Resultados de 2 años de intervención en los participantes del nodo UIB del proyecto PREDIMED-Plus

Resumen

Chronic non-communicable diseases (NCDs) are those diseases that increasingly affect the population of developed countries. Due to longer life expectancy and the well-being achieved it is common to live longer but suffer from a chronic disease with medication to maintain the quality of life. All NCDs in 2016 were associated with 71% of global mortality according to data from the World Health Organization (WHO). On the other hand, its management by the national health system (SNS) involve a high economic cost to which the new SARS-CoV-2 pandemic started on December 2019 should be added. During the SARS-CoV-2 pandemic, some of the NCDs such as abdominal obesity has been linked to elevate the risk of mortality. According to Our World in Data, "obesity pandemic" caused 4.7 million deaths every year and it is expected that by 2030 more than 20% of the adult population will suffer from this disease. In order to provide a solution to obesity, it is important to consider the biopsychosocial context. Some of the factors to consider could be genetic and epigenetic factors, the state of the microbiota, the hormonal environment, stress or lack of rest, the subject's social and economic situation, among others. In Spain, already in 2015, 20% of the adult population was obese, and more than 100 000 deaths were attributed to this disease in 2019. Overweight or obesity is an excess of body fat that affects body weight and can be harmful. Overweight is considered when the fat percentage exceeds in 25% men and 33% in women. Another health indicator used for its diagnosis is the waist circumference that according to the International Diabetes Federation, excess abdominal fat is referred to when the waist circumference is ≥94 cm in men and ≥80 cm in non-pregnant women. Summary XXXII The main condition associated with obesity is the Metabolic Syndrome (MetS). MetS is a clinical condition which increase the risk of Type 2 Diabetes Mellitus (T2DM) and cardiovascular disease (CVD). Among the conditions that contribute to MetS are abdominal obesity, glucose intolerance, hypertension and alterations in the lipid profile (high levels of triglycerides (TG) and low levels of high-density lipoprotein cholesterol (HDL-c)). After many years of research in nutritional epidemiology, it is well known fact that following a healthy diet prevents T2DM and CVD diseases. The PREDIMED study started in 2003. The study has a duration of 4.8 years and included 7447 participants. The PREDIMED study analyzed the effectiveness of a moderate-fat diet such as MedDiet in preventing CVD and survival. Based on this study, in 2014 appear the PREDIMED-Plus study, where researchers wanted to extend the version of the PREDIMED study in order to verify the effectiveness of a traditional MedDiet with reduced intake energy on weight loss in a population with MetS and high cardiovascular risk. A nutritional intervention in the population of Mallorca was needed. Also, between 2008 and 2010, researchers on nutrition and cardiovascular risk study (ENRICA study), observed that there was a poor adherence to MedDiet. Moreover, they observed a low consumption of legumes, eggs, good-quality fatty foods, fruits and vegetables with a higher prevalence for T2DM. All in all, this doctoral thesis has the main objective to know the effects of 2 years of intervention in the population belonging to the UIB node of the PREDIMED-Plus project. The population studied in this research are men aged 55-75 years and women aged 60-75 years with abdominal obesity and MetS but no CVD disease. To sum up, 32.5% of the population of the intensive intervention group (IG) get a 5% of weight loss (p=0.001) 24 months after the intervention. The waist circumference decreased statistically significantly in the group of men (p <0.001) and the biochemical parameters for glucose variable improved. Also, the HbA1c and TG levels. Despite this, for none of these variables a time*group effect was observed. On the other hand, the levels of low HDL-c were statistically significantly improved, which values changed between 41.3 ± 8.9 Summary XXXIII mg/dL to 44.0 ± 9.9 mg/dL, p=0.020. However, a statistically significant reversion of total MetS was observed 6 months of follow-up. After the intervention, the nutritional status was improved with a higher consumption of nuts, blue fish, legumes, fruits and vegetables, and whole grains. On the contrary, it founds a low consumption of sodium and saturated and trans fats present in processed foods. On the other hand, an improvement in the glycemic quality of the diet was observed when sugary drinks were reduced. All these results were reflected in changes in the eating pattern and greater adherence to MedDiet, with and improvement of the 17- MedDiet questionnaire by the IG (before the intervention: 7.8 ± 2.3 points; after the intervention: 12.7 ± 2.5 points (p <0.001)). Finally, this research allowed to understand the effects of this eating pattern on the health-related quality of life (HRQL) through the SF-36 questionnaire (The Short Form-36 Health Survey) and the changes in depression measured by the BECK-II (Beck Depression Inventori) questionnaire. The HRQL improved (p <0.001) with a better score for the vitality scale and for the emotional role. Although only in the emotional role significant differences with a time * group interaction was observed (p=0.032). In turn, the score for depression was improved, but no expecting statistically significant changes. The effort of the research may focus on apply the most effective weight loss treatment with relevant changes in terms of health. The current doctoral thesis and the future intervention by the PREDIMED-Plus study will open new possibilities for future interventions. The interventions with MedDiet may be adjusted to the current obesogenic context. The results of this Thesis will help to create new strategies that combined the use of multiple psychosocial and neurocognitive tools that allow better improvements on obesity and the reversion of its associated comorbidities in the adult population.