The 24h-UFC concentration results from three samples during screening were averaged to obtain baseline. After baseline, mean 24h UFC was determined at week 24. At Week 4, 8, 16 and 20, mean 24h UFC was determined from two 24 hour urine collections collected on two consecutive days occurring before the visit. At Week 12, 24 and 48, the mean 24h-UFC from three 24 hour urine collections, collected over the week before the visit, was determined. After Week 24, the mean 24h UFC was determined at 12-week intervals until end of study visit, from two 24 hour collections during two consecutive days prior to each respective visit (except at Week 48). UFC was determined by liquid chromatography tandem mass spectroscopy (LC/MS/MS). The normal ranges were determined by the central laboratory's own reference range. All samples, including screening samples, were analyzed by a central laboratory.