Impact of Iodination on Thyroid Pathology in Africa

Prevalence of thyroid dysfunction and associated factors among adult type 2 diabetes mellitus patients, 2000-2022: a systematic review and meta-analysis

BACKGROUND

Thyroid dysfunction (TD) and type 2 diabetes mellitus (T2DM) frequently co-occur and have overlapping pathologies, and their risk increases with age. Thyroid dysfunction along with T2DM will worsen macro- and microvascular complications, morbidity, and mortality.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guideline was followed. The databases used were Embase, ScienceDirect, PubMed, and Google Scholar. The Joana Briggs Institute (JBI) scale was used to assess the quality of the included studies. The data was extracted by Microsoft Excel and analyzed through STATA version 14 software. The overall pooled prevalence of TD and its main components were estimated using the random-effects model. The consistency of studies was assessed by I2 test statistics. Pooled meta-logistic regression was used to present the pooled prevalence with a 95% confidence interval (CI). Besides, subgroup and sensitivity analyses were employed.

RESULT

Thirty-eight studies were included. The pooled prevalence of TD was 20.24% (95% CI: 17.85, 22.64). The pooled prevalence of subclinical hypothyroidism, hypothyroidism, subclinical hyperthyroidism, and hyperthyroidism was found to be 11.87% (95% CI: 6.90, 16.84), 7.75% (95% CI: 5.71, 9.79), 2.49% (95% CI: 0.73, 4.25), and 2.51% (95% CI: 1.89, 3.13), respectively. Subgroup analysis based on continent revealed a higher prevalence of TD in Asia and Africa. Factors like being female, HbA1c ≥ 7%, DM duration > 5 years, family history of TD, central obesity, smoking, the presence of retinopathy, and neuropathy were found associated with TD.

CONCLUSION

The current systematic review and meta-analysis showed that the TD's pooled prevalence was relatively higher than the general population. Therefore, regular screening of TD should be done for T2DM patients.

Frequency of thyroid pathologies in the central Black Sea Region: Ultrasound-based field study

Background

Thyroid pathologies are very common diseases. The most common thyroid pathologies are goiter and thyroid nodules. Thyroid ultrasonography is the most widely used examination method in the evaluation of thyroid pathologies. The aim of this field study is to determine the frequency of thyroid pathologies in the province of Tokat and to evaluate its relationship with some factors such as gender and dietary habits.

Materials and Methods

In this population-based prospective study, thyroid US examination was performed on a total of 822 patients. The examination procedure was carried out by one radiologist with at least 10 years of experience. During the examination, thyroid dimensions, parenchyma echo, presence of nodule, echo if any, number, size, and localization were evaluated. The relationships between thyroid pathologies and age, gender, body mass index (BMI), and chronic diseases in the participants were evaluated.

Results

Up to 45.2% (n = 372) of the participants were male and 54.8% (n = 417) were female. The ages of the participants ranged from 20 to 87 years. The mean age of the participants was 47.2. Up to 9.8% of the participants had an increase in thyroid size, defined as goiter. Parenchyma was homogeneous in 72.1% of the participants and heterogeneous in 27.9%. Thyroid nodules were present in the thyroid gland in 40.8% of the participants. There was a statistically significant relationship between thyroid pathologies and female gender, age, and obesity.

Conclusion

Thyroid diseases show regional differences. Older age, female gender, and obesity increase the frequency of thyroid pathologies.

Thyrotoxicosis in Africa: a systematic review and meta-analysis of the clinical presentation

Background

Thyrotoxicosis is a common endocrine disorder. The clinical presentation is variable, and it is often misdiagnosed or diagnosed late in Africa. This study was aimed at collating and analyzing the clinical characteristics of the disease across the continent so as to enhance correct and timely diagnosis.

Methods

The study is a systematic review with a meta-analysis. Studies, done in Africa, which documented the clinical features of thyrotoxicosis were selected. African Journal Online (AJOL), PubMed, SCOPUS and Google Scholar, Research Square, SciELO, and medRxiv were systematically searched using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The study quality was assessed using the Newcastle-Ottawa scale. Heterogeneity was determined using I2 statistic and Cochran’s Q test. LFK index and the symmetry of the Doi plot were used to assess publication bias.

Results

The eligible studies were 59 and the total sample size was 9592. The most common symptoms of thyrotoxicosis on the continent included palpitations (69%), weight loss (65%), heat intolerance (64%), tiredness (49%), increased appetite (49%), hyperhidrosis (48%), and insomnia (47%). The most common signs were thyromegaly (88%), tachycardia (67%), sweaty palms (54%), hand tremor (49%), and exophthalmos (49%). Atrial fibrillation, heart failure, and thyrotoxic heart disease were found in 9, 12, and 22% respectively. Other findings were hypertension (25%) and diabetes (9%).

