In addition, it is noteworthy that being older, treatment with insulin, obesity, a longer duration of diabetes and the presence of depression were associated with a greater risk of cognitive impairment in patients with DNP. While a higher level of education, a better mental and physical component of quality of life, a higher AHT and a poor quality of sleep were associated with a better cognitive function in patients with DNP. This evidence concerns the gene INS and major depressive disorder.