Disease Markers

Research Article

Plasma Cathepsin S and Cathepsin S/Cystatin C Ratios Are Potential Biomarkers for COPD

Table 1

Study populations.


	Healthy nonsmoker (NS)	Healthy smoker (HS)	COPD at risk (AR)	COPD

	52	66	31	94
Male/female	50/2	65/1	27/4	89/5
Age
Current/Ex	0/0	40/26	14/17
Pack-Years	0
BMI	NA	NA
Serum Cr	NA	NA
FEV₁/FVC (%)	NA	NA
% FEV₁ predicted	NA	NA
LAA	NA	NA
HT ()	0/52	0/66	5/26	17/77
ICS ()	0/52	0/66	1/30	16/78

versus NS, HS, AR; versus HS; versus HS, < 0.05 versus AR; versus AR. COPD: chronic obstructive pulmonary disease; BMI: body mass index; Cr: creatinine; FEV₁/FVC (%): ratio of forced expiratory volume in 1 second to forced vital capacity; LAA: low attenuation area; HT: hypertension; ICS: inhaled corticosteroid.