Pulmonary Hypertension in Predialysis Chronic Kidney Disease: Frequency and Potential Mechanisms

Abstract
Background: Pulmonary arterial hypertension (PH) and Chronic Kidney Disease (CKD) both profoundly affect patient outcomes, whether as primary disease states or as comorbid conditions. PH is a common comorbidity in CKD and vice versa. PH is an independent predictor of mortality in such patients. In a recent review, the prevalence of PHT in ESRD patients was reported to be around 40-50% however, the epidemiological data for this disorder in earlier stages of Chronic Kidney Disease (CKD) and the risk factors associated with its presence are scarce.
Aim: To evaluate the frequency of pulmonary hypertension among chronic kidney disease nondialysis dependent patients and to compare clinical and metabolic variables among those patients with the control group to search for possible mecha-nisms.
Subjects and Methods: 40 CKD patients (55% men, 45% women; mean age, 42.9±15.13 years) with. According to the magnitude of Glomerular Filtration Rate (GFR) decrease, the CKD patients have divided into 3 groups: (1) 2 patients with a GFR of 89-60ml/min; (2) 6 with a GFR of 59-45ml/min; (3) 32 with a GFR of 44-15ml/min. A control group consisted of 40 individuals with preserved kidney function (a GFR of >90 ml/min). Physical examination and echocardiography were performed in all the patients. The serum concentrations of homocysteine and serum PTH were determined.
Results: PH was detected in 20 (50%) of the 40 patients with CKD. As CKD progressed, the frequency of pulmonary hypertension in Groups 1, 2, and 3 increased, amounting to 18.2%, 24.2%, and 35%, respectively.
Conclusion: This study demonstrated a high frequency of pulmonary hypertension among patients with CKD without dialysis.
The frequency was highest among patients especially those with older age higher, serum creatinine phosphorus c-reactive protein parathyroid hormone and homocysteine; lower hemoglobin, lower EF% which all positively correlated with PASP and may be involved in the pathogenesis of pulmonary hypertension. Early detection of pulmonary hypertension is important in order to avoid the serious consequences of the disease, also managing these potential mechanisms will result in areduction in the occurrence of pulmonary hypertension and thus reducing the incidence of the cardiovascular compli-cations which are considered as one of the most important causes of death in the group of patients.