Impact of Thyroid Status on Incident Kidney Dysfunction and Chronic Kidney Disease Progression in a Nationally Representative Cohort

OBJECTIVE

To examine the relationship between thyroid status and incident kidney dysfunction/chronic kidney disease (CKD) progression.

PATIENTS AND METHODS

We examined incident thyroid status, ascertained by serum thyrotropin (TSH) levels measured from January 1, 2007, through December 31, 2018, among 4,152,830 patients from the Optum Labs Data Warehouse, containing deidentified retrospective administrative claims data from a large national health insurance plan and electronic health record data from a nationwide network of provider groups. Associations of thyroid status, categorized as hypothyroidism, euthyroidism, or hyperthyroidism (TSH levels >5.0, 0.5-5.0, and <0.5 mIU/L, respectively), with the composite end point of incident kidney dysfunction in patients without baseline kidney dysfunction and CKD progression in those with baseline CKD were examined using Cox models.

RESULTS

Patients with hypothyroidism and hyperthyroidism had higher risk of incident kidney dysfunction/CKD progression in expanded case-mix analyses (reference: euthyroidism): adjusted hazard ratios (aHRs) (95% CIs) were 1.37 (1.34 to 1.40) and 1.42 (1.39 to 1.45), respectively. Incrementally higher TSH levels in the upper reference range and TSH ranges for subclinical, mild overt, and overt hypothyroidism (≥3.0-5.0, >5.0-10.0, >10.0-20.0, and >20.0 mIU/L, respectively) were associated with increasingly higher risk of the composite end point (reference: TSH level, 0.5 to <3.0 mIU/L): aHRs (95% CIs) were 1.10 (1.09 to 1.11), 1.37 (1.34 to 1.40), 1.70 (1.59 to 1.83), and 1.70 (1.50 to 1.93), respectively. Incrementally lower TSH levels in the subclinical (<0.5 mIU/L) and overt (<0.1 mIU/L) hyperthyroid ranges were also associated with the composite end point: aHRs (95% CIs) were 1.44 (1.41 to 1.47) and 1.48 (1.39 to 1.59), respectively.

CONCLUSION

In a national cohort, TSH levels in the upper reference range or higher (≥3.0 mIU/L) and below the reference range (<0.5 mIU/L) were associated with incident kidney dysfunction/CKD progression.

Development and Validation of a Prediction Model for Incident Hypothyroidism in a National Chronic Kidney Disease Cohort

CONTEXT

Hypothyroidism is a common yet under-recognized condition in patients with chronic kidney disease (CKD), which may lead to end-organ complications if left untreated.

OBJECTIVE

We developed a prediction tool to identify CKD patients at risk for incident hypothyroidism.

METHODS

Among 15 642 patients with stages 4 to 5 CKD without evidence of pre-existing thyroid disease, we developed and validated a risk prediction tool for the development of incident hypothyroidism (defined as thyrotropin [TSH] > 5.0 mIU/L) using the Optum Labs Data Warehouse, which contains de-identified administrative claims, including medical and pharmacy claims and enrollment records for commercial and Medicare Advantage enrollees as well as electronic health record data. Patients were divided into a two-thirds development set and a one-third validation set. Prediction models were developed using Cox models to estimate probability of incident hypothyroidism.

RESULTS

There were 1650 (11%) cases of incident hypothyroidism during a median follow-up of 3.4 years. Characteristics associated with hypothyroidism included older age, White race, higher body mass index, low serum albumin, higher baseline TSH, hypertension, congestive heart failure, exposure to iodinated contrast via angiogram or computed tomography scan, and amiodarone use. Model discrimination was good with similar C-statistics in the development and validation datasets: 0.77 (95% CI 0.75-0.78) and 0.76 (95% CI 0.74-0.78), respectively. Model goodness-of-fit tests showed adequate fit in the overall cohort (P = .47) as well as in a subcohort of patients with stage 5 CKD (P = .33).

CONCLUSION

In a national cohort of CKD patients, we developed a clinical prediction tool identifying those at risk for incident hypothyroidism to inform prioritized screening, monitoring, and treatment in this population.

Thyroid Function and Risk of Anemia: A Multivariable-Adjusted and Mendelian Randomization Analysis in the UK Biobank

CONTEXT

Thyroid dysfunction is associated with higher anemia prevalence, although causality remains unclear.

