The relationship between thyroid function and estimated glomerular filtration rate in patients with chronic kidney disease

Thyroid hormone receptor-β analogs for the treatment of Metabolic Dysfunction-Associated Steatohepatitis (MASH)

The association between suboptimal thyroid function ((sub)clinical hypothyroidism or low normal thyroid function) and the metabolic syndrome and metabolic dysfunction-associated steatotic liver disease (MASLD) is clearly established. Furthermore, in MASLD, thyroid hormones have low intracellular concentrations and the activation of the thyroid hormone receptor (THR) is reduced. Administration of thyroid hormone has been shown to reduce liver triglycerides by stimulating fatty acid disposal through lipophagy and beta-oxidation, and to lower LDL-cholesterol. As thyroid hormone exerts it's effects in many different organs, including heart and bone, several drug candidates have been developed acting as selective thyromimetics for the THR-β nuclear receptor with potent and targeted liver actions. Importantly, these compounds have reduced affinity for the THR-α nuclear receptor and tissue distribution profiles that differ from endogenous thyroid hormones thereby reducing unwanted cardiovascular side effects. The most advanced compound, resmetirom, is an oral drug that demonstrated, in a large phase 3 trial in MASH patients, the ability to remove liver fat, reduce aminotransferase levels and improve atherogenic dyslipidemia with a good tolerability profile. This translated into histological improvement that led to accelerated approval of this drug for active fibrotic steatohepatitis, a milestone achievement as a first MASH drug.

Bidirectional negative relationship between thyrotropin and kidney function during alcohol intoxication in males

Introduction

Despite a well-established direct toxic effect of alcohol on renal cells, there is a salutary dose-dependent effect of alcohol consumption on common laboratory parameters related to kidney performance. Alcohol also impacts thyroid hormones, while thyroid status modulates kidney function. The modulation of kidney parameters with thyrotropin (TSH) and thyroid status indicates a possible interaction between alcohol, kidney, and thyroid functions. This retrospective study was conducted to test the hypothesis that the positive effect of alcohol use on the estimated glomerular filtration rate (eGFR) is mediated by alcohol's effect on thyroid hormones.

Methods

We reviewed the electronic medical records of 767 hospitalized adult patients free of thyroid disorders who received medical care in the Mayo Clinic Health System from June 2019 through June 2022 and had blood alcohol concentration (BAC), serum TSH, and serum creatinine measured during the hospitalization. We calculated the eGFR using both the re-expressed Modification of Diet in Renal Disease (MDRD II) study equation and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) Creatinine equation.

Results

We found a significant relationship of BAC with eGFR (CKD-EPI) and TSH in males only. BAC had a positive association with eGFR (b = 0.24, p = 0.0001) and negative with TSH (b=-0.17, p = 0.006). The covariance between the two outcomes (eGFR and TSH) was negative (b = -0.12, p = 0.049). The path analyses using the eGFR MDRD II equation were not significant in males, whereas females had no significant path analyses with either of the eGFR equations.

Discussion

We observed that BAC influences both eGFR and TSH, whereas eGFR and TSH influence each other. After considering important covariates (e.g., age, body mass index, diabetes mellitus, cardiovascular disease, chronic kidney disease, and chronic liver disease) and the negative bidirectional effect of TSH and eGFR, a positive impact of BAC on eGFR was observed in males.

Interrelationship between thyroid hormones and reduced renal function, a review article

BACKGROUND

Understanding the relationship of thyroid hormones with the development of chronic kidney disease (CKD) has important clinical implications for managing patients with both thyroid and kidney dysfunction. In this review, our purpose was to provide a thorough comprehension of the interplay between thyroid hormones, thyroid dysfunctions, and CKD. While there is evidence linking thyroid hormone levels to renal diseases, the association between thyroid hormones, specifically within the normal range, and the risk of CKD incidence is still a subject of debate. The Google Scholar, PubMed, Scopus, and Web of Science, were searched using the medical subject heading (MeSH) terms for the relevant keywords up to December 2023.

CONCLUSION

Based on the review, the development of CKD is more consistently associated with higher serum TSH and thereafter lower serum free T3 levels; however, its association with free T4 is more controversial. Furthermore, subclinical and overt hypothyroidisms were considerably associated with incident CKD. Hyperthyroidism and Hashimoto thyroiditis might increase the risk of CKD.

A high level of thyroid-stimulating hormone is a risk factor for the development of chronic kidney disease in men: a 10-year cohort study

Hypothyroidism has been reported to be associated with chronic kidney disease (CKD). However, the impact of thyroid-stimulating hormone (TSH) on new onset of CKD and its gender dependence remain undetermined. We investigated the association of serum TSH level and the development of CKD defined by estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2 or positive for urine protein in 28,990 Japanese subjects who received annual health examinations. After excluding subjects with no data for serum TSH, urinalysis and eGFR and those with CKD at baseline, a total of 10,392 subjects (men/women: 6802/3590, mean age: 48 years) were recruited. During a 10-year follow-up, 1185 men (6.7%) and 578 women (2.9%) newly developed CKD. Multivariable Cox proportional hazard models after adjustment of age, body mass index, smoking habit, hypertension, diabetes mellitus, dyslipidemia, ischemic heart disease and eGFR (≥ 90 mL/min/1.73 m2) showed that the hazard ratio (HR) for the development of CKD in the high TSH (> 4.2 mU/L) group was significantly higher than that in the low TSH (≤ 4.2 mU/L) group in men (HR [95% confidence interval]: 1.41 [1.09-1.83]) but not in women (1.08 [0.77-1.51]). There was a significant interaction between sex and the category of TSH level for the development of CKD (p = 0.02). The adjusted HR with a restricted cubic spline increased with a higher level of TSH in men but not in women. In conclusion, a high level of TSH is associated with an increased risk for the development of CKD in men but not in women.

Analysis of Thyroid Function in ANCA-Associated Vasculitis Patients with Renal Injury

BACKGROUND

Previous studies indicated common thyroid dysfunction in various kidney diseases. This study aimed to investigate the thyroid function in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV) with renal injury.

METHODS

Briefly, 174 patients diagnosed as having AAV with renal injury and without previous thyroid disease history were included in the retrospective and prospective study. The clinical parameters were collected and compared between different groups.

RESULTS

Of the patients included, 24 exhibited normal thyroid function, while 150 had thyroid dysfunction, including 55 (36.67%) with hypothyroidism. Those AAV patients with thyroid dysfunction showed different clinical parameters from those with normal thyroid function. The patients were followed up for a median of 68.6 (64.3; 72.8) months. Those with thyroid dysfunction were more prone to progressing to dialysis dependence compared to the group with normal thyroid function. Logistic regression analysis showed advanced age and decreased albumin as independent risk factors for thyroid dysfunction in patients with AAV. Survival analysis and multivariate Cox regression analysis showed that thyroid dysfunction was a risk factor for AAV patients with renal injury to progress to the endpoint of dialysis dependence.

CONCLUSION

Thyroid dysfunction, predominantly hypothyroidism, was commonly complicated in AAV patients with renal injury. AAV patients with thyroid dysfunction were presented with different clinical parameters and more prone to progressing to dialysis dependence compared to those with normal thyroid function.

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.

Urinary excretion of thyroid hormone in CKD patients: a proof-of-concept of nephrogenic hypothyroidism

PURPOSE

Patients with chronic kidney disease (CKD) complicated by hypothyroidism exhibit a higher prevalence of urine protein than that in the general population. This study was aimed at investigating thyroid hormones and thyroid hormone-binding proteins excreted in urine to elucidate the urine protein-associated underlying mechanisms of hypothyroidism.

METHODS

Between November 2016 and August 2018, thyroid function (serum free T3 [sFT3], free T4 [sFT4], and thyroid-stimulating hormone [sTSH]), kidney function (estimated glomerular filtration rate [eGFR]), thyroid antibodies and albumin (Alb) were evaluated in 99 Japanese CKD patients with proteinuria at our outpatient clinic. A urine examination was also performed to assess the following parameters: total T3, total T4, TSH, Alb, preAlb, thyroid-binding globulin, and protein.

RESULTS

The median patient age at study recruitment was 60 years; 50 patients (50.5%) were male. The median eGFR and Alb level were 20.3 ml/min/1.73 m2 and 3.8 g/dL, respectively. 21 patients (21.2%) were diagnosed with nephrotic syndrome (NS). The median sFT3, sFT4, and sTSH levels were within normal limits. Approximately 70% of the patients had thyroid dysfunction and 51.5% had overt or subclinical hypothyroidism without predominantly antibody positive. Regarding NS and non-NS patients, age and Alb were significantly different between these groups, while sex and eGFR were not significant, but the urinary T4 and TSH levels were higher in the NS group; thus, more severe hypothyroid.

CONCLUSION

We found a significant association between hypothyroidism and NS regardless of sex and antibodies. Urinary loss of thyroid hormones must be a factor influencing hypothyroidism independent of autoimmunity.

