Vitamin D Deficiency Is Associated with Rapid Decline in Exercise Capacity in Male Patients with Chronic Obstructive Pulmonary Disease.
BACKGROUND
Vitamin D is suggested to play a role in airway and systemic inflammation in chronic obstructive pulmonary disease (COPD). Low serum 25-hydroxyvitamin D (25-OHD) levels have been suggested to be associated with lower lung function and poorer exercise capacity in COPD.


OBJECTIVE
The main purpose of this study was to investigate the effects of vitamin D deficiency on the change in exercise capacity in male COPD patients.


METHODS
A total of 156 male subjects were selected from the Korean Obstructive Lung Disease cohort. Vitamin D deficiency was subdivided into three subgroups: mild, moderate, and severe deficiency groups. Rapid decline was defined as an annual rate of change in exercise capacity ≥17 m. Exercise capacity was assessed by 6-minute walk distance (6MWD).


RESULTS
Significant differences were observed in the serum levels of 25-OHD, the number of patients with vitamin D sufficiency, and moderate-to-severe deficiency between rapid decliners (n = 40) and non-rapid decliners (n = 116). No differences were found between the groups for age, smoking status, lung function, and 6MWD. Multivariate analysis showed that vitamin D deficiency was independently related to rapid decline in exercise capacity (p = 0.028). A statistically significant difference was observed among the subgroups of vitamin D deficiency in terms of the change in exercise capacity (p < 0.001). The annual decline in exercise capacity was prominent in the severe deficiency group (23.1 m/year).


CONCLUSIONS
This study shows that vitamin D deficiency is associated with rapid decline in exercise capacity in male patients with COPD.
Department of Internal Medicine, Jeju National University Hospital, Jeju, Korea.
Changhwan
C
Kim
Ji Ye
JY
Jung
Young Sam
YS
Kim
Jae Seung
JS
Lee
Chin Kook
CK
Rhee
Jin Hwa
JH
Lee
Ji-Hyun
JH
Lee
Tae-Hyung
TH
Kim
Seong Yong
SY
Lim
Seung Soo
SS
Sheen
Kwang Ha
KH
Yoo
Joon Beom
JB
Seo
Yeon-Mok
YM
Oh
Sang-Do
SD
Lee
Yong Bum
YB
Park
D000368:Aged; D015897:Comorbidity; D018450:Disease Progression; D017079:Exercise Tolerance / Q000502:physiology*; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology / Q000503:physiopathology*; D056910:Republic of Korea / Q000453:epidemiology; D012907:Smoking / Q000453:epidemiology; D014797:Vital Capacity; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology; D000070857:Walk Test
D014807:Vitamin D; C104450:25-hydroxyvitamin D