Prevalence and Clinical Significance of Low T3 Syndrome in Non-Dialysis Patients with Chronic Kidney Disease

Abstract

BackgroundThere are few data on the prevalence of low T3 (triiodothyronine) syndrome in patients with non-dialysis chronic kidney disease (CKD) and it is unclear whether low T3 can be used to predict the progression of CKD.Material/MethodsWe retrospectively studied 279 patients who had been definitively diagnosed with CKD, without needing maintenance dialysis. Thyroid function was analyzed in all enrolled subjects and the incidence of thyroid dysfunction (low T3 syndrome, low T4 syndrome, and subclinical hypothyroidism) in patients at different stages of CKD was determined.ResultsGlomerular filtration rate (GFR) of CKD patients was estimated as follows: 145 subjects (52%) had GFR <60 ml/min per 1.73 m2; 47 subjects (16.8%) had GFR between 30 and 59 ml/min per 1.73 m2, and 98 subjects (35.1%) had GFR <30 ml/min per 1.73 m2. Among all enrolled subjects, 4.7% (n=13) had subclinical hypothyroidism, 5.4% (n=15) had low T4 syndrome, and 47% (n=131) had low T3 syndrome. In 114 CKD patients in stages 3–5, serum T3 was positively related to protein metabolism (STP, PA, and ALB) and anemia indicators (Hb and RBC), and negatively related to inflammatory status (CRP and IL-6).ConclusionsA high prevalence of low T3 syndrome was observed in CKD patients without dialysis, even in early stages (1 and 2). The increasing prevalence of low T3 as CKD progresses indicates its value as a predictor of worsening CKD. Furthermore, low T3 syndrome is closely associated with both malnutrition-inflammation complex syndrome (MICS) and anemia.

Low T3 syndrome is a strong prognostic predictor in diffuse large B cell lymphoma

“…In previous epidemiological studies, the evidence indicated that low T3 syndrome was an independent prognostic factor in CKD (Fan et al , ), acute cerebrovascular disorders (Bunevicius et al , ), community acquired pneumonia (Liu et al , ), chronic heart failure (Chen et al , ) and haemodialysis patients (Fragidis et al , ). In consensus with our results, Fan et al () reported that serum T3 was positively related to protein metabolism (albumin) and anaemia indicators (Hb), and negatively related to inflammatory status (CRP). This could give new insight that the possible connection between low T3 syndrome and worse prognosis is via anaemia, inflammation and malnutrition.…”

“…In the last decade, substantial evidences have described the presence of low T3 syndrome in acute and prolonged critical illness, such as acute cerebrovascular disorders, septic shock, multiple trauma, severe burn, community‐acquired pneumonia, CKD, chronic liver failure and heart failure. The prevalence of low T3 syndrome was reported to be 47·0% in CKD (Fan et al , ), 56·6% in acute stroke (Alevizaki et al , ), 30·2% in cardiac disease (Iervasi et al , ), 30·7% in chronic haemodialysis (Fragidis et al , ) and 31·8% in community‐acquired pneumonia patients (Liu et al , ). Regarding malignancies, Yasar et al () found a low T3 syndrome incidence of 42·25% in non‐small cell lung cancer and 44·90% in small cell lung cancer, and the morbidity of low T3 syndrome was 16·50% in breast cancer (Huang et al , ).…”

“…Although low T3 syndrome can be seen as an adaptive mechanism to counteract excessive catabolism and support immune response during acute phase, it might exert disadvantages as critical illness enters a chronic phase, necessitating prolonged life support as confirmed in preclinical and clinical studies (Van den Berghe, ; Weekers et al , ). Several observational studies indicated that low T3 syndrome was an independent prognostic factor for seriously ill hospitalized patients, including those who had septic shock, multiple trauma, severe burn, acute cerebrovascular disorders, community‐acquired pneumonia, chronic kidney disease (CKD), chronic liver failure and heart failure (Gangemi et al , ; Du et al , ; Agiasotelli et al , ; Bunevicius et al , ; Chen et al , ; Fan et al , ; Liu et al , ). With regard to cancer risk and cancer mortality, an evident association was identified between low T3 syndrome and metastasized cancer in a hospitalized older population ( P = 0·0002) (Tognini et al , ).…”

Low T3 syndrome as a predictor of poor prognosis in chronic lymphocytic leukemia

“…In consensus with our findings on a panel of laboratorial data, Fan et al . described that serum T3 was positively correlated with anemia (Hb) and protein‐energy nutrition (serum albumin), and negatively related to inflammation (CRP), suggesting associations among low T3 syndrome, malnutrition–inflammation complex syndrome and anemia.…”

“…Although low T3 syndrome lowers tissue energy requirement and counteracts excessive catabolism as a physiologic adaptive response, it may aggravate clinical problems distinctively associated with prolonged critical illness, such as diminished cognitive status, ileus and cholestasis, glucose intolerance and insulin resistance, anemia and deficient clearance of triglyceride . Accumulating evidence has indicated that low T3 syndrome was associated with inferior clinical outcome in patients with sepsis, multiple trauma, myocardial infarction and heart failure, cerebrovascular diseases, liver cirrhosis, chronic kidney disease and respiratory failure . With regard to malignancies, Bunevicius et al .…”