Conclusion

Clinical presentation of thyrotoxicosis varies, and understanding these peculiarities would mitigate misdiagnosis and delayed diagnosis in Africa.

A systematic review and meta-analysis of the etiology and treatment patterns of thyrotoxicosis in Africa

INTRODUCTION

Thyrotoxicosis is one of the most common endocrine disorders seen in clinical practice. This study aims to determine the etiologies and treatment modalities of thyrotoxicosis in Africa.

AREAS COVERED

The study design is a systematic review with a meta-analysis. Medical databases and the gray literature were systematically searched following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies done in Africa on the etiology and treatment of thyrotoxicosis were selected.

EXPERT OPINION

In Africa, it is still believed that autoimmune diseases, generally, are not as common as what is seen in the western world. The frequency of Graves' disease is reportedly lower in Africa. The treatment of thyrotoxicosis depends on the cause. Therefore, it is of substantial importance to establish the etiology following the diagnosis of the clinical syndrome.

Thyroid Autoimmunity and Dysfunction in Sri Lankan Children and Adolescents After 22 Years of Sustained Universal Salt Iodization

Background: Sri Lanka introduced universal salt iodization (USI) in 1995 after which we demonstrated a high thyroglobulin antibody (TgAb) prevalence in 1998. However, it is unclear whether thyroid autoimmunity persists in the long term in populations exposed to sustained USI and whether such populations have an excess of thyroid dysfunction. We evaluated the prevalence of thyroid autoantibodies and dysfunction in Sri Lankan children and adolescents after more than two decades of sustained USI. Methods: We selected 10- to 18-year-old subjects of both sexes (randomized cluster sampling) from all 9 provinces of Sri Lanka in this cross-sectional study. Blood, urine, and anthropometric data were collected and thyroid ultrasound scans were performed. Validated statistical methods were used to derive local population-specific reference ranges for all thyroid parameters. We also measured urine iodine concentration (UIC), salt, and water iodine concentrations. Results: Blood and urine samples from 2507 and 2473 subjects respectively, and ultrasound scans from 882 subjects were analyzed. Population-derived upper limits for thyroid peroxidase antibody (TPOAb) and TgAb, and reference ranges for triiodothyronine, thyroxine, and thyrotropin (total and age-year-related groups) were significantly different from manufacturer's reference ranges. Using these derived ranges, the prevalence of TPOAb was 10.3% and TgAb was 6.4%. Of the TPOAb-positive subjects, TPOAb were of low concentration in 66.2% (1-3 times the upper limit of the reference range [ULRR]) and showed the strongest association with subclinical hypothyroidism (SCH) at the highest concentrations (>4 ULRR). The prevalence of SCH was 3%. Median UIC (interquartile range) was 138.5 μg/L (79.4-219.0) with regional variability, and median thyroglobulin was 8.3 ng/mL (4.1-13.5). Goiter prevalence was 0.6% and 1.93% (thyroid volume compared to age and body surface area, respectively). Salt and water iodine concentrations were satisfactory. Conclusions: Sri Lanka has safely and effectively implemented USI with good sources of iodine, leading to sustained iodine sufficiency over more than two decades. The early postiodization TgAb surge (42.1%) has settled (6.4%), and despite a persistently high TPOAb prevalence (10.3%), SCH prevalence remains low (3%). Further studies should be undertaken to monitor thyroid autoimmune dysfunction in Sri Lankan children, using age-specific, population-derived reference ranges.

Factors Associated with Urinary Iodine Concentration among Women of Reproductive Age, 20-49 Years Old, in Tanzania: A Population-Based Cross-Sectional Study

BACKGROUND

Universal salt iodization (USI) is the most feasible and cost-effective, and equitable, approach to prevent iodine deficiency. Severe maternal iodine deficiency during pregnancy is associated with serious adverse gestational and birth outcomes.

OBJECTIVES

The aim was to assess iodine status and identify independent factors associated with urinary iodine concentration (UIC) among women of reproductive age in Tanzania.

METHODS

This was a weighted, population-based, cross-sectional study in 2985 women of reproductive age (20-49 y) in Tanzania who participated in the Demographic and Health Surveys in 2015-2016 (DHS 2015-2016) and had measured UIC. Multivariable generalized linear regression was used to identify potential factors that were associated with UIC.

