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Background: Over the last decades an increasing body of evidence suggested a possible relationship between thyroid hormone (TH) and the ageing process, and several efforts have been made to determine the actual role of TH dynamic during human life. It is still unclear whether the serum level shift of Thyroid Stimulating Hormone toward higher value, observed during ageing, is a normal adaptive response associated with senescence or an actual mild thyroid dysfunction. A growing body of evidence supports the hypothesis of a reset of the hypothalamus-pituitary-thyroid axis in order to contrast the catabolic status of the ageing process. On the other hand, several meta-analyses showed a direct link between subclinical hypothyroidism (sHT) and cardiovascular events (both ischemic heart disease and stroke), although mainly in individuals younger than 65 years. Similarly, a recent meta-analysis documented consistent data on a positive relationship between sHT and cognitive impairment, but only in individuals younger than 75 years., Conclusion: The available data suggest a complex relationship between mild thyroid failure and the ageing process as well as the development and progression of several cardiovascular and neurological diseases. In this paper, we reviewed the scientific English literature on sHT and the ageing process focusing on experimental evidences related to cognitive impairment and dementia. Moreover, we focused on new patents of treatments potentially able to improve the care of sHT patients, especially in the elderly, where treatment drawbacks may have negative impact on the long term outcome.

Background: The association between subclinical hypothyroidism (sHT) and cognitive impairment or risk of dementia is not well-defined, especially in the elderly, where the assessment of central nervous system function is challenging. The aim of this systematic review and meta-analysis was to evaluate the possible effect of sHT on cognitive decline and the risk of dementia., Methods: Cognitive function was the primary outcome, evaluated as composite endpoint of incidence or prevalence of dementia or difference of Mini Mental State Examination, Wechsler Adult Intelligence Scale, and Wechsler Memory Scale-Revised scores., Results: Thirteen studies were included in the meta-analysis. A significant risk of cognitive alteration was observed only in sHT individuals younger than age 75 years: composite endpoint odds ratio (OR) 1.56 (95% confidence interval [CI] 1.07-2.27, P = .02, I(2) = 82.5%), risk of dementia OR 1.81 (95% CI 1.43-2.28, P < .01, I(2) = 35%). Mean serum thyroid-stimulating hormone (TSH) levels and the OR of composite endpoint were positively correlated. No significant effect of sHT was found when considering all the studies as a whole: composite endpoint OR 1.26 (95% CI 0.96-1.66, P = .09, I(2) = 87.2%), risk of dementia OR 1.42 (95% CI, 0.97-2.07, P = .07, I(2) = 66.8%), Mini Mental State Examination mean difference -0.059 (95% CI -0.464 to 0.346 P = .78, I(2) = 51.8%)., Conclusions: This meta-analysis demonstrates a relationship between sHT and cognitive impairment only in individuals younger than 75 years of age and those with higher TSH concentrations. No correlation was found while considering all the studies as a whole. The lack of utilization of age-related serum TSH reference ranges and consequent potential misdiagnosis of sHT in older people may account for this.

Subclinical hypothyroidism (sHT) is very common in general population, especially in women and older people. sHT individuals may experience symptoms that resemble those observed in overt hypothyroidism, resulting in impaired quality of life (QOL). Asymptomatic patients may suffer a reduction in perceived health status due to the awareness of disease. Cognitive function represents one of the most important domains of the QOL questionnaires. Given the intrinsic relationship between cognitive status and QOL it is worth to address these topics together, in a systematic review of the literature. Thus, we reviewed the English scientific literature available on National Library of Medicine (www.pubmed.com) sine 1980 regarding hypothyroidism, sHT, elderly, L-thyroxine (LT4) therapy, QOL, cognition, brain. We supplemented the search with records from personal files, textbooks, and relevant articles. The possible link, at molecular level, between cognition and thyroid failure was also assessed. Conflicting results on the association between sHT and cognitive and health related QOL impairment are still present, although the most recent, naturalistic studies did not find any significant relationship. Interestingly, a reduction in health related QOL is frequently reported in patients with thyroid autoimmune diseases regardless of thyroid dysfunction. We also report most significant patents on the topic.

