Iodine status, thyroid function, thyroid volume and thyroid autoimmunity in patients with type 1 diabetes mellitus in an iodine-replete area

Prevalence of latent and overt polyautoimmunity in type 1 diabetes: A systematic review and meta-analysis

BACKGROUND

Patients afflicted by type 1 diabetes (T1D) exhibit polyautoimmunity (PolyA). However, the frequency and distribution of PolyA in T1D is still unknown.

OBJECTIVE

We conducted a systematic review and meta-analysis to define the prevalence of latent and overt PolyA in individuals with T1D.

METHODS

Following PRISMA guidelines, a comprehensive search across medical databases identified studies on latent and overt PolyA in T1D. Two researchers independently screened, extracted data, and assessed study quality. A random effects model was utilized to calculate the pooled prevalence, along with its corresponding 95 % confidence interval (CI), for latent PolyA and overt PolyA. Meta-regression analysis was conducted to study the effect of study designs, age, sex, and duration of disease on pooled prevalence.

RESULTS

A total of 158 articles, encompassing a diverse composition of study designs were scrutinized. The analysis included 270,890 individuals with a confirmed diagnosis of T1D. The gender was evenly distributed (50.30 % male). Notably, our analysis unveiled an overt PolyA prevalence rate of 8.50 % (95 % CI, 6.77 to 10.62), with North America having the highest rates (14.50 %, 95 % CI, 7.58 to 24.89). This PolyA profile was further characterized by a substantial incidence of concurrent autoimmune thyroid disease (7.44 %, 95 % CI, 5.65 to 9.74). Moreover, we identified a notable prevalence of latent PolyA in the T1D population, quantified at 14.45 % (95 % CI, 11.17 to 18.49) being most frequent in Asia (23.29 %, 95 % CI, 16.29 to 32.15) and Oceania (21.53 %, 95 % CI, 16.48 to 27.62). Remarkably, this latent PolyA phenomenon primarily featured an array of autoantibodies, including rheumatoid factor, followed by Ro52, thyroid peroxidase antibodies, and thyroglobulin antibodies. Duration of the disease was associated with a highest frequency of latent (β: 0.0456, P-value: 0.0140) and overt PolyA (β: 0.0373, P-value: 0.0152). No difference in the pooled prevalence by study design was observed.

CONCLUSION

This meta-analysis constitutes a substantial advancement in the realm of early detection of PolyA in the context of T1D. Individuals with T1D should regularly undergo assessments to identify potential concurrent autoimmune diseases, especially as they age.

The prevalence of subclinical hypothyroidism in a pre-diabetes population and an analysis of related factors

BACKGROUND

To investigate the prevalence and related influencing factors of subclinical hypothyroidism (SCH) in a pre-diabetes (PreDM) population.

PATIENTS AND METHODS

A multi-stage stratified cluster random sampling method was used to select the adult Han population in Gansu Province for investigation. General data and related biochemical indices were recorded and SPSS software was used for statistical analyses.

RESULTS

This study selected 2876 patients, including 548 with SCH and 433 with PreDM. In the PreDM population, the levels of thyroid stimulating hormone (TSH), serum phosphorus, TPOAb and TgAb in the SCH group were higher than those in the euthyroid group (P < 0.05). The level of TPOAb in females of SCH group was higher than that in males (P < 0.05). The positive rates of TPOAb and TgAb in females were higher than those in males in the total population and SCH population. The prevalence of SCH in the PreDM group under 60 was significantly higher than that in the normal glucose tolerance (NGT) group (26.02% vs. 20.40%, χ² = 5.150, P < 0.05). We defined SCH as a TSH level of >4.20 mIU/L. Using this criterion, the prevalence of SCH in the total population of PreDM was higher than that in the NGT population (χ² = 8.611, P < 0.05), the prevalence of SCH in the PreDM population generally showed an upward trend. However, we performed a separate analysis considering the accepted impact of age on TSH redefining SCH as TSH >8.86 mIU/L (for individuals over age 65). However, allowing for the expected rise in TSH levels in individuals over age 65, the prevalence of SCH in the elderly over 65 years of age decreased significantly (NGT population from 27.48% to 9.16%, PreDM population from 34.18% to 6.33%, P < 0.05). Logistic regression analysis showed that the risk factors for SCH in the PreDM population were female gender, fasting plasma glucose and TSH (all P < 0.05). Risk factors for SCH in the impaired fasting glucose (IFG) population were female gender, OGTT 2 h, TSH and TPOAb (all P < 0.05).

