cluster sampling. The cross-sectional survey includes questionnaire, examination on thyroid. The prevalence and related factors of thyroid nodules was described, and the possible risk factors for thyroid nodules was analyzed with logistic regression. RESULTS: The prevalence of thyroid nodules in Zhejiang was 21. 78%, and the prevalence of a single nodule was 11. 75%, which was higher than that of multiple nodules( 10. 03%). The prevalence of thyroid nodules in men was less than women, urban residents higher than rural, and both increased gradually with age. The residents in coastal areas had the highest prevalence of thyroid nodules, followed by sub-coastal areas, inland minimum. High education level, consumption of seafood habits, high frequency of anger, the history of thyroid disease and iodine deficiency were potential risk factors for thyroid nodules in this surveyed population. CONCLUSION: The prevalence of thyroid nodules in Zhejiang Province was at the middle level, female prevalence was greater than male, and gradully increased with age, the elderly should be the focus of prevention. Although thyroid nodules of children was at the lower rate, it should be paid attention due to high risk to develop to malignancy. High education level, consumption of seafood habits, high frequency of anger, the history of thyroid disease and iodine deficiency were potential risk factors for thyroid nodules, which need to be confirmed by further epidemiologic study.

A study on the influencing factors of urinary iodine concentration and the relationship between iodised salt concentration and urinary iodine concentration.

The aim of the present study was to explore the influencing factors of urinary iodine concentration (UIC) and the relationship between iodised salt concentration and UIC in order to give suggestions for the surveillance of iodine nutrition status. For this purpose, a multi-stage cluster sampling technique was employed in the present cross-sectional study. Correlations between UIC and salt iodine concentration were evaluated by Spearmen's correlation analysis. Risk factors of having a lower UIC were identified by logistic regression analysis, and the equations of UIC and salt iodine concentration were fitted by curve regression analysis. The median UIC was found to be 162·0 (25th-75th percentile 98·2-248·6) µg/l. The UIC was correlated with salt iodine concentration (Spearman's ρ = 0·144, P< 0·05). The multiple logistic regression analysis found the following influencing factors for having a lower UIC: age (OR 0·98, 95% CI 0·98, 0·98, P< 0·05); sex (OR 0·81, 95% CI 0·71, 0·92, P< 0·05); education level (OR 0·87, 95% CI 0·83, 0·90, P< 0·05); status of occupation (OR 0·91, 95% CI 0·86, 0·96, P< 0·05); occupation (OR 1·03, 95% CI 1·00, 1·05, P< 0·05); pickled food (OR 1·24, 95% CI 1·08, 1·42, P< 0·05); salt iodine concentration (OR 1·03, 95% CI 1·02, 1·03, P< 0·05). The curve regression analysis found that UIC (y) and salt iodine concentration (x) could be expressed by the following equation: y= 1·5772x 1·4845. In conclusion, the median UIC of individuals in Zhejiang Province falls within optimal status as recommended by the WHO/UNICEF/International Council for Control of IDD. To maintain optimal iodine nutrition status, salt iodine concentration should be in the range of 16·4 to 34·3 mg/kg.

An assessment of iodine nutritional status and thyroid hormone levels in children aged 8-10 years living in Zhejiang Province, China: a cross-sectional study.

