Pulmonary hypertension in patients with chronic renal failure: the role of parathormone and pulmonary calcification

ABSTRACT

Cardiovascular complications especially coronary artery disease are considered to be a major cause of mortality in patients with chronic renal failure [CRF] on regular hemodialysis. Abnormal technetium-m99 methylene diphosphonate [99mTc-MDP] lung uptake was reported in 61% of patients with CRF on regular hemodialysis in the presence of normal chest radiographs indicating the presence of pulmonary calcifications. Pulmonary calcification was reported to be a possible cause for the development of pulmonary hypertension [PH] in patients with CRF on regular hemodialysis. 51 patients [28 males and 23 females] who had end stage renal disease and were on regular hemodialysis. Those patients were divided according to the presence of pulmonary hypertension by echo-Doppler study into Group 1 15 patients [5 males and 10 females] with a mean age of 43.5 +/- 9.8 years who had pulmonary hypertension and subjected to 99m Tc-MDP. Group II 15 patients [10 males and 5 females] with a mean age of 40.3 +/- 10.9 years without pulmonary hypertension. Also, those patients were subjected to 99m Tc-MD and were considered as a control group. Group III 21 patients [15 males 6 females] with a mean age of 3g9 +/- 11.0 years without pulmonary hypertension but were not subjected to 99m Tc-MDP scan. All patients were subjected to full clinical evaluation, chest X ray and well standardized 12 leads ECO. Laboratory investigations included BUN, creatinine, calcium [Ca], phosphorus [Ph], alkaline phosphatase [ALK], hemoglobin [Rb] ,complete lipid profile, and intact molecule parathormone hormone [PTH]. Echo-Doppler study was performed mainly for estimation of the pulmonary artery systolic pressure [PASP]. Only patients in groups I and IT were subjected to 99m techn MDP scan. Twenty patients from 30 patients [66.6%] had positive 99m Tc-MDP lung uptake. There was no significant difference between patients with positive or negative 99m Tc-MDP lung uptake regarding the duration of dialysis, the serum level of Ca, Ph, ALK, Rb, cholesterol, triglyceride and PTH .15 patients [29.47%] had pulmonary hypertension [The mean value of PASP was 45.2 +/- 6.7 Hg]. There was no significant difference regarding the mean value of PASP in patients with positive or negative 99m Tc-MDP lung uptake .The mean value of PASP in patients with positive 99m Tc-MDP was 33.9 +/- 11.8 mmHg vs 36.5 +/- 11.8 mmHg in patients with negative 99m Tc-MDP lung uptake [p=0.3]. This study demonstrated that 66.6% of patients with CRF and on regular hemodialysis had pulmonary calcifications. There was no significant difference between patients with or without pulmonary calcifications regarding serum Ca, Ph, ALK, Hb, cholesterol, triglyceride and PTH. There was no correlation between pulmonary calcifications and pulmonary hypertension. The mechanism of pulmonary hypertension is uncertain and other factors rather than pulmonary calcifications and hyperparathyroidism should be considered