#742 High TSH and low FT3 levels are associated with chronic kidney disease in three population-based studies from Germany

Abstract

Abstract Background and Aims High serum thyroid-stimulating hormone (TSH) levels have previously been associated with a low estimated glomerular filtration rate (eGFR), but studies associating thyroid hormone levels with albuminuria revealed inconsistent results. The aim of our study was to investigate associations of serum levels of TSH, fT3 and fT4 with eGFR and albuminuria in population-based cohorts. Method We used cross-sectional data from 7,933 individuals aged 20 to 93 years of the Berlin Aging Study II (BASE II) and the Study of Health in Pomerania (SHIP-START; SHIP-TREND) to associate serum TSH, fT3, and fT4 levels with eGFR and albuminuria. To calculate eGFR, CKD-EPI and FAS equations were used. Albuminuria was defined as an urinary albumin-to-creatinine ratio (UACR) ≥ 30 mg/g. Results In multivariable analyses adjusted for confounding, we found inverse non-linear associations of serum TSH levels with eGFR, while serum fT3 levels showed a positive association with eGFR. High as well as low serum fT4 levels were associated with a lower eGFR. Age but not sex modified the association between thyroid hormone levels and eGFR. The inverse associations between serum TSH levels with eGFR were strongest in the youngest age groups, while the positive associations between serum fT3 levels and eGFR were strongest in older individuals. No significant associations between thyroid hormone levels and albuminuria were found. Conclusion In conclusion, we showed that high TSH, low fT3 as well as low and high fT4 levels were independently associated with a reduced kidney function in a non-linear fashion. Our results indicate that high TSH / hypothyroidism might be associated with a reduced kidney function. Thyroid function might be more tightly related to the eGFR than to albuminuria in the general population.