A hundred and one patients with diabetes mellitus (DM) were included in the study; 42 type 1 and 59 type 2 (DM), in addition to 28 normal and 13 hypertensive controls. They were subjected to different biochemical and clinical evaluations. The patients in each type of DM were further subdivided into normo-, micro- and macroproteinuric groups, depending on their urinary protein excretion [using the urinary protein concentration (microg/dl)/urinary creatinine concentration (mg/dl) index (Ur Ptn/Ur Cr index) ] . A micromethod was employed for the determination of urinary protein based upon the coprecipitation of protein and Ponceau S dye by trichloracetic acid , dissolution of the precipitate in dilute alkali and pectrophotometric determination of the dye in alkaline solution. The present study disclosed the following: I. Diabetic kidney disease manifested by increased urinary protein excretion was found to be a common microvascular complication of DM . and was encountered in 64% of type 1 and 37% of type 2 DM patients. II. In type 1 DM, patients with normoproteinuria were mostly males (73%). while those with abnormal urinary protein excretion, were mostly females (74%). In type 2 DM, the picture was of a lesser extreme. III. Long duration of DM may be considered as a risk factor for the progression to macroproteinuria (more pronounced in type 1 than in type 2 DM). IV. Since in the normoproteinuric group of type 1 DM , the mean systolic and diastolic blood pressures (BP) were slightly higher than those of the normal controls. and the mean Ur Ptn/Ur Cr index (although normal) was higher than that of the normal controls, then BP is associated with increased urinary protein excretion from its early stages, where its value is still within the normal range.But the impact of BP was in the macroprote inuric group of type 1 DM. which showed the highest mean. In all the three groups of type 2 DM . the BP was significantly higher than that of the normal controls; hence, it is an early association with increased urinary protein excretion in type 2 DM also, while still having some association with the progression to micro- and macroproteinuria. V. A value of urinary protein excretion in the upper scale of normal may be considered as a risk factor for the further progression to microproteinuria. VI.A higher creatinine clearance than normal in the normoproteinuric group of type I DM (and to a lesser extent in typt 2 DM) may be considered as a risk factor for the further development of abnormal urinary protein excretion. |VII depending on the glycated haemoglobin (GlyHb) level, there was a generalized defective diabetic control in all the studied groups of patients. Highly defective diabetic control in terms of Glyllb may be regarded as a risk factor for the progression from norma to microproteinuria in type 1 DM and from micro- to maroproteinuria in type 2 DM. VIII. All the three groups of type 2 DM patients exhibited higher mean trialycerides (significant),higher mean low density lipoprotein cholesterol/high density lipoprotein cholesterol fatherogenic index) (significant) and higher mean total cholesterol(not significant) when compared to those of normal controls but the differences between themselves were not significant,giving the impression that high lipid profile accompanies type 2 DM from the beginning. IX. Body mass index behaved in a similar manner to the lipid profile in type 2 DM patients. X. In both types of DM, the frequency of polyneuropathy was shown to be remarkably high. XI. A higher incidence of ischaemic heart disease was disclosed in type 2 DM patients when compared to the normal controls. XII. In type 1 DM, patients in the macroproteinuric group only showed retinopathy in th& advanced stage, while surprisingly in type 2 DM, the severity of retinopathy tended to decrease with advancing from the normo- to the micro, and then to the macroproteinuric group. XIII. The two methods of estimating urinary protein excretion [the Ur Ptn/Ur Cr index and the 24h urinary protein excretion (as measured by the short timed urine collection)] were comparable. XIV. A screening program for the early detection of diabetic kidney disease was set taking into account the biological and technical variability of urinary protein and creatinine clearance estimations