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.

Context: Although the negative impact of subclinical hypothyroidism (sHT) in terms of cardiovascular risk in young adults is mostly acknowledged it remains to be established in the elderly, especially in the oldest old., Evidence Acquisition: We searched Medline for reports published with the following search words: hypothyroidism, sHT, ageing, elderly, L-thyroxin, thyroid, guidelines, treatment, quality of life, cardiovascular risk, heart failure (HF), ischemic heart disease (IHD), endothelial dysfunction. The search was restricted to reports published in English since 1980, but some reports published before 1980 were also incorporated. We supplemented the search with records from personal files and references of relevant articles and textbooks. Parameters analyzed included epidemiology of sHT and thyroid failure the effect of thyroid hormone on ageing process and cardiovascular function as well as the potential benefits of L-thyroxin therapy on quality of life, HF progression and events., Evidence Synthesis: TSH levels increase with age, even in older patients without thyroid disease, in whom higher TSH value might favor longevity; better quality of life and lower IHD mortality in the oldest old population has been reported yet. However, at odds with the relationship between sHT and IHD risk and mortality, which shows a clear age dependent feature, vanishing in the last decades of life, the detrimental effect of sHT on HF progression and events remains evident also in older patients, although no data are available in the oldest old population., Conclusions: The lack of specific randomized trials enrolling either old or very old subjects, aimed at evaluate the efficacy of hormonal replacement on overall survival and cardiovascular risk reduction along with the negative effects of possible over-treatment, makes the decision to treat older people a still unresolved clinical challenge. Moreover, the possibility that restoring euthyroidism may be harmful in the elderly should be always taken into account.

Background: It has been demonstrated that hypothyroidism can lead to significant hemodynamic alterations favoring the onset of chronic heart failure (CHF) as well as its progression. Furthermore, amiodarone, an iodine-containing antiarhythmic drug frequently used in CHF patients, is often the cause of primary hypothyroidism., Aim of the Study: To define the prevalence and incidence of hypothyroidism in a group of CHF outpatients in stable clinical conditions, with particular reference to the role of amiodarone therapy., Results: Among the 422 enrolled patients (326 males, aged 65±12 years), 51 (12%) had a previous diagnosis of hypothyroidism while 21 (5%) were newly diagnosed at the enrolment. Then, the overall prevalence of hypothyroidism at the first evaluation was 17%and, as expected, it was significantly higher in females than males (33% vs 13%; p < 0.001). During follow-up (median 28 months) hypothyroidism occurred in further 19 patients (incidence rate: 26/1000/year) and it was mainly attributable to amiodarone therapy. Considering all together the hypothyroid patients, either those affected by thyroid failure at the enrolment than those developing hypothyroidism during the follow-up, levothyroxine therapy was continued or started in 69% of them; however, normal serum TSH values were obtained only in 76% of treated cases (mean levothyroxine dose: 69±44 mcg/day). In any case, in the group of patients affected by hypothyroidism a significantly greater occurrence of heart failure progression was observed., Conclusions: Hypothyroidism, especially the subclinical form, frequently occurs in patients affected by CHF receiving amiodarone therapy. Given the unfavorable impact of hypothyroidism on the progression and prognosis of CHF, and the opportunity to adequately manage thyroid failure by means of levothyroxine replacement therapy without the need to withdraw amiodarone, we recommend regular testing of thyroid function in CHF patients, in particular in those submitted to amiodarone therapy, in order to early diagnose a condition of hypothyroidism and titrate substitutive treatment.

