Introduction:
Patients with chronic kidney disease are susceptible to develop mineral bone disease by multiple mechanisms. This study was designed to assess the spectrum of mineral bone disease in ESKD patients on maintenance hemodialysis.
Methods:
This cross-sectional study recruited 158 patients who were on maintenance hemodialysis for more than 3 months at our institute from 01/02/2023 to 01/02/2024. Patients with malignancy, liver disease & primary hyperparathyroidism were excluded. Baseline clinical & demographic data was included. Biochemical evaluation was done by measuring serum calcium, phosphorus, Bone specific alkaline phosphatase (ALP), albumin, intact parathyroid hormone, 25-hydroxyvitamin D. Assessment of vascular calcification was done by lateral abdominal radiograph to look for abdominal aortic calcification. Cardiac valvular calcification was evaluated by echocardiography & bone mineral density was studied using DEXA scan.
Results:
Mean age of patients was 59.56±14.48 years out of which 99 (62.7 %) patients were more than 60 years of age. 106 (67.1%) patients were male. The mean duration of hemodialysis was 21.25 ± 17.9 months. 28.5 % patients (n=45) had cardiac illness at baseline and 9.5% patients (n=15) had history of stroke. Of all the patients, 36.7 % patients(n=58) were taking calcium supplements, 9.5% (n=15) were on calcium-based phosphate binders and 59.5% (n=94) were taking non-calcium based phosphate binders. 65.8% patients (n=104) were taking vitamin D supplementation & 39.2% (n=62) were taking active form of vitamin D.
Biochemically and radiologically noted evidence of mineral bone disease was seen in almost all the patients (91.1%). Hypocalcemia was seen in 53.8 % (n=85), hyperphosphatemia in 55.1 %(n=87) and 39.9 %(n=63) had vitamin D deficiency. A total of 40.5%(n=64) had iPTH levels of more than 300 pg/ml.
The mean calcium, phosphorus, iPTH, Vitamin D and bone specific ALP levels were 8.3±0.97 mg/dl, 4.9±1.8 mg/dl, 320.8±300.0 pg/ml, 31.4±26.2 ng/ml and 21.5±17.6 respectively.
43.7% (n=69) had abdominal aorta calcification and 9 of them had a score greater than 10 (score by Kauppila et al). 11.4% (n=18) had cardiac valvular calcification involving mitral valve (n=9), aortic valve (n=3) or both (n=5). Severe cardiac valvular calcification was seen only in 1 patient. Osteopenia was seen in 47.4 % (n=46) & osteoporosis in 28.9% (n=28).
Valvular calcification was seen more commonly in older age (>60 years) (p=0.050) and in those with underlying cardiac illness (p=0.032). Frequency of abdominal aorta calcification was also higher with elderly (p=0.001) and diabetics (p=0.001).
Conclusions:
Mineral bone disease complicates most patients on maintenance hemodialysis. Most patients in our study had some evidence of mineral bone disease. More than half of the patients had hypocalcemia & hyperphosphatemia and were vitamin D deficient despite taking supplementation. Increasing age had a significant influence on valvular & vascular calcification. Also valvular & vascular calcification were more prevalent in patients with cardiac illness & diabetes respectively.
I have no potential conflict of interest to disclose.
I did not use generative AI and AI-assisted technologies in the writing process.