Estimated glomerular filtration rate by serum cystatin C correlates with cardiometabolic parameters in patients with primary hyperparathyroidism

Abstract

Objective: Patients with primary hyperparathyroidism (PHPT) are at risk of chronic kidney disease (CKD). Cystatin C (Cys-C) is considered a more reliable tool to assess glomerular filtration rate (GFR) than creatinine. The study aimed to assess circulating Cys-C and its relationships with biochemical PHPT and cardiometabolic parameters. Design and methods: The present cross-sectional study was performed in academic endocrine units on PHPT patients (nZ190) and non-hypertensive, non-diabetic, age-and sex-matched healthy controls (nZ135) with no established CKD. The main outcomes were creatinine by alkaline picrate method, Cys-C by immunonephelometry and calculation of estimated GFR based on creatinine and Cys-C (eGFRcr-cys) using the CKD-EPI equation. Results: In PHPT patients, circulating Cys-C ranged 0.45-3.13 mg/l and correlated with creatinine, age and BMI. Mean Cys-C level was higher in PHPT patients than in controls (0.93G0.02 vs 0.78G0.14 mg/l; PZ0.03). Cys-C levels in PHPT patients were predicted by age, BMI, ionized calcium, hypertension and HDL-cholesterol, the most significant determinant being ionized calcium. Cys-C positively correlated with cardiovascular disease (CVD) occurrence. Overall, 18.4% of PHPT patients with eGFRcr O60 ml/min per 1.73 m 2 (nZ169) had Cys-C levels higher than the 95th percentile in controls (1.03 mg/l), consistent with a preclinical CKD, which was associated with hypertension and insulin resistance. Considering eGFRcr-cys, CKD (stages G3a, G3b, 4) was diagnosed in 13.7% of PHPT patients. Estimated GFRcr-cys, but not eGFR based on creatinine, was predicted by insulin resistance and hypertension and positively correlated with CVD. Conclusions: Elevated Cys-C levels were associated with ionized calcium, cardiometabolic risk factors and CVD, and identified preclinical CKD in PHPT patients.

Perioperative changes of FGF23 in patients undergoing surgery for primary hyperparathyroidism

“…This results indicate the higher sensitivity of cystatin C compared to creatinine in detecting renal function in patients with pHPT. Similar results were also shown by Ermetici et al ( 31 ).…”

Physical Activity-Dependent Regulation of Parathyroid Hormone and Calcium-Phosphorous Metabolism

“…Nephrolithiasis, which is more common in males [ 127 ], is an indication for PTX [ 106 , 128 , 129 ]. Chronic kidney disease (CKD), a long-term complication of PHPT with a prevalence of 16–17% [ 130 ], is the expression of a severe phenotype and carries an increased risk of morbidity and mortality [ 102 ] due to its association with hypertension, decreased BMD, and worse diabetic status [ 131 ]. PTH levels are associated with the degree of renal impairment in PHPT [ 132 ], and PTX prevents further kidney impairment [ 133 ].…”

MECHANISMS IN ENDOCRINOLOGY: Kidney involvement in patients with primary hyperparathyroidism: an update on clinical and molecular aspects

“…Prolonged hypercalcaemia was considered to impair kidney function, and a reduced glomerular filtration rate was common in advanced severe PHPT (27,28). Supporting the connection between PHPT and renal impairment, in the PEARS cohort of 1424 asymptomatic PHPT patients and 7120 controls, serum creatinine at diagnosis is predictive of mortality at a 3-year term, the (42,43). Evaluation of kidney function in PHPT patients by measurement of cystatin C, a low-molecularweight protein secreted by nearly all cells, freely filtered at renal glomerular level and then metabolized by the proximal tubule, which is considered a more reliable tool to assess GFR than serum creatinine, showed that the most evident determinant of circulating cystatin C …”