Association of Triiodothyronine Levels with Left Ventricular Function, Cardiovascular Events, and Mortality in Hemodialysis Patients

A prognostic role for non-thyroidal illness syndrome in chronic renal failure:a systematic review and meta-analysis

BACKGROUND

Chronic renal failure (CRF) is a serious disease that has become a burden on global and local economics and public health. In addition, non-thyroidal illness syndrome (NTIS) has become increasingly more prevalent in CRF patients.

MATERIALS AND METHODS

A data search was conducted on the PubMed/Medline, Cochrane Library, Web of Science, Embase, and CBM databases to identify studies up to November 1st, 2018, that compared low T3 and normal T3 levels in patients with CRF. Data analysis was done by calculating the relative risks (RR) and 95% confidence intervals (95% CI) and continuous variables were described by weighted mean difference (WMD) and 95% CI. The efficacy outcomes included renal function and mortality. The Newcastle-Ottawa Scale and Agency for Healthcare Research and Quality scale were used to assess the quality of the cohort and cross-sectional studies, respectively. A funnel plot was used to identify publication bias.

RESULTS

Seventeen studies with a total of 4593 patients were finally included in the analysis. Among the 17 studies, 11 reported the mortality of CRF patients with low T3 and normal T3 levels. Subgroups were assigned according to different follow-up times and different methods of treatment. The mortality rate in the low T3 group was much higher than in the normal T3 group. 11 studies reported creatinine (Cr) results in patients with low T3 and normal T3 levels and our analysis found no significant differences between the two groups (95%CI: 0.46-0.25; P-heterogeneity = 0.000; P = 0.559). Five studies reported uric acid results and we found no significant differences between the two groups (95%CI: 0.08-0.22; P-heterogeneity = 0.438; P = 0.377). Five studies reported the urea levels in the two groups and our analysis found no significant differences (95%CI: 1.60-1.23; I² = 0.0%; P-heterogeneity = 0.498;P = 0.798).

CONCLUSION

Low T3 had a greater impact on the short-term prognosis of patients with CRF than on the long-term prognosis. NTIS did not cause substantial kidney damage.

Physical performance across the thyroid function values within the normal range in adult and older persons

BACKGROUND

Thyroid hormone variation may be correlated with adverse health outcomes, even within the normal reference range in euthyroid individuals.

AIMS

To determine the association between plasma thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) levels and physical performance score in middle age and older adults who had levels of all three hormones in the normal range.

METHODS

In this community-based, cross-sectional study, euthyroid participants of the Invecchiare in Chianti study, aged 23-102 years (N = 1060), were considered. Physical performance was evaluated by the Summary Physical Performance Battery (SPPB) score. Plasma TSH, FT3, and FT4 levels were predictors, and SPPB score was the outcome.

RESULTS

At the univariate analyses, TSH, FT4, and FT3 were not significantly associated with SPPB score in young individuals, whereas, in older participants, SBBP score was positively (P < 0.001) associated with FT3, and negatively associated with both TSH (P < 0.02) and FT4 (P < 0.001). After adjusting for multiple confounders, FT3 remained significantly associated with SPPB (beta ± SE, 0.35 ± 0.17, P = 0.04), but FT4 and TSH were not. Results did not change when all the three hormones FT3, FT4, and TSH were simultaneously considered in the fully adjusted model (beta ± SE for FT3, 0.37 ± 0.18, P = 0.04).

DISCUSSION

The results of this study demonstrate that SPPB score is positively associated with circulating FT3 but not with FT4 or with TSH, in older euthyroid individuals.

CONCLUSIONS

In euthyroid older adults, circulating FT3 may play an important role in the thyroid effects on physical function.