Anthropometric index for insulin sensitivity assessment in older adults from Ecuadorian highlands

A marked increase in the population aged 60 years and over is evident; the proportion of the older adult population will rise 18.6% in 2025. On the other hand, obesity, metabolic syndrome (MS), diabetes and insulin resistance (or low insulin sensitivity-IS) are diseases related to lifestyle, they have become a social and public health problem. IS is the ability of cells to react due to insulin's presence; when this ability is diminished, low insulin sensitivity or insulin resistance (IR) is considered. Studies show that IS decreases with age, though no one knows exactly if it is directly due to aging or changes in muscle mass. IS can be determined using direct or indirect methods. This paper aims to propose an insulin sensitivity method design from anthropometries and lipid measures. The methodology consist in a simple correspondence analysis for determine the variables, and a parametrical optimization using Avignon method as optimal function. The database used is composed by 120 Ecuadorian older adults with and without MS. The results show that the proposed optimized method got a better correlation with Avignon compared to non-optimized method. The proposed method could discriminate between subjects with and without IR and with and without MS. This is an important contribution since other methods like HOMA-IR, which is the most used in clinical practice, cannot find these differences, this means that HOMA-IR is not sensitive for IS estimation in elderly people. Future works will focus in the determination of cutoffs for insulin resistance diagnosis in the proposed method.