RELATIONSHIP BETWEEN VITAMIN D LEVEL IN BLOOD WITH MUSCLE STRENGTH AND QUALITY OF LIFE IN PATIENTS WITH CHRONIC HEART FAILURE

Background. Vitamin D can be associated with quality of life (QOL) and muscle strength in patients with chronic heart failure (CHF). Objective: to evaluate the relationship of level 25(OH)D with the indicators of muscle strength and QOL level in patients with CHF. Material and methods. 82 patients with CHF and D-hypovitaminosis were divided into 4 groups: I (n=26) – received cholecalciferol at a dose of 2000 IU/day, II (n=16) – at a dose of 1000 IU/day, III (n=23) – vitamin D-containing oral nutritional supplement, group IV (n=17) – basic therapy. QOL was assessed by Minnesota questionnaire (MQ),muscle strength of the upper limbs by carpal dynamometry, that of lower limbs– by chair lift test. 25(OH)D level was determined by ELISA. Follow-up was performed in 3 months. Results. 25(OH)D level was increased in all groups (p<0.05) and became higher in group I (p=0.0002) and group III (p=0.02) compared with group IV. In group I total score of MQ was reduced (p=0.02), right hand dynamometry value was increased (p=0.04), and in group III - left hand dynamometry was increased (p=0.04). The score of the MQ was negatively correlated with 25(OH)D level (R=-0.35, p=0.001) and right hand dynamometry (R=-0.22, p=0.04) initially and in follow-up (R=-0.24, p=0.03 and R=-0.25, p=0.03, respectively), and positively with chair lift test initially (R=0.24, p=0.03). Direct stepwise regression analysis showed that the dynamics of 25(OH)D level increase (b=-0.37, p=0.003) and a higher level of 25(OH)D in follow-up (b=-0.54, p=0, 04) affect the decrease in the score of the MQ. Conclusions. In patients with CHF 25(OH)D level is associated with QOL, its increase has a positive effect on QOL. QOL is associated with the muscular strength of the lower and upper extremities, the improvement of which is noted when taking vitamin D preparations.