Diabetic kidney disease: difference in the prevalence and risk factors worldwide

Abstract
Diabetic nephropathy, which is defined as elevated urine albumin excretion or reduced glomerular filtration rate or both, is a serious complication that occurs in 20–40% of all diabetic patients. In this review, we try to highlight the prevalence of diabetic nephropathy, which is not an uncommon complication of diabetes all over the world. The prevalence of diabetes worldwide has extended epidemic magnitudes and is expected to affect more than 350 million people by the year 2035. There is marked racial/ethnic difference besides international difference in the epidemiology of diabetic nephropathy, which could be attributed to the differences in economic viability and governmental infrastructures. Approximately one-third of diabetic patients showed microalbuminuria after 15 years of disease duration and less than half develop real nephropathy. Diabetic nephropathy is more frequent in African-Americans, Asian-Americans, and Native Americans. Progressive kidney disease is more frequent in Caucasian patients with type 1 than in those with type 2 diabetes mellitus (DM), although its overall prevalence in the diabetic population is higher in patients with type 2 DM because this type of DM is more prevalent. Hyperglycemia is a well-known risk factor for diabetic kidney disease, in addition to other risk factors such as male sex, obesity, hypertension, chronic inflammation, resistance to insulin, hypovitaminosis D, dyslipidemia, and some genetic loci and polymorphisms in specific genes. Diabetic nephropathy is not an uncommon complication of diabetes (type 1 and 2) all over the world and in geriatric population. Management of its modifiable risk factors might help in reducing its incidence in the nearby future.