Association Between Insulin-like Growth Factor-1 And Serum Calcium And Phosphorus Levels In Patients With Acromegaly

Objective:This study was aimed to investigate the association between serum insulin-like growth factor-1(IGF-1)levels and serum calcium and phosphorus and other bone metabolic indexes in patients with acromegaly,so as to improve the understanding and prevention of bone metabolic disorders in acromegaly.Methods:49 patients with acromegaly who were hospitalized in the Affiliated Hospital of Jining Medical College from January 1,2015 to June 30,2022 were selected in this study.The research collected general data of patients,anthropometric indicators and laboratory indicators.General data included sex,age,past medical history,etc.Anthropometric indicators included height,weight,diastolic blood pressure(DBP),systolic blood pressure(SBP),and calculated body mass index(BMI).Laboratory tests included serum calcium and phosphorus,serum IGF-1,growth hormone(GH),fasting plasma glucose(FPG),liver function,renal function,parathyroid hormone(PTH),blood lipids(LDL-C,HDL-C,TG,TC),estradiol,testosterone,25-hydroxy vitamin D(25-OH-Vit D),etc,and calculated IGF-1 standard deviation score(IGF-1SDS),corrected serum calcium and corrected calcium-phosphorus product.Baseline data of research subjects were described,furthermore,the correlation between IGF-1 SDS and serum calcium,serum phosphorus,calcium-phosphorus product,corrected blood calcium,corrected calcium-phosphorus product and other indexes was analyzed by statistical methods such as single factor analysis,smooth curve fitting and multivariate linear regression.Results:1.Univariate analysis of IGF-1 SDS and clinical indexes in patients with acromegaly:There was a positive correlation between IGF-1 SDS and serum calcium(β0.02,95%CI 0.01,0.03,P=0.006),corrected serum calcium(β0.02,95%CI 0.00,0.05,P=0.036),serum phosphorus(β0.02,95%CI 0.00,0.04,P=0.044),calcium-phosphorus product(β0.92,95%CI0.26,1.57,P=0.009)and corrected calcium-phosphorus product(β1.00,95%CI 0.38,1.61,P=0.002).2.Smooth curve fitting and multivariate linear regression analys is of IGF-1SDS and serum calcium,corrected serum calcium,serum phosphorus,calcium-phosphorus product and corrected calcium-phos phorus product:(1)After adjusting the confounding factors,there was a linear positive correlation between IGF-1 SDS and corrected serum calcium,that is,when IGF-1 SDS increases by one unit,corrected serum calcium increased by 0.02mmol/L(β0.02,95%CI 0.01,0.03,P=0.004);furthermore,there was a nonlinear relationship between IGF-1 SDS and serum calcium.When IGF-1 SDS<11.63,with the increase of IGF-1 SDS,the serum calcium level showed an increasing trend,but there was no statistically significant(β0.01,95%CI 0.00,0.03,P=0.054);when IGF-1 SDS≥11.63,there was a positive correlation between IGF-1 SDS and serum calcium,that is,when IGF-1 SDS increases by one unit,serum calcium increases by 0.16mmol/L(β0.16,95%CI 0.02,0.30,P=0.028).(2)After adjusting the confounding factors,there was a linear positive correlation between IGF-1 SDS and serum phosphorus,that is,when IGF-1SDS increases by one unit,serum phosphorus increased by0.02mmol/L(β0.02,95%CI 0.00,0.04,P=0.044).(3)After adjusting the confounding factors,IGF-1 SDS were still are positively correlated with calcium-phosphorus product,that is,when IGF-1 SDS increases by one unit,the calcium-phosphorus product was increases 0.92(mg/d L)~2(β0.92,95%CI 0.30,1.54,P=0.006);at the same time,there was a linear positive correlation between IGF-1 SDS and corrected calcium-phosphorus product,that is,when IGF-1 SDS increases by one unit,the corrected calcium-phosphorus product was increases 1.00(mg/d L)~2(β1.00,95%CI 0.38,1.61,P=0.003).Conclusions:It was found that IGF-1 SDS was significantly correlated with serum calcium,serum phosphorus,calcium-phosphorus product and other biochemical indices of bone metabolism in patients with acromegaly.IGF-1 SDS has a linear relationship with serum phosphoru,calcium-phosphorus product,corrected serum calcium and corrected calcium-phosphorus product.These results may be helpful for clinicians to monitor IGF-1 levels to assess calcium and phosphorus metabolism in patients with acromegaly at an early stage,focusing on the changes in IGF-1 levels in patients with acromegaly,and improving clinical workers’understanding of bone metabolism disorders in acromegaly and their prevention and treatment ability.