A cross-section analysis of FT3 age-related changes in a group of old and oldest-old subjects, including centenarians' relatives, shows that a down-regulated thyroid function has a familial component and is related to longevity

Diagnosing and treating the elderly individual with hypopituitarism

Hypopituitarism in the elderly is an underestimated condition mainly due to the non-specific presentation that can be attributed to the effects of aging and the presence of comorbidities. Diagnosis and treatment of hypopituitarism often represent a challenging task and this is even more significant in the elderly. Diagnosis can be insidious due to the physiological changes occurring with aging that complicate the interpretation of hormonal investigations, and the need to avoid some provocative tests that carry higher risks of side effects in this population. Treatment of hypopituitarism has generally the goal to replace the hormonal deficiencies to restore a physiological balance as close as possible to that of healthy individuals but in the elderly this must be balanced with the risks of over-replacement and worsening of comorbidities. Moreover, the benefit of some hormonal replacement therapies in the elderly, including sex hormones and growth hormone, remains controversial.

SuperAgers and centenarians, dynamics of healthy ageing with cognitive resilience

Graceful healthy ageing and extended longevity is the most desired goal for human race. The process of ageing is inevitable and has a profound impact on the gradual deterioration of our physiology and health since it triggers the onset of many chronic conditions like dementia, osteoporosis, diabetes, arthritis, cancer, and cardiovascular disease. However, some people who lived/live more than 100 years called 'Centenarians" and how do they achieve their extended lifespans are not completely understood. Studying these unknown factors of longevity is important not only to establish a longer human lifespan but also to manage and treat people with shortened lifespans suffering from age-related morbidities. Furthermore, older adults who maintain strong cognitive function are referred to as "SuperAgers" and may be resistant to risk factors linked to cognitive decline. Investigating the mechanisms underlying their cognitive resilience may contribute to the development of therapeutic strategies that support the preservation of cognitive function as people age. The key to a long, physically, and cognitively healthy life has been a mystery to scientists for ages. Developments in the medical sciences helps us to a better understanding of human physiological function and greater access to medical care has led us to an increase in life expectancy. Moreover, inheriting favorable genetic traits and adopting a healthy lifestyle play pivotal roles in promoting longer and healthier lives. Engaging in regular physical activity, maintaining a balanced diet, and avoiding harmful habits such as smoking contribute to overall well-being. The synergy between positive lifestyle choices, access to education, socio-economic factors, environmental determinants and genetic supremacy enhances the potential for a longer and healthier life. Our article aims to examine the factors associated with healthy ageing, particularly focusing on cognitive health in centenarians. We will also be discussing different aspects of ageing including genomic instability, metabolic burden, oxidative stress and inflammation, mitochondrial dysfunction, cellular senescence, immunosenescence, and sarcopenia.

Thyroid function and thyroid homeostasis parameters are associated with increased urinary albumin excretion in euthyroid individuals over 60 years old from NHANES

Introduction

The relationship between thyroid function/homeostasis parameters and renal function has been extensively studied. However, the relationship between thyroid function and thyroid homeostasis parameters with albuminuria among elderly individuals remains unclear.

Methods

The population was divided into an albuminuria group and a non-albuminuria group for baseline characteristic difference analysis. Multivariable logistic regression was used to test the association between thyroid function, and thyroid homeostasis parameters and albuminuria. The nonlinear relationship was explored with restricted cubic splines. Meanwhile, we investigated whether the relationship also existed in the diabetes and hypertension subgroups. Receiver operating characteristic (ROC) curves were used to assess the effectiveness of the indices.

Results

FT4 and TFQIFT4 were positively correlated with albuminuria (OR = 1.12; 95% CI = 1.02-1.23, p = 0.02; OR = 1.79; 95% CI = 1.08-2.99, p = 0.03), and FT3/FT4 was negatively correlated with albuminuria (OR = 0.03; 95% CI = 0.00-0.26, p = 0.003). Additionally, the nonlinear relationship between FT3/FT4 as well as TSHI and albuminuria was approximately U-shaped. Similar results were observed in the hypertension subgroup but not in the diabetes subgroup. There was a U-shaped nonlinear relationship between FT3 and albuminuria in the diabetes group. In addition, FT3/FT4 performed better than TFQI, TT4RI, and TSHI in ROC analyses for albuminuria prediction.

Conclusion

FT4, TFQIFT4, and a low FT3/FT4 ratio were risk factors for albuminuria in euthyroid individuals over 60 years old. However, FT3 was more associated with albuminuria in the diabetes subgroup. TSH was not associated with albuminuria in any analysis. In our study, we attempted to provide more reasonable thyroid parameters and basis for evaluating patients with underlying albuminuria. FT3/FT4 may be used as a helpful indicator to predict albuminuria and provide novel ideas for the evaluation and treatment of albuminuria.

Hypothyroidism in Older Adults: A Narrative Review

INTRODUCTION

The prevalence of hypothyroidism increases along with aging, resulting in one of the most common comorbidities among patients over 75 years. The leading causes of hypothyroidism in older adults are iatrogenic, Hashimoto's thyroiditis, and medications. The narrative review aimed to discuss the clinical characteristics of hypothyroidism in older adults and the impact of hormonal replacement therapy on survival rates. Thyroid function declines over time due to physiological changes in the thyroid stimulating hormone signaling, iodine absorption and metabolism, thyroid hormone metabolism, and activity at peripheral sites. A serum TSH value over the upper limit of the normal reference range is not necessarily attributable to hypothyroidism. However, an appropriate diagnostic work-up is required to rule out true hypothyroidism and discriminate the etiology (i.e., thyroid autoimmune diseases, iodine deficiency, drug-induced hypothyroidism). Levothyroxine treatment should be considered in cases of overt hypothyroidism. A complete risk-to-benefit assessment, particularly considering the overall health status, life expectancy, cognitive function, mood, and cardiovascular and neurological background, should be considered before treating subclinical hypothyroidism with more potential benefits in patients under 75 years old. Levothyroxine formulations facilitating hormone absorption and increasing compliance to long-term treatment should be preferred. TSH target should usually be set over 3 mIU/ml. Defining optimal diagnostic approaches and targeted therapeutic strategies should be considered in the personalized management of aged patients with hypothyroidism.

