However, the reverse is probably true: a recent meta-analysis concluded that diabetes conferred a 1.25- to 1.91-fold excess risk of cognitive disorders (both cognitive impairment and dementia), and elevated levels of 2 h glucose and HbA1c and low and high levels of fasting plasma insulin were associated with an increased risk of dementia in people with (or with an increased risk of) diabetes [21]. This evidence concerns the gene INS and dementia.