Protocol and Methods: Role of Levothyroxine on the Progression of Chronic Kidney Disease in Subclinical Hypothyroid Populations (LP-CKD) - A Multicenter Randomized Controlled Trial

Introduction

Subclinical hypothyroidism (SCH) is highly prevalent and associated with chronic kidney disease (CKD). However, it is still unanswered whether the restoration of euthyroid status in these patients will be beneficial in retarding a decline in glomerular filtration rate in early CKD patients. We aim to evaluate the efficacy of levothyroxine therapy versus placebo in slowing estimated glomerular filtration rate (eGFR) decline among CKD patients (stage 2-4) with SCH.

Methods

This study will be a multicentric, double-blind, randomized, parallel-group, placebo-controlled study. A total of 500 CKD patients, 250 patients in the treatment group and 250 patients in the placebo group, will be randomized. The randomization between the treatment arm and placebo arm will be performed as per the computer-generated random number table in a 1:1 ratio. The sample size was calculated based on the assumed reduction in eGFR after 1-year follow-up in the treatment and placebo groups of 10% and 25%, respectively, at a minimum two-sided 99% confidence interval and 90% power of the study and considering 20% loss on follow-up. Each patient will be followed every 3 months for at least 1 year after randomization. Individuals completing 1-year follow-up visits will be considered for analysis. The baseline and follow-up data will be compared between the treatment and placebo groups. The study will evaluate the efficacy and safety of levothyroxine therapy versus placebo in slowing eGFR decline among CKD patients (stage 2-4) with SCH. The primary endpoint will be the end of follow-up of the patients, reduction of eGFR by ≥50% from a baseline of that patient, or development of ESKD or death of the patients. The secondary endpoint will be any cardiovascular event or arrhythmia after the institution of the drug.

Management of traditional risk factors for the development and progression of chronic kidney disease

Chronic kidney disease (CKD) and its downstream complications (i.e. cardiovascular) are a major source of morbidity worldwide. Additionally, deaths due to CKD or CKD-attributable cardiovascular disease account for a sizeable proportion of global mortality. However, the advent of new pharmacotherapies, diagnostic tools, and global initiatives are directing greater attention to kidney health in the public health agenda, including the implementation of effective strategies that (i) prevent kidney disease, (ii) provide early CKD detection, and (iii) ameliorate CKD progression and its related complications. In this Review, we discuss major risk factors for incident CKD and CKD progression categorized across cardiovascular (i.e. hypertension, dyslipidemia, cardiorenal syndrome), endocrine (i.e. diabetes mellitus, hypothyroidism, testosterone), lifestyle (i.e. obesity, dietary factors, smoking), and genetic/environmental (i.e. CKDu/Mesoamerican nephropathy, APOL1, herbal nephropathy) domains, as well as scope, mechanistic underpinnings, and management.

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.

Surgical confidence when operating among residents in surgery - a cross-sectional study (SCAR study)

BACKGROUND

Self-confidence, is one of the critical variables influencing surgical resident's abilities, and lack of confidence maybe a reason for not entering medical practice immediately. Measuring the level of confidence of senior surgical residents (SSRs) is a crucial step in assessing preparedness to practice. In this study, we aim to measure their confidence level and the factors that might contribute to it.

METHODS

Cross-sectional survey conducted at King Abdulaziz University Hospital on SSRs in Saudi Arabia (SA). We approached 142 SSRs, 127 responded. Statistical analysis was performed using RStudio v 3.6.2. Descriptive statistics were performed using counts and percentages for categorical variables and using mean ± standard deviation for continuous variables. Multivariate linear regression (t-statistics) was used to assess the factors associated with confidence in performing essential procedures, while the association between demographics and residency-related factor with the number of completed cases was tested using Chi-square. The level of significance was determined as 0.05.

RESULTS

Response rate was 89.4%. Among surveyed residents, 66% had completed < 750 cases as a primary surgeon. More than 90% of SSRs were confident in performing appendectomy, open inguinal hernia repair, laparoscopic cholecystectomy, and trauma laparotomy, while 88% were confident in being on-call in level-I trauma center. No difference was noted in confidence level in relation to the number of performed cases. Residents from the Ministry of Health accounted for 56.3% of the study population and showed a higher confidence level compared to others. 94% of SSRs plan to pursue fellowship training program.

CONCLUSION

The study showed that the confidence of SSRs in performing common general surgery procedures was as expected. However, it's important to recognize that confidence doesn't necessarily reflect competence. Considering the majority of SSRs planned to pursue fellowship training programs, it may be time to consider changing the structure of surgical training in SA to a modular format to allow earlier and more intensive exposure.

Thyroid, Gonadal and Adrenal Dysfunction in Kidney Transplant Recipients: A Review for the Clinician

While chronic kidney disease-associated mineral and bone disorders (CKD-MBD) prevail in the endocrinological assessment of CKD patients, other endocrine abnormalities are usually overlooked. CKD is associated with significant thyroid, adrenal and gonadal dysfunction, while persistent and de novo endocrinological abnormalities are frequent among kidney transplant recipients (KTR). Low T3 levels prior to transplantation may help identify those at risk for delayed graft function and are often found in KTR. Thyroid surveillance after kidney transplantation should be considered due to structural anomalies that may occur. Despite the rapid recovery of gonadal hormonal secretion after renal transplantation, fertility is not completely restored. Testosterone may improve anemia and general symptoms in KTR with persistent hypogonadism. Female KTR may still experience abnormal uterine bleeding, for which estroprogestative administration may be beneficial. Glucocorticoid administration suppresses the hypothalamic-pituitary-adrenal axis in KTR, leading to metabolic syndrome. Patients should be informed about signs and symptoms of hypoadrenalism that may occur after glucocorticoid withdrawal, prompting adrenal function assessment. Clinicians should be more aware of the endocrine abnormalities experienced by their KTR patients, as these may significantly impact the quality of life. In clinical practice, awareness of the specific endocrine dysfunctions experienced by KTR patients ensures the correct management of these complications in a multidisciplinary team, while avoiding unnecessary treatment.

Evaluation of Interactions Between Thyroid Dysfunction in End-Stage Renal Disease Patients: A Cross-Sectional Study

BACKGROUND

Thyroid hormones have a very crucial role in the regulation of metabolism, synthesis of proteins, development, and influencing functions of various other hormones in the human body. While both kidneys play an essential role in the metabolism of thyroid hormone by conversion of thyroxine (T4) to triiodothyronine (T3). In patients with chronic renal failure, frequent abnormal thyroid functions are observed.

AIMS

To evaluate thyroid function in patients of chronic renal failure and to find out their correlation with the severity of the disease.

METHODS

A total of 192 patients were selected for the study after applying inclusion and exclusion criteria. A thyroid function test was done in all enrolled subjects. Serum estimation of T3, T4, and thyroid stimulating hormone (TSH) was done by the chemiluminescent immunoassay (CLIA) method, urea was estimated by the diacetyl monoxide method (DAM, Method), and serum creatinine by Jaffe's method. The results were evaluated for age, sex, and estimated glomerular filtration rate (eGFR) of the patients in view of thyroid dysfunction.

RESULTS

Of all 192 patients enrolled in the study, 124 (64.58%) were male and 68 (35.41%) were females. The observed male-to-female ratio was 1.93:1.18. The mean age of the study group (mean +/- standard deviation, SD) in males was 42+/-18 and in females 38+/-11 years (p value = 0.258). Significant reductions of serum T3, T4, and elevation of TSH were noted in both sexes. A reduced level of T3 was observed in 38.54% (42 males and 32 females) patients, reduced T4 in 34.37% (42 males and 22 females) patients, and subclinical hypothyroidism (SCH) in 16.7% (12 males and 20 females) patients. Biochemical overt hypothyroidism was noted in 7.29% (six males and eight females) of patients.

CONCLUSION

Chronic renal failure is a condition of thyroid hypofunction. A higher prevalence of SCH and clinical hypothyroidism is reported here in chronic kidney disease (CKD) patients. The severity of thyroid hypofunction increases with a progressive reduction in eGFR. Hypothyroidism in CKD patients may be due to different onset mechanisms other than anti-thyroid antibodies.

Kidney disease and thyroid dysfunction: the chicken or egg problem

Patients with non-dialysis-dependant chronic kidney disease (NDD-CKD) and dialysis-dependant chronic kidney disease (DD-CKD) frequently also suffer from thyroid disorders, especially hypothyroidism which is found two to five times more often among them compared to the general population. Emerging research has illustrated the potential prognostic implications of this association as NDD-CKD and DD-CKD patients with hypothyroidism have been shown to have higher mortality rates, and treatment of subclinical hypothyroidism in NDD-CKD patients has been reported to attenuate the decline of glomerular filtration rate over time. This review illustrates the bidirectional, multi-layered interplay between the kidneys and the thyroid gland explaining how pathologies in one organ will affect the other and vice versa. Additionally, it outlines the impact of thyroid disorders on routine parameters of kidney function (especially serum creatinine and serum cystatin C) that nephrologists should be aware of in their clinical practice. Lastly, it summarizes the emerging evidence from clinical studies on how treatment of subclinical hypothyroidism in NDD-CKD and DD-CKD patients may potentially have beneficial effects on kidney function as well as mortality. While most of the research in this area has been performed on adult patients, we specifically discuss what is currently known about thyroid dysfunctions in paediatric CKD patients as well and provide management suggestions. The evidence accumulated so far clearly indicates that further, prospective studies with meticulous methodology are warranted to refine our understanding of thyroid disorders in paediatric and adult CKD patients and establish optimal treatment pathways.

