Relation between middle molecules and parathyroid hormone in patients with chronic renal failure.

In 10 moderately and 41 severely uremic patients the relation between serum parathyroid hormone (PTH) and middle molecule fraction 2 (MMS fr. 2-corresponding to MMS peak 7 of Fürst) was investigated. A significant correlation between PTH and MMS fr. 2 levels was found. This correlation was even better between PTH levels and MMS fr. 2/creatinine ratios. We would like to propose that PTH is one of several factors regulating middle molecule levels in uremic patients and that some 'toxic' effects of PTH may be mediated by middle molecules.