Urinary excretion of albumin, alpha-1-microglobulin, and N-acetyl-B-D-glucosaminidase in relation to smoking habits in diabetic and nondiabetic subjects.

Smoking may be a risk factor for the development of diabetic nephropathy. Therefore, the urinary excretion of albumin, alpha-1-microglobulin, and N-acetyl-BD glucosaminidase was studied in 24 young adult diabetic patients who smoked. None of these patients had urine samples positive for albumin as determined by the Albustix method (i.e., a urinary concentration of albumin of less than 0.5 g in 24 hr). Control groups were nonsmoking diabetic patients (matched for age and duration of diabetes) and nondiabetic subjects (smokers and nonsmokers). Expired breath carbon monoxide and the urinary nicotine metabolite cotinine were measured as objective markers of smoking load. No significant differences in concentrations of urinary proteins were found among any of the four groups. Therefore, smoking is not associated with the development of an increased urinary excretion of albumin within the "microalbuminuria" range. However, further studies are required to determine whether smoking is a risk factor for the progression of established microalbuminuria to Albustix positive proteinuria in diabetic patients.