Frequency of Subclinical Hypothyroidism in Patients With Chronic Kidney Disease

Introduction: Chronic kidney disease (CKD) is the progressive loss of function of the nephron over a long period of time. As the glomerular filtration rate falls, it leads to subclinical hypothyroidism (SCH). This cross-sectional study is carried out to measure the frequency of SCH in CKD patients in our population.

Methods: This case-control research was undertaken at the nephrology unit of the Peoples University of Medical and Health Sciences for Women in Pakistan from March 2021 to January 2022. The research included 200 volunteers with documented evidence of CKD between the ages of 18 and 60 years. A case group of 200 people without CKD was also enlisted, matched by age, gender, and comorbidities. Data were recorded in a self-structured questionnaire and analyzed using Statistical Package for the Social Sciences® software (IBM Corp., Armonk, NY).

Results: Thyroid-stimulating hormone was significantly raised in participants with CKD (4.91 ± 1.10 mIU/L vs. 3.62 ± 0.72 mIU/L; p-value < 0.0001). A significant association between SCH and CKD was established (p-value < 0.00001).

Conclusion: Due to the positive correlation between SCH and CKD, multidisciplinary management, including a team of endocrinologists and nephrologists, is advised to keep a regular check on these patients.

The Effect of Nutrition and Exercise on Body Composition, Exercise Capacity, and Physical Functioning in Advanced CKD Patients

Patients with stages 4 and 5 chronic kidney disease (CKD), and particularly chronic dialysis patients, commonly are found to have substantially reduced daily physical activity in comparison to age- and sex-matched normal adults. This reduction in physical activity is associated with a major decrease in physical exercise capacity and physical performance. The CKD patients are often physically deconditioned, and protein energy wasting (PEW) and frailty are commonly present. These disorders are of major concern because physical dysfunction, muscle atrophy, and reduced muscle strength are associated with poor quality of life and increased morbidity and mortality in CKD and chronic dialysis patients. Many randomized controlled clinical trials indicate that when CKD and chronic dialysis are provided nutritional supplements or undergo exercise training their skeletal muscle mass and exercise capacity often increase. It is not known whether the rise in skeletal muscle mass and exercise capacity associated with nutritional support or exercise training will reduce morbidity or mortality rates. A limitation of these clinical trials is that the sample sizes of the different treatment groups were small. The aim of this review is to discuss the effects of nutrition and exercise on body composition, exercise capacity, and physical functioning in advanced CKD patients.

Associations among Ratio of Free Triiodothyronine to Free Thyroxine, Chronic Kidney Disease, and Subclinical Hypothyroidism

The ratio of free triiodothyronine (FT3) to free thyroxine (FT4) (FT3/FT4), a maker of peripheral thyroxin deiodination, could indicate activity of thyroid hormone. Since positive association between subclinical hypothyroidism (SCH) and chronic kidney disease (CKD) was reported, clarifying the association among FT3/FT4, SCH, and CKD could be an efficient tool to make a strategy for preventing CKD. A cross-sectional study with 1724 Japanese with normal thyroid hormone was conducted. Significant positive association between SCH and CKD was observed; the adjusted odds ratio (OR) and 95% confidence interval (95% CI) was 2.23 (1.38, 3.59). Even though, FT3/FT4 was found to be inversely associated with CKD whereas positively associated with SCH; the adjusted ORs and 95% CIs for 1 standard deviation (SD) increment of FT3/FT4 were 0.51 (0.35, 0.74) for CKD and 2.40 (1.34, 4.29) for SCH, respectively. FT3/FT4 was also found to be positively associated with SCH without CKD but not those with CKD; 1 SD increment of FT3/FT4 were 3.44 (1.72, 6.91) for SCH without CKD and 1.11 (0.40, 3.06) for SCH with CKD, respectively. Although further investigation is necessary, present study indicates that higher activity of peripheral thyroxin deiodination might have beneficial association on absence of CKD even among SCH which is positively associated with CKD.

Determinants of Kidney Function and Accuracy of Kidney Microcysts Detection in Patients Treated With Lithium Salts for Bipolar Disorder

Objectives: Early kidney damage during lithium treatment in bipolar disorder is still hypothetical. We aimed at identifying the determinants of a decreased measured glomerular filtration rate (mGFR) and the accuracy of kidney MRI imaging in its detection.

Methods: In this cross-sectional cohort study, 217 consecutive lithium-treated patients underwent mGFR and kidney MRI with half-Fourier turbo spin-echo and Single-shot with long echo time sequences.

Results: Median age was 51 [27–62] years, and median lithium treatment duration was 5 [2–14] years. 52% of patients had a stage 2 CKD. In multivariable analysis, the determinants of a lower mGFR were a longer lithium treatment duration (β −0.8 [−1; −0.6] ml/min/1.73 m² GFR decrease for each year of treatment), a higher age (β −0.4 [−0.6; −0.3] ml/min/1.73 m² for each year of age, p < 0.001), albuminuria (β −3.97 [−6.6; −1.3], p = 0.003), hypertension (β −6.85 [−12.6; −1.1], p = 0.02) and hypothyroidism (β −7.1 [−11.7; −2.5], p = 0.003). Serum lithium concentration was not associated with mGFR. Renal MRI displayed renal microcyst(s) in 51% of patients, detected as early as 1 year after lithium treatment initiation. mGFR and lithium treatment duration were strongly correlated in patients with microcyst(s) (r = −0.64, p < 0.001), but not in patients with no microcysts (r = −0.24, p = 0.09). The presence of microcysts was associated with the detection of an mGFR <45 ml/min/1.73 m² (AUC 0.893, p < 0.001, sensitivity 80%, specificity 81% for a cut-off value of five microcysts).

Conclusion: Lithium treatment duration and hypothyroidism strongly impacted mGFR independently of age, especially in patients with microcysts. MRI might help detect early lithium-induced kidney damage and inform preventive strategies.

Elevated serum thyrotropin levels and endothelial dysfunction in a prospective hemodialysis cohort

INTRODUCTION

Thyroid dysfunction is a highly prevalent yet under-recognized complication in hemodialysis patients. In the general population, hypothyroidism has been associated with endothelial dysfunction due to impaired vasodilator synthesis and activity. Little is known about the association of serum thyrotropin (TSH), the most sensitive and specific single biochemical metric of thyroid function, with endothelial function in hemodialysis patients.

METHODS

In a secondary analysis of 99 patients from the Anti-inflammatory and anti-oxidative nutrition in hypoalbuminemic dialysis patients (AIONID) trial, we examined measurements of serum TSH and endothelial function ascertained by fingertip digital thermal monitoring (DTM), a novel method used to measure micro-vascular reactivity, collected within a 90-day period. DTM was used to measure changes in fingertip temperature during and after an ischemic stimulus (blood pressure cuff occlusion) as an indicator of changes in blood flow, and two DTM indices were assessed, namely adjusted (a) Temperature Rebound (TR), defined as the maximum temperature rebound post-cuff deflation, and adjusted (b) Area Under the Temperature Curve (TMP-AUC), defined as area under the curve between the maximum and minimum temperatures. We examined the relationship between serum TSH with impaired TR (separately) and TMP-AUC (both defined as less than the median level of observed values) using multivariable logistic regression.

FINDINGS

In unadjusted and case-mix analyses, higher serum TSH levels (defined as the three highest quartiles) were associated with lower (worse) TR (ref: lowest TSH quartile): ORs (95% CI) 2.64 (1.01-6.88) and 2.85 (1.08-7.57), respectively. In unadjusted and case-mix analyses, higher TSH levels were associated with lower (worse) TMP-AUC: ORs (95% CI) 2.64 (1.01-6.88) and 2.79 (1.06-7.38), respectively.

DISCUSSION

In HD patients, higher serum TSH levels were associated with worse micro-vascular reactivity measured by DTM. Further studies are needed to determine if thyroid hormone supplementation improves endothelial function in hemodialysis patients with lower levels of thyroid function.

Association of Reduced Free T3 to Free T4 Ratio with Lower Serum Creatinine in Japanese Hemodialysis Patients

PURPOSE

Low T3 syndrome is defined by a fall in free triiodothyronine (FT3) in spite of normal serum thyroid-stimulating hormone (TSH) and often normal free thyroxin (FT4). A low FT3/FT4 ratio, a relevant marker for low T3 syndrome, is known as a risk of mortality in hemodialysis (HD) patients, as well as low muscle mass in the general population. Because of the local activation of T4 to FT3 in muscle tissue, we examined the association of FT3/FT4 ratio with serum creatinine, a marker of muscle mass and strength in HD patients to investigate the significance of muscle tissue in the development of low T3 syndrome in HD patients.

METHODS

This was a cross-sectional study derived from our prospective cohort study, named DREAM, of Japanese HD patients. After the exclusion of patients with treated and untreated thyroid dysfunction, 332 patients were analyzed in the study.

