The relationship between nutritional status and white matter integrity in older adults: A diffusion tensor imaging study.

OBJECTIVES: The purpose of this study to determinate whether there is a relationship between the nutritional status and white matter integrity in older patients by using Diffusion Tensor Imaging (DTI). METHODS: The patients were evaluated by Mini-Nutritional Assessment Scale. The patients are categorized in the groups of well-nourished, risk of malnutrition, or malnourished, depending on the overall score> 23.5, 17-23.5, or 17; respectively. All patients had brain MRI and DTI. The mean diffusivity (MD), fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD) values were calculated by ROI-based method in white matter tracts. RESULTS: Total of the 224 patients; 86 patients had normal nutrition status (group 1), 107 patients were diagnosed with malnutrition risk (group 2) and 31 patients were diagnosed with malnutrition (group 3). Significantly decreased FA values of genu of corpus callosum, forceps minor and significantly increased MD values of middle cerebellar peduncle, and superior frontooccipital fasciculus were detected in group 2 in comparison to group 1 (p < 0.05). After adjusting for the folate and age, MD and RD values of cingulum remained significantly higher and the AD values of superior cerebellar peduncle remained significantly lower in group 3 (p < 0.05). CONCLUSIONS: Malnutrition was associated with deteriorated DTI values, especially in cingulum and superior cerebellar peduncle. Assessing the nutritional status of older individuals is crucial to avoid its negative impact on brain. ADVANCES IN KNOWLEDGE: Early diagnosis of malnutrition-related impaired WM integrity is important for prevention and intervention, and DTI is a useful non-invasive technique to be used for this purpose.

Evaluation of white matter integrity by diffusion tensor imaging in the deficiencies of vitamin B12 and folate in older patients.

OBJECTIVES: The aim of this study is to investigate whether white matter (WM) integrity is impaired in vitamin B12 and folate deficiency with Diffusion Tensor Imaging (DTI) in older patients. METHODS: All the patients aged ≥65 years admitted to the geriatric clinic and performed DTI-MRI were included in the study. DTI parameters (fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity) were calculated by ROI-based method in white matter tracts. Deficiency threshold for vitamin B12 were defined as <200 pg ml-1 and <400 pg ml-1 separately; and for folate as <3 ng ml-1 and <6 ng ml-1, separately. RESULTS: DTI was performed to older patients having serum vitamin B12 level (n = 106, mean age = 80.7±7.7, 66% female) and folate level (n = 101, mean age = 80.7±7.5, 67.3% female). Significantly lower FA and higher MD and RD levels were observed in multiple WM areas including superior and middle cerebellar peduncles, cingulum and genu of corpus callosum in patients with vitamin B12 <400 pg ml-1 (p < 0.05). DTI indices also showed significant changes in the genu of corpus callosum, and right and left superior longitudinal fasciculus in patients with folate <6 ng ml-1 (p < 0.05). CONCLUSIONS: Deficiencies of vitamin B12 and folate may be associated with impaired white matter integrity in elderly even at high laboratory levels, and DTI is a useful method to detect it. ADVANCES IN KNOWLEDGE: Early detection of impaired WM integrity caused by micronutrient deficiencies poses a great significance in terms of prevention and intervention, and DTI is an effective non-invasive method to be used for this purpose.

The prevalence of undernutrition and associated factors in older obese patients.

BACKGROUND: Both obesity and malnutrition are common health problems in older adults. AIM: The aim of our study is to investigate the prevalence of undernutrition and related factors in older obese patients. METHODS: 1911 older outpatients who underwent comprehensive geriatric assessment were included in this cross-sectional study. Body mass index (BMI) was categorized as follows: 'Underweight' = BMI < 18.5, 'Normal weight' = 18.5 ≤ BMI < 25, 'Overweight' 25 ≤ BMI < 30, and 'Obesity' ≥ BMI 30. Mini-Nutritional Assessment scores > 23.5, 17-23.5, or < 17 were categorized as well-nourished, malnutrition risk, and malnutrition, respectively. Those who were not well-nourished were considered undernutrition. RESULTS: Of 1911 patients, with a mean age of 77.34 ± 8.0 years, 931 (48.7%) were obese. Of whom 6.0% were malnourished and 26.3% were at risk of malnutrition. Age, females, widowed and those living with their children, the number of drugs used, and the presence of heart failure, Parkinson's disease, and dementia, decreased calf circumference and muscle strength were higher in obese patients with undernutrition than obese well-nourished patients (p < 0.05). After adjustment for the aforementioned factors, basic and instrumental activities of daily livings, and Tinetti scores were lower, and falls and Geriatric Depression Scale-15 scores were higher in those with undernutrition compared to those with well-nourished among older obese patients (p < 0.05). CONCLUSIONS: Half of the older patients were obese and undernutrition was observed in one out of every three older obese patients. Undernutrition was associated with decreased functional capacity, impairment in balance and gait functions, falls, and depressed mood. Therefore, we recommend to screen older obese patients for nutritional status.