Chinese Medicine Supplementing Qi and Activating Blood Circulation Relieves the Progression of Diabetic Cardiomyopathy

BACKGROUND

Diabetic cardiomyopathy (DCM) is the leading cause of diabetic death as the final occurrence of heart failure and arrhythmia. Traditional Chinese medicine is usually used to treat various diseases including diabetes.

OBJECTIVE

This study sought to investigate the effects of Traditional Chinese medicine supplementing Qi and activating blood circulation (SAC) in DCM.

METHODS

After the construction of the DCM model by streptozotocin (STZ) injection and high glucose/fat diet feeding, rats were administered intragastrically with SAC. Then, cardiac systolic/diastolic function was evaluated by detecting left ventricular systolic pressure (LVSP), maximal rate of left ventricular pressure rise (+LVdp/dtmax), and fall (-LVdp/dtmax), heart rate (HR), left ventricular ejection fraction (EF), LV fractional shortening (FS) and left ventricular end-diastolic pressure (LVEDP). Masson’s and TUNEL staining were used to assess fibrosis and cardiomyocyte apoptosis.

RESULTS

DCM rats exhibited impaired cardiac systolic/diastolic function manifested by decreasing LVSP, + LVdp/dtmax, -LVdp/dtmax, HR, EF and FS, and increasing LVEDP. Intriguingly, traditional Chinese medicine SAC alleviated the above-mentioned symptoms, indicating a potential role in improving cardiac function. Masson’s staining substantiated that SAC antagonized the increased collagen deposition and interstitial fibrosis area and the elevations in protein expression of fibrosis-related collagen I and fibronectin in heart tissues of DCM rats. Furthermore, TUNEL staining confirmed that traditional Chinese medicine SAC also attenuated cardiomyocyte apoptosis in DCM rats. Mechanically, DCM rats showed the aberrant activation of the TGF-β/Smad signaling, which was inhibited after SAC.

CONCLUSION

SAC may exert cardiac protective efficacy in DCM rats via the TGF-β/Smad signaling, indicating a new promising therapeutic approach for DCM.

Thyroid and Aging

Older adults are more vulnerable to the negative effects of excess thyroid hormone and may even be protected by lower levels of thyroid hormone. The diagnosis and management of thyroid disease in older adults needs to account for aging-related changes in function and resilliance.

Low-Dose Occupational Exposure to Nickel and Thyroid Hormones

INTRODUCTION

The aim of this study was to evaluate the effects of a low-dose exposure to nickel, as it is present in urban air, on thyroid hormones and on thyrotropin in outdoor workers exposed to urban pollutants.

MATERIALS AND METHODS

A total of 164 outdoor workers were studied and divided by sex and smoking habit. Each worker underwent measurement of urinary nickel and of blood triiodothyronine, L-thyroxine, and thyrotropin levels. The statistical analysis was performed.

RESULTS

Statistical analysis shows a significant and positive correlation between urinary nickel and L-thyroxine, both in total sample and in males.

DISCUSSION AND CONCLUSION

The study suggests that occupational exposure to a low dose of nickel may affect thyroid function in municipal police workers. These data may provide information on other categories of outdoor workers with similar exposure.

Thyroid Function Before and After Laparoscopic Sleeve Gastrectomy in Patients with Obesity

BACKGROUND

Effect of laparoscopic sleeve gastrectomy (LSG) on thyroid function of patients with obesity remains unclear. The aim of this study was to evaluate the changes in thyroid function before and after LSG in patients with obesity.

METHODS

Data was retrieved from a retrospectively collected database of patients with morbid obesity and normal thyroid function who received LSG. At 12 months after surgery, changes of thyroid-stimulating hormone (TSH), free thyroxine (FT4), free triiodothyronine (FT3), and intact parathyroid hormone (iPTH) were evaluated. In addition, the correlation between thyroid hormone levels and body mass index (BMI) and other metabolic indicators and anthropometric parameters were analyzed.

RESULTS

Eighty-five patients were included in the study. The concentrations of FT3 (5.7 ± 0.7 vs 5.1 ± 0.6, p < 0.001) and TSH (2.2 ± 1.0 vs 1.9 ± 0.9, p = 0.002) significantly decreased 12 months postsurgery, while mean FT4 levels increased from12.0 ± 1.9 vs 12.4 ± 2.0 pmol/L (p = 0.013). Furthermore, mean iPTH decreased from 53.3 ± 48.3 to 38.7 ± 13.2 pg/mL (p = 0.011). Multiple stepwise regression analysis showed that changes in LDL levels were an independent factor contributing to changes in TSH levels (β = 0.362, p = 0.001). Moreover, TSH did not correlate with BMI.

CONCLUSIONS

In this study, FT3, TSH, and iPTH were decreased in euthyroid patients with obesity after LSG, while FT4 was significantly increased. Changes in TSH were positively correlated with LDL, but no statistically significant correlation was found with BMI. Additionally, FT3, FT4, and iPTH were correlated with VB12, age, and BMI, respectively.

