The Association of Therapy Adherence and Thyroid Function in Adult Patients with Phenylketonuria

2019 ◽  
Vol 75 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Csaba Sumanszki ◽  
Erika Kiss ◽  
Erika Simon ◽  
Erika Galgoczi ◽  
Aron Soos ◽  
...  

Background: The standard, lifelong therapy of phenylketonuria (PKU) is a natural protein-restricted diet complemented with phenylalanine (Phe)-free L-amino acid mixtures that provide the daily necessary micronutrients. Objective: To assess thyroid function and structure and the iodine status of early-treated adult PKU (ETPKU) patients in Hungary. Methods: Sixty-nine PKU patients (aged 18–41 years) and 50 healthy controls were enrolled in the study. Thyroid hormones, serum thyroglobulin, thyroid antibodies, urinary iodine, and selenium concentrations were measured, and thyroid ultrasound was performed. Results: The incidence of thyroid dysfunction was infrequent (n = 2). Blood Phe was negatively correlated with thyroid-stimulating hormone (TSH), and PKU patients had higher free thyroxine and lower TSH levels than healthy controls. Although optimal iodine status was found in the entire PKU population, by dividing the patients according to their therapy compliance, we observed that lower therapy adherence was associated with mild iodine deficiency and lower urinary selenium levels. Conclusions: The results of this study suggest that iodine status is strongly influenced by the adherence to therapy in ETPKU patients. No or not enough medical food consumption combined with a low-Phe diet can lead to subclinical iodine deficiency.

2018 ◽  
Vol 7 (5) ◽  
pp. 762-767 ◽  
Author(s):  
Verônica Carneiro Borges Mioto ◽  
Ana Carolina de Castro Nassif Gomes Monteiro ◽  
Rosalinda Yossie Asato de Camargo ◽  
Andréia Rodrigues Borel ◽  
Regina Maria Catarino ◽  
...  

Objectives Iodine deficiency during pregnancy is associated with obstetric and neonatal adverse outcomes. Serum thyroglobulin (sTg) and thyroid volume (TV) are optional tools to urinary iodine concentration (UIC) for defining iodine status. This cross-sectional study aims to evaluate the iodine status of pregnant women living in iodine-adequate area by spot UIC and correlation with sTg, TV and thyroid function. Methods Two hundred and seventy-three pregnant women were evaluated at three trimesters. All had no previous thyroid disease, no iodine supplementation and negative thyroperoxidase and thyroglobulin antibodies. Thyroid function and sTg were measured using electrochemiluminescence immunoassays. TV was determined by ultrasonography; UIC was determined using a modified Sandell–Kolthoff method. Results Median UIC was 146 µg/L, being 52% iodine deficient and only 4% excessive. TSH values were 1.50 ± 0.92, 1.50 ± 0.92 and 1.91 ± 0.96 mIU/L, respectively, in each trimester (P = 0.001). sTg did not change significantly during trimesters with median 11.2 ng/mL and only 3.3% had above 40 ng/mL. Mean TV was 9.3 ± 3.4 mL, which positively correlated with body mass index, but not with sTg. Only 4.5% presented with goitre. When pregnant women were categorized as iodine deficient (UIC < 150 µg/L), adequate (≥150 and <250 µg/L) and excessive (≥250 µg/L), sTg, thyroid hormones and TV at each trimester showed no statistical differences. Conclusions Iodine deficiency was detected frequently in pregnant women living in iodine-adequate area. sTg concentration and TV did not correlate to UIC. Our observation also demonstrated that the Brazilian salt-iodization programme prevents deficiency, but does not maintain iodine status within adequate and recommended ranges for pregnant women.


Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3483
Author(s):  
Inger Aakre ◽  
Lidunn Tveito Evensen ◽  
Marian Kjellevold ◽  
Lisbeth Dahl ◽  
Sigrun Henjum ◽  
...  

