[The factors associated with vitamin D levels in patients with chronic obstructive pulmonary disease in combination with renal dysfunction.].

The goal of study was to find factors associated with vitamin D levels in patients with chronic obstructive pulmonary disease (COPD) and early stages of kidney dysfunction. The study included 338 patients with 1-2 COPD stages (66,9% of men, mean age was 69,4±6,1 years, mean COPD duration was 18,5±4,1 years); 33,1% of women (mean age 64,8±7,3 years, mean COPD duration was 12,1±5,1 years). All patients were diagnosed with 1-2 stages of chronic kidney disease (CKD). In addition to general clinical examination, potential risk factors for vitamin D deficiency were assessed. During multiple regression with step-by-step inclusion method the following factors showed a significant contribution to the formation of vitamin D levels in patients with COPD and early stages of renal dysfunction: the frequency of exacerbations of COPD in the preceding 12 months (3 (2-4), β=0,932, p=0,003), SI (44 (15-87), β=0,038, p=0,006), fibrinogen level (5 (3-7), β=0,413, p=0,016), GFR (74,9 (68,4-89), β=0,119, p=0,041), insolation (94,5 (38,5-152), β=0,026, p=0,0008),the total score on a GDS scale (9 (8-11), β=0,536, p=0,014). R2 for this model was 0,87. BMI made a significant contribution to the formation of vitamin D level at the step of inclusion to the multivariate analysis, but when included in the analysis of insolation markers, the relationship weakened and completely disappeared when the values of SI were included. FEV1 values do not affect on vitamin D level in COPD patients in combination with early stages of kidney dysfunction.