*2.1. Urinary Albumin Excretion and Proteinuria*

In obese subjects, albuminuria is more frequent. A significant association of albuminuria with either obesity or central obesity has been reported [56–58], being higher in the presence of central obesity. The presence of a cluster of cardiovascular risk factors increases the risk [59].

Albuminuria associated with obesity has been observed in children and adolescents. In moderate obese adolescents, the prevalence was reported at 2.4% [60]; however, in severe obesity, 3% displayed proteinuria, 14% microalbuminuria, and 3% had a GFR <60 mL/min/1.73 m<sup>2</sup> [61]. In addition, Goknar et al. [62] reported that severely obese children had a higher number of urinary markers for tubular damage, such as N-acetyl-beta-D-glucosaminidase (NAG), and kidney injury molecule (KIM)-1.

Even though the prevalence of albuminuria in the presence of obesity has been demonstrated, this condition remains underdiagnosed due to the absence of clinical symptoms and lack of specific search of low-grade albuminuria.
