Nutritional and cognitive relationships and long-term mortality in patients with various dementia disorders

Abstract

Background: Subjects with dementia are at risk for protein-energy malnutrition.

Objective: To study the nutritional status, the short-term effects of adapted nutritional routines and the long-term mortality in subjects admitted for evaluation of cognitive dysfunction.

Design: prospective observational study.

Setting: University Hospital.

Subjects: A total of 231 patients (80 +/- 7 years, 65% women).

Methods: Body mass index (BMI, kg/m2), serum concentrations of albumin, ferritin, vitamin B12, folic acid and haemoglobin as well as Mini-Mental State Examination (MMSE, 0-30 p) results and co-morbidity were recorded at hospital admittance and before discharge. Seven years later, mortality was registered.

Results: Mean BMI was in the normal range (23.3 +/- 4) as were the biochemical indices, and they did not vary among patients with Alzheimer's disease (AD), vascular dementia (VaD), mild cognitive impairment, mixed dementia and other diagnoses. A BMI of <23 was found in 108 (52%) subjects. Weight and MMSE score correlated weakly (r = 0.18, P < 0.01) at inclusion. During a median hospital stay of 3 weeks, an average weight gain of 0.5 +/- 1.8 kg (P < 0.001) and an increase in MMSE score of 0.9 +/- 3 (P < 0.001) was observed. However, these changes did not correlate. A BMI of <23 was associated with an increased risk for 7-year mortality (OR 3, 95% CI = 1.3-6.7), which was independent of age, male gender, dementia diagnosis and co-morbidity.

Conclusions: Nutritional status did not vary in patients with various dementia diagnoses. A BMI of <23 was related to reduced 7-year survival, but this result was independent of co-morbidity, male gender and age.