Association of thyroid function with insulin resistance: data from two population-based studies

OBJECTIVE

Thyroid dysfunction is associated with relevant disturbances in glucose metabolism. Moreover, thyroid function undergoes important changes with ageing. The objective of this study was to investigate the association of thyroid function with insulin resistance with particular consideration of possible age-related effect modifications.

DESIGN

A sample of 4193 participants from two independent epidemiological studies, the Study of Health in Pomerania-TREND-0 and the Berlin Aging Study II, was included in this cross-sectional analysis.

METHODS

Insulin resistance was estimated by homeostasis model of insulin resistance (HOMA-IR) and the insulin sensitivity index (ISI). Associations of thyroid biomarkers (thyroid-stimulating hormone, free thyroxine, and free triiodothyronine (fT3)) with parameters of glucose metabolism were analysed by regression models adjusted for age, sex, smoking status, and study site.

RESULTS

A higher fT3 was significantly associated with higher fasting glucose and higher fasting and 2-h postload insulin levels, a higher HOMA-IR, and lower ISI. A higher fT3 was also associated with a higher risk for impaired fasting glucose (RR 1.09, 95 CI 1.02; 1.18; P = 0.017). Many of these associations between thyroid markers and parameters of glucose metabolism were significant in young and middle-aged participants but not in older individuals.

CONCLUSIONS

The main finding of this study was a consistent association of fT3 with almost all markers of insulin resistance. However, this effect seems to be wearing off in higher age highlighting a potential age-related modification of the interaction between thyroid function and glucose metabolism. Further studies are needed to clarify causal relationships.

Heterogeneity and Dynamics of Vasculature in the Endocrine System During Aging and Disease

The endocrine system consists of several highly vascularized glands that produce and secrete hormones to maintain body homeostasis and regulate a range of bodily functions and processes, including growth, metabolism and development. The dense and highly vascularized capillary network functions as the main transport system for hormones and regulatory factors to enable efficient endocrine function. The specialized capillary types provide the microenvironments to support stem and progenitor cells, by regulating their survival, maintenance and differentiation. Moreover, the vasculature interacts with endocrine cells supporting their endocrine function. However, the structure and niche function of vasculature in endocrine tissues remain poorly understood. Aging and endocrine disorders are associated with vascular perturbations. Understanding the cellular and molecular cues driving the disease, and age-related vascular perturbations hold potential to manage or even treat endocrine disorders and comorbidities associated with aging. This review aims to describe the structure and niche functions of the vasculature in various endocrine glands and define the vascular changes in aging and endocrine disorders.

Sources of variation and establishment of Russian reference intervals for major hormones and tumor markers

OBJECTIVES

A multicenter study was organized to explore sources of variation (SVs) of reference values (RVs) for 22 major immunochemistry analytes and to determine reference intervals (RIs) for the Russian population.

METHODS

According to IFCC Committee on Reference Intervals and Decision Limits (C-RIDL) protocol, 758 healthy volunteers were recruited in St. Petersburg, Moscow, and Yekaterinburg. Serum samples were tested for five tumor markers, 17 hormones and related tests by Beckman Coulter's UniCel DxI 800 immunochemistry analyzer. SVs were explored using multiple regression analysis and ANOVA. Standard deviation ratio (SDR) of 0.4 was used as primary guide for partitioning RIs by gender and age.

RESULTS

SDR for between-city difference was <0.4 for all analytes. Secondary exclusion of individuals was done under the following conditions: for female sex-hormones, those with contraceptives (8%); for CA19-9, those supposed to have negative Lewis blood-group (10.5% males and 11.3% females); for insulin, those with BMI≥28 kg/m2 (31%); for the thyroid panel, those with anti-thyroid antibodies (10.3% males; 24.5% females), for CEA those with smoking habit (30% males and 16% females). Gender-specific RIs were required for all analytes except CA19-9, CA15-3, thyroid-related tests, parathyroid hormone, and insulin. Age-specific RIs were required for alpha-fetoprotein, CEA, all sex-hormones for females, FSH and progesterone for both sexes. RIs were generally derived by parametric method after Gaussian transformation using modified Box-Cox formula. Exceptions were growth hormone, estradiol for females in postmenopause, and progesterone for females in premenopause, for which nonparametric method was required due to bimodal distribution and/or insufficient detection limit.

CONCLUSION

RIs for major hormones and tumor markers specific for the Russian population were derived based on the up-to-date internationally harmonized protocol by careful consideration of analyte-specific SVs.

Thyroid hormones and frailty in persons experiencing extreme longevity

CONTEXT

The aging phenotype is quite heterogeneous, being the result of the capability of each individual to successfully or unsuccessfully response to stressors. The reduction of homeostatic reserve characterizing aging is accompanied by a remodeling of the endocrine system. Frailty has been indicated as a promising way for capturing the physiological decline as well as the biological aging of the individuals. In particular, the Frailty Index (FI), based on the assumption that health deficits tend to accumulate with aging, represents a quantitative measure of extreme interest.

OBJECTIVE

The study aims to correlate the thyroid hormone levels with FI in a population of centenarians and their offspring to capture the effects of thyroid remodeling in extreme longevity.

STUDY DESIGN

The study described 593 well-characterized Italian subjects, including 180 centenarians, as well as 276 centenarian's offspring and 137 age-matched controls.

