Iodine knowledge is associated with iodine status in Portuguese pregnant women: results from the IoMum cohort study

The state of iodine deficiency in Kyrgyzstan: Insights from studies of knowledge, attitudes and practices

OBJECTIVE

This study aimed to assess the knowledge, attitudes, and practices (KAPs) regarding iodine deficiency among the population of Kyrgyzstan, with a focus on pregnant women, and to correlate these factors with the urinary iodine concentration (UIC).

METHODS

A cross-sectional study was conducted using structured questionnaires and urine sample analysis to evaluate iodine status. A multistage stratified sampling method ensured a representative sample from both urban and rural areas. Descriptive statistics were used to summarize demographic characteristics and KAP variables, whereas chi-square tests and multivariate logistic regression analysis were used to identify predictors of KAP outcomes.

RESULTS

The study included 690 participants, with balanced representation from both urban and rural areas. The mean knowledge score was moderate, with significant gaps in the understanding of iodine deficiency. The participants generally had positive attitudes toward iodine intake but exhibited suboptimal practices, especially in rural areas. Pregnant women demonstrated greater knowledge, but fewer practical behaviors related to iodine intake. Compared with rural participants, urban participants had higher UIC levels, indicating better iodine nutrition. Multivariate regression analysis revealed that residence, knowledge, attitudes, and practices significantly influenced UIC levels.

CONCLUSION

Despite existing iodization programs, significant gaps remain in the knowledge and practices related to iodine intake, particularly in rural areas. This study highlights the need for targeted public health interventions to improve iodine nutrition and reduce the burden of iodine deficiency disorders in Kyrgyzstan. Enhancing public health education, improving the accessibility and affordability of iodized salt, and regularly monitoring the iodine status are essential strategies for addressing these issues.

Nutrition knowledge among pregnant women in Lebanon: A cross-sectional study

BACKGROUND

Women's knowledge of the nutritional guidelines during pregnancy can affect the health and nutritional status of both mother and child. Having good nutritional information related to maternal dietary intake and healthy lifestyles is therefore of great importance. However, there is limited published research that demonstrates pregnant women's knowledge of the nutritional guidelines during pregnancy in Lebanon.

OBJECTIVE

To assess the knowledge on food sources and energy recommendations as well as food safety practices and diet-health relationship among women during pregnancy in Lebanon.

DESIGN

A cross-sectional study.

METHODS

The study was conducted at prenatal care clinics in Lebanon, and all pregnant women present, regardless of nationality, were invited to complete the self-administered nutrition knowledge questionnaire. The study assessed five different nutrition knowledge domains (food sources of nutrients, dietary behaviors, food safety knowledge, micronutrients for fetal development, and energy requirements and weight gain) and the demographic characteristics of pregnant women who completed a multidimensional online survey based on validated and existing measures.

RESULTS

Four-hundred and ten responses were obtained. Approximately half of respondents (47%) held a university degree, for 42% of women this was their first pregnancy, and 71% had a planned pregnancy. Among the different nutrition knowledge domains, the highest levels of knowledge were for the behaviors that can minimize the effect of nausea/vomiting, heartburn, and constipation during pregnancy (63.9%) and the lowest levels of knowledge was for the importance of iodine and omega-3 fatty acids in pregnancy (28.4%). Most of females knew about food safety practices during pregnancy (72.9%) but less than half were knowledgeable about listeriosis contamination (45.9%), and the types of fish that are the safest to select during pregnancy (47.8%).

CONCLUSION

Despite the fact that pregnant women had an adequate level of knowledge in different nutrition-related areas, there was inadequate level of awareness related to critical nutrients and behaviors that can have adverse effects on mother and/or baby. Therefore, there is a need to focus on specific maternal nutrition aspects such as iron-rich foods, listeriosis food contamination, and nutrients that aid in fetal brain and retina development.

Iodine deficiency and real-life supplementation ineffectiveness in Polish pregnant women and its impact on thyroid metabolism

Introduction

Iodine is a pivotal component of thyroid hormones, and its deficiency leads to negative pregnancy outcomes. Therefore, during gestation, additional iodine supplementation is recommended.

Objectives

By evaluating a group of women from western Poland, the study updated on iodine status during pregnancy and the effectiveness of iodine supplementation in relation to the maternal and neonatal thyroid function.

Patients and methods

A total of 91 women were recruited before the delivery between 2019 and 2021. During the medical interview, the patients declared their dietary supplements intake. Thyroid parameters (TSH, ft3, ft4, a-TPO, a-Tg, and TRAb) were measured in the serum of mothers and in the cord blood of newborns after birth. Urinary iodine concentration (UIC) and urine/creatinine (UIC/crea) ratio were assessed in single urine samples using a validated high-performance liquid chromatography with ultraviolet detection (HPLC-UV). Neonatal TSH screening from dried blood spot was analyzed.