RESULTS

The serum FT4 and TSH of HD patients (n = 332) were 0.9 ± 0.1 ng/dL. and 2.0 ± 0.9 μIU/mL, which were within the respective normal range, while serum FT3 was 2.2 ± 0.3 pg/mL. As many as 101 out of 332 (30.4%) HD patients exhibited a serum FT3 less than the normal lower limit of 2.2 pg/mL. The serum FT3/FT4 ratio correlated significantly positively with serum creatinine, and inversely with serum log CRP and total cholesterol, while it exhibited a tendency towards positive correlation with serum albumin. Multiple regression analysis, which included serum creatinine, albumin, and log CRP, simultaneously, in addition to sex, age, diabetic kidney disease or not, log HD duration, body mass index, systolic blood pressure, and Kt/V, as independent variables, revealed an independent and significant positive association of serum creatinine, but not serum albumin or CRP, with the serum FT3/FT4 ratio.

CONCLUSIONS

The present study demonstrated an independent and positive correlation of serum creatinine with the serum FT3/FT4 ratio in HD patients. The lack of association of the serum FT3/FT4 ratio with serum albumin and CRP suggested the presence of a creatinine-specific mechanism to associate with serum FT3/FT4 ratio. Because of the local activation of T4 to T3 at muscle tissue, a lower muscle mass may be causatively associated with low T3 syndrome.

A Study to Evaluate the Association Between Thyroid Function and Serum Potassium Level in Diagnosed Cases of Diabetic Nephropathy

Introduction Coexistence of diabetes mellitus and thyroid diseases is common. One of the main microvascular complications of diabetes is diabetic nephropathy (DN) and it is found to be the leading cause of chronic kidney disease. The aim of the present study was to assess the association between hypothyroidism and serum potassium levels in diabetic nephropathy patients. Materials and methods A cross-sectional study was conducted from March 2020 to January 2021. We enrolled 100 patients with DN along with 50 healthy controls belonging to the same localities. Serum potassium, creatinine, thyroid-stimulating hormone (TSH) and total triiodothyronine (T3) levels of all the cases were measured to establish the correlation of serum potassium along with each parameter separately. Results Serum potassium, creatinine, TSH levels were increased in all the cases of diabetic nephropathy showing positive correlations of serum potassium with serum TSH and serum creatinine levels with correlation coefficient values 0.71 and 0.7 respectively and serum T3 levels were decreased in all the cases significantly showing negative correlation with serum potassium levels with correlation coefficient value -0.34. Conclusion Estimation of serum TSH and T3 levels along with serum potassium levels is important and helpful in patients with diabetic renal disease. Changes in thyroid parameters like decreased TSH or increased T3 are significantly associated with deterioration in the severity of renal function in diabetic patients.

Nephrotic Syndrome as a Cause of Transient Clinical Hypothyroidism

Nephrotic syndrome may trigger the onset of hypothyroidism, promoting massive urinary protein losses including thyroxine (T4) and triiodothyronine (T3) along with their binding proteins. At an early stage, a clinical and biochemical euthyroid state is expected. However, in patients with prolonged and severe proteinuria, especially with concomitant low thyroid reserve, urinary losses of free and protein-bound thyroid hormones are sufficiently pronounced to induce a subclinical or overt hypothyroidism. Despite its high prevalence in clinical practice, the literature lacks case reports of newly diagnosed clinical hypothyroidism due to NS in adults, making this condition under-recognized. We report a case of a 23-year-old man with previous normal thyroid function who developed overt hypothyroidism due to a severe nephrotic syndrome, requiring supplementation with levothyroxine (LT). After the patient had undergone bilateral nephrectomy, treatment with LT was discontinued and thyroid function normalized.

Association between albuminuria and thyroid function in patients with chronic kidney disease

PURPOSE

The relationship between proteinuria and thyroid function remains controversial in patients with chronic kidney disease (CKD). We prospectively investigated the association between kidney and thyroid function in thyroid antibody-negative patients through all CKD stages.

METHODS

We enrolled 184 nondialysis patients (mean age: 63.1 ± 16.9 years) without previous thyroid disease or thyroid-specific antibodies. Kidney function was assessed by estimating the glomerular filtration rate (eGFR) classified according KDIGO (CKD G1-5). Kidney damage was assessed by albuminuria (albumin-to-creatinine ratio, ACR) and classified as mild, moderate, or severe (ACR1: <300, ACR2: 300-3000, and ACR3: 3000 mg/g). To evaluate thyroid function, TSH, T4, fT4, T3, fT3, reverse T3 (rT3), and thyroxine-binding globulin (TBG) were measured.

RESULTS

rT3 concentrations correlated negatively with albuminuria (r = -0.286, p < 0.001) and were significantly lower in patients with severe albuminuria than in those with mild or moderate albuminuria (ACR3: 0.28 vs. ACR2: 0.32 vs. ACR1: 0.36 nmol/l, p < 0.001). The severity of albuminuria revealed no impact on TSH, fT4, T3, fT3, and TBG. EGFR correlated with increasing T4, fT4, T3, fT3, and TBG (T4: r = 0.289, p < 0.01; fT4: r = 0.196, p < 0.01; T3: r = 0.408, p < 0.01; fT3: r = 0.390, p < 0.01) but not with rT3.

CONCLUSIONS

In thyroid antibody-negative patients presenting advanced CKD (stages 4 and 5), even severe kidney protein loss failed to influence thyroid hormone status. However, albuminuria severity correlated negatively with rT3, which was significantly lower in patients with albuminuria in the nephrotic range.

Non-alcoholic fatty liver and chronic kidney disease: Retrospect, introspect, and prospect

With the growing prevalence of obesity and diabetes in the United States and across the world, a rise in the overall incidence and prevalence of non-alcoholic fatty liver disease (NAFLD) is expected. The risk factors for NAFLD are also associated with the development of chronic kidney disease (CKD). We review the epidemiology, risk factors, genetics, implications of gut dysbiosis, and specific pathogenic mechanisms linking NAFLD to CKD. Mechanisms such as ectopic lipid accumulation, cellular signaling abnormalities, and the interplay between fructose consumption and uric acid accumulation have led to the emergence of potential therapeutic implications for this patient population. Transplant evaluation in the setting of both NAFLD and CKD is also reviewed. Potential strategies for surveillance and management include the monitoring of comorbidities, the use of non-invasive fibrosis scoring systems, and the measurement of laboratory markers. Lastly, we discuss the management of patients with NAFLD and CKD, from preventative measures to experimental interventions.

Thyroid hormone status in patients with impaired kidney function

PURPOSE

We aimed to investigate the prevalence of thyroid hormone abnormalities and the relationship between free triiodothyronine (fT3), thyroid stimulating hormone (TSH) and free thyroxine (fT4) serum levels with kidney function and proteinuria in 4108 subsequent patients admitted to a Nephrology Clinic at a tertiary Medical Centre.

METHODS

All patients were categorized based on their estimated glomerular filtration rate (eGFR) as follows: normal-eGFR ≥ 60 ml/min, mild kidney impairment-30 ≤ eGFR < 60 ml/min, and severe kidney impairment-eGFR < 30 ml/min.

RESULTS

Subjects with normal eGFR presented a laboratory constellation of hypothyroidism in 3.38% and "low-T3 syndrome" in 8.28%, while subjects with severe kidney impairment were diagnosed with hypothyroidism in 2.82% and "low-T3 syndrome" in 22.9%. Multivariate regression analysis showed that eGFR was a strong independent predictor of serum fT3 levels in patients with eGFR < 60 ml/min. Impaired kidney function was associated with low fT4 and fT3 but not TSH. Our findings showed an inverse correlation of fT3 and fT4 levels and proteinuria range. FT4 inversely correlated with the extent of proteinuria in all subgroups of patients. In contrast, the inverse correlation of fT3 serum levels and proteinuria disappeared in patients with eGFR < 60 ml/min.

CONCLUSION

In a large cohort of inpatients, the prevalence of low-T3 syndrome was 2.5 times higher in patients with advanced kidney disease, compared to those with normal kidney function. In advanced CKD, both eGFR and proteinuria were strongly correlated with thyroid hormones. Therefore, close screening of the "thyroid profile" in patients with any stage of CKD, especially to those with proteinuria, might be warranted.

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.

The Interplay Between Thyroid Dysfunction and Kidney Disease

Hypothyroidism is a highly prevalent endocrine complication in chronic kidney disease (CKD) patients. A large body of evidence has shown that there is a bidirectional relationship between thyroid dysfunction and kidney disease, yet there are many remaining gaps in knowledge in regards to the clinical management of CKD patients with hypothyroidism, including those receiving hemodialysis and peritoneal dialysis. Given that hypothyroidism has been associated with many deleterious outcomes including a higher risk of (1) mortality, (2) cardiovascular disease, (3) impaired health-related quality of life, and (4) altered body composition in both non-CKD and CKD patients, future research is needed to establish the appropriate screening, diagnosis, and treatment approaches in these populations.

A Pilot Trial on the Effect of Levothyroxine on Proteinuria in Patients With Advanced CKD

INTRODUCTION

Thyroid hormones can directly affect kidney function; elevated levels of thyroid-stimulating hormone (TSH) and chronic kidney disease (CKD) are associated with proteinuria, decreased estimated glomerular filtration rate (eGFR), and progression to end-stage renal disease. Our hypothesis is that in patients with CKD and TSH at levels considered to be in the low subclinical hypothyroidism (SCH) range, lowering TSH with levothyroxine (LVX) improves the clinical parameters of renal function.