Seaweeds, or macroalgae, may be a good dietary iodine source but also a source of excessive iodine intake. The main aim in this study was to describe the iodine status and thyroid function in a group of macroalgae consumers. Two urine samples were collected from each participant (n = 44) to measure urinary iodine concentration (UIC) after habitual consumption of seaweed. Serum thyroid stimulating hormone (TSH), free thyroxine (fT4), free triiodothyronine (fT3), and peroxidase autoantibody (TPOAb), were measured in a subgroup (n = 19). A food frequency questionnaire and an iodine-specific 24 h recall were used to assess iodine intake and macroalgae consumption. The median (p25–p75) UIC was 1200 (370–2850) μg/L. Median (p25–p75) estimated dietary iodine intake, excluding macroalgae, was 110 (78–680) μg/day, indicating that seaweed was the major contributor to the iodine intake. TSH levels were within the reference values, but higher than in other comparable population groups. One third of the participants used seaweeds daily, and sugar kelp, winged kelp, dulse and laver were the most common species. Labelling of iodine content was lacking for a large share of the products consumed. This study found excessive iodine status in macroalgae consumers after intake of dietary seaweeds. Including macroalgae in the diet may give excessive iodine exposure, and consumers should be made aware of the risk associated with inclusion of macroalgae in their diet.


2009 ◽  
Vol 161 (3) ◽  
pp. 475-481 ◽  
Author(s):  
Pernille Vejbjerg ◽  
Nils Knudsen ◽  
Hans Perrild ◽  
Peter Laurberg ◽  
Allan Carlé ◽  
...  

ObjectiveThe iodine status of a population is traditionally evaluated by either urinary iodine (UI) excretion or by some measure of thyroid volume and the prevalence of goitre. In this prospective study of a mandatory iodization programme, we aimed to evaluate serum thyroglobulin (Tg) as a marker of iodine status in the population.MethodsTwo identical cross-sectional studies were performed before (1997–1998,n=4649) and after (2004–2005,n=3570) the initiation of the Danish iodization programme in two areas with mild and moderate iodine deficiency. Serum Tg was measured from blood samples. Thyroid volume was measured by ultrasonography.ResultsBefore iodization, the median serum Tg was considerably higher in moderate than in mild iodine deficiency. Iodization led to a lower serum Tg in all examined age groups. The marked pre-iodization difference in Tg level between the regions was eliminated. The prevalence of Tg above the suggested reference limit (40 μg/l) decreased from 11.3 to 3.7% (P<0.0001). Using bootstrapping, we demonstrated a higher efficacy of Tg than of thyroid volume to show a difference between pre- and post-iodization values.ConclusionWe found serum Tg to be a suitable marker of iodine nutrition status in the population. The results may suggest that the Danish iodization programme has led to a sufficient iodine intake, even if the median UI excretion is still marginally low according to WHO criteria.


1970 ◽  
Vol 10 (2) ◽  
pp. 56-59 ◽  
Author(s):  
Tahrim Mehdi ◽  
Md Mozammel Hoque ◽  
Zinnat Ara Nasreen ◽  
Farzana Shirin ◽  
Md Maqsudul Hakim Khan

Background: Pregnant ladies are most likely to develop relative iodine deficiency during pregnancy to affect thyroid function in our population unless specific dietary care or therapeutic iodine supplementation is taken into account which is yet to be materialized. Methods: In this cohort study sixty uncomplicated normal pregnant women were enrolled in 1st trimester and followed up till delivery. In every trimester maternal iodine status & thyroid status were determined by urinary iodine & serum thyroid hormone concentration respectively. Results: Women progressively become more iodine deficient & tends to be hypothyroid as pregnancy advances. At 3rd trimester of pregnancy maternal Urinary Iodine found to be negatively correlated with their serum TSH. Conclusion: During pregnancy women develop iodine deficiency which adversely affects the thyroid function. So adequate iodine monitoring and iodine nutrition during pregnancy is necessary. Keywords: Urinary iodine level, TSH, FT3, FT4. doi: 10.3329/jom.v10i2.2815 J MEDICINE 2009; 10 : 56-59


2014 ◽  
Vol 170 (1) ◽  
pp. 49-54 ◽  
Author(s):  
Annenienke C van de Ven ◽  
Romana T Netea-Maier ◽  
H Alec Ross ◽  
Teun A E van Herwaarden ◽  
Suzanne Holewijn ◽  
...  

