Secondary hyperparathyroidism is associated with pulmonary hypertension in older patients with chronic kidney disease and proteinuria.

PURPOSE: Hyperparathyroidism is associated with pulmonary vascular calcification and pulmonary hypertension (PH) in a chronic kidney failure dog model, and increased prevalence of PH and a PH-hyperparathyroidism relationship in pre-dialysis chronic kidney disease (CKD) and hemodialysis patients are reported. This study investigated the prevalence of PH and relationships between PH and metabolic abnormalities in patients with stage 1-4 proteinuria CKD.

METHODS

One-hundred and ninety patients (mean age 61 ± 17.4, 116 males) with proteinuria CKD and no coronary diseases, congestive heart failure, smoking history, and pulmonary diseases were enrolled. Estimated glomerular filtration rate was 39.7 ± 23 ml/min. CKD etiology was diabetes mellitus in 52 (27.3 %), chronic glomerulonephritis or tubulointerstitial nephritis in 56 (29.4 %), hypertension in 36 (19 %), and other etiologies (nephrolithiasis, obstructive nephropathy, and amyloidosis) in 46 (25.3 %) patients. Echocardiography was performed, and systolic pulmonary artery pressure (PAP) and left ventricular ejection fraction were determined. Laboratory tests examined lipid parameters, serum albumin, urea, creatinine, calcium, phosphorus, C-reactive protein, parathyroid hormone, ferritin, and hemoglobin levels.

RESULTS

PH (PAP >35 mmHg) was detected in 68 patients (35.9 %). Patients with PH were older (68 ± 12.3 vs. 52.1 ± 16.7, p = 0.03), had lower ejection fractions (51.3 ± 13.4 vs. 60.8 ± 9.1 %, p = 0.003), lower hemoglobin (11.3 ± 1.5 vs. 12.1 ± 1.9, p = 0.05), and higher parathyroid hormone (218 ± 159.3 vs. 127.7 ± 67.4 pg/ml, p = 0.05) levels. The remaining parameters were similar between groups.

CONCLUSIONS

Older age, lower ejection fraction, and secondary hyperparathyroidism may contribute to PH in stage 1-4 proteinuria CKD.