The time-dependent effects of mild hypothyroidism on endothelial function were assessed in rat mesenteric arteries. Male Wistar rats were treated with methimazole (MMI; 0.003%) or placebo up to 16 wk. Endothelial function of mesenteric small arteries was assessed by pressurized myograph. MMI-treated animals displayed a decrease in serum thyroid hormones, an increment of plasma TSH and inflammatory cytokines, and a blunted vascular relaxation to acetylcholine, as compared with controls. Endothelial dysfunction resulted from a reduced nitric oxide (NO) availability caused by oxidative excess. Vascular-inducible NO synthase (iNOS) expression was up-regulated. S-methylisothiourea (an iNOS inhibitor) normalized endothelium-dependent relaxations and restored NO availability in arteries from 8-wk MMI-animals and partly ameliorated these alterations in 16-wk MMI rats. Similar results were obtained when MMI-induced hypothyroidism was prevented by T(4) replacement. Among controls, an impaired NO availability, secondary to oxidative excess, occurred at 16 wk, and it was less pronounced than in age-matched MMI animals. Both endothelial dysfunction and oxidant excess secondary to aging were prevented by apocynin (nicotinamide adenine dinucleotide phosphate oxidase inhibitor). Mesenteric superoxide production was reduced by S-methylisothiourea and T(4) replacement in MMI animals and abolished by apocynin in controls (dihydroethidium staining). MMI-induced mild hypothyroidism is associated with endothelial dysfunction caused by a reduced NO availability, secondary to oxidative excess. It is suggested that in this animal model, characterized by TSH elevation and low-grade inflammation, an increased expression and function of iNOS, resulting in superoxide generation, accounts for an impaired NO availability.

The aim of the present study was to evaluate cardiac function and texture in patients with subclinical hypothyroidism (sHT) both by conventional and new ultrasonic intramyocardial tissue techniques. sHT was characterized by normal serum free tetraiodotironine and free triiodotironine levels and slightly increased serum TSH level. Twenty-four patients affected by sHT and 24 sex- and age-matched healthy volunteers were studied. All subjects were submitted to conventional two-dimensional (2D)-color Doppler echocardiography, pulsed wave tissue Doppler imaging (PWTDI) for the analysis of the diastolic function, color Doppler myocardial imaging (CDMI) for the analysis of regional strain and strain-rate and integrated backscatter (IBS) for the evaluation of intrinsic contractility and tissue characterization. The results of the present study were: (a) the detection in sHT subjects of a lower cyclic variation index (CVI) indicating an altered myocardial intrinsic contractility; (b) a higher ultrasonic myocardial reflectivity indicating an altered myocardial texture; (c) the detection of lower systolic strain and strain-rate indicating an alteration of myocardial regional deformability; (d) an initial impairment of left ventricular diastolic function indicated by a decrease of peak E mitral flow velocity and an increase of peak A mitral flow velocity. All parameters studied with conventional 2D-echo in sHT patients were comparable with controls, except for a mild alteration in diastolic function. A significant correlation among systo-diastolic modifications detected by CDMI and IBS and serum TSH levels were found. The CVI at septum, the PWDTI S-peak wave and the systolic strain at septum were inversely related to the serum TSH levels. In conclusion, the new intramyocardial ultrasonic techniques confirm and extend the previous knowledge on the effect of the sHT on the heart, allowing the detection of early ultrastructural and regional functional systolic and diastolic abnormalities.