ObjectiveSeveral cross-sectional studies on populations with iodine deficiency showed that TSH-levels are negatively associated with age, while in populations with high iodine intake TSH is positively associated with age. The question is whether such an age-thyroid function relation is an ongoing process apparent also in longitudinal studies and whether it reflects an actual iodine deficiency or an iodine insufficiency in the past.MethodsIn an area with a borderline iodine status in the past, we studied 980 participants of the Nijmegen Biomedical Study. We measured serum TSH, free thyroxine (FT4), total triiodothyronine (T3), peroxidase antibodies, and the urine iodine and creatinine concentration 4 years after our initial survey of thyroid function, in which we reported a negative association between TSH and age.ResultsWithin 4 years, TSH decreased by 5.4% (95% CI 2.5–8.3%) and FT4increased by 3.7% (95% CI 2.9–4.6%). Median urinary iodine concentration was 130 μg/l. Estimated 24-h iodine excretion was not associated with TSH, T3, change of TSH, or FT4over time or with the presence of antibodies against thyroid peroxidase. Only FT4appeared to be somewhat higher at lower urine iodine levels: a 1.01% (95% CI 0.17–1.84%) higher FT4for each lower iodine quintile.ConclusionsIn this longitudinal study, we found an ongoing decrease in TSH and increase in FT4in a previously iodine insufficient population, despite the adequate iodine status at present. This suggests that low iodine intake at young age leads to thyroid autonomy (and a tendency to hyperthyroidism) that persists despite normal iodine intake later in life.


2020 ◽  
Author(s):  
Saroj Kunwar ◽  
Saroj Khatiwada ◽  
Basanta Gelal ◽  
Saroj Thapa ◽  
Gaurishankar Shah ◽  
...  

Abstract Objective: Both iodine deficiency and excess can negatively impact thyroid function. The present study was conducted to assess iodine nutrition among children and thyroid function in iodine deficient children. Results: A total of 1012 school aged children (6-14 years) from several schools of Udayapur district were enrolled initially for the assessment of urinary iodine concentration (UIC). Blood samples (n=83) were collected from a subgroup of children who had UIC<100 µg/L to measure serum thyroglobulin (Tg), thyroid stimulating hormone (TSH), free triiodothyronine (fT3) and free thyroxine (fT4). Serum UIC was measured by ammonium persulfate digestion method and Tg, TSH, fT4 and fT3 were measured by ELISA kits from Diametra Company. The prevalence of insufficient UIC (UIC<100 µg/L) was 11.1% in school children’s of Udayapur district. The median UIC was 236 µg/L. The mean fT3, fT4 and TSH among children with insufficient UIC were 2.55±0.43 pg/mL, 0.96±0.28 ng/dL and 3.60±1.44 mIU/L respectively. The Median Tg was 17.5 ng/mL. Overt hypothyroidism and subclinical hypothyroidism was seen in 6% and 3.6% cases with UIC<100 µg/L respectively.


2007 ◽  
Vol 10 (12A) ◽  
pp. 1547-1552 ◽  
Author(s):  
P Laurberg ◽  
S Andersen ◽  
R I Bjarnadóttir ◽  
A Carlé ◽  
AB Hreidarsson ◽  
...  