RESULTS

FT3 levels and FT3/FT4 ratio were significantly lower (p < 0.001) and TSH levels higher (p < 0.001) in centenarians compared to the other groups, analysing both overall subjects and excluding subjects with hormone levels out of the normal ranges. In overall centenarians, we observed a negative correlation between FI and FT3 (ρ: -0.281, p < 0.001), FT3/FT4 (ρ: -0.344, p < 0.001) and TSH (ρ: -0.223, p 0.003) and a positive association between FI and FT4 (ρ: 0.189, p = 0.001). In centenarians with hormone levels within the normal ranges, similar negative correlations were observed between FI and FT3 (ρ: -0.201, p = 0.02) and FT3/FT4 (ρ: -0.264, p = 0.002). In this sub-analysis, FI positively correlated with FT4 and age (ρ: 0.167, p = 0.05; ρ: 0.219, p = 0.005, respectively). Conversely, no significant correlations were observed between hormone levels and FI in offspring and controls.

CONCLUSIONS

We found an association between thyroid hormone levels and frailty in centenarians, underlying the significant role of thyroid in the aging process and longevity.

ROLE of IGF-1 System in the Modulation of Longevity: Controversies and New Insights From a Centenarians' Perspective

Human aging is currently defined as a physiological decline of biological functions in the body with a continual adaptation to internal and external damaging. The endocrine system plays a major role in orchestrating cellular interactions, metabolism, growth, and aging. Several in vivo studies from worms to mice showed that downregulated activity of the GH/IGF-1/insulin pathway could be beneficial for the extension of human life span, whereas results are contradictory in humans. In the present review, we discuss the potential role of the IGF-1 system in modulation of longevity, hypothesizing that the endocrine and metabolic adaptation observed in centenarians and in mammals during caloric restriction may be a physiological strategy for extending lifespan through a slower cell growing/metabolism, a better physiologic reserve capacity, a shift of cellular metabolism from cell proliferation to repair activities and a decrease in accumulation of senescent cells. Therefore, understanding of the link between IGF-1/insulin system and longevity may have future clinical applications in promoting healthy aging and in Rehabilitation Medicine.

Overt and Subclinical Hypothyroidism in the Elderly: When to Treat?

Hypothyroidism is characterized by increased thyrotropin (TSH) levels and reduced free thyroid hormone fractions while, subclinical hypothyroidism (sHT) by elevated serum TSH in the face of normal thyroid hormones. The high frequency of hypothyroidism among the general population in Western Countries made levothyroxine (LT4) one of the 10 most prescribed drugs. However, circulating TSH has been demonstrated to increase with aging, regardless the existence of an actual thyroid disease. Thus, when confronting an increase in circulating TSH levels in the elderly, especially in the oldest old, it is important to carry an appropriate diagnostic path, comprehensive of clinical picture as well as laboratory and imaging techniques. In the current review, we summarize the recommendations for a correct diagnostic workup and therapeutic approach to older people with elevated TSH value, with special attention to the presence of frailty, comorbidities, and poly-therapy. The treatment of choice for hypothyroid patients is hormone replacement with LT₄ but, it is important to consider multiple factors before commencing the therapy, from the age dependent TSH increase to the presence of an actual thyroid disease and comorbidities. When treatment is necessary, a tailored therapy should be chosen, considering poly-pharmacy and frailty. A careful follow-up and treatment re-assessment should be always considered to avoid the risk of over-treatment. It is important to stress the need of educating the patient for a correct administration of LT₄, particularly when poly-therapy is in place, and the importance of a tailored therapeutic approach and follow-up, to avoid overtreatment.

An Age-Specific Serum Thyrotropin Reference Range for the Diagnosis of Thyroid Diseases in Older Adults: A Cross-Sectional Survey in China

Background: The fact that serum thyrotropin (TSH) levels increase with age may influence the diagnosis of thyroid diseases in older adults. This study aimed to establish an age-specific serum TSH reference range, examine the prevalence of thyroid diseases in older adults ≥65 years, and analyze the risk factors. Methods: A cross-sectional study of adult populations in 10 cities in China was conducted from 2010 to 2011. A total of 15,008 subjects were randomly selected and completed the present study. Urinary iodine concentration, serum TSH, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) titers were measured. Thyroid ultrasonography and questionnaires were completed by all the subjects. When the TSH level was abnormal, free thyroxine and/or free triiodothyronine levels were measured. Results: When the reference range of the general population was used, the prevalence rates of overt hypothyroidism (Ohypo) and subclinical hypothyroidism (Shypo) in older adults ≥65 years were significantly higher than those in younger adults <65 years (2.09% vs. 0.80% and 19.87% vs. 16.23%, respectively; p < 0.001). Positive TPOAb and positive TgAb were associated with the prevalence of Shypo in older adults. An age-specific serum TSH reference range was formulated according to guidelines set forth by the National Academy of Clinical Biochemistry. Both the median and upper limit values of serum TSH in older adults were higher than those in younger adults (2.58 [0.75-8.86] mIU/L vs. 2.38 [0.76-6.57] mIU/L; p < 0.001). Using the age-specific serum TSH reference range, the prevalence of Shypo in older adults was 3.3%, which was significantly lower than the prevalence based on the reference range of the general population (3.3% vs. 19.87%). The prevalence rates of Ohypo, overt hyperthyroidism (Ohyper), and subclinical hyperthyroidism (Shyper) did not change much (Ohypo: 1.6% vs. 2.09%; Ohyper: 0.7% vs. 0.52%; and Shyper: 3.8% vs. 0.73%). Positive TPOAb, but not positive TgAb, was also associated with the prevalence of Shypo as diagnosed with the age-specific serum TSH reference range. Conclusion: The serum TSH level increases with age, which may represent a normal compensatory phenomenon in older adults ≥65 years. To prevent misdiagnosis and mistreatment, the use of an age-specific serum TSH reference range is recommended in older adults for the diagnosis of thyroid diseases.

Hypothyroidism in the Elderly: Who Should Be Treated and How?

