Bone formation markers (N-terminal propeptide type I rocollagen, osteocalcin and vitamin D) as early predictors of osteoporosis in patients suffering from chronic obstructive lung disease

Abstract

The aim of the work was to find out whether markers of bone formation can be early predictors of osteoporosis in patients with COPD. The study involved 66 patients with COPD with disease duration from 10 to 30 years, age 53.59±12.83 years. 37 (66.06%) patients smoked, the pack / year index was (29.08±16.62). According to the results of CAT testing, all patients were divided into 4 clinical groups: GOLD I-IV. The content of serum markers of bone formation was determined: N-terminal procollagen type I propeptide (PINP), osteocalcin and vitamin D depending on the age and severity of COPD. A decrease in all markers of bone formation was found with the age of patients and the severity of COPD. Thus, in patients under 45 years, the P1NP level was 48.75% higher than in patients aged 75 and older (p<0.001). A significant relationship was established between the age of patients and the P1NP level (r= -0.46; p=<0.05). With GOLD I, a decrease in the P1NP content was observed in 40.0% of patients, with GOLD II - 48.0%, GOLD III - in 45.0%, and with GOLD IV, such a decrease was in 66.67% of patients. The level of osteocalcin decreased in patients with COPD of old age compared with the control by 2.72 times and in young people - by 1.88 times. With GOLD I, a decrease in osteocalcin content was observed in 66.67%, with GOLD II - 89.0%, GOLD III - in 85.0%, and with GOLD IV, a decrease was observed in all (100%) patients. The concentration of vitamin D was reduced in all patients with COPD, and severe vitamin D deficiency was diagnosed in 23.08% of patients under 45 years, in 70.59% of elderly patients, in 100% of elderly people. Among the representatives of GOLD IV, the level of vitamin D decreased by 1.75 times as compared with patients with GOLD I. A severe form of vitamin D deficiency was diagnosed in 46.67% of patients with GOLD I, 40.0% in GOLD II, 65.0% in GOLD III, and in 100% of patients with GOLD IV. The data obtained indicate that with increasing age and increasing severity of COPD, the formation of markers of bone tissue formation is inhibited. These processes occur against the background of vitamin D deficiency. As a result of this imbalance, favorable conditions are created for the development of osteoporosis. Considering that the first signs of these disorders, in particular a decrease in the levels of vitamin D and osteocalcin, are diagnosed already with GOLD I, it can be argued that COPD is the leading factor.