Thyroid hormone abnormalities and frailty in elderly patients with chronic kidney disease: a hypothesis

Nocturnal haemodialysis is associated with a reduced occurrence of low triiodothyronine serum levels in haemodialysed patients

Background

End-stage renal disease (ESRD) is associated with a broad spectrum of morphological and functional thyroid disorders. Recent studies have shown that low free triiodothyronine (fT3) levels are related to inflammatory status and endothelial activation in ESRD patients on haemodialysis (HD). Limited data exist about a possible relationship between dialysis regimen, namely long nocturnal haemodialysis (LNHD), and thyroid function parameters. The aim of this study was to evaluate the relationship between dialysis regimen and thyroid function, and consequently with the main patient outcomes.

Methods

To this purpose, we performed a retrospective, single-centre cohort study including 220 incident chronic HD patients treated during an 8-year period (from January 2010 to December 2017). The main clinical and haematochemical parameters, including thyroid function, were evaluated and related to the main patient outcomes.

Results

Patients with low fT3 levels (<3.05 ng/mL) showed significantly lower survival rates than patients with normal fT3 levels (>3.05 ng/mL) (P < 0.001), although there were no substantial differences in the demographic and clinical characteristics between the two groups. After propensity score 1:3 matching of 25 patients treated with nocturnal HD to 75 patients treated with diurnal HD, LNHD patients showed significantly higher survival rates (88.0% versus 61.3%, P = 0.001) and lower incidence of cardiovascular events than patients on diurnal dialysis (8.0% versus 40.0%, P = 0.001). Moreover, an 8-year time-dependent analysis showed that at any time, except for baseline, the rate of patients with fT3 levels >3.05 ng/mL was significantly higher in LNHD patients than in patients treated with diurnal dialysis.

Conclusions

Our data suggest that the application of alternative dialysis regimens, also reducing the frequency of low T3, could ameliorate outcomes and therefore reduce the incidence of cardiovascular events in HD patients.

Low FT3: a possible marker of frailty in the elderly

Introduction

Frailty is associated with a functional decline of multiple physiological systems, of which they may be a cause or consequence. The objective of the study was to evaluate the prevalence of thyroid hormone modifications in elderly frail subjects and its relationship with frailty.

Study population and methods

An observational study was carried out at the University Hospital “Tor Vergata” in Rome among ambulatory and hospitalized patients. The study population consisted of 112 elderly subjects: 62 were hospitalized following hip fracture and 50 control subjects were outpatients. Participating patients received a multidimensional geriatric evaluation. The Survey of Health, Ageing and Retirement in Europe Frailty Instrument (SHARE-FI) was used to assess the degree of frailty. Thyroid stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) were measured to evaluate thyroid status.

Results

FT3, but not FT4, was significantly correlated with Frailty score, both in patients with hip fracture and in patients from the control group. In the entire study population, FT3 under normal limits is effective in discriminating frail/prefrail subjects from nonfrail subjects.

Discussion

The reduction in serum concentrations of FT3 is a clear manifestation of stress associated with fractures. Numerous preexisting factors, such as the fracture patients’ nutritional status, sarcopenia, disability and comorbidities, which characterize the condition of frailty and influence its pathogenesis, are strongly correlated with FT3 values, suggesting the existence of latent nonthyroidal illness syndrome (NTIS).

Conclusion

We conclude that measuring FT3 can be a useful laboratory parameter in clinical assessment, which can play an important role in identifying vulnerable elderly subjects and in quantifying the condition of frailty.

Thyroid Function Test Derangements and Mortality in Dialysis Patients: A Systematic Review and Meta-analysis

BACKGROUND

We evaluated current evidence associating thyroid function test result derangements with risk for mortality in patients with chronic kidney failure treated by long-term dialysis.

STUDY DESIGN

Systematic review and meta-analysis of cohort studies.

SETTING & POPULATION

Dialysis patients.

SELECTION CRITERIA FOR STUDIES

We searched PubMed, Web of Science, Science Citation Index, Cochrane Library, and Embase databases from inception through December 2015.

PREDICTORS

Hypothyroidism (thyrotropin level greater than reference range) and low triiodothyronine (T₃) and thyroxine (T₄) levels.

OUTCOMES

All-cause and cardiovascular mortality.

RESULTS

12 studies involving 14,766 participants (4,450 deaths) were identified. Of those, 6 studies provided data for cardiovascular mortality (2,772 participants with 327 cardiovascular deaths). Overall, confidence in the available evidence was moderate. Pooled adjusted HRs for all-cause mortality associated with hypothyroidism, low T₃ level, and low T₄ level were 1.24 (95% CI, 1.14-1.34), 1.67 (95% CI, 1.23-2.27), and 2.40 (95% CI, 1.47-3.93), respectively. Pooled adjusted HRs for cardiovascular mortality associated with low T₃ and T₄ levels were 1.84 (95% CI, 1.24-2.74) and 3.06 (95% CI, 1.29-7.24), respectively.

