Table 4. Comparison of aging-related systemic manifestations and telomere length between smokers with low K_CO and those with normal K_CO .

	Univariate analysis			Adjusted for age and gender
	Normal KCO (n = 50)	KCO<80% (n = 39)	P*	Normal KCO (n = 50)	KCO<80% (n = 39)	P value †
Pulse wave velocity, m/s	11.2 [10–12]	10.8 [9.7–12.2]	0.77
BMD, total lumbar, g/cm2 **
In females	1.19 [1.07–1.24]	0.98 [0.91–1.12]	0.001	1.18	1.02	0.003
In males	1.09 [1.05–1.29]	1.14 [1.06–1.16]	0.87	-	-	-
BMD, left hip, g/cm2 **				-	-
In females	0.98 [0.93–1.12]	0.84 [0.76–0.94]	0.002	0.99	0.85	0.007
In males	0.99 [0.95–1.08]	1.02 [0.95–1.06]	0.92
BMD, right hip, g/cm2 **
In females	0.99 [0.95–1.08]	0.88 [0.74–0.92]	0.01	1.01	0.87	0.000
In males	1.01 [0.95–1.10]	1.01 [0.96–1.05]	0.71
ASMMI, Kg/m2	7.7 [7.1–8.7]	6.9 [5.9–7.6]	0.000	7.6	7.00	0.03
Pinch test, Kg	6.5 [5–8.5]	6 [4–8]	0.13
Grip test, Kg	39 [29–46]	32 [22–43]	0.02	40.3	32.0	0.01
HOMA-IR	2.18 [1.15–3.26]	1.94 [1.09–2.21]	0.29
Glomerular flow rate, mL/min	84.9 [74.8–91.4]	74.5 [64.4–93.5]	0.12
Telomere length (T/S) ratio**
In females	0.52 [0.41–0.57]	0.40 [0.36–0.46]	0.023	0.50	0.40	0.037
In males	0.43 [0.4–0.5]	0.46 [0.4–0.5]	0.16

Definition of abbreviations: K_CO, transfer coefficient of the lung for carbon monoxide; BMD, bone mineral density; ASMMI, appendicular skeletal muscle mass index; HOMA-IR, homeostatic model assessment of insulin resistance; T/S, ratio of telomere-repeat copy number over single-gene copy number

Data are median [interquartile range].

* P value by nonparametric Kruskal-Wallis test

†P value by quantile regression models adjusted for age and gender unless stated otherwise

** Females and males were analyzed separately because of a significant interaction between gender and aging-related parameters.