METHODS

This was a double-blind, randomized, pilot clinical trial in patients with proteinuric CKD (eGFR <60 ml/min per 1.73 m2 and proteinuria >150 mg/d) performed at the Hospital Civil de Guadalajara, with the intention of lowering TSH (levels of 1.25-2.5 μIU/l) in patients with TSH (levels of 2.6-9.9 μIU/ml with FT4 in the range of 0.7-1.8 ng/dl). Patients were randomized 1:1 to receive LVX or placebo for 12 weeks. The primary objective was to evaluate absolute levels of proteinuria at the beginning compared to the end of the study and, as a secondary objective, the changes in serum creatinine (sCr), eGFR, cholesterol, triglycerides, low-density lipoprotein (LDL), and blood pressure, and to assess the tolerability and safety of LVX.

RESULTS

Between March and November 2018, a total of 163 patients were assessed for eligibility; 119 patients did not meet the inclusion criteria or were excluded, and 32 patients were randomized. The demographic and clinical characteristics of the 2 study groups were essentially not different. Subjects were 66.87 (SD 12.19) years of age, 62.5% were female, 75% were diabetes mellitus, eGFR was 23.55 (±12.91) ml/min per 1.73 m2, TSH was 5.37 ± 2.13 μIU/ml, proteinuria in 24-hour urine collection was 1.52 ± 1.12, and all of them were taking angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin II receptor blockers (ARBs). Proteinuria at 12 weeks in the LVX group was 0.89 SD ± 1.28 g/d, and in the placebo group it was 1.35 SD ± 0.85 g/d; when compared to placebo, LVX showed a significant decrease in proteinuria of 1.1 g/d (P = 0.0011). The eGFR in the LVX group showed an improvement of 4 ml/min/1.73 m2 (P = 0.049); in the placebo group, there was a decrease of 1.98 ml/min per 1.73 m2. The sCr, cholesterol, triglycerides, low-density lipoprotein, systolic blood pressure, and diastolic blood pressure were not different between groups. Adverse events were reported in the LVX group in 7.14% of patients and in 11.11% of patients in the placebo group; none left the study because of adverse effects, and there were no serious adverse events.

CONCLUSION

This single-center, randomized, double-blind, placebo-controlled pilot clinical trial in patients with advanced proteinuric CKD who already used ACEIs or ARBs demonstrated that administering LVX to obtain a TSH range close to 2.5 μIU/ml decreased proteinuria and improved eGFR. Future research is needed to confirm our results and to determine whether our findings generalize to patient groups not explicitly enrolled in this small pilot trial.

Prevalence of hypothyroidism in Japanese chronic kidney disease patients

Background: Major symptoms of progressive chronic kidney disease (CKD) are similar to those of hypothyroidism. Hidden symptoms of hypothyroidism underlying CKD are often observed in clinical practice. This study aimed to ascertain the frequency of hypothyroidism complicated by CKD, and to analyze factors impacting thyroid function.Methods: During the period from April 2012 through October 2016, 510 CKD patients at our outpatient clinic were measured thyroid and kidney function for diagnosing hypothyroidism (overt hypothyroidism, OH; subclinical hypothyroidism, SH; non-thyroidal illness, NTI) and evaluating the stage of CKD. All patients were over 15 years of age.Results: There were significant differences in age, estimated glomerular filtration rate (eGFR), urinary protein (UP), and serum albumin (Alb) among patients with OH, SH, and NTI compared to the normal group in univariate and multivariate analyses. UP showed the highest odds ratio of OH, SH, and NTI but no differences were recognized in gender in each group. Frequency distribution showed that the prevalence of thyroid dysfunction was greater among more severe stage of CKD with higher amount of UP. OH and SH did not show high positive ratio of anti-thyroglobulin antibody (TgAb) and anti-thyroid peroxidase antibody (TPOAb). NTI and normal subjects showed higher positive ratio as 50.0% and 42.9% of TgAb and TPOAb than OH and SH.Conclusions: Hypothyroidism complicated by CKD exhibited a high prevalence. Age, eGFR, UP, and serum Alb were related to the prevalence of hypothyroidism, whereas gender was not and this was contradicted to the prevalence of hypothyroidism in general population. The prevalence of OH and SH was higher among patients with higher stage of CKD with increased UP. Hypothyroidism complicated by CKD may involve different onset mechanisms unrelated to antithyroid antibodies (ATAb). In CKD patients, assessments of OH and SH, as well as NTI, are needed for proper diagnosis.

Novel Approaches to Target Mutant FLT3 Leukaemia

Simple Summary

Acute myeloid leukemia (AML) is a haematologic disease in which oncogenic mutations in the receptor tyrosine kinase FLT3 frequently lead to leukaemic development. Potent treatment of AML patients is still hampered by inefficient targeting of leukemic stem cells expressing constitutive active FLT3 mutants. This review summarizes the current knowledge about the regulation of FLT3 activity at cellular level and discusses therapeutical options to affect the tumor cells and the microenvironment to impair the haematological aberrations.

Abstract

Fms-like tyrosine kinase 3 (FLT3) is a member of the class III receptor tyrosine kinases (RTK) and is involved in cell survival, proliferation, and differentiation of haematopoietic progenitors of lymphoid and myeloid lineages. Oncogenic mutations in the FLT3 gene resulting in constitutively active FLT3 variants are frequently found in acute myeloid leukaemia (AML) patients and correlate with patient’s poor survival. Targeting FLT3 mutant leukaemic stem cells (LSC) is a key to efficient treatment of patients with relapsed/refractory AML. It is therefore essential to understand how LSC escape current therapies in order to develop novel therapeutic strategies. Here, we summarize the current knowledge on mechanisms of FLT3 activity regulation and its cellular consequences. Furthermore, we discuss how aberrant FLT3 signalling cooperates with other oncogenic lesions and the microenvironment to drive haematopoietic malignancies and how this can be harnessed for therapeutical purposes.

Cystatin C, a Controversial Biomarker in Hypothyroid Patients under Levothyroxine Therapy: THYRenal, a Pilot Cohort Observational Study

BACKGROUND

Cystatin C (Cys-C) is recognized as one of the most reliable renal function parameters in the general population, although it might be biased by thyroid status. Herein, we tested Cys-C and conventional renal parameters in a cohort of hypothyroid patients treated with Levothyroxine.

METHODS

Eighty-four hypothyroid patients were recruited and subgrouped according to their serum thyroid-stimulating hormone (TSH) values as a paradigm for therapeutic targeting (n = 54, optimal TSH range = 0.5-2 µIU/mL; n = 30, TSH > 2µIU/mL). Serum Cys-C, creatinine, measured and estimated glomerular filtration rates (mGFR and eGFR) were assessed. Results-mGFR and eGFR were comparable among the two subgroups, whereas Cys-C was significantly higher in patients with suboptimal TSH values (>2 µIU/mL) (p < 0.0001). TSH significantly correlated with Cys-C in the overall patient group, and in the subgroup with TSH above the target value (>2 µIU/mL). Out of 20 patients with abnormal Cys-C, 19 had suboptimal TSH levels. Receiver operating characteristic (ROC) analysis indicated Cys-C as a moderately accurate diagnostic tool (AUC = 0.871) to assess Levothyroxine replacement efficacy in hypothyroid patients (63% sensitivity, and 98% specificity).

CONCLUSIONS

The observation of increased serum Cys-C in patients with suboptimal TSH would suggest the importance of a careful interpretation by clinicians of this biomarker in the case of hypothyroid patients.

Association of Serum Thyroid Hormones with the Risk and Severity of Chronic Kidney Disease Among 3563 Chinese Adults

Background

Chronic kidney disease (CKD) is a global health problem with an increasing prevalence. We explored the association of serum thyroid hormones with the risk and severity of CKD among Chinese adults.

Material/Methods

This retrospective study involved 3563 participants. CKD was diagnosed according to the clinical practice guidelines of the 2012 Kidney Disease Improving Global Outcomes guidelines. Effect-size estimates are expressed as odds ratio (OR) and 95% confidence interval (CI).

Results

Given the strong magnitude of correlation, only 3 thyroid hormones were analyzed: free triiodothyronine (FT3), free thyroxin (FT4), and thyroid-stimulating hormone (TSH). After propensity score matching on age, sex, diabetes, and hypertension, per 0.2 pg/mL increase in FT3 was significantly associated with 35–38% reduced risk of CKD at stage 1–4, and per 0.3 ng/dL increase in FT4 was only significantly associated with 21% reduced risk of CKD at stage 5 (OR, 95% CI: 0.79, 0.69–0.89), and per 0.5 μIU/mL increment in TSH increased the risk of CKD stage 5 by 8% (1.08, 1.02–1.14). Importantly, 3 thyroid hormones acted interactively, particularly for the interaction between FT3 and FT4 in predicting CKD at stage 5 (OR, 95% CI: 1.81, 1.30–2.55 for high FT3-low FT4, 17.72, 7.18–43.74 for low FT3-high FT4, and 22.28, 9.68–51.30 for low FT3-low FT4).