LIMITATIONS

Fewer studies reporting on T₄ and thyrotropin outcomes.

CONCLUSIONS

In patients treated with long-term dialysis, (cardiovascular) mortality is consistently higher in the presence of thyroid function test result derangements.

Abnormal Expression of DNA Double-Strand Breaks Related Genes, ATM and GammaH2AX, in Thyroid Carcinoma

ATM and γH2AX play a vital role in the detection of DNA double-strand breaks (DSB) and DNA damage response (DDR). This study aims to investigate ATM and γH2AX expression in thyroid cancer and discuss possible relationship between thyroid function tests and DNA damage. The expression of ATM and γH2AX was detected by immunohistochemistry in 30 cases of benign nodular goiter, 110 cases of well differentiated thyroid cancer, 22 cases of poorly differentiated thyroid cancer, and 21 cases of anaplastic thyroid cancer. Clinicopathological features, including differentiation stages, distant metastasis, lymph node metastasis, T classification, TNM stage, and tests of thyroid functions (TPOAb, Tg Ab, T3, FT3, T4, FT4, TSH, and Tg), were reviewed and their associations with γH2AX and ATM were analyzed. γH2AX and ATM expressed higher in thyroid cancer tissues than in benign nodular goiter and normal adjacent tissues. γH2AX was correlated with ATM in thyroid cancer. Both γH2AX and ATM expression were associated with FT3. γH2AX was also associated with T classification, TNM stage, FT4, TSH, and differentiation status. Therefore both of ATM and γH2AX seem to correlate with thyroid hormones and γH2AX plays a role in the differentiation status of thyroid cancer.

Standard laboratory tests to identify older adults at increased risk of death

BACKGROUND

Older adults are at an increased risk of death, but not all people of the same age have the same risk. Many methods identify frail people (that is, those at increased risk) but these often require time-consuming interactions with health care providers. We evaluated whether standard laboratory tests on their own, or added to a clinical frailty index (FI), could improve identification of older adults at increased risk of death.

METHODS

This is a secondary analysis of a prospective cohort study, where community dwelling and institutionalized participants in the Canadian Study of Health and Aging who also volunteered for blood collection (n = 1,013) were followed for up to six years. A standard FI (FI-CSHA) was constructed from data obtained during the clinical evaluation and a second, novel FI was constructed from laboratory data plus systolic and diastolic blood pressure measurements (FI-LAB). A combined FI included all items from each index. Predictive validity was tested using Cox proportional hazards analysis and discriminative ability by the area under receiver operating characteristic (ROC) curves.

RESULTS

Of 1,013 participants, 51.3% had died by six years. The mean baseline value of the FI-LAB was 0.27 (standard deviation 0.11; range 0.05 to 0.63), the FI-CSHA was 0.25 (0.11; 0.02 to 0.72), and the combined FI was 0.26 (0.09; 0.06 to 0.59). In an age- and sex-adjusted model, with each increment in the FI-LAB, the hazard ratios increased by 2.8% (95% confidence interval 1.02 to 1.04). The hazard ratios for the FI-CSHA and the combined FI were 1.02 (1.01 to 1.03) and 1.04 (1.03 to 1.05), respectively. The FI-LAB and FI-CSHA remained independently associated with death in the face of the other. The areas under the ROC curves were 0.72 for FI-LAB, 0.73 for FI-CSHA and 0.74 for the combined FI.

CONCLUSIONS

An FI based on routine laboratory data can identify older adults at increased risk of death. Additional evaluation of this approach in clinical settings is warranted.

Pretransplantation serum FT3 concentration in kidney recipients is useful to identify higher risk of graft failure

BACKGROUND

Free triiodothyronine (FT3) is a marker of comorbidity in end-stage renal disease and in many acute and chronic diseases. The objective of the present study was to investigate the effects of pretransplantation FT3 concentration on graft function.

MATERIALS AND METHODS

Between 2003 and 2008, the study enrolled 86 patients who underwent renal transplantation. Twenty-six patients were women, and 60 were men, with overall mean (SD) age of 38 (10) years. In all patients, serum FT3, free thyroxine, and thyroid-stimulating hormone concentrations were determined before transplantation. Demographic data and laboratory values were evaluated at 2 years posttransplantation.

RESULTS

The overall graft survival rate at 2 years was 82.1%. Pretransplantation serum FT3 concentration was inversely correlated with 2-year serum creatinine concentration (r=-0.29; P=.01) and proteinuria (r=-0.37; P<.00). Linear regression analysis demonstrated that serum FT3 (r2=0.63; 95% confidence interval, 0.52-0.74; P=.00) was a statistically significant risk factor for increased serum creatinine concentration. No correlation was observed for thyroid-stimulating hormone or free thyroxine and posttransplantation data.

CONCLUSION

Patients with end-stage renal disease with low pretransplantation serum FT3 concentration are at greater risk of subsequent graft failure. Measurement of pretransplantation serum FT3 concentration could be a clinically useful method of identifying patients at increased risk of graft failure.