OBJECTIVE

This study aimed to investigate the association between thyroid function and anemia.

METHODS

This cross-sectional and Mendelian randomization study included 445 482 European participants from the UK Biobank (mean age 56.77 years (SD 8.0); and 54.2% women). Self-reported clinical diagnosis of hypothyroidism was stated by 21 860 (4.9%); self-reported clinical diagnosis of hyperthyroidism by 3431 (0.8%). Anemia, defined as hemoglobin level of < 13 g/dL in men and < 12 g/dL in women, was present in 18 717 (4.2%) participants.

RESULTS

In cross-sectional logistic regression analyses, self-reported clinical diagnoses of hypo- and hyperthyroidism were associated with higher odds of anemia (OR 1.12; 95% CI, 1.05-1.19 and OR 1.09; 95% CI, 0.91-1.30), although with wide confidence intervals for hyperthyroidism. We did not observe an association of higher or lower genetically influenced thyrotropin (TSH) with anemia (vs middle tertile: OR for lowest tertile 0.98 [95% CI, 0.95-1.02]; highest tertile 1.02 [95% CI, 0.98-1.06]), nor of genetically influenced free thyroxine (fT4) with anemia. Individuals with genetic variants in the DIO3OS gene implicated in intracellular regulation of thyroid hormones had a higher anemia risk (OR 1.05; 95% CI, 1.02-1.10); no association was observed with variants in DIO1 or DIO2 genes.

CONCLUSION

While self-reported clinical diagnosis of hypothyroidism was associated with higher anemia risk, we did not find evidence supporting a causal association with variation of thyroid function within the euthyroid range. However, intracellular regulation of thyroid hormones might play a role in developing anemia.

Urinary iodine and sodium concentration and thyroid status in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

OBJECTIVES

To evaluate urinary iodine concentration (UIC) in civil servants aged 35-74 years of the Brazilian Study of Adults Health (ELSA-Brasil) to analyze its relationship with sociodemographic, clinical risk factors, lifestyle, urinary Na and thyroid status.

DESIGN

Cross-sectional study in six Brazilian cities.

METHODS

This analysis included 792 participants with information about urinary iodine concentration (UIC). Thyroid status was defined by serum levels of TSH/FT4 and the current use of antithyroid drugs for treatment of overt hyperthyroidism or levothyroxine to treat overt hypothyroidism. The determination of UIC was carried out with an inductively coupled plasma mass spectrometer (ICP-MS) and was expressed as median with Interquartile Range (IQR).

RESULTS

In 792 participants, thereof 52% women, mean age was 51.9 (9.0) years. The median UIC was 219 (IQR, 166-291) for all persons studied, thereof 211 (IQR, 157-276) for women and 231 (IQR, 178-304) for men. According to the WHO classification, for all persons studied, 60% had more than adequate iodine-supply (UIC ≥200 μg/L), 37% were adequately supplied (UIC 100-199 μg/L) and <3% had a deficient iodine status (<100 μg/L). In the 35-44-year age strata, which includes women of childbearing age, 23.2% of women presented less than 150 μg/L of UIC. No differences in UIC were detected according to thyroid status. (P = 0.39) The correlation between Ur-Na and UIC showed a Spearman coefficient of 0.52 (P < 0.0001) and it was also found an association of Ur-Na with UIC: Beta of 1.76 (95% Confidence Interval (95% CI): 1.01 to 2.51. The urinary Na concentration showed a synergy with the UIC, that means medians of 57, 72, 107 and 141 mmol Na/L urine (P < 0.001) in the groups with the four UIC classes according to the WHO grading mentioned above. The very low Na content in the persons exhibiting <100 μg/L UIC seems to reflect also a higher urine volume due to the frequent use of diuretics. The strong relationship between the urinary Na concentration and the UIC points to a dependence of the UIC on the individual consumption of iodized salt, which should be more considered in future studies. The strong relationship between the urinary Na concentration and the UIC points to a dependence of the UIC on the individual consumption of iodized salt, which should be more considered in future studies.

CONCLUSIONS

Euthyroid persons were dominating by more than four fifths and no significant association was found between UIC and thyroid status. Although most of the persons studied present more than adequate iodine intake it was observed that nearly a quarter of women in childbearing age are iodine deficient.