Results

Pregnant women showed a median (interquartile range) UIC of 106 (69-156) µg/liter and UIC/crea ratio of 104 (62-221) µg/g, whereas approximately 20% had UIC/crea below 50 µg/g, indicating iodine deficiency. The iodine supplementation ratio was 68%. No significant differences in UIC, UIC/crea and thyroid parameters were found between iodine supplemented and non-supplemented groups; however, the highest ioduria was detected when iodine was supplemented in addition to levothyroxine in comparison with both substances administered separately. Patients with UIC/crea within 150-249 µg/g demonstrated the lowest TSH and a-TPO levels. Screening TSH was above 5 mIU/liter in 6% of children.

Conclusions

Despite the national salt iodization and the recommendation to supplement iodine during gestation, the status of the abovementioned microelement and real-life intake revealed the ineffectiveness of the current iodine-deficiency prophylaxis model in pregnancy.

Relationship between mild iodine deficiency in pregnant women and thyroid function: A meta-analysis

BACKGROUND

Pregnant women are among the key groups in iodine nutrition evaluation. The purpose of the present study was to summarize the evidence supporting the relationship between mild iodine deficiency (UIC: 100-150 μg/L) in pregnant women and levels of thyroid function tests.

METHODS

This review follows the guidelines for systematic reviews (PRISMA 2020). Three electronic databases (PubMed, Medline, and Embase) were searched for relevant publications in English on the association between mild iodine deficiency in pregnant women and thyroid function. Articles published in Chinese were searched in China's electronic databases (CNKI, WanFang, CBM, and WeiPu). Pooled effects were presented as standardized mean differences (SMDs) and odds ratios (ORs) with 95% confidence intervals (CIs) using fixed or random effect models, respectively. This meta-analysis was registered at www.crd.york.ac.uk/prospero as CRD42019128120.

RESULTS

We summarized the results from 7 articles with 8261 participants. The overall pooled results showed that the levels of FT₃, FT4, and abnormal TgAb (the antibody levels exceeded the upper limit of the reference range) were significantly increased in pregnant women with mild iodine deficiency compared to pregnant women with adequate iodine status (FT₃: SMD=0.854, 95% CI: 0.188, 1.520; FT₄: SMD=0.550, 95% CI: 0.050, 1.051; TgAb: OR=1.292, 95% CI: 1.095; 1.524). Subgroup analysis was carried out on the sample size, ethnicity, country, and gestation of FT₃, FT_4, and TSH, but no plausible factor was found. Egger's tests indicated no publication bias.The increase in FT₃ and FT_4, as well as TgAb levels, in pregnant women is associated with mild iodine deficiency.

CONCLUSION

Mild iodine deficiency is associated with an increase in FT_3，FT₄ and TgAb levels in pregnant women. Mild iodine deficiency may increase the risk of thyroid dysfunction in pregnant women.

Iodine intake assessment in the staff of a Porto region university (Portugal): the iMC Salt trial

PURPOSE

Iodine deficiency disorder (IDD) is an ongoing worldwide recognized problem with over two billion individuals having insufficient iodine intake. School-aged children and pregnant women are often target groups for epidemiological studies, but there is a lack of knowledge on the general adult population. The aim of this study was to assess the iodine status among a Portuguese public university staff as a proxy for the adult working population.

METHODS

The population study covered 103 adults within the iMC Salt randomized clinical trial, aged 24-69 years. Urinary iodine concentration was measured spectrophotometrically using the Sandell-Kolthoff reaction. Iodine food intake was assessed using a 24-h dietary recall. The contribution of discretionary salt to the iodine daily intake was assessed through 24-h urinary sodium excretion (UIE) and potentiometric iodine determination of household salt.

RESULTS

The mean urine volume in 24 h was 1.5 L. The median daily iodine intake estimated from 24-h UIE was 113 µg/day, being lower among women (p < 0.05). Only 22% of participants showed iodine intake above the WHO-recommended cutoff (150 µg/day). The median daily iodine intake estimated from the 24-h dietary recall was 58 µg/day (51 and 68 µg/day in women and men, respectively). Dairy, including yoghurt and milk products, were the primary dietary iodine source (55%). Iodine intake estimated from 24-h UIE and 24-h dietary recall was moderately correlated (Spearman rank correlation coefficient r = 0.34, p < 0.05). The average iodine concentration in household salt was 14 mg I/kg, with 45% of the samples below the minimum threshold preconized by WHO (15 mg I/kg). The contribution of discretionary salt to the daily iodine intake was around 38%.

CONCLUSION

This study contributes new knowledge about iodine status in Portuguese working adults. The results revealed moderate iodine deficiency, particularly in women. Public health strategies and monitoring programs are needed to ensure iodine adequacy in all population groups.

Biomarkers of Micronutrients and Phytonutrients and Their Application in Epidemiological Studies

Nutritional biomarkers can be used as important indicators of nutritional status and play crucial roles in the prevention as well as prognosis optimization of various metabolism-related diseases. Measuring dietary with the deployment of biomarker assessments provides quantitative nutritional information that can better predict the health outcomes. With the increased availability of nutritional biomarkers and the development of assessment tools, the specificity and sensitivity of nutritional biomarkers have been greatly improved. This enables efficient disease surveillance in nutrition research. A wide range of biomarkers have been used in different types of studies, including clinical trials, observational studies, and qualitative studies, to reflect the relationship between diet and health. Through a comprehensive literature search, we reviewed the well-established nutritional biomarkers of vitamins, minerals, and phytonutrients, and their association with epidemiological studies, to better understand the role of nutrition in health and disease.

