figure indicates a high degree of correlation between serum alkaline
phosphatase and urinary hydroxyproline excretion (expressed as hydroxyproline/creatinine
ratio) in a series of 197 untreated patients with Paget's disease.
Note the close relationship between the two measurements over a 100-fold
range of values (log scale). Upper limit of normal is 105 IU/L for
alkaline phosphatase and 40 umol/mmol for hydroxyproline/creatinine.
Source: Modified from Kanis JA. Pathophysiology and Treatment of Paget's
Disease of Bone. Durham, NC; Carolina Academic Press; 1991:99. (Fig.