Factors involved in body weight loss and its maintenance in morbidly obese inpatients.

BACKGROUND: Body weight loss in patients with obesity improves abnormal glucose tolerance, dyslipidemia and hypertension; however, it is difficult to maintain this loss of body weight. The objective of this study was to examine factors involved in body weight loss and its maintenance in morbidly obese inpatients. METHOD: The subjects were 31 patients (11 males and 20 females) who were admitted to hospital for obesity management. Factors involved in body weight changes during hospitalization and after discharge were examined retrospectively. The mean age was 58.1 ± 13.6 years and body mass index (BMI) was 40.2 ± 10.2 kg/m2. Twenty-four patients were complicated with type 2 diabetes mellitus. Diet therapy was 23.8 ± 3.9 kcal/kg ideal body weight/day. RESULTS: Excess weight loss (EWL) during hospitalization varied from 4.2 to 61.7%. Since EWL was affected by duration of hospital stay, the subjects were divided by the median of EWL per day. The subjects with greater EWL per day had lower body weight, BMI and fat mass on admission in the entire (n = 31), diabetic (n = 24), and non-diabetic subjects (n = 7), respectively. EWL per day was not different between diabetic and non-diabetic subjects. Follow-up data revealed that BMI remained unchanged 3 months after discharge but modestly increased 1 year after discharge, irrespective of EWL per day during hospitalization. In diabetic subjects followed up 1 year after discharge (n = 15), the increase in body weight was smaller than that in non-diabetic subjects (n = 3). CONCLUSION: These results suggest that EWL in morbidly obese inpatients is greater than those with lower baseline BMI and fat mass. The presence of diabetes had no effects on EWL during hospitalization. EWL during hospitalization was not correlated with its maintenance after discharge. Diabetic patients displayed lesser degree of body weight gain after discharge, possibly due to the effects of anti-diabetic medications.