CONCLUSION

The prevalence of SCH in the PreDM population not considering the known physiological increase in age related TSH was relatively high and was significant in female and the IFG population. However, the effect of age on these findings needs to attract more attention.

Determining the relationship between dietary iodine intake, urinary iodine excretion and thyroid functions in people with type 2 diabetes mellitus

Objective Type 2 diabetes mellitus (T2DM) is a worldwide health problem, and medical nutrition therapy is essential for improving the quality of life of patients with type 2 diabetes. Salt restriction may lead to iodine deficiency in these patients. Moreover, type 2 diabetes can be an indirect reason for thyroid disorders. This study was conducted to determine the relationship between dietary iodine intake, urinary iodine excretion and thyroid functions in people with T2DM. Materials and methods Iodine nutritional status was determined by a one day 24-h dietary recall and food-frequency questionnaire. Iodine status was detemined by urinary iodine excretion with morning urine sample. Results Iodine intake according to one day 24-h dietary recall was lower in T2DM patients [94.8 (76.0-112.0) μg] than people in control group [137.1 (123.1-165.4) μg] (p < 0.05). Iodine intake determined by food-frequency questionnaire rich in iodine was lower in T2DM patients [93.1 (84.4-113.9) μg] than people in control group [140.2 (125.1-166.1) μg] (p < 0.05). Mild iodine deficiency was found in %38.8 of diabetic and %55.1 of healthy individuals (p < 0.05). No significant relationship was found between urinary iodine excretion and thyroid function tests in groups (p > 0.05). However, the relationship between dietary iodine excretion and urinary iodine intake in the diabetic group was lower than in the control group (p < 0.05). Conclusion With this respect, the results showed that while planning medical nutrition therapy for diabetic individuals, the risk of iodine deficiency should be considered.

Selenium and iodine in diabetes mellitus with a focus on the interplay and speciation of the elements

Diabetes mellitus is a chronic metabolic disease caused by insulin deficiency (type I) or dysfunction (type II). Diabetes is a threatening public health concern. It is considered as one of the priority non-communicable diseases, due to its high and increasing incidence, the associated healthcare costs, and threatening medical complications. Two trace elements selenium (Se) and iodine (I) were intensively discussed in the context of diabetic pathology and, possibly, etiology. It seems there is a multilayer involvement of these essential nutrients in glucose tolerance, energy metabolism, insulin signaling and resistance, which are mainly related to the antioxidant selenoenzymes and the thyroid hormones. Other factors might be related to (auto)immunity, protection against endoplasmic reticulum stress, and leptin signaling. The aim of the current review is to evaluate the current understanding of the role of selenium and iodine in diabetes with a focus on the biochemical interplay between the elements, their possible role as biomarkers, and their chemical speciation. Possible impacts from novel analytical techniques related to trace element speciation and isotopic analysis are outlined.

Ultrasound assessment of thyroid gland volume in diabetic patients without overt thyroid disease

BACKGROUND

Diabetes mellitus and thyroid disease are known to mutually influence each other. Thyroid disease can worsen glycaemic control in diabetes, and patients with diabetes mellitus have increased incidence of thyroid disorders such as increase in size, compared to the normal population.

AIMS/OBJECTIVES

The aim of the study was to sonographically assess thyroid gland volume in Nigerian adult diabetic patients and compare with apparently healthy adults (controls).

SUBJECTS AND METHODS

The study setting was the Department of Radiology, University of Benin Teaching Hospital (UBTH) Nigeria. The thyroid gland in 120 diabetic subjects and equal number of apparently healthy controls was scanned with a 5-12 MHz linear transducer of a SONOACE X4 Machine. Thyroid gland volume was assessed. Statistical analysis was done with Statistical Package for the Social Sciences (SPSS) version 17 (SPSS Inc, Chicago, IL, USA).

RESULTS

Diabetics had significantly increased thyroid volume compared to age matched male and female control subjects (11.5 ± 5.2 cm3 vs 7.4 ± 1.9 cm3; P< 0.001 for males) and (9.9 ± 6.2 cm3 vs 7.1 ± 3.4 cm3; P< 0.001 for females) respectively. Gender did not significantly influence thyroid volume among diabetics.