UNLABELLED: Iodine is an essential nutrient for the synthesis of thyroid hormones that are critical for brain development. Iodine deficiencies were prevalent in China until the introduction of universal salt iodization (USI) in 1995. USI has been considered as the world's best achievements. This study aims to assess children's iodine nutrition and goiter status in Zhejiang Province in order to provide reasonable suggestions to the government for policy-making under the USI period. A cross-sectional survey in Zhejiang Province was conducted to children aged 8-10 years by stage cluster random sampling method. Spot urine samples were collected and analyzed. Thyroid ultrasonography examination was performed by special trained technicians using a 7.5-MHz transducer. Fasting venous blood samples were collected and analyzed for thyroid functional status. The median urinary iodine concentration was found to be 173.3 µg/L. The percentage of urine samples with iodine concentration <100 µg/L, 100-300 µg/L, and >300 µg/L was 15.5, 42.0, and 13.3 %, respectively. Goiter prevalence rate with iodine concentration <100 µg/L, 100-300 µg/L, and >300 µg/L was 6.8, 10.0, and 14.9 %, respectively, with no significant difference. Children with goiter have lower serum FT3 and T3 concentrations compared to those without goiter (p < 0.05). CONCLUSIONS: The median urinary iodine concentration of children aged 8-10 years falls in optimal iodine status as recommended by WHO/UNICEF/ICCIDD. Maintaining USI at an appropriate level is an important part of preventing iodine deficiency disorders and should always be based on routine monitoring urinary iodine concentration by the province.

Iodine nutritional status after the implementation of the new iodized salt concentration standard in Zhejiang Province, China.

BACKGROUND: Iodine deficiencies were prevalent in China until the introduction of universal salt iodization (USI) in 1995. In 2012, the standard salt iodine concentration was adjusted to 20-30 mg/kg. The success of USI for the control of iodine deficiency disorders requires monitoring its effect at a population level. METHODS: Two cross sectional surveys of a representative sample of children aged 8-10 years in Zhejiang Province were carried out in 2011 and 2013. Data on participants' socio-demographic characteristics were collected from the children using a structured questionnaire. Spot urine samples were collected and delivered to local Center for Disease Control and Prevention laboratory for measuring urinary iodine concentration. In 2011, out of 420 selected children aged 8-10 years, 391 were recorded and provided urine samples. In 2013, out of 1560 selected children aged 8-10 years, 1556 were recorded and provided urine samples. RESULTS: The median urinary iodine concentration of subjects in the 2013 survey was 174.3 µg/L, significantly lower than that of 2011(p = 0.000). The median urinary iodine concentration of subjects living in urban and rural areas in the 2013 survey was 169.0 µg/L, and 186.1 µg/L respectively, significantly lower than that of 2011 only for subjects living in urban areas (p = 0.000). There were no significant differences for subjects living in rural areas in the survey in 2011 and in 2013 (p = 0.086). CONCLUSIONS: At the time the new local iodization policy put forward, iodine nutrition was generally adequate in both urban and rural areas, suggesting that the new policy for adjusting the standard salt iodine concentration is effective. Our data also indicate that the reason people living in urban areas had a lower urinary iodine concentration than people in rural areas may be due to their preference for using non-iodized salt in the last 2 or 3 years. Maintaining USI at an appropriate level is an important part of preventing iodine deficiency disorders and should always be based on regular monitoring and comparison of urinary iodine concentration by province.

Assessment of Individual and Mixed Effects of Six Minerals on Thyroid Hormones in Chinese Pregnant Women.

The biosynthesis of thyroid hormones is essential for brain and neurological development. It requires iodine as a key component but is also influenced by other nutrients. Evidence for the combined nutrient status in relation to thyroid hormones during pregnancy is limited. We aimed to investigate the joint associations of iodine, selenium, zinc, calcium, magnesium and iron with maternal thyroid functions in 489 pregnant women from Hangzhou, China. Serum levels of six essential minerals and thyroid function parameters were measured during the first antenatal visit. Linear regression, quantile g-computation and Bayesian kernel machine regression were used to explore the individual and joint relationships between the six minerals and thyroid hormones. Linear regression analyses revealed that calcium was positively associated with free triiodothyronine (FT3). Zinc was positively associated with free thyroxine (FT4). Iodine was negatively associated with thyroid-stimulating hormone (TSH) and positively associated with FT3 and FT4. The quantile g-computation and BKMR models indicated that the joint nutrient concentration was negatively associated with TSH and positively associated with FT3 and FT4. Among the six minerals, iodine contributed most to thyroid function. The findings suggested that maintaining the appropriate concentration of minerals, either as individuals or a mixture, is important for thyroid health during pregnancy.

