Background: Cardiovascular risk factors are a significant burden in end-stage renal disease patients under hemodialysis. Cardiovascular-related diseases are the leading cause of death among these patients and responsible for almost half of all deaths in dialysis patients. The influence of parathormone (PTH) on myocardial function as a toxin of uremia is attracting more attention and evaluation because of growing evidence that the effects of PTH on cardiac function may be the most serious consequence of secondary hyperparathyroidism in renal failure. In this study we aimed to consider the role of the excess PTH in the development of left ventricular hypertrophy (LVH) and its effects on LV ejection fraction in patients with end-stage renal disease under regular hemodialysis.
Methods: This cross-sectional study was done on patients with end-stage renal disease (ESRD) undergoing maintenance hemodialysis treatment. Calcium, phosphorus, alkaline phosphatase and intact PTH (iPTH) were measured. Hypertensive patients were stratified into stages one to three. Echocardiography for left ventricular (LV) hypertrophy and ejection fraction (percent) were done and LV stratified into normal, mild, moderate and severe hypertrophy.
Results: The total number of patients was 73 (F = 28, M = 45), consisting of 58 non-diabetic hemodialysis patients (F = 22, M = 36) and 15 diabetic hemodialysis patients (F = 6, M = 9). The age of patients was 46.5 +/- 16 years. The length of time patients had been on hemodialysis was 21.5 +/- 23.5 months. The LV ejection fraction (EF%) was 51 +/- 8 percent. Mean +/- SD of iPTH of total patients was 309 +/- 349 pg/ml. Mean +/- SD of iPTH of diabetic group and non-diabetic group was 234 +/- 265 pg/ml and 329 +/- 368 pg/ml respectively. The value of serum alkaline phosphatase of total patients was also 413 +/- 348 IU/L. Serum alkaline phosphatase (ALP) of diabetic group and non-diabetic group was 295 +/- 179 IU/L and 443 +/- 375 IU/L respectively. Serum albumin of total patients was 4 +/- 0.75 g/dl. Serum albumin of diabetic group and non-diabetic group was 3.6 +/- 0.7 g/dl and 4.2 +/- 0.7 g/dl respectively. Significant inverse correlation of serum ALP with percent of LV ejection fraction and marginal significant correlation of serum ALP with LVH were seen and marginal significant correlation of serum iPTH with LVH was also found. Significant inverse correlation between serum iPTH with percent of LV ejection fraction in non-diabetic HD patients was observed.
Conclusions: Adverse effects of secondary hyperparathyroidism on LV function and structure in this study shows the role of excess PTH in the development of left ventricular hypertrophy as well as low LV ejection fraction. In patients with end-stage renal disease under hemodialysis, more attention needs to be given to the control of secondary hyperparathyroidism to reduce the risk of cardiovascular morbidity and mortality in dialysis patients.