Efficacy of a Multimodal Intervention in the Prevention of Frailty in Obese Elderly People and Study of the Pathophysiological Mechanisms Involved

Rationale: There is increasing evidence that obesity may be a risk factor for frailty in the elderly. Obesity favors a state of chronic inflammation and insulin resistance, involves a fatty infiltration of the muscle and an increased cardiovascular risk and, in addition, obese people usually perform less physical activity. All this favors the loss of mass and muscular function (sarcopenia), a key component of the fragility and the functional deterioration. Objectives: To evaluate the effectiveness of a multimodal intervention to lose weight in the prevention of frailty in obese elderly people, as well as to know the main mechanisms involved in the frailty process. Methodology: Design: Controlled, randomized, open-label clinical trial with two parallel intervention arms and 2 years follow-up. Study population: People between 65 and 75 years of age, obese (BMI ≥30), without criteria of fragility and living in the community. Study intervention: multimodal and personalized intervention with the support of a "personal trainer" that has two main axes of action: a) diet: assessment of nutritional status and nutritional requirements and establishment of personalized nutritional plan with monthly dietetic controls and b) physical exercise: a multi-component physical exercise program that will include aerobic exercise and strengthening, balance and flexibility exercises as well as a weekly group session of health education, during six months. Main outcome measures (to be evaluated annually for 2 years): Fragility (according to the L Fried criteria) and Sarcopenia (according to the criteria of the European Working Group on Sarcopenia in Older People -EWGSOP). Sarcopenia is considered if there is a decrease in gait velocity or muscle grip strength (measured with a dynamometer) and a decrease in muscle mass assessed by bioimpedance (BIA). Intermediate outcome measures (at 6, 12 and 24 months): a) weight loss, b) changes in body composition and distribution of body fat, c) glycemic control (HbA1) and insulin resistance (by HOMA index (HOmeostasis Model Assessment)), d) cardiovascular risk according to the REGICOR algorithm, e) functional capacity (according to Barthel Index and 2 Minute Walking Test), f) inflammatory markers (IL-6, CRP(C reactive protein), TNF(Tumor Necrosis Factor)-alpha and leptin) and g) anabolic hormones (IGF-1, ghrelin and testosterone).