Unveiling the bioinformatic genes and their involved regulatory mechanisms in type 2 diabetes combined with osteoarthritis.

Background: Type 2 Diabetes Mellitus (T2D) and Osteoarthritis (OA) are both prevalent diseases that significantly impact the health of patients. Increasing evidence suggests that there is a big correlation between T2D and OA, but the molecular mechanisms remain elusive. The aims of this study are to investigate the shared biomarkers and potential molecular mechanisms in T2D combined with OA. Methods: T2D and OA-related differentially expressed genes (DEGs) were identified via bioinformatic analysis on Gene Expression Omnibus (GEO) datasets GSE26168 and GSE114007 respectively. Subsequently, extensive target prediction and network analysis were finished with Gene Ontology (GO), protein-protein interaction (PPI), and pathway enrichment with DEGs. The transcription factors (TFs) and miRNAs coupled in co-expressed DEGs involved in T2D and OA were predicted as well. The key genes expressed both in the clinical tissues of T2D and OA were detected with western blot and qRT-PCR assay. Finally, the most promising candidate compounds were predicted with the Drug-Gene Interaction Database (DGIdb) and molecular docking. Results: In this study, 209 shared DEGs between T2D and OA were identified. Functional analysis disclosed that these DEGs are predominantly related to ossification, regulation of leukocyte migration, extracellular matrix (ECM) structural constituents, PI3K/AKT, and Wnt signaling pathways. Further analysis via Protein-Protein Interaction (PPI) analysis and validation with external datasets emphasized MMP9 and ANGPTL4 as crucial genes in both T2D and OA. Our findings were validated through qRT-PCR and Western blot analyses, which indicated high expression levels of these pivotal genes in T2D, OA, and T2D combined with OA cases. Additionally, the analysis of Transcription Factors (TFs)-miRNA interactions identified 7 TFs and one miRNA that jointly regulate these important genes. The Receiver Operating characteristic (ROC) analysis demonstrated the significant diagnostic potential of MMP9 and ANGPTL4.Moreover, we identified raloxifene, ezetimibe, and S-3304 as promising agents for patients with both T2D and OA. Conclusion: This study uncovers the shared signaling pathways, biomarkers, potential therapeutics, and diagnostic models for individuals suffering from both T2D and OA. These findings not only present novel perspectives on the complex interplay between T2D and OA but also hold significant promise for improving the clinical management and prognosis of patients with this concurrent condition.

Role of Iodine Status and Lifestyle Behaviors on Goiter among Children and Adolescents: A Cross-Sectional Study in Zhejiang Province, China.

BACKGROUND: Iodine deficiency is a well-established cause of goiter, while the impact of lifestyle factors on goiter development remains underexplored. The study aims to explore the associations between iodine status, lifestyle factors, and the prevalence of goiter among children and adolescents in Zhejiang Province, China. METHODS: A cross-sectional survey was conducted in 2022 using a stratified multistage sampling, involving 2261 children aged 6-17. Among these 1562 participants underwent both urinalysis and thyroid ultrasound. Lifestyle factors were assessed through self-reported questionnaires. RESULTS: The prevalence of goiter in the study population was 10.8%. A high urinary iodine concentration (UIC) (>300 µg/L) was significantly associated with a decreased risk of goiter (OR = 0.49, 95%CI: 0.27-0.88). Excessive recreational screen time and a high frequency of dining out were associated with an increased Tvol, while adequate physical activity and sleep were inversely associated with goiter risk, while the combined effect of high UIC and healthy lifestyle showed a protective effect against goiter. CONCLUSION: Ensuring adequate iodine status and promoting healthy lifestyles are crucial for preventing goiter and enhancing thyroid health in children and adolescents, suggesting that public health strategies should integrate nutritional and lifestyle interventions.

Differences in Vitamin A Levels and Their Association with the Atherogenic Index of Plasma and Subclinical Hypothyroidism in Adults: A Cross-Sectional Analysis in China.

