A Narrative Review on Strategies for the Reversion of Prediabetes to Normoglycemia: Food Pyramid, Physical Activity, and Self-Monitoring Innovative Glucose Devices

In 2019, "Nutrition Therapy for Adults with Diabetes or Prediabetes: A Consensus Report" was published. This consensus report, however, did not provide an easy way to illustrate to subjects with prediabetes (SwPs) how to follow a correct dietary approach. The purpose of this review is to evaluate current evidence on optimum dietary treatment of SwPs and to provide a food pyramid for this population. The pyramid built shows that everyday consumption should consist of: whole-grain bread or potatoes eaten with their skins (for fiber and magnesium) and low glycemic index carbohydrates (GI < 55%) (three portions); fruit and vegetables (5 portions), in particular, green leafy vegetables (for fiber, magnesium, and polyphenols); EVO oil (almost 8 g); nuts (30 g, in particular, pistachios and almonds); three portions of dairy products (milk/yogurt: 300-400 g/day); mineral water (almost 1, 5 L/day for calcium intake); one glass of wine (125 mL); and three cups of coffee. Weekly portions should include fish (four portions), white meat (two portions), protein plant-based food (four portions), eggs (egg portions), and red/processed meats (once/week). At the top of the pyramid, there are two pennants: a green one means that SwPs need some personalized supplementation (if daily requirements cannot be satisfied through diet, vitamin D, omega-3, and vitamin B supplements), and a red one means there are some foods and factors that are banned (simple sugar, refined carbohydrates, and a sedentary lifestyle). Three to four times a week of aerobic and resistance exercises must be performed for 30-40 min. Finally, self-monitoring innovative salivary glucose devices could contribute to the reversion of prediabetes to normoglycemia.

Risk and management of pre-diabetes

Type 2 diabetes mellitus (T2DM) is associated with a two- to four-fold increased risk of developing cardiovascular disease (CVD) and microvascular complications, which may already be present before diagnosis. It is, therefore, important to detect people with an increased risk of T2DM at an early stage. In order to identify individuals with so-called 'pre-diabetes', comprising impaired fasting glucose (IFG) and impaired glucose tolerance (IGT), current guidelines have developed definitions based on fasting plasma glucose, two-hour glucose concentrations and haemoglobin A1c. Subjects with pre-diabetes are at an increased risk of developing T2DM and CVD. This elevated risk seems similar according to the different criteria used to define pre-diabetes. The risk of progression to T2DM or CVD does, however, depend on other risk factors such as sex, body mass index and ethnicity. Based on the risk factors to develop T2DM, many risk assessment models have been developed to identify those at highest risk. These models perform well to identify those at risk and could be used to initiate preventive interventions. Many studies have shown that lifestyle modification and metformin are effective in preventing the development of T2DM, although lifestyle modification seems to have a more sustainable effect. In addition, lifestyle modification seems more effective in those with IGT than those with IFG. In this review, we will describe the different definitions used to define pre-diabetes, progression from pre-diabetes to T2DM or other vascular complications, risk factors associated with progressions and the management of progression to T2DM, ending with clinical recommendations.

The global epidemics of diabetes in the 21st century: Current situation and perspectives

Diabetes is on the rise worldwide, with a global prevalence in adults in 2017 being 8.8% of the world population, with the anticipation of a further increase to 9.9% by 2045. In total numbers, this reflects a population of 424.9 million people with diabetes worldwide in 2017, with an estimate of a 48% increase to 628.6 million people by 2045. Depending on age, global diabetes prevalence is about 5%, 10%, 15% and close to 20%, respectively, for the age groups 35-39, 45-49, 55-59 and 65-69 years. On a global scale, diabetes hits particularly 'middle aged' people between 40 and 59 years, which causes serious economic and social implications. Furthermore, diabetes affects especially low and middle income countries, as 77% of all people with diabetes worldwide live in those countries. In addition to overt diabetes, an estimated 352.1 million people worldwide are at risk of diabetes, i.e. have defined pre-diabetes, a figure which is anticipated to rise to 531.6 million by 2045. Some 70-75% of all patients with established coronary artery disease, e.g. with acute myocardial infarction, show concomitant diabetes or abnormal glucose regulation, i.e. close to 50% have overt diabetes, with as many as 20% of those being undiagnosed and another 25% having pre-diabetes.