Caloric Restriction in Obese Patients With Mild Cognitive Impairment: Effects on Adiposity, Comorbidity and Cognition

Caloric Restriction in Obese Patients With Mild Cognitive Impairment: Effects on Adiposity, Comorbidity and Cognition

Caloric Restriction in Obese Patients With Mild Cognitive Impairment: Effects on Adiposity, Comorbidity and Cognition

Obesity has been associated with cognitive impairments, lower blood flow, metabolic activity and brain volume. Obesity in adulthood is a risk factor for Alzheimer's disease in the elderly. The mild cognitive impairment (MCI) is a condition that may precede dementia. We hypothesized that promotion of weight loss in obese people with MCI, through caloric restriction could lead to improvement in cognitive performance or reduction in the rate of decline and decreased risk of dementia. A sample of 80 patients aged ≥ 60 years, obese, with MCI, will be randomized to two groups that will be followed for 12 months. The control group will receive conventional medical care. The intervention group will receive nutritional counseling individually and in groups, aiming to promote weight loss through caloric restriction, and medical monitoring. Before and after intervention patients will be evaluated for anthropometry, body composition, physical performance, control of comorbidities, laboratory tests (glucose, insulin, lipid profile, leptin, adiponectin, interleukin 6, tumor necrosis factor alpha, CRP), Genotyping apolipoprotein E, neuropsychological battery, questionnaires about activities of daily living, physical activity and diet.

Objectives: To evaluate the cognitive performance of obese patients with MCI and the effect of weight loss induced by caloric restriction on cognition, conversion to dementia, to assess weight loss, changes in inflammatory and metabolic parameters, change in physical capacity, performance in neuropsychological tests and correlate with effects of the intervention. Methods: The patients will be randomized to two groups that will be followed for 12 months. The control group will receive conventional medical care. The intervention group will receive nutritional counseling individually and in groups, aiming to promote weight loss (10% of body weight) through caloric restriction, and medical monitoring. Everyone will be advised to physical activity. Before and after 12 months patients will be evaluated for anthropometry, body composition, physical performance, control of comorbidities, laboratory tests (glucose, insulin, lipid profile, leptin, adiponectin, interleukin 6, tumor necrosis factor alpha, CRP), Genotyping apolipoprotein E, neuropsychological battery, questionnaires about activities of daily living, physical activity and diet.

Mild cognitive impairment, Dementia, Obesity, Overweight, diet, caloric restriction, body composition, weight loss

Conventional medical care, geriatric consultations at least 6 times in 12 months, short lifestyle counseling (exercise+healthy diet)

Nutritional counseling individually and in groups, aiming to promote weight loss (10% of body weight) through caloric restriction, +Conventional medical care, geriatric consultations at least 6 times in 12 months, short lifestyle counseling (exercise)

Conventional medical care, geriatric consultations at least 6 times in 12 months, short lifestyle counseling (exercise+healthy diet)

Nutritional guidance: through at least 2 individual assistance and group sessions, lasting 1 hour, weekly for 4 months, and biweekly for 2 months and monthly thereafter (26-28 meetings/1year).The diet plan will recommend a deficit from 500 to 750 kcal/day in order to promote loss of about 0.5kg/week, containing 1g/kg of protein per day (minimum 1200kcal/day), high in fiber, vegetables and whole foods. The goal of weight loss will be 10% of initial weight. Group activities consist of lectures on nutrition education, food composition and its importance to health, food preparation techniques, self-monitoring weight, eating behavior and count calories.

Montreal Cognitive Assessment (MoCA), Mini Mental State Examination (MMSE), Subjective Memory Complaints scale and CAMcog from CAMDEX (The Cambridge Examination for Mental Disorders of the Elderly, The Rivermead Behavioural Memory, The Wisconsin Card Sorting Task, trail making test part A and B, The Rey auditory-verbal learning test, semantic and phonologic verbal fluency test, digits (WAIS-III), vocabulary (WAIS - III), matrix (WAIS - III)

The diagnosis of dementia will be given from the DSM IV TR: The diagnosis of Alzheimer's disease will be defined according to DSM IV.

anthropometry (weight, height, BMI, waist circumference, hip circumference), body composition by bioimpedance

glucose, insulin, lipid profile, leptin, adiponectin, interleukin 6, tumor necrosis factor alpha, CRP

Inclusion Criteria: body mass index (BMI) ≥ 30 kg/m2 independent for most of the instrumental activities of daily life; literate; able to walk, diagnosis of mild cognitive impairment Exclusion Criteria: weight loss greater than 3 kg over the past two months, presence of uncontrolled disease that potentially interfere with metabolism and weight gain or whose treatment would influence the cognitive performance, such as major depression, bulimia, hypothyroidism, Cushing's disease, heart failure, neoplasia in the last 3 years, alcoholism, infectious diseases and auto-immune activity; use of anti-obesity drugs, benzodiazepines, neuroleptics or estrogen replacement therapy in the past 2 months; previous bariatric surgery, severe sensory deficit