CONCLUSION

Diabetics have higher thyroid gland dimensions, compared to apparently healthy subjects. Gland proliferation from circulating insulin may play a role. This is not influenced by gender.

Papillary thyroid carcinoma risk factors in the Yunnan plateau of southwestern China

Objective

This study investigated clinical and pathological characteristics and risk factors in papillary thyroid carcinoma (PTC) patients’ native to Yunnan plateau in southwestern China.

Methods

Clinical data from 1,198 patients diagnosed with PTC (n=578) and control subjects (n=620) with benign thyroid disease (ie, thyroid nodule disease, benign thyroid diseases [BTD]) in Yunnan province were analyzed retrospectively.

Results

The mean patient age was lower for PTC than for BTD. Positive ratios of thyroid peroxidase antibody, thyroglobulin antibody (TGAb), and thyrotrophin receptor antibody (TRAb) were higher in PTC than in BTD patients. The ratio of PTC coexisting with Hashimoto’s thyroiditis (HT) or with lymphocytic thyroiditis was higher than that of BTD. The number of patients whose age at menarche was ≤13 years, who had given birth to less than or equal to two children, or who were in premenopause were higher in the PTC than in the BTD group. Multivariate conditional logistic regression analyses revealed that age >45 years, nodal size >1 cm, and elevated TG levels were protective factors against PTC. Abnormally elevated TGAb and TRAb levels were independent risk factors for PTC in females.

Conclusion

HT was not an independent risk factor for but was associated with PTC. TRAb is a risk factor for PTC in individuals living in the Yunnan plateau, but not for those in the plains region.

Iodine status and thyroid function among Spanish schoolchildren aged 6-7 years: the Tirokid study

I deficiency is still a worldwide public health problem, with children being especially vulnerable. No nationwide study had been conducted to assess the I status of Spanish children, and thus an observational, multicentre and cross-sectional study was conducted in Spain to assess the I status and thyroid function in schoolchildren aged 6-7 years. The median urinary I (UI) and thyroid-stimulating hormone (TSH) levels in whole blood were used to assess the I status and thyroid function, respectively. A FFQ was used to determine the consumption of I-rich foods. A total of 1981 schoolchildren (52 % male) were included. The median UI was 173 μg/l, and 17·9 % of children showed UI<100 μg/l. The median UI was higher in males (180·8 v. 153·6 μg/l; P<0·001). Iodised salt (IS) intake at home was 69·8 %. IS consumption and intakes of ≥2 glasses of milk or 1 cup of yogurt/d were associated with significantly higher median UI. Median TSH was 0·90 mU/l and was higher in females (0·98 v. 0·83; P<0·001). In total, 0·5 % of children had known hypothyroidism (derived from the questionnaire) and 7·6 % had TSH levels above reference values. Median TSH was higher in schoolchildren with family history of hypothyroidism. I intake was adequate in Spanish schoolchildren. However, no correlation was found between TSH and median UI in any geographical area. The prevalence of TSH above reference values was high and its association with thyroid autoimmunity should be determined. Further assessment of thyroid autoimmunity in Spanish schoolchildren is desirable.

Serum concentrations of anti-thyroid peroxidase and anti-thyroglobulin antibodies in children and adolescents without apparent thyroid disorders

OBJECTIVE

The age-dependent prevalence and clinical relevance of anti-thyroid peroxidase (TPOAb) and anti-thyroglobulin (TGAb) antibodies in children and adolescents without thyroid diseases are unknown. The aim of this study was to measure the concentration of these thyroid autoantibodies in a large cohort of hospitalized and out-patient subjects. Additionally, we investigated the correlation of TPOAb and TGAb with thyroid parameters as well as with putative confounding parameters such as standard deviation scores (SDS) of height, BMI-SDS and CRP.

METHODS

Serum samples from 841 patients with non-thyroid related diseases between 1 day post partum and 20 years of age were used in a cross-sectional study. TPOAb, TGAb, thyroid parameters (TSH, fT3, fT4 and thyroglobulin) and CRP were measured by the Modular System (Roche, Mannheim).

