This study was approved by the Research Ethics Committee from UNICASTELO (protocol no. 8926). A total of 70 patients (40 women and 30 men) were enrolled, which were divided as follows: 18 normoglycemic and normotensive patients (CTR), 20 DM and HT patients with no apparent complications (low risk of renal disease, LR), 16 DM and HT patients who have other complications than diagnosed renal failure (high risk of renal disease, HR), and 16 DM and HT patients who have renal failure and are being submitted to blood dialysis (DI). The overall average age was years and the average age for each group was , , , and years for CTR, LR, HR, and DI, respectively. Urines from single collection were obtained in the morning in fasting, bottled and stored in freezer until biochemical and spectral analysis. For spectroscopy, urine samples were unfrozen to reach room temperature and placed in an aluminum holder with a vessel of about 100 μL. Spectra were taken in the vessel by means of a Raman probe connected to a dispersive Raman spectrometer. The spectrometer (Lambda Solutions, MA, model P-1 Raman) is composed of a diode laser (830 nm) coupled to a Raman probe (Lambda Solutions, MA, model Vector Probe) that is used to illuminate sample and collect the scattered light. The probe is connected to a spectrograph with a Peltier-cooled, deep depleted/back illuminated charge-coupled device camera (), which collects high-resolution Raman spectrum from the sample in the fingerprint region (400 to ). The laser power was adjusted to 300 mW and the integration/accumulation time to collect the Raman signal was set to 20 s. Triplicate spectra were obtained from each sample, which were averaged after preprocessing. For comparison purposes, the reference spectra of organic components of urine were obtained: glucose (Sigma-Aldrich Brasil, São Paulo, Brazil, ref. 49163), urea (Bio-Rad Laboratórios Brasil, Rio de Janeiro, Brazil, ref. 161–0730), and creatinine (Sigma-Aldrich Brasil, São Paulo, Brazil, ref. C4255).