Hypothyroidism is among the most frequent chronic diseases in the elderly, and levothyroxine (l-T4) is worldwide within the 10 drugs more prescribed in the general population. Hypothyroidism is defined by increased serum thyroid-stimulating hormone (TSH) values and reduced circulating free thyroid hormones, whereas subclinical hypothyroidism (sHT) is characterized by free hormone fractions within the normal ranges and has been divided into two classes, depending on circulating TSH levels (above or below 10 mIU/L). Given that during aging, a natural trend toward higher values of circulating TSH has been reported, it is necessary to verify carefully the diagnosis of sHT to tailor an appropriate follow-up and ad hoc therapy, avoiding unnecessary or excessive treatment. In the current review, we evaluate the state of the art on hypothyroidism in the elderly with special focus on the effect of sHT on cognition and the cardiovascular system function. We also summarize the recommendations for a correct diagnostic workup and therapeutic approach to older people with an elevated TSH value, with special attention to the presence of frailty, comorbidities, and poly therapy. In conclusion, personalized therapy is crucial in good clinical practice, and in the management of older patients with sHT, multiple factors must be considered, including age-dependent TSH cutoffs, thyroid autoimmunity, the burden of comorbidities, and the possible presence of frailty. l-T4 is the drug of choice for the treatment of hypothyroid older people, but the risk of overtreatment, potential adverse drug reactions, and patient compliance should always be considered and thyroid status periodically reassessed.

Elevated serum growth differentiation factor 15 levels are associated with thyroid nodules in type 2 diabetes aged over 60 years

In order to investigate whether serum growth differentiation factor 15 is associated with thyroid nodules in type 2 diabetes. We recruited 723 type 2 diabetic patients aged over 30 years who attended the clinic of Endocrinology of Xinhua Hospital from January 2013 to January 2015. Thyroid nodule was diagnosed by thyroid ultrasonographic examination. Serum growth differentiation factor 15, thyroid function, thyroid autoantibodies, thyroglobulin and other biochemical indicators were measured and compared between thyroid nodule positive and negative groups. We found that overall, serum growth differentiation factor 15 levels were significantly higher in subjects with thyroid nodules compared with nodule negative subjects (181.76±98.49 pg/ml vs. 162.32±83.63 pg/ml, p<0.05), and this was influenced by age. In the patients over 60 years, this difference became more significant (211.23±103.66 pg/ml vs. 177.38±85.51 pg/ml, p<0.01), but in patients under 60 years, there was no difference between the two groups. Multivariate logistic regression analysis showed that serum growth differentiation factor 15 levels were independently associated with thyroid nodule in diabetic patients over 60 years (P <0.001). After multiple adjustments, the odds ratios were substantially higher for thyroid nodule (odds ratio 2.63, 95% confidence interval 1.30-5.13, p<0.01) in the highest growth differentiation factor 15 quartile compared to those in the lowest quartile in patients over 60 years. In conclusion, serum growth differentiation factor 15 is increased significantly in subjects with thyroid nodules in type 2 diabetic patients aged over 60 years.

Thyroid hormones in extreme longevity

The aim of the present review was to summarize knowledge about thyroid hormones (THs) and longevity. Longevity is a complex multifactorial phenomenon on which specific biological pathways, including hormonal networks involved in the regulation of homeostasis and survival, exert a strong impact. THs are the key responsible for growth, metabolism rate and energy expenditure, and help in maintaining cognition, bone and cardiovascular health. THs production and metabolism are fine tuned, and may help the organism to cope with a variety of environmental challenges. Experimental evidence suggests that hypothyroid state may favor longevity by reducing metabolism rate, oxidative stress and cell senescence. Data from human studies involving healthy subjects and centenarians seem to confirm this view, but THs changes observed in older patients affected by chronic diseases cannot be always interpreted as a protective adaptive mechanism aimed at reducing catabolism and prolonging survival. Medications, selected chronic diseases and multi-morbidity can interfere with thyroid function, and their impact is still to be elucidated.

Centenarians' offspring as a model of healthy aging: a reappraisal of the data on Italian subjects and a comprehensive overview

Within the scenario of an increasing life expectancy worldwide it is mandatory to identify determinants of healthy aging. Centenarian offspring (CO) is one of the most informative model to identify trajectories of healthy aging and their determinants (genetic and environmental), being representative of elderly in their 70th whose lifestyle can be still modified to attain a better health. This study is the first comprehensive investigation of the health status of 267 CO (mean age: 70.2 years) and adopts the innovative approach of comparing CO with 107 age-matched offspring of non-long-lived parents (hereafter indicated as NCO controls), recruited according to strict inclusion demographic criteria of Italian population. We adopted a multidimensional approach which integrates functional and cognitive assessment together with epidemiological and clinical data, including pro- and anti-inflammatory cytokines and adipokines, lipid profile, and insulin resistance. CO have a lower prevalence of stroke, cerebral thrombosis-hemorrhage, hypertension, hypercholesterolemia, and other minor diseases, lower BMI and waist circumference, a better functional and cognitive status and lower plasma level of FT4 compared to NCO controls. We conclude that a multidimensional approach is a reliable strategy to identify the health status of elderly at an age when interventions to modify their health trajectory are feasible.