RESULTS

The values of TPOAb and TGAb showed an age-dependent maximum of antibody frequency for both genders during the first year of life with concentrations of 163 IU/mL and 161 IU/mL in the 95th percentile. In girls, a second maximum was observed during puberty with concentrations of 82 IU/mL TPOAb and 582 IU/mL TGAb in the 95th percentile. Both antibodies correlated significantly (p<0.05) with each other, with fT3, fT4, BMI-SDS (only TPOAb) and CRP and TSH (only TGAb).

CONCLUSION

The prevalence of TPOAb and TGAb was shown to be age-dependent with increased values in the first year of life and during puberty. The increased "physiological" concentrations of TPOAb and TGAb have to be considered when used as diagnostic indicators of autoimmune thyroid disease in a paediatric population.

Autoimmune thyroid disease in patients with anti-GAD positive type 1 diabetes mellitus

The aim of the study was to determine the frequency and titers of anti-thyroid peroxidase (Anti-TPO), anti-thyroglobulin (Anti-TG), and anti-glutamic acid decarboxylase (Anti-GAD) antibodies in Turkish patients with type 1 diabetes mellitus (DM), and to compare the frequency of anti-TPO and anti-TG titers in the presence or absence of anti-GAD. A total of 104 patients including 56 males and 48 females with type 1 DM and their age-, gender-, and body mass index-matched control group, including 31 males and 27 females, 58 cases in total with an age range of 15-50 years, were recruited into this study. In patients with type 1 DM, positive anti-GAD was detected in 30.8% (n=32). In patients with positive anti-GAD, rate of positive anti-TPO was 37.5%; however, in patients with negative anti-GAD, the rate of positive anti-TPO was 9.7% and the difference was statistically significant (p=0.001). In patients with positive anti-GAD, the rate of positive anti-TG was 18.8%. In patients with negative anti-GAD, the rate of positive anti-TG was 2.8%, and the difference between them was statistically significant (p=0.005). In patients with positive and negative anti-GAD, rates of both positive anti-TPO and anti-TG were 15.6% and 1.4%, respectively, with the difference showing statistical significance (p=0.004). Thyroid autoimmunity in type 1 DM patients with positive anti-GAD was apparently higher; therefore, these patients should be followed more frequently and carefully.

Melatonin improves oxidative stress parameters measured in the blood of elderly type 2 diabetic patients

An elevated oxidative status in the aging organism may be involved in the development of non-insulin dependent diabetes mellitus (NIDDM). Melatonin, a potent antioxidant agent, is essential for glucose homeostasis and regulation. The aim of this study was to determine the influence of melatonin supplementation on the oxidative stress parameters in elderly NIDDM patients. The malondialdehyde (MDA) concentration, Cu-Zn superoxide dismutase (SOD-1) activity in erythrocytes, the level of nitrate/nitrite in plasma and morning melatonin concentration and oxidase activity of ceruloplasmin (Cp) in serum in 15 elderly NIDDM patients at baseline and after the 30 days of melatonin supplementation (5 mg daily) in comparison with levels in 15 healthy elderly volunteers were determined. A significant increase of MDA level and decrease of SOD-1 activity and melatonin concentration were observed in NIDDM patients. Cp oxidase activity and nitrate/nitrite level were similar in both examined groups. Melatonin administration in NIDDM patients resulted in a significant increase in the morning melatonin concentration and SOD-1 activity, and a reduction in the MDA level and Cp oxidase activity. Statistically significant alterations in nitrate/nitrite levels were not observed. These results indicate an improvement of antioxidative defense after melatonin supplementation in the NIDDM individuals and suggest melatonin supplementation as an additional treatment for the control of diabetic complications.

Screening of diabetes, thyroid, and celiac diseases-related autoantibodies in a sample of Turkish children with type 1 diabetes and their siblings

OBJECTIVE

The purpose of this study was to investigate the presence of diabetes, thyroid, and celiac diseases (CD)-related autoantibodies in children with type 1 diabetes (DM1) and their siblings.

MATERIALS AND METHODS

The study population included 57 children with DM1, aged 11.7+/-4.5 years and their 89 healthy siblings, aged 11.0+/-5.4 years. Autoantibodies to glutamic acid decarboxylase (GAD65), islet cell (ICAs), insulin (IAAs), antiendomisial antibody (EMA), thyroid peroxidase, thyroglobulin, and thyrotropin receptor antibodies were studied both in diabetic patients and their siblings.

