Obesity treatment in elderly outpatients: predictors of efficacy and drop-out

OBJECTIVE: Obesity is increasing in the elderly and it is associated with an increased risk of medical complications, decline in physical function and disability. Very few studies specifically evaluated the outcome of obesity treatment in the aging patients. Aim of this work is therefore the evaluation of the efficacy of medical therapy in a group of obese patients >or=65 years old. METHODS: The study has been performed on the clinical records of obese outpatients treated at the medical branch of the Unit for Medical and Surgical Therapy of Obesity at the University of Padova. Patients were recruited from January 1st, 2001 to June 30th, 2006 in order to have patients with at least one year of potential follow-up. In particular two groups were enrolled: 100 patients >or=65 years old and 200 patients <65 years old. The baseline characteristics, the prescriptions and the treatment outcome were compared. RESULTS: Mean age of the elderly patients was 69.1+/-3.7 years (range 65-80 years). We did not find any significant difference between elderly and adult patients in the sex distribution (female patients 76% in the elderly group and 72% in the adult group; p=0.276) and in the severity of overweight (body mass index: 37.8+/-6.0 kg/m2 in the elderly; 37.2+/-6.3 kg/m2 in adults; p=0.425). The elderly group was characterized by a higher incidence of comorbidities and a lower incidence of eating behavior disorders at baseline. No significant differences in the dietary prescription were found, whereas physical activity was prescribed in 27/100 elderly patients (27%) and in 97/200 (48%) adults patients (p<0.000). Weight loss was evaluated by analyzing the percentage of patients reaching at least a 10% weight loss from baseline after 12 months of treatment. In elderly patients still in active treatment after 12 months, only 5/28 (18%) patients reached the specified goal, whereas in adult patients still in treatment, 18/47 (38%) patients reached the goal (p<0.05). Lower age at baseline, female sex, and lower body mass index were found to be the only significant predictors of 10% weight loss in logistic regression. In our experience, drop-out rate after 12 months was similar in adults (77%) and in older patients (72%). In a multivariate Cox regression model, the risk of drop-out was reduced by married or widowed status, the prescription of physical activity at baseline, and the presence of type 2 diabetes. The risk of drop-out was increased by the presence of osteoarthritis. Even after adjustments for these confounding variables, age did not play any significant role as drop-out predictor. CONCLUSION: Advanced age seems to be a predictor of poor response to treatment in obese outpatients treated by conventional medical therapy. Drop-out rate was not significantly influenced by age.