Association of 3-Phenoxybenzoic Acid Exposure during Pregnancy with Maternal Outcomes and Newborn Anthropometric Measures: Results from the IoMum Cohort Study

The aims of this study were to characterize the exposure of pregnant women living in Portugal to 3-phenoxybenzoic acid (3-PBA) and to evaluate the association of this exposure with maternal outcomes and newborn anthropometric measures. We also aimed to compare exposure in summer with exposure in winter. Pregnant women attending ultrasound scans from April 2018 to April 2019 at a central hospital in Porto, Portugal, were invited to participate. Inclusion criteria were: gestational week between 10 and 13, confirmed fetal vitality, and a signature of informed consent. 3-PBA was measured in spot urine samples by gas chromatography with mass spectrometry (GC-MS). The median 3-PBA concentration was 0.263 (0.167; 0.458) µg/g creatinine (n = 145). 3-PBA excretion was negatively associated with maternal pre-pregnancy body mass index (BMI) (p = 0.049), and it was higher during the summer when compared to winter (p < 0.001). The frequency of fish or yogurt consumption was associated positively with 3-PBA excretion, particularly during the winter (p = 0.002 and p = 0.015, respectively), when environmental exposure is low. Moreover, 3-PBA was associated with levothyroxine use (p = 0.01), a proxy for hypothyroidism, which could be due to a putative 3-PBA-thyroid hormone antagonistic effect. 3-PBA levels were not associated with the anthropometric measures of the newborn. In conclusion, pregnant women living in Portugal are exposed to 3-PBA, particularly during summer, and this exposure may be associated with maternal clinical features.

Noncompliance to iodine supplementation recommendation is a risk factor for iodine insufficiency in Portuguese pregnant women: results from the IoMum cohort

PURPOSE

After a recommendation for iodine supplementation in pregnancy has been issued in 2013 in Portugal, there were no studies covering iodine status in pregnancy in the country. The aim of this study was to assess iodine status in pregnant women in Porto region and its association with iodine supplementation.

METHODS

A cross-sectional study was conducted at Centro Hospitalar Universitário São João, Porto, from April 2018 to April 2019. Pregnant women attending the 1st trimester ultrasound scan were invited to participate. Exclusion criteria were levothyroxine use, gestational age < 10 and ≥ 14 weeks, non-evolutive pregnancy at recruitment and non-signing of informed consent. Urinary iodine concentration (UIC) was measured in random spot urine by inductively coupled plasma-mass spectrometry.

RESULTS

Median UIC was 104 μg/L (IQR 62-189) in the overall population (n = 481) of which 19% had UIC < 50 µg/L. Forty three percent (n = 206) were not taking an iodine-containing supplement (ICS) and median UIC values were 146 µg/L (IQR 81-260) and 74 µg/L (IQR 42-113) in ICS users and non-users, respectively (p < 0.001). Not using an ICS was an independent risk factor for iodine insufficiency [adjusted OR (95% CI) = 6.00 (2.74, 13.16); p < 0.001]. Iodised salt use was associated with increased median iodine-to-creatinine ratio (p < 0.014).

CONCLUSIONS

A low compliance to iodine supplementation recommendation in pregnancy accounted for a mild-to-moderately iodine deficiency. Our results evidence the need to support iodine supplementation among pregnant women in countries with low household coverage of iodised salt. Trial registration number NCT04010708, registered on the 8th July 2019.

The association of milk and dairy consumption with iodine status in pregnant women in Oporto region

The role of milk and dairy products in supplying iodine to pregnant women is unknown in Portugal. The aim of this study was to evaluate the association between milk and dairy product consumption and the iodine status of pregnant women in the IoMum cohort of the Oporto region. Pregnant women were recruited between 10 and 13 weeks of gestation, when they provided a spot urine sample and information on lifestyle and intake of iodine-rich foods. Urinary iodine concentration (UIC) was determined by inductively coupled plasma MS. A total of 468 pregnant women (269 iodine supplement users and 199 non-supplement users) were considered eligible for analysis. Milk (but not yogurt or cheese) intake was positively associated with UIC, in the whole population (P = 0·02) and in the non-supplement users (P = 0·002), but not in the supplement users (P = 0·29). In non-supplement users, adjusted multinomial logistic regression analysis showed that milk consumption <3 times/month was associated with a five times increased risk of having UIC < 50 µg/l when compared with milk consumption ≥2 times/d (OR 5·4; 95 % CI 1·55, 18·78; P = 0·008). The highest UIC was observed in supplement users who reported consuming milk once per d (160 µg/l). Milk, but not yogurt or cheese, was positively associated with iodine status of pregnant women. Despite the observed positive association, daily milk consumption may not be sufficient to ensure adequate iodine intake in this population.