Conclusions

Our findings indicate that serum FT3 can be used as an early-stage biomarker for CKD, and FT4 and TSH can be used as advanced-stage biomarkers among Chinese adults.

Association of thyroid status prior to transition to end-stage renal disease with early dialysis mortality

BACKGROUND

Advanced chronic kidney disease (CKD) patients, including those receiving dialysis, have a high prevalence of thyroid dysfunction. Although hypothyroidism is associated with higher death risk in end-stage renal disease (ESRD) patients, no studies have examined whether thyroid status in the pre-ESRD period impacts mortality after dialysis initiation.

METHODS

Among US veterans with CKD identified from the national Veterans Affairs database that transitioned to dialysis over the period from October 2007 to September 2011, we examined the association of pre-ESRD serum thyrotropin (TSH) levels averaged over the 1-year pre-dialysis ('prelude') period with all-cause mortality in the first year following dialysis initiation.

RESULTS

Among 15 335 patients in the 1-year prelude cohort, TSH levels >5.0 mIU/L were associated with higher mortality in expanded case-mix Cox models (reference: TSH 0.5-5.0 mIU/L): adjusted hazard ratio (aHR) [95% confidence interval (CI) 1.20 (1.07-1.33). Similar findings were observed for TSH >5.0 mIU/L and mortality in the 2- and 5-year cohorts: aHRs (95% CI) 1.11 (1.02-1.21) and 1.15 (1.07-1.24), respectively. Analyses of finer gradations of TSH in the 1-year prelude cohort demonstrated that incrementally higher levels >5.0 mIU/L were associated with increasingly higher mortality in expanded case-mix models (reference: TSH 0.5-3.0 mIU/L): aHRs (95% CI) 1.18 (1.04-1.33) and 1.28 (1.03-1.59) for TSH levels >5.0-10.0 mIU/L and >10.0 mIU/L, respectively. In the 2- and 5-year cohorts, mortality associations persisted most strongly for those with TSH >10.0 mIU/L, particularly after laboratory covariate adjustment.

CONCLUSIONS

Among new ESRD patients, there is a dose-dependent relationship between higher pre-ESRD TSH levels >5.0 mIU/L and post-ESRD mortality. Further studies are needed to determine the impact of TSH reduction with thyroid hormone supplementation in this population.

Association between hypothyroidism and chronic kidney disease observed among an adult population 55 years and older

Hypothyroidism and chronic kidney disease (CKD) are highly prevalent conditions with a potential mechanistic link. We sought to determine whether hypothyroidism is associated with CKD among a large diverse community-based cohort.A cross-sectional study was performed (January 1, 1990-December 31, 2017) within a large integrated health system. Individuals age ≥55 years of age with outpatient measurements of thyroid stimulating hormone (TSH) and ≥2 serum creatinine values were included. Hypothyroidism was defined as TSH >4 mIU/L and/or receipt of thyroid hormone replacement and further categorized as hypothyroid status: TSH >4 mcIU/mL and attenuated-hypothyroid status: TSH <4 mcIU/mL with receipt of thyroid hormone replacement. Euthyroidism was defined as TSH <4 mIU/L and no thyroid hormone replacement. Our primary measure was CKD defined as an estimated glomerular filtration rate (eGFR) <45 mL/min/1.73 m. Multivariable logistic regression adjusting for age, sex, race, and comorbidities was used to estimate odds ratios (OR) for CKD by thyroid status.Among 378,101 individuals, 114,872 (30.4%) had hypothyroidism among whom 31,242 and 83,630 had hypothyroid and attenuated-hypothyroid statuses, respectively. Individuals with hypothyroidism had a CKD OR (95%CI) of 1.25 (1.21-1.29) compared with those with euthyroidism. Granular examination of thyroid statuses showed that hypothyroid and attenuated-hypothyroid statuses had CKD ORs (95% CI) of 1.59 (1.52-1.66) and 1.12 (1.08-1.16), respectively. A similar relationship was observed in analyses that defined CKD as an eGFR <60 L/min/1.73 m.Among individuals 55 years and older, we observed that those with hypothyroidism were more likely to have CKD. A stronger association was found among patients of hypothyroid status compared with attenuated-hypothyroid status suggesting a dose dependent relationship.

Hypothyroidism and Kidney Function: A Mendelian Randomization Study

Background: Uncertainty in the mechanism and directionality of observational associations between thyroid function and kidney function may be addressed by genetic analysis with an instrumental variable method termed bidirectional Mendelian randomization (MR). Methods: In the Women's Genome Health Study (WGHS), observational associations between thyroid measures and kidney function were evaluated. Genetic instruments for MR were from recent genome-wide association studies (GWAS) of hypothyroidism, thyrotropin (TSH), and free thyroxine (fT4) concentrations within the reference range, thyroid peroxidase antibodies (TPOAb), estimated glomerular filtration rate from creatinine (eGFR_crea), eGFR from cystatin C (eGFR_cys), and chronic kidney disease (CKD). In WGHS individual-level data, these instruments were used for bidirectional MR between thyroid (N = 3336) and kidney (N = 23,186) functions. To increase power, MR was also performed using GWAS summary statistics from the Chronic Kidney Disease Genetics Consortium (CKDGen) for eGFR_crea (N = 567,460), eGFR_cys (N = 24,063), CKD [N(total) = 480,698, N(cases) = 41,395], and urinary albumin/creatinine ratio (UACR/N = 54,450). Results: In the WGHS, hypothyroidism was observationally associated with decreased eGFR_crea [beta (standard error, SE): -0.024 (0.009) ln(mL/min/1.73 m²), p = 0.01]. By MR, hypothyroidism was associated with decreased eGFR_crea in the WGHS [beta (SE): -0.007 (0.002) per doubled odds hypothyroidism, p = 1.7 × 10^-3] and in CKDGen [beta (SE): -0.004 (0.0005), p = 2.0 × 10^-22], and robust to sensitivity analysis. Hypothyroidism was also associated by MR with increased CKD in CKDGen (odds ratio, OR [confidence interval, CI]: 1.05 [1.03-1.08], p = 3.3 × 10^-5), but not in the WGHS (OR [CI]: 1.02 [0.95-1.10], p = 0.57). Increased TSH within the reference range had an MR association with increased eGFR_crea in the WGHS [beta (SE): -0.018 (0.007) ln(mL/min/1.73 m²)/standard deviation, SD, p = 6.5 × 10^-3] and CKDGen [beta (SE): -0.008 (0.001) ln(mL/min/1.73 m²)/SD, p = 6.8 × 10^-17], and with CKD in CKDGen (OR [CI]: 1.10 [1.04-1.15], p = 3.1 × 10^-4). There were no MR associations of hypothyroidism or TSH with eGFR_cys or UACR, and MR associations of fT4 in the reference range with kidney function were inconsistent in both the WGHS and CKDGen. However, by MR in CKDGen, TPOAb were robustly associated with decreased eGFR_crea [beta (SE): -0.041 (0.009), p = 6.2 × 10^-6] and decreased eGFR_cys [beta (SE): -0.294 (0.065), p = 6.2 × 10^-6]. TPOAb were less robustly associated with CKD but not associated with UACR. In reverse MR in the WGHS, kidney function was not consistently associated with thyroid function. Conclusions: Bidirectional MR supports a directional association from hypothyroidism, increased TSH, and TPOAb, but not fT4, to decreased eGFR_crea and increased CKD.

Effect of Thyroid Hormones on Kidney Function in Patients after Kidney Transplantation

Elevated levels of thyroid-stimulating-hormone (TSH) are associated with reduced glomerular filtration rate (GFR) and increased risk of developing chronic kidney disease even in euthyroid patients. Thyroid hormone replacement therapy has been shown to delay progression to end-stage renal disease in sub-clinically hypothyroid patients with renal insufficiency. However, such associations after kidney transplantation were never investigated. In this study the association of thyroid hormones and estimated GFR (eGFR) in euthyroid patients after kidney transplantation was analyzed. In total 398 kidney transplant recipients were assessed retrospectively and association between thyroid and kidney function parameters at and between defined time points, 12 and 24 months after transplantation, was studied. A significant inverse association was shown for TSH changes and eGFR over time between months 12 and 24 post transplantation. For each increase of TSH by 1 µIU/mL, eGFR decreased by 1.34 mL/min [95% CI, −2.51 to −0.16; p = 0.03], corresponding to 2.2% eGFR decline, within 12 months. At selected time points 12 and 24 months post transplantation, however, TSH was not associated with eGFR. In conclusion, an increase in TSH between 12 and 24 months after kidney transplantation leads to a significant decrease in eGFR, which strengthens the concept of a kidney-thyroid-axis.

Low thyroid function is not associated with an accelerated deterioration in renal function

BACKGROUND

Chronic kidney disease (CKD) is frequently accompanied by thyroid hormone dysfunction. It is currently unclear whether these alterations are the cause or consequence of CKD. This study aimed at studying the effect of thyroid hormone alterations on renal function in cross-sectional and longitudinal analyses in individuals from all adult age groups.

