Serum Phosphorus and Calcium as Biomarkers of Disease Status in Acromegaly.

Acromegaly is a chronic disease caused by the hypersecretion of growth hormone (GH), leading to changes in the growth of visceral tissues and glucose impairment. Serum biomarkers that correlate with disease status are still unclear. This study aims to assess the potential of phosphorus and calcium as biomarkers in the clinical evaluation of patients with acromegaly and clarify their relationship with SAGIT and other common biomarkers. We retrospectively analyzed data from 306 medical records of patients with acromegaly hospitalized between 2015 and 2020. Factors such as patient biometrics, duration of disease, SAGIT score, tumor size, GH, insulin-like growth factor 1 (IGF-1), calcium, phosphorus, parathormone, and vitamin D were analyzed concerning current disease status (naïve, non-remission, remission). The results showed that serum phosphorus significantly correlated with IGF-1 and SAGIT scores for patients with active acromegaly. Specifically, the best predictor for the remission of acromegaly was a phosphorus level < 3.98 mg/dL and serum calcium levels < 9.88 mg/dL. Based on logistic regression, the higher the serum phosphorus level, the lower the odds of achieving remission (an increase in one unit leads to a decrease in the chance of about 80%). In conclusion, phosphorus and calcium can be effective biochemical markers for predicting disease status in acromegaly.

The potential utility of the SAGIT instrument in the clinical assessment of patients with acromegaly, a large single-centre study.

SAGIT is an instrument created for the clinical assessment of acromegaly. Our objective was to test the usefulness of this tool in assessing disease activity of acromegalic patients in a single centre of Poznan, Poland using a retrospective study. Medical records of patients with acromegaly hospitalised at the Department of Endocrinology, Metabolism and Internal Medicine of Poznan University of Medical Sciences in Poland between January 2015 and December 2020 were analysed. SAGIT scores were assessed according to each patient's clinical and biochemical data. The results show that SAGIT scores were higher in treatment-naïve patients and the lowest in controlled patients. There were positive correlations between SAGIT scores and concentrations of calcium, phosphorus, HbA1C levels, and tumour invasiveness at the time of diagnosis. However, parameters such as age, vitamin D concentration, and time from diagnosis showed an inverse relationship with the SAGIT score. In ROC curve analysis, SAGIT scores of 5 or less discriminated controlled patients from uncontrolled (p < 0.0001, sensitivity 76.7%, specificity 78.5%, AUC 0.867). Also, SAGIT higher than 6 indicated for treatment start or escalation (p < 0.0001, sensitivity 80.88%, specificity 77.59%, AUC 0.866). Lack of signs and symptoms (S = 0) could not discriminate between controlled and uncontrolled disease, but predicted therapy maintenance (p < 0.0004, sensitivity 59.5%, specificity 58.2%, AUC 0.604). In conclusion, The SAGIT instrument is easy to use even when completed in the retrospective medical record review. It can be useful for distinguishing clinical stages of acromegaly and in decision-making.