BACKGROUND: This study evaluates the association between vitamin A levels, AIP (the atherogenic index of plasma), and subclinical hypothyroidism. METHODS: A cross-sectional analysis was conducted involving a representative sample of 3530 Chinese adults. Linear and logistic regression models were utilized to evaluate the associations between AIP and subclinical hypothyroidism, stratified by vitamin A levels. These analyses were further differentiated by sex and age groups to identify any demographic-specific associations. RESULTS: In the vitamin A-sufficient group, an increase in AIP was associated with elevated total triiodothyronine (TT3) levels (ß = 0.26, 95%CI: 0.09, 0.41, p = 0.003). Conversely, in the group with severe vitamin A deficiency, higher AIP levels were linked to increased free triiodothyronine (fT3) and TT3 levels and decreased free thyroxine (fT4) levels (ß = 0.12, 0.03, and -0.29, respectively). Additionally, severe vitamin A deficiency increased the risk associated with AIP and subclinical hypothyroidism (OR = 1.66, 95%CI: 1.07, 2.58, p = 0.025). This risk was notably more pronounced in women and older adults, with odds ratios of 2.44 (95%CI: 1.55, 3.86, p < 0.001) and 2.14 (95%CI: 1.36, 3.38, p = 0.001), respectively. CONCLUSIONS: Vitamin A deficiency may increase the risk of the association between AIP and subclinical hypothyroidism, particularly among women and the elderly.

Dietary Iodine Intake and Sources among Residents in Zhejiang Province 10 Years after Reducing Iodine Concentration in Iodized Salt.

We aimed to assess dietary iodine intake and sources in Zhejiang Province a decade after a reduction in iodine concentration in iodized salt. Three-day 24 h dietary recall and household weighing were used, complemented by "Chinese Food Composition" data. Household water and salt samples were collected from 5890 residents and analyzed. Differences in iodized salt consumption rates were observed across the following regions: inland (84.20%), subcoastal (67.80%), and coastal (37.00%) areas. The median (P25, P75) iodine concentration in water and diet were 2.2 (0.9, 4.0) µg/L and 142.05 (58.94, 237.11) µg/d, respectively, with significant regional differences in dietary concentration (inland [185.61 µg/d], subcoastal [153.42 µg/d], and coastal [75.66 µg/d]). Males (149.99 µg/d) and iodized salt consumers (191.98 µg/d) had a significantly higher dietary iodine intake than their counterparts. Regions were ranked as follows based on the proportions of individuals meeting the recommended dietary iodine intake: inland (69.40%), subcoastal (56.50%), and coastal (34.10%) areas. Dietary sources included salt (48.54%), other foods (32.06%), drinking water (8.84%), laver (4.82%), kelp (3.02%), and other seafood (2.32%). The qualified iodized salt consumption rate was significantly lower than the national standard. Zhejiang Province should continue implementing measures to control iodine deficiency through salt iodization, education efforts, and increasing the qualified iodized salt consumption rate.

A Comparative Study on the Dietary Iodine Intake and the Contribution Rates of Various Foods to the Dietary Iodine Intake among Residents in Zhejiang in 2010 and 2022.

