Serum resistin and insulin-like growth factor-1 levels in patients with hypothyroidism and hyperthyroidism

Association between circulating resistin levels and thyroid dysfunction: A systematic review and meta-analysis

Background

As a product of adipose tissue, resistin exceeds other adipokines in its role in regulating appetite, energy expenditure, insulin sensitivity, inflammation, and immunity, similar to thyroid hormones. This study aimed to evaluate the association between resistin levels and thyroid dysfunction and to explore variations in circulating resistin levels before and after treatment for thyroid dysfunction.

Methods

This study was conducted according to the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. A comprehensive search of PubMed, Embase, and Cochrane databases was conducted until June 15, 2022, with no start date restriction, according to the preregistered protocol (PROSPERO-CRD42022336617). RevMan version 5.4 and R software package version 4.2.0 were used for statistical analyses.

Results

Fourteen studies with 1716 participants were included in this study. The findings of the meta-analysis confirmed that the resistin levels of patients with thyroid dysfunction were significantly higher than those of the euthyroid function control group (mean difference [MD] = 2.11, 95% confidence interval [CI] = 1.11-3.11, P < 0.00001). Furthermore, the resistin levels of patients with hyperthyroidism (MD = 3.23, 95% CI = 0.68-5.79, P = 0.01) and subclinical hypoidism (MD = 1.37, 95% CI = 0.31-2.42, P = 0.01) were significantly higher than those of euthyroid controls. The resistin levels of patients with thyroid dysfunction after treatment were significantly lower than those before treatment (MD = 1.00, 95% CI = 0.34-1.65, P = 0.003), especially in patients with hyperthyroidism (MD = 2.16, 95% CI = 1.00-3.32, P = 0.0003). Correlation analysis confirmed a positive correlation between resistin levels and free triiodothyronine (FT3) levels in patients with thyroid dysfunction (r = 0.27578, P = 0.001).

Conclusions

Our meta-analysis demonstrates that resistin levels are significantly higher in patients with thyroid dysfunction, and the resistin levels after treatment in patients with thyroid dysfunction are significantly lower than those before treatment. Correlation analysis shows a positive correlation between resistin levels and FT3 levels in patients with thyroid dysfunction.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022336617.

Teprotumumab-associated chronic hearing loss screening and proposed treatments

We report a case of a woman in her 50s with chronic teprotumumab-associated sensorineural hearing loss. The patient presented with chronic thyroid eye disease with proptosis and diplopia despite systemic thyroid control and orbital decompression. She was started on teprotumumab but developed tinnitus after the third dose, followed by frank hearing loss after the fifth dose. Her audiogram showed bilateral mild to moderate-severe hearing loss, which was significantly worse compared with her baseline audiogram obtained prior to treatment. Teprotumumab was immediately stopped, however repeat audiogram 6 weeks later showed no improvement. Given potentially irreversible sensorineural hearing loss, we recommend close monitoring with regular audiometric testing before, during and after teprotumumab therapy and propose potential treatment to reverse its effects in the ear.

Obesity and Thyroid Axis

Development of obesity is primarily the result of imbalance between energy intake and energy expenditure. Thyroid hormones influence energy expenditure by regulating cellular respiration and thermogenesis and by determining resting metabolic rate. Triiodothyronine influences lipid turnover in adipocytes and impacts appetite regulation through the central nervous system, mainly the hypothalamus. Thyroid-stimulating hormone may also influence thermogenesis, suppress appetite and regulate lipid storage through lipolysis and lipogenesis control. Subclinical hypothyroidism may induce changes in basal metabolic rate with subsequent increase in BMI, but obesity can also affect thyroid function via several mechanisms such as lipotoxicity and changes in adipokines and inflammatory cytokine secretion. The present study investigated the complex and mutual relationships between the thyroid axis and adiposity.

Serum concentrations of insulin-like growth factor-1 as a biomarker of improved circadian rhythm sleep-wake disorder in school-aged children

STUDY OBJECTIVES

We aimed to investigate whether improvements in the symptoms of circadian rhythm sleep-wake disorder after treatment were associated with an increase in serum insulin-like growth factor-1 (IGF-1) concentration.

