Correlation between parathyroid hormone, bone alkaline phosphatase and N-telopeptide of type 1 collagen in diabetic and non-diabetic haemodialysis patients.

BACKGROUND

Haemodialysis (HD) patients with diabetes mellitus often have renal osteodystrophy (ROD) characterized by reduced bone turnover, but little is known about the correlation between bone formation and bone resorption in this population.

METHODS

The authors measured serum parathyroid hormone (PTH), bone alkaline phosphatase (BAP), N-telopeptides of type 1 collagen (NTx) and fasting glucose in 48 patients with diabetic nephropathy (DN) and 80 patients with glomerulonephritis (non-DN) who had received <or=10 years of regular HD. Spearman's correlation coefficients (r) were derived.

RESULTS

In the whole patients, the DN group had a lower PTH and NTx level than the non-DN group. Serum PTH was not correlated with NTx in the DN group, whereas all three markers were correlated with each other in the non-DN group. Subdividing the DN patients according to HD duration revealed remarkable differences in the correlation between BAP and NTx: in patients receiving >or=5 years HD (r = 0.568) this correlation was similar to that in the non-DN group (r = 0.653), whereas there was no significant correlation in those receiving <5 years HD. Patients receiving >or=5 years HD had a comparable glucose level (111.1 +/- 19.2 mg/dL) to the non-DN group, whereas those receiving <5 years had a higher level (196.1 +/- 53.1 mg/dL).

CONCLUSION

Differences in the interaction between bone cells between DN and non-DN patients are one potential cause of lower bone turnover in the former group. Research of this correlation is needed to increase understanding of the complexities of bone metabolism in DN patients.