Thyroid Hormones-An Underestimated Player in Dilated Cardiomyopathy?

Dilated cardiomyopathy (DCM) is the most prevalent cardiomyopathy, typified by left ventricular dilation and systolic dysfunction. Many patients with DCM have altered thyroid status, especially lower levels of free triiodothyronine (T3) and elevated levels of thyroid-stimulating hormone. Moreover, growing evidence indicates that even subtle changes in thyroid status (especially low T3) are linked with a worse long-term prognosis and a higher risk of mortality. Notably, recent discoveries have shown that not only local myocardial thyroid hormones (THs) bioavailability could be diminished due to impaired expression of the activating deiodinase, but virtually all genes involved in TH biosynthesis are also expressed in the myocardium of DCM patients. Importantly, some studies have suggested beneficial effects of TH therapy in patients suffering from DCM. Our aim was to discuss new insights into the association between TH status and prognosis in DCM, abnormal expression of genes involved in the myocardial synthesis of TH in DCM, and the potential for TH use in the future treatment of DCM.

Association of gestational diabetes mellitus and thyroid status during pregnancy: a cross-sectional study in a tertiary health care center of Bangladesh

OBJECTIVE

To find out any association between gestational diabetes mellitus (GDM) and thyroid status (TS) throughout pregnancy in Bangladesh.

METHODOLOGY

This study, designed as a cross-sectional study, was performed on randomly chosen 628 patients attending the Ad-Din Women's Medical College antenatal service from January 1 2019 to December 31 2019. After taking a detailed history, oral glucose tolerance test was done for all the participants. If eligible, then thyroid-stimulating hormone (TSH) and free thyroxine (F.T4) tests were done. t-test and Chi-square test were used to compare variables between various classes as necessary.

RESULTS

The mean gestational age in GDM and non-GDM groups was 20.5 ± 9.1 years and 17.5 ± 9.2 years, which were significantly different (p<.001). There was a substantial (p<.001) high incidence of thyroid disorder (TD) in the non-GDM community. Mean F.T4 of the GDM group was lower in all three trimesters. The mean TSH of the GDM group was more deficient in the early stage of pregnancy but higher in the later stage (3rd trimester). Euthyroid cases were significantly higher (83.8%; p<.001) while subclinical hypothyroidism (9.5%; p<.001) and transient hyperthyroidism (2.4%; p<.001) cases were significantly lower in GDM group.

CONCLUSIONS

Even though GDM and TD are the most prevalent endocrine disorders during pregnancy, neither TS during pregnancy nor any risk factors for TD have been associated with the development of GDM.

Thyroid function, renal events and mortality in chronic kidney disease patients: the German Chronic Kidney Disease study

BACKGROUND

Hypothyroidism and low free triiodothyronine (FT3) syndrome [low FT3 levels with normal thyroid-stimulating hormone (TSH)] have been associated with reduced kidney function cross-sectionally in chronic kidney disease (CKD) patients with severely reduced estimated glomerular filtration rate (eGFR) or end-stage kidney disease (ESKD). Results on the prospective effects of impaired thyroid function on renal events and mortality for patients with severely reduced eGFR or from population-based cohorts are conflicting. Here we evaluated the association between thyroid and kidney function with eGFR (cross-sectionally) as well as renal events and mortality (prospectively) in a large, prospective cohort of CKD patients with mild to moderately reduced kidney function.

METHODS

Thyroid markers were measured among CKD patients from the German Chronic Kidney Disease study. Incident renal endpoints (combined ESKD, acute kidney injury and renal death) and all-cause mortality were abstracted from hospital records and death certificates. Time to first event analysis of complete data from baseline to the 4-year follow-up (median follow-up time 4.04 years) of 4600 patients was conducted. Multivariable linear regression and Cox proportional hazards models were fitted for single and combined continuous thyroid markers [TSH, free thyroxine (FT4), FT3] and thyroid status.

RESULTS

Cross-sectionally, the presence of low-FT3 syndrome showed a significant inverse association with eGFR and continuous FT3 levels alone showed a significant positive association with eGFR; in combination with FT4 and TSH, FT3 levels also showed a positive association and FT4 levels showed a negative association with eGFR. Prospectively, higher FT4 and lower FT3 levels were significantly associated with a higher risk of all-cause mortality (N events = 297). Per picomole per litre higher FT3 levels the risk of reaching the composite renal endpoint was 0.73-fold lower (95% confidence interval 0.65-0.82; N events = 615). Compared with euthyroid patients, patients with low-FT3 syndrome had a 2.2-fold higher risk and patients with hypothyroidism had a 1.6-fold higher risk of experiencing the composite renal endpoint.