RESULTS

The frequencies of GAD65, ICAs and IAAs positivity were found to be 63.2, 56.1 and 84.2% in patients with DM1 and 53.9, 24.4 and 3.4% in their siblings, respectively. The frequencies of autoimmune thyroid diseases (ATD) as determined by positive thyroid-related autoantibodies were 38.6 and 21.4% (p=0.024) among patients with DM1 and siblings, respectively. Subclinical hypothyroidism or hyperthyroidism was detected in 5.3% of patients with DM1 but in none of their siblings. EMA was positive in 3.5% of diabetic patients and 1.1% of their siblings.

CONCLUSIONS

Our findings supported the view that children with DM1 should be screened annually for ATD. Relatively lower frequency of CD in the present study indicated that screening for CD-related autoantibodies might be postponed to older ages in asymptomatic patients. The present findings also suggested that the screening for diabetes- (especially GAD65) and thyroid diseases-related autoantibodies in siblings may ensure some useful information about the clinical course.

An analysis of the prevalence of thyroid autoantibodies: thyroid peroxidase antibodies (ATA) and thyroglobulin antibodies (ATG) in children with newly diagnosed diabetes mellitus type 1 during 2000-2004 in the Upper Silesia region, Poland

The aim of this study was to evaluate the prevalence of thyroid autoantibodies and clinical significance of thyroid autoimmunity in children with the diagnosis of diabetes mellitus type 1. The study group comprised 222 children all with newly diagnosed diabetes mellitus type 1 (122 boys) with a mean age 9.92 +/- 4.5 years, who were admitted to a regional diabetes division in 2000-2004. Assessment of ATA and ATG were performed and two emerging groups-ATA/ATG (+) and ATA/ATG (-) were compared, including anthropometric data, HbA1C, plasma lipids, TSH, fT4. Positive antibodies titre was found in 27 (12.16%) of the children. Apart from older age in the antibody positive group (11.67 vs. 9.67 years, p < 0.05), there were no significant differences among these groups regarding other clinical and laboratory characteristics. Concluding, the presence of thyroid autoantibodies in 12.16% of subjects with newly diagnosed diabetes confirms the necessity of screening of all children, especially adolescents from the time of diagnosis of diabetes mellitus type 1 onwards. No association between existence of autoantibodies and the clinical status of a child at the presentation of diabetes was demonstrated by this study.

Factors associated with elevated serum concentrations of anti-TPO antibodies in subjects with and without diffuse goitre. Results from the Ukrainian-American Cohort Study of thyroid cancer and other thyroid diseases following the Chornobyl accident

OBJECTIVES

To examine factors associated with the prevalence of elevated anti-thyroid peroxidase antibodies (ATPO) among iodine-deficient adolescents and young adults and test whether associations vary according to the presence of diffuse goitre.

DESIGN

Subjects were members of the Ukrainian-American Cohort Study exposed to the Chornobyl accident whose (131)I thyroid dose estimates were below 0.2 Gy.

MEASUREMENTS

The odds ratios (ORs) for ATPO above 60 U/ml were estimated using logistic regression models for a number of factors in the total population (N = 5133), and separately for thyroid disease-free subjects (N = 3875), those with diffuse goitre (N = 921), and diffuse goitre without autoimmune thyroiditis (AIT; N = 883).

RESULTS

Elevated ATPO was found in 9.9% of the total population and ORs were significantly higher in females, older individuals, those examined in earlier calendar years, residents of Kyiv and Chernihiv oblasts, subjects with a family history of thyroid disease, higher thyroid ultrasound volume, suppressed or elevated TSH, blood collection in March to May, very low thyroglobulin (Tg), and shorter serum storage time. When thyroid disease-free subjects and those with diffuse goitre were compared, there were few differences in antibody prevalence, and after excluding individuals with AIT, the only difference was an increased prevalence of elevated ATPO at low urinary iodine in those with goitre alone.

CONCLUSIONS

Although a number of factors are associated with the prevalence of elevated ATPO in our study group, with the exception of urinary iodine these factors are independent of goitre, and differences between thyroid disease-free subjects and those with diffuse goitre are largely due to AIT.