Table 4– Characteristics of subjects who did, or did not, show a decline in pulmonary function

	FVC decline	No FVC decline	p-value	FEV₁ decline	No FEV₁ decline	p-value
Subjects	28	119		29	118
Age years	61.79±10.42	60.79±8.81	0.651	63.55±9.50	60.20±8.91	0.063
BMI kg·m⁻²	23.65±3.53	22.73±2.71	0.187	23.51±3.02	22.76±2.68	0.326
Brinkman index cigarette-years	737.6±409.8	754.4±416.4	0.866	863.3±387.8	725.9±417.1	0.028*
mean BP mmHg	100.8±10.4	97.8±13.5	0.128	99.25±11.61	98.19±13.38	0.436
HbA1c %	5.03±0.36	5.14±0.57	0.288	5.09±0.36	5.13±0.57	0.963
ALT U·L⁻¹	26.64±12.81	26.75±14.99	0.782	28.00±13.85	26.42±14.77	0.377
sCr mg·dL⁻¹	0.696±0.096	0.759±0.114	0.007*	0.728±0.107	0.752±0.115	0.3
Triglycerides mg·dL⁻¹	148.57±97.66	139.29±86.68	0.632	132.58±67.66	143.14±93.15	0.851
Total cholesterol mg·dL⁻¹	192.39±29.34	194.40±30.07	0.805	194.86±30.47	193.80±29.81	0.748
Homocysteine μM	12.4 (11.1–14.3)	11.9 (10.0–14.0)	0.148	13.8 (11.7–18.4)	11.0 (9.6–12.8)	0.001*
Log homocysteine	1.09±0.11	1.07±0.12	0.148	1.13±0.11	1.06±0.01	0.001*
FVC % pred
First visit	97.79±15.57	97.88±13.83	0.668	95.70±16.06	98.39±13.62	0.668
Second visit	90.76±15.40	104.55±13.58	<0.0001*	92.09±16.17	104.34±13.61	<0.0001*
FEV₁ % pred
First visit	92.63±18.44	97.49±16.04	0.236	90.71±20.94	98.01± 15.08	0.158
Second visit	84.01±19.23	98.73±16.35	0.0001*	78.44±21.07	100.23±14.01	<0.0001*
FEV₁/FVC %
First visit	74.27±7.68	77.95±8.47	0.039*	73.78±10.12	78.11±7.77	0.019*
Second visit	71.99±10.64	73.27±9.02	0.657	65.86±12.86	74.79±7.28	<0.0001*

Data are presented as n, mean±sd or median (interquartile range), unless otherwise stated. Data on homocysteine levels were not available for four of the 147 subjects. Brinkman index data were not available for 19 subjects due to the lack of information on precise smoking habits. Differences in Brinkman index and homocysteine levels between subjects who did, or did not, show a decline in pulmonary function were evaluated by the Mann–Whitney U-test. Differences in all other variables were evaluated by t-test. BMI: body mass index; BP: blood pressure; Hb: haemoglobin; ALT: alanine aminotransferase; sCr: serum creatinine; FVC: forced vital capacity; % pred: % predicted; FEV₁: forced expiratory volume in 1 s.