CONCLUSIONS

Patients with mild to moderate CKD suffering from thyroid function abnormalities are at an increased risk of adverse renal events and all-cause mortality over time.

Changes in Thyroid and Glycemic Status and Food Intake in Children with Excess Weight Who Were Submitted for a Multi-Component School Intervention for 16 Months

We investigated if children with excess weight who submitted to two types of intervention at school for 16 months showed improvements in thyroid and glycemic function and food intake. Children (8-11 years) with a body mass index-for-age (BMI/A) of ≥1 Z score were divided into two groups: Treatment 1 (n = 73) involved motivation to adopt healthier lifestyle; Treatment 2 (n = 103) involved performing weekly nutritional education, motivational, and physical activities at school. A semi-quantitative food frequency questionnaire was used. The delta BMI/A were similar after 16 months; Treatment 1 showed higher decrease in thyroid-stimulating hormone (TSH; median (range)): -0.45 (-3.19 to 2.17) and 0.06 (-4.57 to 1.63) mIU/L, p = 0.001), FreeT3 (-0.46 (-2.92 to 1.54) and -0.15 (-2.46 to 1.38) pmol/L, p = 0.038), and FreeT4 -1.41 (-6.18 to 3.47) and -0.90 (-4.89 to 2.96) pmol/L, p = 0.018), followed by decrease in energy intake (7304 (6806 to 7840) and 8267 (7739 to 8832) kJ, Ptreatment = 0.439, Ptime <0.001, interaction group-time p < 0.001), macronutrients and sugar. A positive correlation between FreeT3 and BMI/A, and a negative correlation with FreeT4 and insulin were found at baseline (r 0.212, p < 0.01; r -0.155, p < 0.01, respectively) and follow-up (r 0.222, p < 0.01; r -0.221, p < 0.01). The decrease in overall diet and particularly sugar intake was accompanied by a greater reduction in TSH and FreeT3 in Treatment 1, demonstrating the impact of dietary intake on thyroid function.

Comparison of thyroid function tests and blood count in pregnant women with versus without gestational diabetes mellitus

AIM

The aim of this study was to compare thyroid function and complete blood count parameters in pregnant women with versus without gestational diabetes mellitus (GDM).

METHODS

A total of 269 pregnant women patients with (n = 110, GDM group) or without (n = 159, non-GDM group) GDM were included in this study. Data on age, rate of cesarean section, birthweight of neonate, hemogram, and thyroid function tests were collected. Multivariate analysis was performed to determine factors predicting increased risk of GDM.

RESULTS

Rate of cesarean section (70.9 vs 57.2%, P = 0.022), median (max-min) age (33.0 [26.0] vs 26.0 [20.0] years, P < 0.001), platelet count (246.7 ± 68.3 vs 227.8 ± 64.2 ×10³ /μL, P = 0.021) and thyroid-stimulating hormone (1.3 [97.6] vs 1.0 [4.1] μIU/mL, P = 0.028) were significantly higher in the GDM than in the non-GDM group; whereas mean platelet volume (10.4 [5.3] vs 10.6 [5.6] fL, P = 0.031) and free triiodothyronine (FT3) (2.9 [3.6] vs 3.1 [3.0] pg/mL, P < 0.001) levels were significantly lower in the GDM than in the non-GDM group. Older age (odds ratio, 1.281; 95% confidence interval, 1.182-1.389, P < 0.001) and lower FT3 levels (odds ratio, 0.295; 95% confidence interval, 0.149-0.586, P < 0.001) were independently associated with increased risk of GDM.

CONCLUSION

Our findings revealed that lower FT3 levels and older age predict the likelihood of developing GDM in euthyroid pregnant women, with no influence of other thyroid hormones or blood counts on the risk of GDM.

The relationship between sex and symmetry in thyroid eye disease

Purpose

To examine the relationships between sex and symmetry in the context of disease activity, severity, and thyroid status in thyroid eye disease.