MECHANISMS IN ENDOCRINOLOGY: Impact of isolated TSH levels in and out of normal range on different tissues

Routine treatment of thyroid cancer (TC) includes long-term suppression of TSH. The necessity of this treatment in low- and intermediate-risk patients as well as the extent of TSH suppression is currently under discussion. A literature search was performed to illustrate the role of TSH in extrathyroidal cells and to identify potential reasons for different effects of exogenously suppressed and endogenously low TSH levels. Although adverse effects of subnormal and supranormal TSH blood levels on heart and brain have not been consistently found, studies show a clear negative effect of suppressed TSH levels on bone mineral density. Experimental data also support an important role of TSH in the immune system. The ability of levothyroxine (l-T4) to regulate TSH levels and triiodothyronine levels in a physiological manner is limited. Reduction of circadian changes in TSH levels, decrease of thyroid hormone-binding proteins, prevention of potential compensatory increases of TSH levels (e.g., in old age), and unresponsiveness of TSH-producing cells to TRH on l-T4 treatment might cause adverse effects of suppressed TSH levels. In view of the adverse effects of aggressive TSH suppression, achieving the suggested levels of TSH between 0.9 and 1 mU/l in the treatment of low-to-intermediate risk TC patients appears justified.

Association between increased serum thyrotropin concentration and the oldest old: what do we know?

To assess studies that evaluate the relation between serum thyrotropin concentration, very old subjects, and their events. We searched the PubMed, SciELO, and LILACS databases for articles published between 2004 and 2012. Our search was restricted to studies involving humans aged 65 years or older, and written in English, Spanish, or Portuguese. Studies that evaluated the association between elevated serum thyrotropin concentration among elderly subjects with subclinical hypothyroidism were chosen since at least in part they included a subpopulation of individuals aged 80 years and above. Thirteen studies were selected. No significant increase in risk of cardiovascular events, coronary heart disease, or total mortality was observed. Elevated thyrotropin concentration was associated with longevity. More randomized controlled trials are required to better define the potential benefits of elevated thyrotropin concentration in this oldest old population, hormone replacement, and longevity.

Lower-but-normal serum TSH level is associated with the development or progression of cognitive impairment in elderly: Korean Longitudinal Study on Health and Aging (KLoSHA)

CONTEXT

The association between subclinical hyperthyroidism and the risk of dementia has been validated in several studies. However, the effect of thyroid function within reference range on the risk of cognitive dysfunction including mild cognitive impairment (MCI) and dementia is still unclear.

OBJECTIVE

Our aim was to investigate the association between thyroid function and the risk of MCI and dementia in euthyroid elderly subjects.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a population-based prospective study as a part of the Korean Longitudinal Study on Health and Aging. A total of 313 participants who were euthyroid and nondemented at baseline and completed cognitive function tests at a 5-year follow-up evaluation (mean age 72.5 ± 6.9 y) were analyzed in the present study.

MAIN OUTCOME MEASURE

Baseline thyroid function was compared according to the development of MCI or dementia during the study period. Binary logistic regression analysis was performed to investigate the independent association between thyroid function and cognitive impairment.

RESULTS

At baseline evaluation, 237 subjects were cognitively normal, and 76 subjects had MCI. Diagnoses of cognitive function in 259 subjects remained unchanged or improved during the study period (nonprogression group), whereas 54 subjects showed progression of cognitive impairment to MCI or dementia (progression group). In the progression group, baseline serum TSH levels were lower than those in nonprogression group. Baseline serum free T₄ levels were not significantly different between these two groups. The association between lower baseline serum TSH levels and the development of MCI or dementia was maintained after adjustment for conventional baseline risk factors.

CONCLUSIONS

Lower serum TSH level within the reference range was independently associated with the risk of cognitive impairment including MCI and dementia in elderly subjects.

Clinical evaluation of various thyroid hormones on thyroid function

To clarify the clinical value of serums total triiodothyronine (TT3), total thyroxine (TT4), free triiodothyronine (FT3), and free thyroxine (FT4) and provide a more eligible and economic strategy to assess thyroid function. A total of 2,673 participants (500 patients with hyperthyroidism, 500 patients with hypothyroidism, and 1,673 healthy people) were involved in our study. Serums TT3, TT4, FT3, and FT4 and thyrotropin (TSH) were measured with VIDAS fluorescent enzyme immunoassay. The Pearson correlation between TT3, TT4, FT3, and FT4 and TSH was determined to identify the most important indicator for thyroid function besides TSH. The correlation of TT4, and FT4 with TSH was statistically significant in healthy individuals (P < 0.01), and the R-values were -0.065 and -0.152, respectively. The correlation of TT4, FT4, TT3, and FT3 with TSH was statistically significant in patients with hyperthyroidism, and the R-values were -0.241, -0.225, -0.195, and -0.176, respectively. The correlation of TT4, FT4, TT3, and FT3 with TSH was statistically significant in patients with hypothyroidism, and the R-values were -0.322, -0.262, -0.179, and -0.136, respectively. In our opinion, TSH and FT4 are the most valuable indicators in assessing thyroid function in a healthy population, and TSH and TT4 are the most meaningful in hyperthyroidism and hypothyroidism.

Cardiovascular risk and quality of life in elderly people with mild thyroid hormone deficiency

Subclinical hypothyroidism (sHT) is a common condition in the general population, the prevalence increases with age, especially in women. An association between sHT and increased coronary heart disease (CHD) and heart failure (HF) risk and mortality has been described. However, this association is far to be established in older people (>65 years), especially in the oldest old (>85 years). Individuals with sHT may experience symptoms that resemble those observed in the overt form of the disease, leading to an impaired quality of life (QoL). Although very old people are frequently frail and potentially more susceptible to the effects of a disease, few studies were designed to assess the effect of sHT on QoL in this subset of population. Interestingly, the serum TSH concentration curve of general population has a skewed distribution with a "tail" toward higher values, which is amplified with aging. Thus, the diagnosis of sHT and the interpretation of its potential effects on CV function and QoL in older people may be a challenge for the clinician. Giving these premises, we reviewed the English scientific literature available on National Library of Medicine (www.pubmed.com) since 1980 regarding hypothyroidism, sHT, elderly, cardiovascular risk, CHD or HF events and mortality, health-related QoL, and LT4 therapy. Consistent results among large prospective cohort studies suggest an age-independent relationship between sHT and HF progression, while an impact of sHT on CHD events and mortality is essentially reported in young adults (aged below 65-70 years) with long-lasting disease. Scanty data are available on QoL of older people with sHT (>65 years) and, generally, no significant alterations are described.

