The association between thyroid function and incidence of metabolic syndrome in euthyroid subjects: Tianjin chronic low-grade systemic inflammation and health cohort study

Association of longitudinal trends in thyroid function with incident carotid atherosclerosis in middle-aged and older euthyroid subjects: the Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) cohort study

BACKGROUND

Previous studies have posited that an association exists between thyroid function and the heart and vasculature. It remains unclear, however, whether longitudinal trends in thyroid function contribute to the development of atherosclerosis. We conducted a cohort study to examine the association of longitudinal trends in thyroid function with incident carotid atherosclerosis (CA) in middle-aged and older euthyroid subjects.

METHODS

This cohort study's participants were recruited from the Tianjin Chronic Low-grade Systemic Inflammation and Health Cohort Study in Tianjin, China. Free triiodothyronine (FT3), thyroxine (FT4) and thyroid-stimulating hormone (TSH) were measured using chemiluminescence immunoassay. CA was assessed using carotid ultrasonography. Thyroid function and ultrasonography were assessed yearly during follow-up. Multivariable Cox proportional hazards regression models were used to assess the association between thyroid function and incident CA.

RESULTS

A total of 3,181 participants were enrolled in the cohort study. Within 7,762 person-years of follow-up, 944 participants developed CA, the incidence rate of CA was 122 per 1,000 person-years. The fully adjusted hazards ratios (95% confidence interval) of CA for per 1-unit increase in changes of FT3, FT4 and TSH were 1.34(1.22-1.47), 1.22(1.19-1.26) and 0.92 (0.77-1.09) (P < 0.0001, <0.0001 and = 0.32, respectively), respectively. Similar significant associations between mean levels of FT3 and FT4 and incident CA were observed. However, baseline thyroid function was not associated with incident CA.

CONCLUSIONS

These findings suggest that higher mean levels and higher values of changes in thyroid hormones were associated with a higher risk of incident CA in middle-aged and older euthyroid subjects.

Clinical-epidemiological and radiological characteristics of stroke patients: A multicentre study

INTRODUCTION AND AIM

Stroke is the leading cause of disability in adults and the second most common cause of death, at a rate of 11.8% worldwide. The purpose of this study was to examine the aetiological, demographic, and clinical characteristics of patients admitted to hospital because of acute strokes.

MATERIALS AND METHODS

This multicentre study retrieved information for all patients admitted to hospital because of an acute cerebrovascular event over a six-month period, and sociodemographic, aetiological, and clinical characteristics were recorded.

RESULTS

A total of 1136 patients, 520 of whom were women (45.7%), with a mean age of 70.3 ± 12.8 years, were included in the study. Of these, 967 were diagnosed with ischaemic stroke (IS) (85.1%), 99 with haemorrhagic stroke (HS) (8.7%), and 70 with transient ischaemic attack (6.1%). The most common risk factor for stroke was hypertension (73%). Carotid disease and hyperlipidaemia rates were higher in patients with HS. Numbers of functionally dependent patients with severe neurological status according to the National Institutes of Health Stroke Scale and modified Rankin scale were significantly higher in the HS group (P < .001). When IS was classified according to the Trial of Org 10172 in Acute Stroke Treatment, small vessel disease emerged as the most common cause (41%). The most common lesion localisations were the parietal lobe (23%) in the IS group and the thalamus (35.3%) in the HS group. Eighty-eight patients (7.7%), 62 (6.4%) in the ischaemic subgroup, and 26 (26.3%) in the haemorrhagic subgroup, died within the first month.

CONCLUSION

Current and accurate evaluations of stroke aetiology are essential for stroke prevention and treatment planning. This study, shows that no change occurred in the aetiology of stroke and epidemiological characteristics and that accurate identification of modifiable stroke risk factors is still a major goal.

