Free Triiodothyronine Levels Are Associated with Diabetic Nephropathy in Euthyroid Patients with Type 2 Diabetes

Abstract

Objective. To investigate the association of thyroid function and diabetic nephropathy (DN) in euthyroid patients with type 2 diabetes. Methods. A total of 421 patients were included in this cross-sectional study. The following parameters were assessed: anthropometric measurements, fast plasma glucose, serum creatinine, lipid profile, HbA1c, free triiodothyronine (FT3), free thyroxine, thyroid-stimulating hormone levels, and urinary albumin-to-creatinine ratio (UACR). Patients with UACR of ≥30 mg/g were defined as those suffering from DN. Results. Of the 421 patients, 203 (48.2%) suffered from DN, and no difference was found between males and females. The patients with DN yielded significantly lower FT3 levels than those without DN (P < 0.01). The prevalence of DN showed a significantly decreasing trend across the three tertiles based on FT3 levels (59.6%, 46.4%, and 38.6%, P < 0.01). After adjustment for gender and age, FT3 levels were found to correlate positively with estimated glomerular filtration rate (P = 0.03) and negatively with UACR (P < 0.01). Multiple linear regression analysis showed that FT3 level was independently associated with UACR (β = −0.18, t = −3.70, and P < 0.01). Conclusion. Serum FT3 levels are inversely associated with DN in euthyroid patients with type 2 diabetes, independent of traditional risk factors.

Thyroid Parameters and Kidney Disorder in Type 2 Diabetes: Results from the METAL Study

“…reported about the association of TSH and kidney status in euthyroid DM subjects [14,36,37]. The HUNT study reported that TSH within the reference range was negatively associated with eGFR [14] in type 2 diabetes, while others [7,38] reached a different conclusion.…”

Association between Normal Thyroid Hormones and Diabetic Retinopathy in Patients with Type 2 Diabetes

“…Furthermore, there is a distinct lack of relevant research on the relationship between microvascular complications in T2DM and normal thyroid hormones. Qi et al [7] demonstrated no association between high thyroid stimulating hormone (TSH) levels and an increased risk of DR. To date, only one study conducted by Wu et al [8] attempted to elucidate these issues; the results showed that high normal levels of FT3 were negatively correlated with the incidence of diabetic kidney disease (DKD), but FT3 levels were not associated with DR in T2DM patients with normal thyroid function. We have previously deeply studied the relationship between normal thyroid function and DKD.…”

Thyroid hormones and diabetic nephropathy: An essential relationship to recognize

“…6,7 Previous studies had demonstrated the interaction between thyroid hormones and kidney function, and free triiodothyronine (FT3) was also associated with renal dysfunction. 8,9 Additionally, Aziz 10 suggested that thyroxine replacement therapy was essential for controlling microalbuminuria, spot urine protein, and blood pressure in diabetic patients with CKD and hypothyroidism. One recent study in db/db mice of T2 DM noted that thyroid hormone could interfere with accumulation of collagenous components in cortical interstitium and glomerular mesangial matrix by impacting TGF-β1 expression and regulate renal structure.…”

“…The prevalence of sub‐clinical hypothyroidism (SCH) in patients with type 2 diabetes mellitus (T2DM) is 10.2%, while the incidence of hypothyroidism is also higher in T2DM than in non‐diabetic controls . Previous studies had demonstrated the interaction between thyroid hormones and kidney function, and free triiodothyronine (FT3) was also associated with renal dysfunction . Additionally, Aziz suggested that thyroxine replacement therapy was essential for controlling microalbuminuria, spot urine protein, and blood pressure in diabetic patients with CKD and hypothyroidism.…”