We aim to analyze the changes in dietary iodine intake and the contribution rates of various foods to it after the reduction in salt iodine concentration in Zhejiang. We used data from two cross-sectional nutrition surveillance surveys conducted by the Zhejiang Provincial Center for Disease Control and Prevention in 2010 (9798 residents) and 2022 (5980 residents). In both surveys, multi-stage stratified and systematic sampling were adopted, and uniformly trained investigators conducted the dietary surveys using a 24 h dietary review and weighing record methods for 3 consecutive days. From 2010 to 2022, the median salt iodine concentration and the consumption rate of qualified iodized salt in Zhejiang households dropped from 28.80 to 22.08 mg/kg and from 76.65% to 64.20%, respectively. Moreover, the residents' median dietary iodine intake decreased from 277.48 to 142.05 µg/d. Significant interregional differences in dietary iodine intake were found in 2010 and 2022 (H = 639.175, p < 0.001; H = 588.592, p < 0.001, respectively); however, no significant differences existed between urban and rural areas (p > 0.05). From 2010 to 2022, the proportion of residents with dietary iodine intake below the estimated average requirement increased from 15.10% to 34.80%, while that of residents with intake above the tolerable upper limit decreased from 15.00% to 2.90%. The contribution rate of salt to dietary iodine intake among residents in Zhejiang decreased from 74.92% to 48.54%, showing an apparent overall downward trend despite the dietary intake being generally adequate (markedly inadequate in coastal regions). The salt iodine concentration and the consumption rate of qualified iodized salt in households in Zhejiang showed downward trends. Salt remained the main source of dietary iodine; however, its contribution decreased significantly. Zhejiang may need to reverse the trend of the continuous decline in the consumption rate of qualified iodized salt to protect the health of its residents.

[Analysis of the prevalence and its influencing factors of diffuse goiter in Zhejiang].

OBJECTIVE: To evaluate the status of diffuse goiter of population in Zhejiang Province and to analyze the relevant influencing factors. METHODS: A total of 18 188 subjects were recruited in the cross sectional survey, by multistage stratified cluster random sampling method. B ultrasound measurement were carried among the subjects to detect the thyroid volume, and the basic information and life styles were interviewed by questionnaires. Then, we analyzed the distribution and its influencing factors of diffuse goiter. RESULTS: The ratio of diffuse goiter among the surveyed population was 2.2% (403/18 188), the difference showed statistical significance (χ(2) = 267.11, P < 0.05). The ratio among the group aged 6-7 years old and 8-10 years old was comparatively high, separately 10.3% (27/262) and 9.8% (51/519). The ratio among women (2.9%, 305/10 470) was higher than it among men (1.3%, 97/7672) (χ(2) = 55.55, P < 0.05). The residents from inland areas had the highest prevalence (3.2%, 138/4374), followed by residents from sub-coastal areas (2.0%, 131/6411), coastal areas minimum (1.8%, 138/4374) (χ(2) = 24.31, P < 0.05). The content of water iodine and salt iodine among people with symptoms of goiter had statistical difference with it among ordinary population (water iodine:χ(2) = 4.95, P = 0.026; salt iodine: χ(2) = 11.03, P < 0.01). The median(quartile) of water iodine in ordinary population was 2.41 (1.96-6.15) µg/L and among people with symptoms of goiter was 1.88 (1.49-5.15) µg/L. The median(quartile) of salt iodine in ordinary population was 30.18 (24.69-32.65) mg/kg and among people with symptoms of goiter was 29.1 (24.70-31.95) mg/kg. The influential factors of goiter were as follows: the family income, the education degree, the job and profession status, the diet character, the habitual sea food consumption, the alcohol intake status (χ(2) were separately 8.08, 37.85, 98.78, 68.69, 10.91, 12.21, 26.94, P < 0.05). Multi-factor analysis showed the results as follows: female (OR = 0.27 95%CI:0.18-0.39), school students (OR = 8.05, 95%CI:3.87-16.73), vegetarian (OR = 1.60, 95%CI:1.15-2.22) took a higher risk of getting pathogenic goiter; while the group of those who had university degree or above (OR = 0.84, 95%CI: 0.73-0.97), ate sea food frequently (OR = 0.62, 95%CI:0.44-0.88) took a lower risk. CONCLUSIONS: The ratio of diffuse goiter in the group aged among 6-7 years old and 8-10 years old was comparatively high. The ratio was influenced by many factors.

[Analysis of urine iodine level and its influencing factors in Zhejiang from 2009 to 2011].