Subclinical hypothyroidism is defined as an elevated serum thyroid-stimulating hormone (TSH) level in the face of normal free thyroid hormone values. The overall prevalence of subclinical hypothyroidism is 4-10% in the general population and up to 20% in women aged >60 years. The potential benefits and risks of therapy for subclinical hypothyroidism have been debated for 2 decades, and a consensus is still lacking. Besides avoiding the progression to overt hypothyroidism, the decision to treat patients with subclinical hypothyroidism relies mainly on the risk of metabolic and cardiovascular alterations. Subclinical hypothyroidism causes changes in cardiovascular function similar to, but less marked than, those occurring in patients with overt hypothyroidism. Diastolic dysfunction both at rest and upon effort is the most consistent cardiac abnormality in patients with subclinical hypothyroidism, and also in those with slightly elevated TSH levels (>6 mIU/L). Moreover, mild thyroid failure may increase diastolic blood pressure as a result of increased systemic vascular resistance. Restoration of euthyroidism by levothyroxine replacement is generally able to improve all these abnormalities. Early clinical and autopsy studies had suggested an association between subclinical hypothyroidism and coronary heart disease, which has been subsequently confirmed by some, but not all, large cross-sectional and prospective studies. Altered coagulation parameters, elevated lipoprotein (a) levels, and low-grade chronic inflammation are regarded to coalesce with the hypercholesterolemia of untreated patients with subclinical hypothyroidism to enhance the ischemic cardiovascular risk. Although a consensus is still lacking, the strongest evidence for a beneficial effect of levothyroxine replacement on markers of cardiovascular risk is the substantial demonstration that restoration of euthyroidism can lower both total and low-density lipoprotein-cholesterol levels in most patients with subclinical hypothyroidism. However, the actual effectiveness of thyroid hormone substitution in reducing the risk of cardiovascular events remains to be elucidated. In conclusion, the multiplicity and the possible reversibility of subclinical hypothyroidism-associated cardiovascular abnormalities suggest that the decision to treat a patient should depend on the presence of risk factors, rather than on a TSH threshold. On the other hand, levothyroxine replacement therapy can always be discontinued if there is no apparent benefit. Levothyroxine replacement therapy is usually safe providing that excessive administration is avoided by monitoring serum TSH levels. However, the possibility that restoring euthyroidism may be harmful in the oldest of the elderly population of hypothyroid patients has been recently raised, and should be taken into account in making the decision to treat patients with subclinical hypothyroidism who are aged >85 years.

Background: Neuromuscular symptoms and impaired muscle energy metabolism have been described in subclinical hypothyroidism (sHT)., Aim: The aim of the study was to evaluate the energy and substrate response to exercise in sHT patients using a standardized protocol and to test the effect of L-T(4) replacement in a double-blind, randomized, placebo-controlled fashion., Patients and Methods: We studied 23 sHT patients and 10 matched euthyroid controls. Oxygen uptake (VO(2)), carbon dioxide output, and heart rate were measured during incremental step-up exercise. Blood glucose, lactate, pyruvate, free fatty acid, glycerol, and beta-hydroxybutyrate concentrations were measured at rest, every 2 min during exercise, and during 20 min of recovery. The exercise protocol was repeated after 6 months of placebo or L-T(4)-restored euthyroidism., Results: Maximal power output (P = 0.02) and VO(2) max (P = 0.04) were reduced in sHT, and, with increasing workload, patients achieved higher heart rates (P < 0.03) at VO(2) values equivalent to those of controls. The respiratory quotient increments were significantly higher in patients than controls (P < 0.04). Blood lactate and pyruvate and their ratio rose with a steeper slope (P < 0.0001, P < 0.001, and P < 0.01, respectively) in patients than controls. Resting plasma free fatty acid and blood glycerol levels were significantly higher in patients than controls (P < 0.0003 and P < 0.003, respectively) throughout baseline, exercise, and recovery. L-T(4) replacement, while improving neuromuscular symptoms, did not produce significant changes in the energy or substrate response to exercise., Conclusions: The response to exercise is altered both in terms of tolerance and pattern of substrate utilization in sHT patients. Restoring stable euthyroidism does not correct this defect over a 1-yr period.

Subclinical hypothyroidism (sHT) is associated with enhanced cardiovascular risk. To test the hypothesis that patients with sHT are characterized by endothelial dysfunction and impaired nitric oxide (NO) availability, in 14 patients [serum cholesterol, 218 +/- 41 mg/dl (5.6 +/- 0.9 mM)] and 28 euthyroid subjects, subdivided into groups A and B [serum cholesterol, 170 +/- 19 mg/dl (4.4 +/- 0.5 mM) and 217 +/- 21 mg/dl (5.6 +/- 0.5 mM), respectively], we studied the forearm blood flow (strain-gauge plethysmography) response to intrabrachial acetylcholine, an endothelium-dependent vasodilator, at baseline and during infusion of N(G)-monomethyl-L-arginine (L-NMMA), a NO synthase inhibitor. Response to sodium nitroprusside and minimal forearm vascular resistances were also evaluated. In sHT patients, vasodilation to acetylcholine was reduced, compared with group B (+358 +/- 29% vs. +503 +/- 19%, P = 0.0003) and group A (663 +/- 65%, P = 0.02 vs. group B and P = 0.0002 vs. sHT). L-NMMA blunted the vasodilation to acetylcholine in groups A and B (49.1 +/- 6.3% and 42.7 +/- 5.5% maximal forearm blood flow reduction, respectively, P < 0.0001 vs. acetylcholine), whereas it was ineffective in sHT patients (12.8 +/- 2.5%). Response to sodium nitroprusside and minimal vascular resistances were similar. In sHT (n = 9) patients, 6 months of euthyroidism by levothyroxine replacement increased acetylcholine-vasodilation and restored L-NMMA inhibition. Patients with sHT are characterized by endothelial dysfunction resulting from a reduction in NO availability, an alteration partially independent of dyslipidemia and reversed by levothyroxine supplementation.