RESULTS

The median UICs among women consuming inadequately iodized salt (93.6 μg/L; 25th and 75th percentiles: 43.1, 197.9 μg/L) and women in the lowest socioeconomic status (92.3 μg/L; 45.6, 194.4 μg/L) were below the WHO-recommended ranges (≥150 μg/L for pregnant women and ≥100 μg/L for nonpregnant women). The results of multivariable models indicated that pregnant women had 1.21 μg/L lower UIC than nonpregnant women (β = -1.21; 95% CI: -3.42, -0.12), breastfeeding women had 1.02 μg/L lower UIC than nonbreastfeeding women (β = -1.02; 95% CI: -2.25, -0.27), and women with no education had a 1.88 μg/L lower UIC compared with those with secondary/highest education (β = -1.88; 95% CI: -4.58, -0.36). Women consuming inadequately iodized salt had 6.55 μg/L lower UIC than those consuming adequately iodized salt (β = -6.55; 95% CI: -9.24, -4.33). The median UIC varied substantially across geographic zones, ranging from 83.2 μg/L (45.9, 165.3) in the Western region to 347.8 μg/L (185.0, 479.8) in the Eastern region.

CONCLUSIONS

Our findings indicated a great heterogeneity in median UIC across regions of Tanzania among women of reproductive age. Poverty, consuming inadequately iodized salt, and lack of education appeared to be the driving factors for lower UIC in Tanzania.

Causes and predictors of mortality among Ghanaians hospitalised with endocrine disorders

Background

Endocrine disorders have been noted to be on the increase in the developing world, but little is known about their outcomes on the African continent.

Methods

We conducted a retrospective longitudinal study to evaluate the demographic characteristics and determinants of endocrine-related mortality among adult patients over 9 y in a leading tertiary hospital in Ghana. We determined the predictors of inpatient mortality using Kaplan–Meier survival curves and Cox proportional hazard regression analysis.

Results

Overall, 6265 patients (9.7% of all medical admissions) were admitted with various endocrine disorders during the period. The most common endocrine cause of hospitalisation was diabetes mellitus (86.0%), followed in order of decreasing frequency by thyroid disorders (7.7%) and miscellaneous disorders (1.4%). The overall crude mortality rate of endocrine admissions was 16.7%. Death was predicted by increasing age with an adjusted hazard ratio of 1.25 (95% confidence interval 1.15 to 1.65) for every 10-y increase in age.

Conclusions

Almost one in six adults admitted with an endocrine disorder to a tertiary care centre in Ghana died in hospital, and many of the deaths were due to non-communicable disease complications. Enhanced public health disease prevention strategies and endocrine inpatient care processes are warranted.

Non-iodized salt consumption among women of reproductive age in sub-Saharan Africa: a population-based study

OBJECTIVE

To identify countries in sub-Saharan Africa (SSA) that have not yet achieved at least 90 % universal salt iodization and factors associated with the consumption of non-iodized salt among women of reproductive age.

DESIGN

A cross-sectional study using data from Demographic and Health Surveys (DHS). The presence of iodine in household salt (iodized or non-iodized), which was tested during the survey process, was the study outcome. Multivariable logistic regression models were used to determine independent factors associated with the consumption of non-iodized salt among women of reproductive age.

SETTING

There were eleven countries in SSA that participated in the DHS since 2015 and measured the presence of iodine in household salt.

PARTICIPANTS

Women (n 108 318) aged 15-49 years.

RESULTS

Countries with the highest rate of non-iodized salt were Senegal (29·5 %) followed by Tanzania (21·3 %), Ethiopia (14·0 %), Malawi (11·6 %) and Angola (10·8 %). The rate of non-iodized salt was less than 1 % in Rwanda (0·3 %), Uganda (0·5 %) and Burundi (0·8 %). Stepwise multivariable logistic regression showed that women were more likely to be using non-iodized salt (adjusted OR; 95 % CI) if they were poor (1·62; 1·48, 1·78), pregnant (1·16; 1·04, 1·29), aged 15-24 years (v. older: 1·14; 1·04, 1·24) and were not literate (1·14; 1·06, 1·23).

CONCLUSIONS

The use of non-iodized salt varies among SSA countries. The higher level of use of non-iodized salt among poor, young women and pregnant women is particularly concerning.

PATTERN OF THYROID DISORDERS AMONG PATIENTS IN HAZARA DIVISION, PAKISTAN

Background: Thyroid disorders are a commonly encountered problem in hilly areas of Pakistan. The objectives of the study were to determine the frequency and distribution of thyroid disorders among patients presenting with suggestive signs & symptoms of thyroid disorders in Hazara Division, Pakistan. Material and Methods: This cross-sectional study was conducted in Departments of Medicine and Pediatrics & Neonatology, Ayub Medical College, Abbottabad, KP, Pakistan from January, 2017 to January, 2018. Exclusion criteria was patients taking medicines such as Lithium and Cordarone. Sample size was 55 selected using consecutive sampling technique. Reference values were taken as follows; serum TSH=0.4-4.0 µIU/L, serum T3=100-200 ng/dL), serum T4=5-13.5 µgm/dL. Demographic variables were sex and age. Research variables were thyroid status (euthyroid/ hyperthyroid/ hypothyroid) and levels of thyroid function tests (TFT). Categorical variables such as sex and thyroid status were calculated by frequency and percentages whereas numeric variables such as age and TFT by Mean and SD. Descriptive statistics were calculated using SPSS Version 20. Results: Out of the total 55 patients, 11 patients were males and 44 patients were females. The minimum age was 20 years, maximum age was 90 years. Mean age was 43.24 years±15.118. Out of the total 55 patients, 14 (25.5%) were euthyroid, 30 patients (54.5%) were hyperthyroid and 11 (20%) patients were hypothyroid. Out of the 14 patients that were euthyroid, seven were males and seven were females. Out of the 30 hyperthyroid patients 26 were females and only 4 were males. All 11 hypothyroid were females. Conclusions: Hyperthyroidism is more common thyroid disorder in Hazara Division specially in adult females.