Methods

Retrospective chart review of 31 men and 31 women with untreated thyroid eye disease. Subjective complaints, smoking status, thyroid status, and objective findings pertinent to the clinical activity score (CAS) and “NO SPECS” classification were recorded. Overall disease asymmetry was defined as having simultaneous asymmetry of both more than one symptom and more than one external finding. Asymmetry was compared across sex and thyroid status. CAS and NO SPECS severity were compared across sex, symmetry, and thyroid status.

Results

Asymmetric appearance was reported by 58% of men and 19% of women. Asymmetric proptosis (>2 mm difference) was seen in 45% of men and 23% of women (P=0.036). Overall asymmetry was seen in 55% of men and 19% of women (P=0.017). Thyroid status and sex had a combined effect on symmetry, as 15 of 16 hyperthyroid females (94%) demonstrated symmetric disease. Average NO SPECS severity was 3.5 (standard deviation [SD] 1.4) in men and 3.3 (SD 1.1) in women (P=0.51), and was 3.8 (SD 1.4) in asymmetric patients versus 3.2 (SD 1.3) in symmetric patients (P=0.08). The CAS was higher in asymmetric than symmetric patients (1.84 versus 0.97; P=0.012).

Conclusion

Men demonstrated more asymmetric disease (proptosis and overall asymmetry) than women, while hyperthyroid females demonstrated more symmetry than euthyroid and hypothyroid males and females. NO SPECS severity score was unaffected by sex, thyroid status, or symmetry. Asymmetric patients demonstrated higher clinical activity scores.

A cross-sectional study on thyroid status in North Indian elderly outpatients with dementia

BACKGROUND

Several population based studies have demonstrated an association between hypo-or hyperthyroidism and dementia in last two decades. As a consequence, thyroid stimulating hormone has become part of the screening laboratory test for dementia.

AIM

The aim of the present study was to evaluate the association between thyroid function and Alzheimer's disease (AD) and vascular dementia (VaD) and to determine the risk of AD and VaD in clinically euthyroid patients.

MATERIALS AND METHODS

A cross-sectional hospital based study was carried out in subjects diagnosed with AD/VaD and were assessed for thyroid status as routine screening test.

RESULTS

Free T3, free T4 and TSH were studied in 114 AD patients (mean age: 65 years), 35 VaD patients (mean age: 62 years) and 105 control subjects (mean age: 62 years). In AD group, TSH levels were significantly lower than controls (P = 0.00) and for each unit increase in TSH level, the odds of having dementia decreased by 37.1%. No such relation was seen in VaD.

CONCLUSION

The results suggest a consistent association of subclinical hyperthyroidism and AD.

PPARγ activation attenuates cold-induced upregulation of thyroid status and brown adipose tissue PGC-1α and D2

Here, we investigated whether pharmacological PPARγ activation modulates key early events in brown adipose tissue (BAT) recruitment induced by acute cold exposure with the aim of unraveling the interrelationships between sympathetic and PPARγ signaling. Sprague-Dawley rats treated or not with the PPARγ ligand rosiglitazone (15 mg·kg(-1)·day(-1), 7 days) were kept at 23°C or exposed to cold (5°C) for 24 h and evaluated for BAT gene expression, sympathetic activity, thyroid status, and adrenergic signaling. Rosiglitazone did not affect the reduction in body weight gain and the increase in feed efficiency, Vo(2), and BAT sympathetic activity induced by 24-h cold exposure. Rosiglitazone strongly attenuated the increase in serum total and free T4 and T3 levels and BAT iodothyronine deiodinase type 2 (D2) and PGC-1α mRNA levels and potentiated the reduction in BAT thyroid hormone receptor (THR) β mRNA levels induced by cold. Administration of T3 to rosiglitazone-treated rats exacerbated the cold-induced increase in energy expenditure but did not restore a proper activation of D2 and PGC-1α, nor further increased uncoupling protein 1 expression. Regarding adrenergic signaling, rosiglitazone did not affect the changes in BAT cAMP content and PKA activity induced by cold. Rosiglitazone alone or in combination with cold increased CREB binding to DNA, but it markedly reduced the expression of one of its major coactivators, CREB binding protein. In conclusion, pharmacological PPARγ activation impairs short-term cold elicitation of BAT adrenergic and thyroid signaling, which may result in abnormal tissue recruitment and thermogenic activity.