The association between longitudinal trends of thyroid hormones levels and incident hypertension in a euthyroid population

Thyroid hormones, including free triiodothyronine (FT3), free thyroxine (FT4), have well-recognized effects on the cardiovascular system. However, the evidence is lacking regarding the relationship between repeated FT3, FT4, and thyroid-stimulating hormone (TSH) measurements and incident hypertension. The aim of this cohort study was to examine how longitudinal trends of serum FT3, FT4, and TSH levels are related to the development of hypertension in a euthyroid population. A prospective study (n = 5926) was performed in Tianjin, China. Participants without a history of hypertension were followed up for ~4 years (median: 3 years). Hypertension was defined according to the criteria of JNC7. FT3, FT4, and TSH were determined by chemiluminescence immunoassay methods. FT3, FT4, TSH, and blood pressure were assessed yearly during follow-up. Adjusted Cox proportional hazards regression models were used to assess the relationships between baseline, means, and annual changes in FT3, FT4, TSH, and hypertension. The incidence rate of hypertension per 1000 person-years was 73. Compared with the lowest quartile, the multivariable-adjusted hazards ratios (95% confidence interval) for hypertension in the highest quartiles of changes in FT3, FT4, and TSH were 1.51 (1.23-1.84), 2.04 (1.67-2.48), and 1.20 (0.99-1.45), respectively. Similar relationships were observed between the means of FT3, FT4, TSH, and hypertension. However, we found no correlations between baseline FT3, FT4, TSH, and incident hypertension. The present study is the first to demonstrate that the annual changes and means, but not baseline FT3 and FT4 values are independently related to the risk of incident hypertension in the euthyroid general population.

Heart Disease and Stroke Statistics-2020 Update: A Report From the American Heart Association

BACKGROUND

The American Heart Association, in conjunction with the National Institutes of Health, annually reports on the most up-to-date statistics related to heart disease, stroke, and cardiovascular risk factors, including core health behaviors (smoking, physical activity, diet, and weight) and health factors (cholesterol, blood pressure, and glucose control) that contribute to cardiovascular health. The Statistical Update presents the latest data on a range of major clinical heart and circulatory disease conditions (including stroke, congenital heart disease, rhythm disorders, subclinical atherosclerosis, coronary heart disease, heart failure, valvular disease, venous disease, and peripheral artery disease) and the associated outcomes (including quality of care, procedures, and economic costs).

METHODS

The American Heart Association, through its Statistics Committee, continuously monitors and evaluates sources of data on heart disease and stroke in the United States to provide the most current information available in the annual Statistical Update. The 2020 Statistical Update is the product of a full year's worth of effort by dedicated volunteer clinicians and scientists, committed government professionals, and American Heart Association staff members. This year's edition includes data on the monitoring and benefits of cardiovascular health in the population, metrics to assess and monitor healthy diets, an enhanced focus on social determinants of health, a focus on the global burden of cardiovascular disease, and further evidence-based approaches to changing behaviors, implementation strategies, and implications of the American Heart Association's 2020 Impact Goals.

RESULTS

Each of the 26 chapters in the Statistical Update focuses on a different topic related to heart disease and stroke statistics.

CONCLUSIONS

The Statistical Update represents a critical resource for the lay public, policy makers, media professionals, clinicians, healthcare administrators, researchers, health advocates, and others seeking the best available data on these factors and conditions.

Low-Normal Thyroid Function Predicts Incident Anemia in the General Population With Euthyroid Status

CONTEXT

Thyroid hormones (THs) have direct and indirect effects on hematopoiesis. However, few studies have directly evaluated the effect of THs on incident anemia among euthyroid subjects. This cohort study aimed to explore whether THs under physiological conditions can affect the development of anemia in the general population.

DESIGN

A total of 12,310 participants were enrolled in the cohort study (∼5-year follow-up period; mean, 3.1 years). A chemiluminescence immunoassay was used to measure free T3 (FT3), free T4 (FT4), and TSH, and anemia was defined according to the World Health Organization recommendation. THs, TSH, and Hb were assessed yearly during follow-up. Multivariable Cox proportional hazards regression models were used to assess the association between THs, TSH, and incident anemia.

RESULTS

The fully adjusted hazards ratios (95% CI) of anemia per 1-unit change in FT3, FT4, and TSH concentrations were 0.70 (0.56, 0.87), 0.93 (0.88, 0.98), and 1.19 (0.94, 1.50) (P < 0.01, P < 0.01, and P = 0.14, respectively). Moreover, a significant and positive association between FT3, FT4, and annual changes in Hb (standard regression coefficients of 0.056 and 0.028, respectively; both P < 0.01) was observed. Similar associations were observed when the participants who had thyroid dysfunction upon follow-up were excluded.