OBJECTIVE: To evaluate the iodine nutrition level of population in Zhejiang province and to analyze the relevant influencing factors from 2009 to 2011. METHODS: From October 2009 to October 2011, a total of 19 517 subjects were recruited in this cross sectional survey, by multistage stratified cluster random sampling method. The subjects were all living over three years in Zhejiang province. The basic information and life styles were interviewed by questionnaires; and the samples of drinking water, edible salt and urines were separately collected from the subjects to test the content of iodine. In total, 16 228 subjects answered the questionnaire, and 265 samples of drinking water, 7811 samples of edible salt and 19 517 samples of urine were collected. Then, we analyzed the distribution of iodine in water, edible salt and urine samples, as well as the relevance. RESULTS: The median (25% - 75% percentile) of water iodine was 2.42 (1.17 - 6.28) µg/L in drinking water among Zhejiang residents; while separately 2.79 (1.60 - 6.87) µg/L in city and 2.04 (1.03 - 5.29) µg/L in country side (Z = 2.07, P < 0.05). The figures turned out to be 2.17 (1.22 - 5.73) µg/L, 2.77 (1.88 - 6.87) µg/L, and 1.40 (0.77 - 5.65) µg/L, respectively, in coastal areas, coastal periphery areas and inland areas (χ(2) = 11.16, P < 0.05). The median (25% - 75% percentile) of salt iodine was 28.80 (22.93 - 32.40) mg/kg; while separately 29.00 (24.50 - 32.60) mg/kg and 28.50 (13.90 - 32.29) mg/kg in city and country side (Z = 6.32, P < 0.05). The figures turned out to be 25.19 (0.00 - 30.20) mg/kg, 29.00 (26.60 - 31.70) mg/kg and 32.40 (28.94 - 36.30) mg/kg, respectively, in coastal areas, coastal periphery areas and inland areas (χ(2) = 1581.62, P < 0.05). The coverage rate of iodized salt was 79.54% (6213/7811) in all province. The urinary iodine median was 160.74(97.20 - 247.00) µg/L, while the urinary iodine median in pregnant women was 137.99 (82.40 - 215.30) µg/L, lower than the recommended optimal levels, which was 150 - 249 µg/L. The figures turned out to be 153.45(92.00 - 237.50) µg/L in city and 168.00 (102.18 - 257.00) µg/L in country side (Z = -9.25, P < 0.05); while in coastal, coastal periphery place and inland areas, the median were separately 156.00 (94.29 - 242.80) µg/L, 150.14 (94.70 - 227.00) µg/L and 187.70 (109.00 - 276.80) µg/L (χ(2) = 194.12, P < 0.05). The analysis of relevance between urine iodine, water iodine and iodized salt showed that the urine iodine would increase as long as the iodized salt increased; and the difference had statistical significance (χ(2) = 440.88, P < 0.01). And there were no relevance between urine iodine level and the water iodine level (χ(2)cmh = 0.57, P = 0.45). The analysis of the influencing factors showed that education background (χ(2) = 14.17, P < 0.05), different styles of career (χ(2) = 16.15, P < 0.01) and diet habits (χ(2) = 108.63, P < 0.01) could influence the level of urine iodine. CONCLUSION: Iodine was deficient in Zhejiang province. The nutrition level of iodine was fine in Zhejiang in 2009, however, the coverage rate of iodine was commonly low in coastal areas, especially the pregnant women suffered from iodine deficiency. In our study, the factors influencing the urine iodine level included iodized salt, age, education background and diet habits.

[Study on level of dietary iodine intake and its contribution rate of residents in Zhejiang].

