Euthyroid sick syndrome in hip fractures: Valuation of vitamin D and parathyroid hormone axis

Femur fracture is an acute event with a high incidence and mortality worldwide. Euthyroid sick syndrome (ESS) is a disease characterized by an alteration of fT3 in the absence of a primary thyroid pathology. The aim of the study is evaluating the association between femur fracture and ESS and post-operative fluctuations of the parathyroid hormone (PTH) and vitamin D and their physio-pathological implications.

All patients older than 65 years, admitted in our emergency care unit with a diagnosis of proximal femur fracture were recruited. Exclusion criteria were acute cardio-pulmonary events, neoplastic diseases, any thyroid or endocrine pathology and use of drugs with thyroidal interactions. All patients underwent surgery within 48 h from the injury. The outcome of the study is the presence of ESS, moreover, post-operative fluctuations of the PTH and vitamin D are also evaluated.

45 patients (13 men and 32 females) were enrolled. 20 patients had a normal thyroidal function, while 23 had a diagnosis of ESS. Mean age was 81.9. BMI was lower in the ESS group than the controls (25,3 vs 22,7; p < 0.02). In the ESS group a significantly higher decrease in Vitamin D levels was observed, compared to controls (3.96 ng/ml, p<0.001). Values of PTH were significantly different between the two groups, with a level 44.29 pg/ml lower among the ESS group compared to controls (p = 0.002). In the ESS group a significant decrease of serum calcium on the first post-surgery day was observed, compared to controls (8,7 vs 8,3; p < 0,01). There were no differences in the CCI, serum electrolytes and other variables collected between the two groups.

Part of the geriatric population suffering from fractures of the proximal femur are affected by ESS. This population displays anomalies of the Vitamin d-PTH axis and a lower BMI.