The relationship between subclinical hypothyroidism (SCH) and an atherogenic lipoprotein profile is still controversial. We measured lipoproteins in 49 SCH patients by comparison with 33 euthyroid controls. Total cholesterol (TC), triglyceride, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol (LDLc), apolipoprotein A(1), apolipoprotein B, and lipoprotein (a) [Lp(a)] were measured after an overnight fast. Patients were randomly assigned to levothyroxine therapy or placebo and re-evaluated after 6 months of euthyroidism. SCH patients showed significantly higher TC (P < 0.01), LDLc (P = 0.01), and apolipoprotein B (P = 0.001) levels than controls, positively correlated with baseline TSH levels (P = 0.003, P = 0.01, and P = 0.03, respectively). Elevated Lp(a) levels were significantly more frequent in SCH (P < 0.05) and associated with familial diabetes mellitus and/or coronary heart disease (P < 0.01). Levothyroxine treatment resulted in a significant decrease of both TC and LDLc concentrations (P = 0.003), in direct proportion to the respective baseline values (P < 0.05 and P < 0.01, respectively), whereas no change in Lp(a) level was observed. No changes occurred in the placebo group. In conclusion, only serum LDLc levels are increased specifically and reversibly in association with SCH. Altered Lp(a) values reflect a genetic influence rather than a reduced thyroid hormone action.

(1) Background: Subclinical hypothyroidism (SHT) is a condition that has been a subject of controversy in the literature due to its association with psychological and psychiatric symptoms as well as autonomic imbalances. To gain a better understanding of the effects of SHT on patients, a research study has been undertaken to investigate the presence of psychological symptoms and autonomic imbalances in a group of individuals diagnosed with SHT. (2) Methods: In this case–control study, 50 patients diagnosed with SHT who accessed the Department of Endocrinology of the University of Pisa were consecutively recruited. Psychological symptoms were measured through the Crown–Crisp Experiential Index (CCEI), whereas autonomic imbalance was described using the Psychophysiological Stress Profile (PSP), with simultaneous recording of the following psychophysiological parameters: Surface Electromyogram (sEMG), Skin Conductance Level (SCL), heart rate (HR), and peripheral temperature (PT). The patients' values were compared to those of 50 healthy control subjects. (3) Results: The comparison between groups highlighted significant differences in the CCEI and PSP. In particular, patients reported higher rates of psychological symptoms (anxiety, depression, somatic complaints, and hysteria behavior). Significantly higher levels of autonomic arousal were also recorded. More specifically, the sEMG, SCL, HR, and PT values were different between the two groups. (4) Conclusions: The study has confirmed the presence of autonomic hyperarousal in patients diagnosed with subclinical hypothyroidism. This is likely due to the body's attempt to compensate for a general lack of energy by accelerating the autonomic activity. The findings also underline the significance of a comprehensive assessment approach that takes into account various dimensions such as psychological and psychophysical well-being. Such an approach helps in evaluating the impact of subclinical diseases on overall health and well-being. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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 longlasting disease. Scanty data are available on QoL of older people with sHT (>65 years) and, generally, no significant alterations are described. [ABSTRACT FROM AUTHOR]