METHODS

Individual participant data (IPD) from 16 independent cohorts having measured thyroid stimulating hormone, free thyroxine levels and creatinine levels were included. Thyroid hormone status was defined using clinical cut-off values. Estimated glomerular filtration rates (eGFR) were calculated by means of the four-variable Modification of Diet in Renal Disease (MDRD) formula. For this IPD meta-analysis, eGFR at baseline and eGFR change during follow-up were computed by fitting linear regression models and linear mixed models in each cohort separately. Effect estimates were pooled using random effects models.

RESULTS

A total of 72 856 individuals from 16 different cohorts were included. At baseline, individuals with overt hypothyroidism (n = 704) and subclinical hypothyroidism (n = 3356) had a average (95% confidence interval) -4.07 (-6.37 to -1.78) and -2.40 (-3.78 to -1.02) mL/min/1.73 m2 lower eGFR as compared with euthyroid subjects (n = 66 542). In (subclinical) hyperthyroid subjects (n = 2254), average eGFR was 3.01 (1.50-4.52) mL/min/1.73 m2 higher. During 329 713 patient years of follow-up, eGFR did not decline more rapidly in individuals with low thyroid function compared with individuals with normal thyroid function.

CONCLUSIONS

Low thyroid function is not associated with a deterioration of renal function. The cross-sectional association may be explained by renal dysfunction causing thyroid hormone alterations.

Thyroid disease in end-stage renal disease

PURPOSE OF REVIEW

Hypothyroidism is a highly prevalent endocrine disorder in the end-stage renal disease (ESRD) population, yet many cases may remain latent and undiagnosed.

RECENT FINDINGS

Epidemiologic data show that there is a nearly five-fold higher prevalence of hypothyroidism in advanced chronic kidney disease (CKD) patients vs. those without CKD. Given that the metabolism, degradation, and excretion of thyroid hormone and its metabolites, as well as the regulation of the hypothalamic-pituitary-thyroid axis may be altered in ESRD, certain considerations should be made when interpreting thyroid functional tests in these patients. Growing evidence shows that hypothyroidism and other thyroid functional test derangements are associated with higher risk of cardiovascular disease, worse patient-centered outcomes, and survival in the advanced CKD population, including those with ESRD. Although limited data examining treatment of hypothyroidism suggests benefit, further studies of the efficacy and safety of thyroid hormone supplementation, including clinical trials and rigorous longitudinal observational studies are needed to inform the management of thyroid dysfunction in CKD.

SUMMARY

Given the high burden of hypothyroidism in ESRD patients, and potential ill effects on their cardiovascular health, patient-centered outcomes, and survival, further research is needed to inform the optimal management of thyroid dysfunction in this population.

The association between thyroid dysfunction (TD) and diabetic kidney disease (DKD) in type 2 diabetes mellitus (T2DM)

BACKGROUND

Epidemiological studies have identified an association between thyroid dysfunction (TD) and various kidney diseases. In this study, the prevalence of TD in type 2 diabetic mellitus (T2DM) patients with diabetic kidney disease (DKD) was evaluated to analyse the potential association between TD and DKD in T2DM patients.

METHODOLOGY

A total of 2108 T2DM patients from Anhui Provincial Hospital were recruited in this study. Demographic and clinical characteristics were collected from 834 T2DM patients with DKD and 1274 T2DM patients without DKD (non-DKD). All patients were stratified into a number of groups based on UACR (urine albumin-to-creatinine ratio) or eGFR (estimated glomerular filtration rate): (a) A1: normoalbuminuria (<30), A2: microalbuminuria (30-300) and A3: macroalbuminuria (>300); (b) F1: normal filtration (60-139), F2: hyper filtration (≥140) and F3: low filtration (<60).

RESULTS

Significant differences were observed between the non-DKD and DKD groups (P < .05) in age, sex ratio, duration, systolic blood pressure, total cholesterol, low density lipoprotein cholesterol, serum creatinine, blood urea nitrogen, free triiodothyronine (FT3), free thyroxine (FT4) and sensitive thyrotropin hormone (sTSH). The macroalbuminuira and low filtration groups had the lowest levels of FT3 and FT4 and the highest level of sTSH, compared with all other groups (P < .0167). The prevalence of subclinical hypothyroidism in the DKD group was significantly higher than that in the non-DKD group (χ2  = 13.92, P < .01). Logistic regression analysis showed that hypothyroidism was associated with increased UACR or reduced eGFR in T2DM patients. Compared with controls, T2DM patients with hypothyroidism exhibited a higher UACR and urinary excretion of transferrin, as well as a lower excretion of urinary Tamm-Horsfall protein (THP) (P < .0167).

CONCLUSION

Subclinical hypothyroidism is more prevalent in T2DM patients with DKD than in T2DM patients without DKD. Hypothyroidism is associated with albuminuria and decreased eGFR in T2DM patients.

The relationship between thyroid dysfunction and nephrotic syndrome: a clinicopathological study

Abnormalities of thyroid function are common in patients with nephrotic syndrome (NS). However, a limited number of studies have reported on the association between clinicopathologic features and thyroid dysfunction in patients with NS. We retrospectively studied 317 patients who had been definitively diagnosed with NS. The NS patients with thyroid dysfunction showed higher urine protein, creatinine and lipid levels and lower albumin and hemoglobin than those with normal thyroid function, with no significant differences of pathological types. After dividing thyroid dysfunction groups into five subgroups, interestingly, membranous nephropathy was the most common pathologic type, both in normal thyroid group and in subclinical hypothyroidism group (40.4% and 46.7%, respectively), followed by minimal change disease (28.1% and 21.7%, respectively); while in the hypothyroid, low T3, and low T3T4 groups minimal change disease is now the leading type (48.8%, 33.3% and 38.6%, respectively). High levels of urinary protein, creatinine, cholesterol, and platelets were independent risk factors predicting thyroid dysfunction, while higher albumin and hemoglobin were protective factors. We demonstrated that the type of renal pathology was different among NS patients in different thyroid dysfunction subgroups. Interpretation of the interactions between thyroid and renal function is a challenge for clinicians involved in the treatment of patients with NS.

Thyroid disorders in Brazil: the contribution of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Thyroid disorders are common diseases, both in Brazil and worldwide. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is a prospective cohort study that investigates cardiovascular diseases, diabetes, and associated factors, including non-classical cardiovascular risk factors such as thyroid function. Thyroid function was classified according to thyrotropin stimulating hormone (TSH), free thyroxine (FT4), and use of medication to treat thyroid disorders, after excluding participants who reported use of any medication that could alter the results of the TSH and FT4 tests. All analyses included in this review are cross-sectional using baseline data (2008 to 2010). The results showed an association of subclinical thyroid disorders with biomarkers of subclinical atherosclerosis, measured by carotid intima-media thickness and coronary artery calcium, insulin resistance, metabolic syndrome, and some psychiatric disorders. No association was found with the biomarker of inflammation high-sensitivity C-reactive protein, or changes in pulse wave velocity or heart rate variability.

Comparison of automated and retrospectively calculated estimated glomerular filtration rate in electronic health record data

BACKGROUND

Estimated glomerular filtration rate (eGFR) is the clinical standard for assessing kidney function and staging chronic kidney disease. Automated reporting of eGFR using the Modification of Diet in Renal Disease (MDRD) study equation was first implemented within the Department of Veterans Affairs (VA) in 2007 with staggered adoption across laboratories. When automated eGFR are not used or unavailable, values are retrospectively calculated using clinical and demographic data that are currently available in the electronic health record (EHR). Due to the dynamic nature of EHRs, current data may not always match past data. Whether and to what extent the practice of re-calculating eGFR on retrospective data differs from using the automated values is unknown.

METHODS

We assessed clinical data for patients enrolled in VA who had their first automated eGFR lab in 2013.We extracted the eGFR value, the corresponding serum creatinine value, and patient race, gender, and date of birth from the EHR. The MDRD equation was applied to retrospectively calculate eGFR. Stage of chronic kidney disease (CKD) was defined using both eGFR values. We used Bland-Altman plots and percent agreement to assess the difference between the automated and calculated values. We developed an algorithm to select the most parsimonious parameter set to explain the difference in values and used chart review on a small subsample of patients to determine if one approach more accurately describes the patient at the time of eGFR measurement.

RESULTS

We evaluated eGFR data pairs from 266,084 patients. Approximately 33.0% (n = 86,747) of eGFR values differed between automated and retrospectively calculated methods. The majority of discordant pairs were classified as the same CKD stage (n = 74,542, 85.93%). The Bland-Altman plot showed differences in the data pairs were centered near zero (mean difference: 0.8 mL/min/1.73m²) with 95% limits of agreement between - 6.4 and 8.0. A change in recorded age explained 95.6% (n = 78,903) of discordant values and 85.02% (n = 9371) of the discordant stages.

CONCLUSIONS

Values of retrospectively calculated eGFR can differ from automated values, but do not always result in a significant classification change. In very large datasets these small differences could become significant.

Prevalence of hypothyroidism in patients with hyponatremia: A retrospective cross-sectional study

Objective

Hypothyroidism has been suggested to be an uncommon cause of hyponatremia. However, little is known about the prevalence of hypothyroidism in patients with different levels of hyponatremia. The objective of this study was to investigate the prevalence of hypothyroidism among patients with hyponatremia of varying severity while taking into consideration potential confounders associated with thyroid function.