Thyroid Cancer and Iodine Deficiency Status: A 10-Year Review at a Single Cancer Center in Tanzania

Objective

To highlight the magnitude and distribution of thyroid cancer at the largest cancer center in Tanzania and to correlate patient region of residence with regions of dietary iodine adequacy and deficiency in the country.

Study Design

A retrospective cross-sectional chart review to characterize patients with thyroid cancer and regions of residence.

Setting

Ocean Road Cancer Institute (ORCI), the largest cancer center in Tanzania.

Subjects and Methods

Subjects had histologically confirmed thyroid cancer and no history of cancer treatment. Between January 2006 and April 2016, the cases of 139 consecutive patients with thyroid cancer at ORCI were retrospectively reviewed. Patients were grouped into those from iodine-adequate and iodine-deficient regions, based on the Tanzania demographic and health survey.

Results

Patients' median age was 47 years (range, 17-73 years), and the male:female ratio was 1:5. The number of people with thyroid cancer seen at ORCI increased steadily during the study period, with no significant difference between papillary (46%) and follicular (45%) diagnoses. Nonpapillary cancers occurred more frequently among males and patients ≥45 years of age, but these did not reach statistical significance. Seventy-five percent of all thyroid cancers were from areas of iodine deficiency, and this was similar in papillary and follicular cancer subtypes.

Conclusion

The incidence of differentiated thyroid cancer is increasing at the largest cancer center in Tanzania, whereby papillary and follicular subtypes were significantly higher in regions with long-standing dietary iodine deficiency.

Global epidemiology of hyperthyroidism and hypothyroidism

Thyroid hormones are essential for growth, neuronal development, reproduction and regulation of energy metabolism. Hypothyroidism and hyperthyroidism are common conditions with potentially devastating health consequences that affect all populations worldwide. Iodine nutrition is a key determinant of thyroid disease risk; however, other factors, such as ageing, smoking status, genetic susceptibility, ethnicity, endocrine disruptors and the advent of novel therapeutics, including immune checkpoint inhibitors, also influence thyroid disease epidemiology. In the developed world, the prevalence of undiagnosed thyroid disease is likely falling owing to widespread thyroid function testing and relatively low thresholds for treatment initiation. However, continued vigilance against iodine deficiency remains essential in developed countries, particularly in Europe. In this report, we review the global incidence and prevalence of hyperthyroidism and hypothyroidism, highlighting geographical differences and the effect of environmental factors, such as iodine supplementation, on these data. We also highlight the pressing need for detailed epidemiological surveys of thyroid dysfunction and iodine status in developing countries.

Iodine deficiency

Iodine deficiency has multiple adverse effects in humans, termed iodine deficiency disorders, due to inadequate thyroid hormone production. Globally, it is estimated that 2 billion individuals have an insufficient iodine intake, and South Asia and sub-Saharan Africa are particularly affected. However, about 50% of Europe remains mildly iodine deficient, and iodine intakes in other industrialized countries, including the United States and Australia, have fallen in recent years. Iodine deficiency during pregnancy and infancy may impair growth and neurodevelopment of the offspring and increase infant mortality. Deficiency during childhood reduces somatic growth and cognitive and motor function. Assessment methods include urinary iodine concentration, goiter, newborn TSH, and blood thyroglobulin. But assessment of iodine status in pregnancy is difficult, and it remains unclear whether iodine intakes are sufficient in this group, leading to calls for iodine supplementation during pregnancy in several industrialized countries. In most countries, the best strategy to control iodine deficiency in populations is carefully monitored universal salt iodization, one of the most cost-effective ways to contribute to economic and social development. Achieving optimal iodine intakes from iodized salt (in the range of 150-250 microg/d for adults) may minimize the amount of thyroid dysfunction in populations. Ensuring adequate iodine status during parenteral nutrition has become important, particularly in preterm infants, as the use of povidone-iodine disinfectants has declined. Introduction of iodized salt to regions of chronic iodine deficiency may transiently increase the incidence of thyroid disorders, but overall, the relatively small risks of iodine excess are far outweighed by the substantial risks of iodine deficiency.