D vitaminin Kognisyon, Fiziksel Fonksiyon ve Ultrasonografik Cilt, Cilt Altı Yağ Dokusu ve Kas Ölçümleri Üzerine Etkilerinin Değerlendirilmesi

Abstract

Doğan, Y., Evaluation of the Effects of Vitamin D on Cognition, Physical Function and Ultrasonographic Measurements of Skin, Subcutaneous Fat Tissue and Muscle Measurements, Hacettepe University Medical School, Thesis In Physical and Rehabilitation Medicine, Ankara, 2021. In this study, we aimed to evaluate the relationship between vitamin D level and skin, subcutaneous fat and muscle tissue thicknesses, cognitive status and physical function. 200 adults (125 F, 75 M) were included in the study. Demographic/clinical characteristics, body mass index (BMI), waist and hip circumference measurements were recorded. Skin, fat and muscle tissue thickness were measured from the hand dorsum, anterior sides of the forearm, arm, and thigh by ultrasonography. Muscle strength was evaluated with handgrip strength. Physical performance was evaluated by gait speed, timed up and go test (TUG), 5 times sit to stand test (CST). Standardized Mini Mental Test (SMMT) was used to assess cognitive functions. Patients were divided into two groups according to their vitamin D levels (deficient; <20 ng/ml and normal; ≥20 ng/ml). Vitamin D deficiency was found in 61% of the patients. Women with vitamin D deficiency were found to be younger (p<0.05). In women with vitamin D deficiency; all fat and forearm muscle thicknesses and SMMT scores were increased while in men, an increase in only CST duration was observed (all p<0.05). In logistic regression analyses for factors affecting the fat thickness; forearm and arm were associated with BMI and vitamin D deficiency, while thigh was associated with BMI, vitamin D deficiency and age in women (all p<0.05). In men; forearm and arm values were associated with BMI and vitamin D deficiency, and thigh was associated with BMI and age (all p<0.05). In regression analyses for CST; age and vitamin D deficiency were found to be independently related in men, and age and exercise in women (all p<0.05). In conclusion, vitamin D deficiency was found to be associated with an increase in adipose tissue in women and prolonged CST in men. Measurement of regional adipose tissue thickness with ultrasound may be useful in revealing body composition in vitamin D deficiency. To this end, prospective studies with larger sample sizes and older populations are needed. Key Words: Hand grip strength, performance, power, strength, ultrasound