Methods

All data on thyrotropin (TSH), free thyroxine (T4), and serum sodium (Na) levels were retrospectively collected from medical records at two Japanese tertiary hospitals. The main outcome measure was overt hypothyroidism, defined as TSH > 10.0 μIU/mL and free T4 < 1.01 ng/dL.

Results

Of 71,817 patients, 964 patients (1.3%) had overt hypothyroidism. The prevalence of overt hypothyroidism in each category of hyponatremia (Na ≥136, 130–135, and ≤129 mEq/L) was 1.2% (787/65,051), 2.4% (124/5,254) and 3.5% (53/1,512), respectively. A significant increase in prevalence was observed as the severity of hyponatremia increased (P < 0.001 for trend). Multivariate logistic regression with adjustment for age, sex, kidney function, and serum albumin level showed that the odds ratios for overt hypothyroidism increased with increasing severity of hyponatremia when compared with Na ≥ 136 mEq/L (130–135 mEq/L: 1.43, 95% confidence interval [CI], 1.15 to 1.78, P = 0.001; ≤129 mEq/L: 1.87, 95% CI, 1.32 to 2.63, P < 0.001; P< 0.001 for trend).

Conclusion

The prevalence of overt hypothyroidism was significantly higher as the severity of hyponatremia progressed, even after adjusting for potential confounders. Hypothyroidism should be differentiated in patients with hyponatremia.

The relationship between inflammatory factors, oxidative stress and DIO-1 concentration in patients with chronic renal failure accompanied with or without euthyroid sick syndrome

Objective

To investigate the relationship between inflammatory factors, oxidative stress and type 1 deiodinase (DIO-1) concentration in patients with chronic renal failure (CRF) with or without euthyroid sick syndrome (ESS).

Methods

This study recruited patients with CRF and divided them into two groups: group 1 had low free triiodothyronine (FT3) levels; and group 2 had normal FT3 levels. Group 3 consisted of healthy volunteers. Serum levels of interleukin (IL)-6, IL-1β, tumour necrosis factor (TNF)-α, 8-isoprostane and DIO-1 were measured using enzyme-linked immunosorbent assays. Multiple regression analysis was used to analyse correlations between parameters.

Results

Sixty patients were enrolled into each group and the groups were comparable in terms of vital signs, white blood cell count, free thyroxine and thyroid stimulating hormone concentrations. The serum DIO-1 concentration was significantly higher in group 2 than in groups 1 and 3. Multivariate regression analysis revealed that the DIO-1 concentration was inversely correlated with the TNF-α concentration.

Conclusions

Patients with CRF without ESS showed higher concentrations of DIO-1 than patients with ESS. The DIO-1 concentration was inversely correlated with the TNF-α concentration, which might indicate that the inflammatory response was milder in the patients with CRF without ESS than in those with ESS.

Subclinical hypothyroidism: new trials, old caveats

The indications for levothyroxine replacement therapy for subclinical hypothyroidism (SH) remain a subject of debate, especially when prescribed for older adults. The results of the recent TRUST trial indicate that levothyroxine does not improve clinical symptom scores among elderly patients with SH. While there is much concern regarding the dilemma of introducing or withholding levothyroxine, less attention may be paid to the differential diagnosis of an elevated TSH level, which is the prerequisite for diagnosing SH. Herein, we review these issues facing endocrinologists and internists/generalists either in practice or in training. When a patient presents abnormal thyroid test results compatible with SH, a series of issues need to be addressed before the implementation of replacement therapy is considered: first, an isolated TSH elevation not linked to a primary thyroid pathology should be excluded; second, the persistent nature of the patient's TSH elevation and SH profile should be verified; third, SH symptoms and potential complications relevant for the specific patient should be documented; fourth, expectations from levothyroxine substitution therapy for SH in the specific patient should be clarified. Only then can the decision be made whether levothyroxine substitution should be introduced or not.

Thyroid Status and Death Risk in US Veterans With Chronic Kidney Disease

OBJECTIVE

Given that patients with non-dialysis-dependent chronic kidney disease (NDD-CKD) have a disproportionately higher prevalence of hypothyroidism compared with their non-CKD counterparts, we sought to determine the association between thyroid status, defined by serum thyrotropin (TSH) levels, and mortality among a national cohort of patients with NDD-CKD.

PATIENTS AND METHODS

Among 227,422 US veterans with stage 3 NDD-CKD with 1 or more TSH measurements during the period October 1, 2004, to September 30, 2012, we first examined the association of thyroid status, defined by TSH categories of less than 0.5, 0.5 to 5.0 (euthyroidism), and more than 5.0 mIU/L, with all-cause mortality. We then evaluated 6 granular TSH categories: less than 0.1, 0.1 to less than 0.5, 0.5 to less than 3.0, 3.0 to 5.0, more than 5.0 to 10.0, and more than 10.0 mIU/L. We concurrently examined thyroid status, thyroid-modulating therapy, and mortality in sensitivity analyses.

RESULTS

In expanded case-mix adjusted Cox analyses, compared with euthyroidism, baseline and time-dependent TSH levels of more than 5.0 mIU/L were associated with higher mortality (adjusted hazard ratios [aHRs] [95% CI], 1.19 [1.15-1.24] and 1.23 [1.19-1.28], respectively), as were baseline and time-dependent TSH levels of less than 0.5 mIU/L (aHRs [95% CI], 1.18 [1.15-1.22] and 1.41 [1.37-1.45], respectively). Granular examination of thyroid status showed that incrementally higher TSH levels of 3.0 mIU/L or more were associated with increasingly higher mortality in baseline and time-dependent analyses, and TSH categories of less than 0.5 mIU/L were associated with higher mortality (reference, 0.5-<3.0 mIU/L) in baseline analyses. In time-dependent analyses, untreated and undertreated hypothyroidism and untreated hyperthyroidism were associated with higher mortality (reference, spontaneous euthyroidism), whereas hypothyroidism treated-to-target showed lower mortality.

CONCLUSION

Among US veterans with NDD-CKD, high-normal TSH (≥3.0 mIU/L) and lower TSH (<0.5 mIU/L) levels were associated with higher death risk. Interventional studies identifying the target TSH range associated with the greatest survival in patients with NDD-CKD are warranted.

Circulating antithyroid antibodies contribute to the decrease of glomerular filtration rate in lithium-treated patients: a longitudinal study

Background

Concerns about the adverse effects of long-term treatment with lithium include reduced renal function. In the present study, we examined comorbidities which may be associated with chronic kidney disease in a cohort of patients treated with lithium for up to 41 years.

Methods

We studied 394 patients who were treated with lithium for ≥ 5 years. The potential role of comorbidities (diabetes, concurrent antihypertensive medication, treatment with l-thyroxine, and presence of antithyroid peroxidase/microsomes, anti-thyroglobulin, and/or anti-thyrotropin-receptor antibodies) was analysed. We focused on the categories of patients with an estimated glomerular filtration rate (eGFR) lower than 60 or 45 mL/min/1.73 m² as calculated from serum creatinine according to the Modification of Diet in Renal Disease Study Group. We applied multivariate regression analysis and Cox survival analysis to study the effects exerted by sex, age, duration of lithium treatment, and comorbidities using eGFR categories as the dependent variable. Kaplan–Meier curves were generated to measure the time to decline to an eGFR lower than 45 mL/min/1.73 m² in patients with positive or negative thyroid antibodies.

Results

Age was associated with a decline to an eGFR lower than 60 mL/min/1.73 m² after controlling for sex, duration of lithium treatment, and comorbidities. Circulating thyroid antibodies were associated with a decline to an eGFR lower than 45 mL/min/1.73 m².

Conclusions

The present study is the first to suggest a potential role of circulating thyroid antibodies in the severe decline of eGFR in lithium-treated patients.

Thyroid hormone status in Ghanaian patients with chronic kidney disease

Introduction

There is limited data on the prevalence of thyroid dysfunction in Ghanaian individuals with chronic kidney disease (CKD). Studies exploring the effect of thyroid hormones on renal function decline are also scanty. Unrecognized thyroid dysfunction in CKD may increase the burden of adverse health outcomes. The aim of this study was to determine thyroid hormone status and lipid profiles in patients with CKD attending the Renal Unit of the Korle-Bu Teaching Hospital.

Methods

60 clinically euthyroid patients with CKD, and 65 clinically euthyroid subjects without CKD were recruited for this study. Estimation of effective glomerular filtration rate (eGFR) was done using the 4-variable Modification of Diet in Renal Disease (MDRD) formula with subsequent staging of CKD (stages 2-4). Collected venous blood samples from all study participants were analyzed for creatinine, free triiodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), total cholesterol (TC), high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) and triglycerides (TG).

Results

Levels of TC, HDL, LDL, and TSH levels did not differ significantly between the two study groups. However, TG, VLDL, FT3 and FT4 levels were significantly higher in CKD patients than in the control group. TC, TG, HDL, LDL, VLDL and TSH levels were not significantly different between stages of CKD in study subjects, although FT4 and FT3 levels were significantly different between all stages of CKD.

Conclusion

Higher levels of FT3 and FT4 but not TSH, are associated with the incidence of CKD and eGFR decline in Ghanaian CKD patients.