AbstractObjective:To review methods for evaluating iodine deficiency in pregnant women and young infants and to discuss factors to be considered in the interpretation of their results.Design:Review of the literature regarding the various methods available for assessing iodine status.Setting:Population surveys and research studies.Subjects:Pregnant women and young infants.Results:Several factors to consider when assessing iodine status in pregnant women and young infants include: 1) the urinary iodine (UI) concentration (μg l-1) is not interchangeable with 24 h UI excretion (μg per 24 h); 2) the concentration of iodine in a spot or casual urine sample cannot be used to diagnose iodine deficiency in an individual; 3) a moderate fall in the concentration of serum free T4 during pregnancy is not a sign of maternal iodine deficiency; 4) an increase in the concentration of serum thyroglobulin (Tg) during pregnancy is not a sign of maternal iodine deficiency; 5) a higher concentration of TSH and Tg in cord blood than in maternal blood is not a sign of iodine deficiency in the mother or neonate; and 6) thyroid function in a full-term foetus, a neonate or a small child is not more sensitive to a mild iodine deficiency than in the mother.Conclusions:If the iodine status of pregnant women and small children is not to be misjudged, the above six factors need to be taken into account.


2019 ◽  
Vol 22 (16) ◽  
pp. 3063-3072 ◽  
Author(s):  
Molla Mesele Wassie ◽  
Lisa N Yelland ◽  
Lisa G Smithers ◽  
Enzo Ranieri ◽  
Shao Jia Zhou

AbstractObjective:The present study aimed to evaluate the effect of mandatory iodine fortification of bread on the iodine status of South Australian populations using newborn thyroid-stimulating hormone (TSH) concentration as a marker.Design:The study used an interrupted time-series design.Setting:TSH data collected between 2005 and 2016 (n 211 033) were extracted from the routine newborn screening programme in South Australia for analysis. Iodine deficiency is indicated when more than 3 % of newborns have TSH > 5 mIU/l.Participants:Newborns were classified into three groups: the pre-fortification group (those born before October 2009); the transition group (born between October 2009 and June 2010); and the post-fortification group (born after June 2010).Results:The percentage of newborns with TSH > 5 mIU/l was 5·1, 6·2 and 4·6 % in the pre-fortification, transition and post-fortification groups, respectively. Based on a segmented regression model, newborns in the post-fortification period had a 10 % lower risk of having TSH > 5 mIU/l than newborns in the pre-fortification group (incidence rate ratio (IRR) = 0·90; 95 % CI 0·87, 0·94), while newborns in the transitional period had a 22 % higher risk of having TSH > 5 mIU/l compared with newborns in the pre-fortification period (IRR = 1·22; 95 % CI 1·13, 1·31).Conclusions:Using TSH as a marker, South Australia would be classified as mild iodine deficiency post-fortification in contrast to iodine sufficiency using median urinary iodine concentration as a population marker. Re-evaluation of the current TSH criteria to define iodine status in populations is warranted in this context.


2021 ◽  
Vol 9 (1) ◽  
pp. 75-78
Author(s):  
Saroj Kunwar ◽  
Saroj Khatiwada ◽  
Basanta Gelal ◽  
Saroj Thapa ◽  
Gaurishankar Shah ◽  
...  

Iodine deficiency during childhood affects physical and mental development. Iodine deficiency or excess both can negatively impact thyroid function. We conducted this study to assess iodine nutrition and thyroid function in children with insufficient urinary iodine concentration. A community-based cross-sectional study was conducted among the selected schools of Udayapur district. Urinary iodine concentration (UIC) was measured in 1012 school children (6-14 years). Based on UIC data, 83 blood samples were collected to measure serum thyroglobulin (Tg), thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4). UIC was measured by ammonium persulfate digestion method, and Tg, TSH, fT4, and fT3 were measured using ELISA kits. The median UIE was 236 µg/L, and 11.1% of the children had insufficient UIC. The mean fT3, fT4, and TSH in children with insufficient UIC were 2.55±0.43 pg/mL, 0.96±0.28 ng/dL, and 3.60±1.44 mIU/L respectively. Among children with low UIC levels, the median Tg was 17.5 ng/mL. Overt hypothyroidism was seen in 6%, and subclinical hypothyroidism in 3.6%. The children had sufficient iodine nutrition, and the frequency of thyroid dysfunction was low among the children with insufficient UIC.


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