Its well known that secondary hyperparathyroidism (SHPT) is common in patients with chronic kidney disease stage 5 (CKD5D), on dialysis. The aim of our study was to analyze peculiarities of SHPT in diabetic patients in comparison to those with other course of CKD5D.
We studied 25 diabetic and 180 non-diabetic patients with CKD5D, mean age 47.5±10.8 years; age at dialysis onset 42.7±11.7 years; dialysis duration 4.7±3.9 years. Groups were matched for age, gender age at dialysis onset and dialysis duration. We measured serum levels of intact parathyroid hormone (iPTH), N-terminal mid-fragment osteocalcin (N-Mid-OC), C-terminal telopeptide of type I collagen (β-CTx), total calcium (Ca), phosphates (P), alkaline phosphotase in both groups by immunoassay.
Median level of iPTH was significantly lower in diabetic patients than in non-diabetic (97.2 vs 245.5 pg/ml; P=0.001). Prevalence of secondary hyperparathyroidism was significantly lower in diabetic patients (12.0 vs 47.8%; P=0.0004) while frequency of normal uremic iPTH level (150300 pg/ml) and low iPTH level was higher in diabetic patients (28.0 vs 11.7%; P=0.035 and 60.0 vs 40.6%; P=0.05 respectively). Analysis of biochemical markers of bone metabolism shown that N-Mid-OC and β-CTx are significantly lower in diabetic group: 194.6 vs 331.5 ng/ml, P=0.02 and 1.69 vs 1.98 ng/ml, P=0.05 respectively. Serum level of phosphates was the same in both groups, at the same time serum calcium was significantly lower in diabetic patients (2.17±0.27 vs 2.47±0.33; P=0.0001).
We can assume that diabetic patients with CKD5D are at lower risk of developing SHPT than patients with other course of CKD5D. Our data allows suggesting that diabetic patients on dialysis are at greater risk of low-turnover bone disease. Further study is required to develop differentiated approach for diagnostics and treatment of parathyroid function abnormality and associated mineral and bone disorders in diabetic patients with CKD5D.