OBJECTIVE: To assess the level of dietary iodine intake and its contribution in Zhejiang. METHODS: A total of 9798 subjects were recruited in this survey with multi-stage stratified cluster random sampling method in April, 2010, the 24-hours dietary recall method and the "food composition table" were used to obtain the dietary iodine intake, and edible salt and drinking water samples were collected to detect the content of iodine. RESULTS: A total of 9798 subjects were included in this survey. The mean intake of dietary iodine in Zhejiang residents per standard man-days was (395.13 ± 78.16) µg/d, which in between of Recommended Nutrient Intake (RNI) 150 µg/d and Tolerable Upper Intake Level (UL) 1000 µg/d; the iodine intake of 18.40% (1803/9798) subjects was lower than estimated average requirement of iodine (EAR), 4.68% (459/9798) subjects was higher than the UL. The means of dietary iodine intake in various areas were (498.85 ± 96.77) µg/d, (384.50 ± 88.76) µg/d and (326.33 ± 78.32)µg/d in inland areas, sub-coastal areas and coastal areas, successively (F = 27.17, P < 0.05); the proportions of dietary iodine intake lower than EAR were 34.89% (1239/3551), 10.48% (370/3530) and 7.14% (197/2717) in coastal areas, sub-coastal area and inland areas, successively (χ(2) = 62.87, P < 0.01) , while those higher than UL were 5.10% (180/3530), 4.86% (132/2717) and 4.14% (147/3551) in sub-coastal area, inland areas and coastal areas.In the condition of ignoring cooking loss, the mean contribution of dietary iodine intake in edible salt, all kinds of food and drinking water were 74.92% (296.03/395.13), 23.85% (94.24/395.13) and 1.23% (4.86/395.13), successively; the contributions of edible salt in inland areas, sub-coastal areas and coastal areas were 83.72% (417.64/498.85), 73.05% (280.88/384.50) and 66.83% (280.09/326.33), successively; the contributions of drinking water in sub-coastal areas, coastal areas and inland areas were 1.61% (6.19/384.50) , 1.44% (4.70/326.33) and 0.65% (3.24/498.85) , successively (χ(2) = 7.24, P = 0.032) ; the contribution of laver in coastal areas, sub-coastal areas and inland areas were 22.57% (73.65/326.33), 17.11% (65.79/384.50) and 8.09% (40.36/498.85), successively (χ(2) = 82.17, P < 0.01) ; the contribution of sea fish in coastal areas, sub-coastal areas and inland areas were 2.38% (7.77/326.33), 0.72% (2.77/384.50) and 0.68% (3.39/498.85) (χ(2) = 19.47, P = 0.012). CONCLUSIONS: The dietary iodine intake of Zhejiang residents was at recommended intake levels; the iodized salt turns out to be the main source, the iodine nutrition level was relatively low in coastal areas of Zhejiang, which the coverage of iodized salt should be improved.

Thyroglobulin as a Sensitive Biomarker of Iodine Status in Mildly and Moderately Iodine-Deficient Pregnant Women.

Pregnant women are more susceptible to iodine deficiency. However, there are limitations in existing indicators for the evaluation of iodine nutrition in pregnant women. The study aimed to explore whether thyroglobulin (Tg) can be used as a more sensitive biomarker for pregnant women with mild and moderate iodine deficiency. A repeated-measure study was conducted among 1332 pregnant women in Zhejiang Province, China. Serum and urine specimens were collected at a mean of 10, 17, and 32 weeks of pregnancy, respectively; thyroid-stimulating hormone (TSH), Tg, and urinary iodine concentrations were measured. Linear mixed effects models were used to determine the associations between interaction of iodine concentrations and increasing gestation week and TSH and Tg, where participants were divided by urinary iodine concentration (UIC). The median Tg concentration was 11.56, 11.45, and 12.43 µg/L in the first, second, and third trimesters, respectively. After controlling the covariates, the interaction effects between the iodine status and gestation week were significant for both TSH and Tg (p = 0.038 and p = 0.007, respectively). TSH increased with the week of gestation in both iodine concentration groups. Tg increased with advancing pregnancy in the iodine-deficient group whereas it did not in the iodine-sufficient group. There was no significant variation in TSH at each trimester, and Tg was higher in the iodine-deficient group than in the iodine-sufficient group. Tg may be a more sensitive iodine status biomarker than TSH for pregnant women with mild-to-moderate iodine insufficiency.

The effects of temperature variability on mortality in patients with chronic obstructive pulmonary disease: a time-series analysis in Hangzhou, China.