Thyroid function and cognition in the euthyroid elderly: a case-control study embedded in Quebec longitudinal study - NuAge

It is presently unclear whether there is a significant association between thyroid function and cognitive decline in euthyroid elderly. This case-control study aimed to examine serum thyroid stimulating hormone (TSH), total thyroxine, free thyroxine, total triiodothyronine, and free triiodothyronine in relation to cognitive decline over a 3-year period in a subsample of 62 participants (31 pairs) aged 67 years and over at baseline from the NuAge study (Quebec longitudinal study). They were matched for age, sex and global cognition. In conditional regression logistic models, there was no significant association between any thyroid function indices and the 3-year risk of cognitive decline as measured with the Modified Mini-Mental State Examination (3MS). TSH and thyroid hormones do not appear to be associated with cognitive decline in euthyroid older persons. These findings need confirmation given the small number of pairs of subjects.

Subclinical hypothyroidism and indices for metabolic syndrome in Japanese women: one-year follow-up study

CONTEXT

Subclinical hypothyroidism (SCH) and metabolic syndrome (MetS) increase with age; however, their relationship remains unclear.

OBJECTIVE

Our objective was to investigate the relationship between SCH and indices of metabolic syndrome and follow up subjects for 1 year.

DESIGN

Cross-sectional and longitudinal follow-up studies of cases were collected from Takasaki Hidaka Hospital between 2003 and 2007.

PARTICIPANTS

Overall, 11 498 participants of health checkups were analyzed. The mean age was 48 ± 9 years.

MAIN OUTCOME MEASURES

The relationship between SCH and indices of MetS were examined.

RESULTS

Serum free T4 levels were lower in women than men in most of the age groups, and the prevalence of SCH, 6.3% in women vs 3.4% in men, increased with age, reaching 14.6% in 70-year-old women. Multivariate logistic-regression analyses revealed that waist circumference and the serum triglyceride and low-density lipoprotein-cholesterol levels were significantly higher in subjects with SCH than without among women. Reflecting these findings, the adjusted odds ratio of MetS in patients with SCH was higher than in the euthyroid subjects in women with an odds ratio of 2.7 (95% confidence interval 1.1-5.6; P = .017) but not in men. Furthermore, progression from euthyroid into SCH resulted in a significant increase in the serum triglyceride levels but not low-density lipoprotein-cholesterol in women.

CONCLUSION

Japanese women exhibited a high prevalence of SCH associated with low free T4 levels. There was a strong association between SCH and several indices of metabolic syndrome in women. SCH may affect serum triglyceride levels and be a risk factor for metabolic syndrome.

Is subclinical hypothyroidism a cardiovascular risk factor in the elderly?

CONTEXT

The negative impact of subclinical hypothyroidism (sHT) on cardiovascular risk, widely recognized in young adults (aged <55-60 y), is still debated in the elderly (>65 y), especially in the oldest olds (>80 y).

EVIDENCE ACQUISITION

We searched Medline for reports published with the following search terms: "hypothyroidism," "subclinical hypothyroidism," "ageing," "elderly," "L-thyroxin," "thyroid," "guidelines," "treatment," "quality of life," "cardiovascular risk," "heart failure," "coronary heart disease" (CHD), "atherosclerosis," and "endothelial dysfunction." We limited our search to reports in English published after 1980, although we incorporated some reports published before 1980. We supplemented the search with records from personal files, textbooks, and relevant articles. Analyzed parameters included the epidemiology of thyroid failure, the effect of thyroid hormone on the aging process, cardiovascular function, and CHD risk factors. We also included the potential benefits of L-T4 therapy on the quality of life, cardiovascular events, and survival.

EVIDENCE SYNTHESIS

TSH levels increase with age, even in older people without thyroid disease. Most longitudinal studies show an increased risk for CHD events and mortality in sHT participants. This increase is less evident in the elderly, mainly in cases of serum TSH values above 10 mIU/L. Lower mortality rate in a cohort of the oldest olds (>85 y) has been reported.

CONCLUSIONS

sHT in older people should be not regarded as a unique condition, and moderately old patients (aged <70-75 y) could be considered clinically similar to the adult population, albeit with a higher optimal TSH target value. Conversely, the oldest old subjects should be carefully followed with a wait-and-see strategy, generally avoiding hormonal treatment. The decision to treat elderly people is still an unresolved clinical challenge--first, due to a lack of appropriately powered randomized controlled trials of L-T4 in sHT patients, examining cardiovascular hard endpoints in various classes of age; and second, because of the negative effects of possible overtreatment.

Oxidative stress and the ageing endocrine system

Ageing is a process characterized by a progressive decline in cellular function, organismal fitness and increased risk of age-related diseases and death. Several hundred theories have attempted to explain this phenomenon. One of the most popular is the 'oxidative stress theory', originally termed the 'free radical theory'. The endocrine system seems to have a role in the modulation of oxidative stress; however, much less is known about the role that oxidative stress might have in the ageing of the endocrine system and the induction of age-related endocrine diseases. This Review outlines the interactions between hormones and oxidative metabolism and the potential effects of oxidative stress on ageing of endocrine organs. Many different mechanisms that link oxidative stress and ageing are discussed, all of which converge on the induction or regulation of inflammation. All these mechanisms, including cell senescence, mitochondrial dysfunction and microRNA dysregulation, as well as inflammation itself, could be targets of future studies aimed at clarifying the effects of oxidative stress on ageing of endocrine glands.