METHODS

Eighty-seven school-aged children (32 males, 55 females), aged 14.31 ± 1.50 years (mean ± standard deviation), who were admitted to our hospital with circadian rhythm sleep-wake disorder received treatment for 6-8 weeks consisting of the following protocol: (1) lights-out for sleep occurred at 21:00, (2) phototherapy for waking started at 06:00 or 07:00, and (3) light exercise was required every day (eg, a 20- to 30-minute walk). Blood samples were collected at 08:00 am to measure the serum concentrations of IGF-1, pre- and posttreatment.

RESULTS

The mean times of day of sleep onset and offset at the pre- and posttreatment timepoints were 23:32 ± 4.21 and 10:27 ± 2.98, and 21:26 ± 0.55 and 06:50 ± 0.70, respectively. The mean times of day of sleep onset and offset measured at the posttreatment timepoint were significantly earlier compared with the pretreatment baselines (P < .01). The mean serum levels of IGF-1 significantly increased from 315.59 ± 68.26 ng/mL at pretreatment to 335.09 ± 69.78 ng/mL at posttreatment (P < .01).

CONCLUSIONS

Improvements in the symptoms of patients with circadian rhythm sleep-wake disorders were associated with increased serum concentrations of IGF-1, suggesting that serum IGF-1 may be a biomarker of improvements in school-aged children with circadian rhythm sleep-wake disorder.

Serum levels of insulin-like growth factor 1 are negatively associated with log transformation of thyroid-stimulating hormone in Graves' disease patients with hyperthyroidism or subjects with euthyroidism: A prospective observational study

Insulin-like growth factor 1 (IGF-1) has a molecular structure similar to that of insulin. As an essential mediator of growth hormone, IGF-1 plays a vital role in growth of children and anabolic effects of adults. We evaluated the serum levels of IGF-1 in patients with hyperthyroidism or euthyroidism.In this study, 30 patients each of Graves' disease with hyperthyroidism (HY group) and euthyroid individuals (EU group) were recruited. The HY patients were treated with antithyroid regimens as clinically indicated. No medications were given to EU patients. The demographic characteristics and anthropometric and laboratory data of both groups at baseline and 6 months were compared. Associations between levels of IGF-1 and free thyroxine (fT4), thyroid-stimulating hormone (TSH), or log transformation of TSH (logTSH) were analyzed.At baseline, the HY patients had significantly higher serum IGF-1 levels than EU patients (median [Q1, Q3]: 305.4 [257.4, 368.1] vs. 236.7 [184.6, 318.8] ng/mL, P = .007). At 6 months, the HY patients still had higher serum levels of IGF-1 than EU patients (299.5 [249.9, 397.9] vs 222.1 [190.2, 305.4] ng/mL, P = .003). At baseline, the serum levels of IGF-1 in the HY and EU patients were positively associated with fT4 (β = 29.02, P = .002) and negatively associated with TSH (β = -31.46, P = .042) and logTSH (β = -29.04, P = .007). The associations between serum levels of IGF-1 with fT4 or TSH became insignificant at 6 months. However, the serum IGF-1 levels had persistent negative associations with logTSH at 6 months (β = -26.65, P = .021). The negative associations between IGF-1 and logTSH at baseline and 6 months remained significant even after adjustment with sex and age (β = -20.22, P = .023 and β = -20.51, P = .024, respectively).The HY patients had higher serum IGF-1 levels than EU patients. The serum IGF-1 concentrations were negatively associated with logTSH in patients with hyperthyroidism or euthyroidism.