Chronic obstructive pulmonary disease (COPD) is a leading cause of death in people aged over 60 years old. Research has been reported that ambient temperature and diurnal temperature range (DTR), as representative indices of temperature variability, are contributors to the development and exacerbation of COPD. However, few studies are available in Chinese population. In this study, we aimed to assess the associations of temperature variability on COPD mortality in a fast developing city in China. Using the mortality surveillance system, we obtained a total of 7,863 deaths attributed to COPD from 2014 to 2016. Quasi-Poisson generalized linear regression with distributed lag non-linear model was applied to explore the associations between temperature variability and COPD deaths, after controlling for the potential confounders, including relative humidity, day of week, public holiday, and long-term trend. A J-shaped association of DTR and a reversely J-shaped association of temperature for COPD mortality were observed. Risk estimates showed that the relative risks (RRs) of COPD mortality with extreme high DTR at lag 0 and 0-7 days were 1.045 (95% CI: 0.949-1.151) and 1.460 (95% CI: 1.118-1.908), and the extreme high temperature at lag 0 and 0-7 days were 1.090 (95% CI: 0.945-1.256) and 1.352 (95% CI: 1.163-1.572). Our findings suggest that short-term exposure to extreme temperature was associated with mortality for COPD in Hangzhou. The evidence has implications for policy decision-making and targeted interventions.

Low Iodine Intake May Decrease Women's Fecundity: A Population-Based Cross-Sectional Study.

Salt iodization is one of the most cost-effective strategies to eliminate iodine deficiency disorders (IDD). However, China's dismantling of salt monopoly has reduced the availability of iodized salt in the susceptible population in pregnancy, which might cause IDD and have adverse health effects on both themselves and their offspring. The aim of our study was therefore to explore the association between IDD and women's reproductive health. This is a population-based cross-sectional study conducted in 2018 in Zhejiang Province, China. A total of 1653 pregnant women participated in this study. Median urinary iodine concentration (UIC) in the population was used to assess iodine intake. Cox regression analyses were used to estimate the association between iodine intake and time to pregnancy, which was indicated with fecundability ratio (FR) and 95% confidence interval (CI). The percentage of participants with iodine deficiency who had been waiting longer than 13 months to get pregnant (20%; median UIC 119.6 µg/L) was significantly higher than those with iodine sufficiency (14%; median UIC 147.1 µg/L). A significant decrease in fecundity was observed in participants with iodine deficiency (FR, 0.820; 95% CI, 0.725-0.929) than those with iodine sufficiency. These findings indicate the importance of ongoing monitoring of iodine nutrition in women of reproductive age. Keeping a safe and optimal level of iodine nutrition during pregnancy should be emphasized.

Geographical influences on thyroid abnormalities in adult population from iodine-replete regions: a cross-sectional study.

The studies on the increasing incidence of thyroid abnormalities are scarce. The aim of this current study was to ascertain the effects of geographical region on thyroid abnormalities under the context of universal salt iodization (USI). We randomly selected 1255 participants residing in inland and 1248 in coast, with the determination of urinary iodine concentration (UIC) and functional and morphological abnormalities of thyroid gland. The median UIC was significantly higher for the inland participants (188.5 µg/L) than the coastal participants (128.5 µg/L; p < 0.001), indicating iodine sufficiency in both populations according to the recommended assessment criteria by the World Health Organization. However, the spectrum of thyroid abnormalities varied between regions, with hypothyroidism prevalent in inland and thyroid nodules in coast. The associations between region and thyroid abnormalities via binary logistic regression models showed that the coastal participants were at a higher risk of total thyroid abnormalities than those from the inland (OR 1.216, 95% CI 1.020-1.449), after the adjustment of ten confounders (demographical characteristics, smoking status, metabolism syndrome, and hyperuricemia). These results indicated that further investigations of the adverse effects of hypothyroidism and thyroid nodules on health burden is urgently needed to sustain USI program.