Insulin resistance, type 2 diabetes, and AD

Type 2 diabetes (T2D) affects over a fifth of persons over the age of 60 years in the United States.1 The total cost to the US economy is $174 billion a year. Another 35% of persons 60 years and older have prediabetes; thus, prediabetes and T2D represent an enormous public health burden in the elderly. The main cause of the epidemic of prediabetes and T2D is the rise in adiposity in all age groups, resulting from increased caloric intake and decreased physical activity. Elevated adiposity causes increased insulin resistance, which in turn leads to increased insulin levels to maintain normal glucose levels. If the pancreas fails to maintain insulin levels high enough to overcome insulin resistance, prediabetes and T2D ensues. Diagnosis and treatment of T2D is the main focus of clinicians, but it is clear that prediabetes and insulin resistance also have important adverse consequences. Insulin resistance and hyperinsulinemia precedes or accompanies most cases of prediabetes and T2D, but not all insulin resistance results in prediabetes and T2D. It is important, therefore, to utilize measures of insulin resistance and glycemia when studying outcomes. In this issue of Neurology ®, Matsuzaki et al.2 have …