Down-regulated resistin level in consequence of decreased neutrophil counts in untreated Grave's disease

Resistin, belongs to cysteine-rich secretory protein, is mainly produced by circulating leukocytes, such as neutrophils monocytes and macrophages in humans. To date, few but controversial studies have reported about resistin concentrations in hyperthyroid patients, especially in Graves' disease (GD). We undertaked a controlled, prospective study to explore the serum resistin concentration in GD patients before and after -MMI treatment. In addition, we also investigated the main influencing factor on serum resistin level and discuessed the potential role of serum resistin plays in GD patients. 39 untreated GD (uGD) patients, including 8 males and 31 females, were enrolled in our investigation. All of these patients were prescribed with MMI treatment, in addition to 25 healthy controls. Anthropometric parameters and hormone assessment were measured. Enzyme-linked immunosorbent assay was used to detect serum resistin concentration in different stages of GD patients. Furthermore, neutrophil cell line NB4 with or without T3 treatment to detect the effect of thyroid hormones on resistin expression. The serum resistin level and neutrophil counts in untreated GD patients were significantly declined. And all of these parameters were recovered to normal after MMI treatment in ethyroid GD (eGD) and TRAb-negative conversion (nGD) patients. Resistin concentration exhibited a negative correlation with FT3 and FT4, but a positive correlation with absolute number of neutrophiles in uGD patients, whereas did not correlate with thyroid autoimmune antibodies and BMI. Neutrophile cell line, NB4, produced decreased expression of resistin when stimulated with T3. Our study showed a decrease of serum resistin level in GD patients and we suggested that the serum resistin might primarily secreted from circulating neutrophils and down-regulated by excessive thyroid hormones in GD patients.

Changes in profile of lipids and adipokines in patients with newly diagnosed hypothyroidism and hyperthyroidism

Changes in profile of lipids and adipokines have been reported in patients with thyroid dysfunction. But the evidence is controversial. The present study aimed to explore the relationships between thyroid function and the profile of lipids and adipokines. A cross-sectional study was conducted in 197 newly diagnosed hypothyroid patients, 230 newly diagnosed hyperthyroid patients and 355 control subjects. Hypothyroid patients presented with significantly higher serum levels of total cholesterol, triglycerides, low-density lipoprotein cholesterol (LDLC), fasting insulin, resistin and leptin than control (p < 0.05). Hyperthyroid patients presented with significantly lower serum levels of high-density lipoprotein cholesterol, LDLC and leptin, as well as higher levels of fasting insulin, resistin, adiponectin and homeostasis model insulin resistance index (HOMA-IR) than control (p < 0.05). Nonlinear regression and multivariable linear regression models all showed significant associations of resistin or adiponectin with free thyroxine and association of leptin with thyroid-stimulating hormone (p < 0.001). Furthermore, significant correlation between resistin and HOMA-IR was observed in the patients (p < 0.001). Thus, thyroid dysfunction affects the profile of lipids and adipokines. Resistin may serve as a link between thyroid dysfunction and insulin resistance.

Thyroid function alters during neoadjuvant chemotherapy in breast cancer patients: results from the NEOZOTAC trial (BOOG 2010-01)

This side study investigated the effect of chemotherapy on thyroid function and the extent to which it can predict pathological complete response (pCR) in patients with early breast cancer taking part in NEOZOTAC phase III trial, randomizing between neoadjuvant chemotherapy with or without additional zoledronic acid. Moreover, we examined the impact of thyroid function on toxicity. Serum samples of 38 patients were available for analyses. Free thyroxin (fT4) and thyroid stimulating hormone (TSH) levels were compared between baseline and before the 6th cycle and between subjects with and without pCR. The relation between toxicity and the variation in fT4 and TSH levels during chemotherapy was tested. Samples at baseline and before the 6th cycle were available for 31 and 21 patients, respectively. The mean baseline fT4 level was 16.0 pmol/L and TSH level 1.11 mU/L, and these did not differ between both arms at each time point. During six cycles of chemotherapy, fT4 levels decreased (p = 0.0001), and TSH levels increased significantly (p = 0.019). Interestingly, the decrease of fT4 was significantly greater in patients without nausea, vomiting, or neuropathy, than in patients with those side effects (p = 0.037, p = 0.043, and p = 0.050, respectively). Baseline TSH levels tended to be higher in patients with pCR (p = 0.035 univariate analysis and p = 0.074 multivariate analysis). Chemotherapy blunts thyroid function, which was associated with less side effects. These data urge further evaluation of the effects of thyroid function on toxicity and outcome of breast cancer therapy.