Thyroid hormones as predictors of short- and long-term mortality in very old hospitalized patients

BACKGROUND

Although extensively investigated, the prognostic role of thyroid hormone abnormalities in older participants remains uncertain. We investigated the relationship between thyroid hormones and mortality during hospitalization and in a prolonged follow-up in frail older patients.

METHODS

A nonconcurrent cohort study was conducted by enrolling 450 participants hospitalized for an acute disease, who were classified into four groups (euthyroidism, hypothyroidism, hyperthyroidism, and low triiodothyronine [T3] syndrome), according to clinical and laboratory data. Multidimensional geriatric assessment variables were considered in order to identify short- and long-term predictors of death.

RESULTS

Participants were very old (mean age: 84 years) and frail, as indicated by severely impaired functional status, extensive comorbidity, high prevalence of dementia, and hospital mortality (8%). Prevalence of any thyroid dysfunction was 40.7%; 32% of participants had low T3 syndrome, which was associated with an excess hospital mortality risk (odds ratio: 2.7, 95% confidence interval [CI]: 1.1-6.5; p = .025), adjusted for demographic, clinical, functional, and laboratory data. Conversely, long-term mortality was unrelated to low T3 syndrome. In euthyroid participants, increasing levels of free thyroxine (FT4) were associated with a slightly greater mortality (hazard ratio, CI: 2.12, 0.99-4.54; p = .053) in adjusted Cox regression models.

CONCLUSIONS

This observational study on a cohort of very old, frail hospitalized patients gives support to the independent prognostic short-term, but not long-term, role of low T3 syndrome. Moreover, in older euthyroid participants, increasing levels of FT4 are a weak marker of poorer long-term survival. Thyroid hormones may help monitor changes in general health status and predict short- and long-term clinical outcomes in very old, frail patients.

The thyroid gland and the process of aging; what is new?

The endocrine system and particular endocrine organs, including the thyroid, undergo important functional changes during aging. The prevalence of thyroid disorders increases with age and numerous morphological and physiological changes of the thyroid gland during the process of aging are well-known. It is to be stressed that the clinical course of thyroid diseases in the elderly differs essentially from that observed in younger individuals, because symptoms are more subtle and are often attributed to normal aging. Subclinical hypo- and hyperthyroidism, as well as thyroid neoplasms, require special attention in elderly subjects. Intriguingly, decreased thyroid function, as well as thyrotropin (TSH) levels - progressively shifting to higher values with age - may contribute to the increased lifespan.This short review focuses on recent findings concerning the alterations in thyroid function during aging, including these which may potentially lead to extended longevity, both in humans and animals.

Negative association between free triiodothyronine level and international normalized ratio in euthyroid subjects with acute myocardial infarction

AIM

To investigate the relationship between free triiodothyronine (FT3) and the international normalized ratio (the ratio of the prothrombin time of a patient to the normal sample, INR) in Chinese euthyroid subjects with acute ST-segment elevation myocardial infarction (STEMI).

METHODS

A total of 231 consecutive patients (177 males, 54 females) with STEMI were enrolled. Anthropometric and laboratory measurements, including heart rate, respiratory rate, blood pressure, body temperature, platelet count, INR, prothrombin time, activated partial thromboplastin time, FT3, free thyroxine (FT4), and thyroid-stimulating hormone, were collected from all the patients. The levels of FT3 and FT4 were measured with a full-automatic immune analyzer. The INR was determined using a coagulation analyzer.

RESULTS

Patients were classified into 4 groups according to their quartile FT3 and FT4 levels: 0.40-3.09 (n=52), 3.10-3.69 (n=56), 3.70-4.29 (n=64) and 4.30-7.10 (n=59) for FT3; 4.9-14.8 (n=57), 14.9-16.8 (n=58), 16.9-18.7 (n=57) and 18.8-29.0 (n=59) for FT4. Subjects with a high FT3 level had significantly lower values of INR than those with a low FT3 level (P=0.01). Multiple linear regression analysis revealed decreased serum FT3 as an independent risk factor for elevated INR values (β=-0.139, P=0.025). The value of INR was similar among the 4 groups according to the quartile FT4 levels (P=0.36).

CONCLUSION

Free triiodothyronine was negatively associated with INR in the patients with acute STEMI and normal thyroid function.

Thyroid disease in older people

Several changes in thyroid hormone secretion, metabolism, and action occur with the increase in age. Aging is often associated with a decrease in serum thyroid stimulating hormone and T3 levels, whereas serum free T4 levels usually remain unchanged. The prevalence of thyroid dysfunction is higher in the elderly as compared to the younger population. In elderly individuals the non-specific clinical manifestations of thyroid hormone excess or deprivation can cause confusion in the clinical setup; while some of the symptoms of thyroid disease are similar to those in younger patients, it is not uncommon for both hyperthyroidism and hypothyroidism to be manifested in subtle ways in older patients, often mimicking symptoms of aging or masquerading as diseases of the cardiovascular, gastrointestinal, or nervous system. In addition, diagnosis of thyroid disorders is commonly complicated, due to chronic, non-thyroidal illness or medication therapy. Early diagnosis and treatment of overt thyroid disorders is crucial, since these disorders are associated with increased morbidity and mortality in the elderly, usually due to common coexistent diseases such as diminished cardiovascular reserve. Treatment of subclinical thyroid disease should also be considered, based on a combination of age, symptoms and risk factors in the individual patients. In addition, both prevalence and aggressiveness of thyroid cancer increase with age. This review summarizes the changes of thyroid function, as well as the clinical manifestations and treatment of thyroid disorders with advancing age.