CONCLUSIONS

The current study demonstrated that THs significantly predict future anemia and annual changes in Hb, even in the euthyroid population.

Thyroid disease and the metabolic syndrome

PURPOSE OF REVIEW

To summarize recent developments in the association of thyroid function with metabolic syndrome (MetS).

RECENT FINDINGS

Although thyroid hormones even within low normal range are associated with various metabolic abnormalities, the risk of MetS remains a controversial issue. Hyperthyroid state might be associated only with insulin resistance and dysglycemia. Autoimmune thyroid diseases may be a potential risk factor for metabolic abnormalities even in those with low normal thyroid function.

SUMMARY

The interrelation between thyroid stimulating hormone, free T3, freeT4 and metabolic parameters is complex and might be affected by age, sex, BMI, insulin resistance, smoking, iodine intake and inflammatory markers.

Thyroid hormones, metabolic syndrome and Vitamin D in middle-aged and older euthyroid subjects: a preliminary study

AIM

To explore the relationship between thyroid hormones, Vitamin D (Vit.D) serum concentrations and metabolic syndrome (MetS) in euthyroid subjects.

METHODS

123 community-dwelling subjects were enrolled. According to thyroid-stimulating hormone (TSH) values the sample was divided into: (1) group 1 (TSH ≤ 2 mU/L); (2) group 2 (TSH > 2 mU/L).

RESULTS

Group 2 showed higher percentage of subjects with MetS (p = 0.003) and hypertension (p = 0.031), higher values of waist circumference (WC) (p = 0.007), parathyroid hormone (p = 0.016), glycaemia (p = 0.045), triglycerides (p = 0.034) and free T4 (fT4) (p = 0.013). Correlation analysis showed several weak significant correlations: MetS with TSH (r = 0.202, p = 0.031) and fT3 (r = - 0.206, p = 0.028); THS with body mass index (r = 0.187, p = 0.047) and hypertension (r = 0.199, p = 0.034); Vit.D with WC (r = - 0.185, p = 0.04).

CONCLUSIONS

Our results showed a possible association between thyroid hormones and MetS. Visceral fat and insulin resistance may be an interesting link between Vit.D and TSH levels.

Relationship between serum levels of immunoglobulins and metabolic syndrome in an adult population: A population study from the TCLSIH cohort study

BACKGROUND AND AIMS

Metabolic syndrome (MetS) is a combination of metabolic disorders that increase the risk of developing cardiovascular disease, and inflammation is considered as a pathological basis for MetS. Immunoglobulins (Igs) are the major secretory products of the adaptive immune system. However, no large-scale population study has focused on a possible relationship between Igs and MetS. We designed a cross-sectional study to investigate the relationship between Igs and prevalence of MetS in a large-scale adult population.

METHODS AND RESULTS

A total of 10,289 participants were recruited among residents in Tianjin, China. Metabolic syndrome was defined in accordance with the criteria of the American Heart Association scientific statements of 2009. Serum levels of Igs were determined by immunonephelometry. Multiple logistic regression models were used to assess the relationship between the quintiles of serum levels of Igs and the prevalence of MetS. The overall prevalence of MetS was 36.1%. The mean (standard deviation) values of Igs (IgG, IgE, IgM, and IgA) were 1205.7 (249.3) mg/dL, 93.1 (238.9) IU/mL, 105.7 (57.3) mg/dL, and 236.2 (97.6) mg/dL, respectively. The adjusted odds ratios (95% confidence interval) of MetS for the highest quintile of Igs (IgG, IgE, IgM, and IgA), when compared to the lowest quintile, were 0.81 (0.70, 0.95), 0.97 (0.83, 1.12), 1.13 (0.97, 1.33), and 1.52 (1.30, 1.77), respectively.

CONCLUSIONS

This study demonstrated that decreased IgG and increased IgA are independently related to a higher prevalence of MetS. The results indicate that the Igs might be useful predictive factors for MetS in the general adult population.