A Study On The Effect Of Calcitonin Level On Bone-related Complications In Secondary Hyperparathyroidism

Objective:To explore the correlation between preoperative calcitonin level and bone-related complications including vascular calcification and renal bone disease in patients with secondary hyperparathyroidism.In order to provide a theoretical basis for better understanding and management of calcitonin,and to find new diagnostic and therapeutic targets for bone-related complications of secondary hyperparathyroidism.Methods:85 secondary hyperparathyroidism(SHPT)patients who underwent surgery and calcitonin(Ctn)monitoring in our center were retrospectively analyzed from February 2017 to February 2022.The medical history and basic clinical information of 85 SHPT patients were collected,including gender,age,dialysis age,serum creatinine(SCr),whether accompanied by chronic lymphocytic thyroiditis,whether accompanied by vascular calcification(VC),body mass index(BMI),serum calcium,serum phosphorus,parathyroid hormone(PTH),Ctn,alkaline phosphatase(ALP)and other relevant clinical data.The influence of Ctn on VC in SHPT was analyzed through independent sample T test,Mann-Whitney U,Chi-square test and logistic regression analysis.85 SHPT patients were divided into two subgroups according to whether preoperative Ctn level was elevated or not,and the correlation between Ctn level and bone mineral density and bone conversion markers was further analyzed.Results:Among the 85 hemodialysis-dependent SHPT patients in this study,there were 56 males(65.9%)and 29 females(34.1%),with a male to female ratio of 1.93:1;32 cases had elevated Ctn levels(37.6%).1.Correlation between preoperative Ctn level and vascular calcification in SHPTCalcification of the cardiovascular system occurred in 17 of 85 SHPT patients(20%).Univariate analysis showed that vascular calcification was not associated with gender(P=0.208),age(P=0.509),eGFR(P=0.156),serum calcium(P=0.487),serum phosphorus(P=0.304),cholesterol(P=0.123),high density lipoprotein-cholesterol(P=0.549),low density lipoprotein-cholesterol(P=0.263),hypertension(P=0.130),Ctn(P=0.085)and triglyceride(TG)(P=0.051).It is related to BMI(P=0.006)and PTH(P=0.037).BMI and PTH were included in the logistic regression model withP<0.05,but Ctn was not included.According to literature,Ctn may be a non-traditional influencing factor of VC,so we tried to adjust the inclusion criteria as P<0.10.Ctn,TG,PTH,and BMI were further included in the logistic regression analysis.Preoperative PTH(P=0.016)and Ctn(P=0.026)were independent influencing factors of vascular calcification in SHPT.The higher the PTH,the higher the risk of VC(OR=1.001,95%CI:1.000～1.002).The higher the Ctn,the lower the risk of VC(OR=0.904,95%CI:0.828～0.988).2.Influencing factors of preoperative Ctn level32 patients(37.6%)had elevated preoperative Ctn levels,and the male to female ratio was 9.7:1(29:3).Univariate analysis showed that Ctn level was related to gender(P<0.001),BMI(P=0.039),serum phosphorus(P=0.007)and PTH(P=0.046),but was not related to age,dialysis age,serum calcium,eGFR,bone density,β receptor blocker,and chronic lymphocytic thyroiditis,white blood cell,percentage of neutrophils(P>0.05).Multivariate analysis showed that gender(P=0.015)was the independent factor affecting the preoperative Ctn level in SHPT.In SHPT patients,the probability of preoperative Ctn increase was 5.576 times in males compared with females(OR=5.576,95%CI:1.398～22.235).3.Correlation between preoperative Ctn and renal bone diseaseIn the normal Ctn level group,the preoperative Ctn level was negatively correlated with ALP(correlation coefficient=-0.286,P=0.038),but such trend was not found in the Ctn level elevated group.The ratio of PTH to Ctn(PTH/Ctn)was positively correlated with ALP,and this trend was more obvious in the normal Ctn group(correlation coefficient=0.537,P<0.001).There is no correlation between Ctn level and bone mineral density(P>0.05).Conclusion:1.Ctn is an inhibitory factor of VC in SHPT.Patients with elevated preoperative Ctn levels are less likely to develop VC in SHPT.2.Relative inadequacy of Ctn may exacerbate bone metabolic transformation in SHPT.3.The reason for the preoperative increase of Ctn level in SHPT is not clear.Male patients are more likely to have elevated Ctn levels.Mild elevations in Ctn levels do not indicate MTC.