Hand grip strength is associated with fatigue among men with COPD: epidemiological data from northern Sweden

Figures & data

Figure 1. Flow chart, recruitment of study population.

Notes: ^aIndividuals who were unable to attend examination; ^bIndividuals who denied participation or could not be located; ^cIndividuals with complete data on FACIT-Fatigue; ^dIndividuals with complete data on HGS; ^eIndividuals with complete data on IPAQ; ^fIndividuals with complete data on HGS & FACIT-Fatigue; ^gIndividuals with complete data on HGS & IPAQ; ^hIndividuals with complete data on HGS, FACIT-Fatigue & IPAQ.

Table 1. Basic characteristics of individuals participating in clinical examination and measure of hand grip strength (HGS), comparing individuals with and without COPD, among women and men, respectively.

	Women			Men
Variables	Non-COPD n = 198^a	COPD n = 164^a	p-value^b	Non-COPD n = 239^a	COPD n = 217^a	p-value^b
Age, mean (SD)	70.3 (9.8)	72.8 (8.7)	0.011	70.1 (9.0)	71.6 (9.0)	0.083
Smoker, n (%)	17 (8.6)	29 (17.7)		10 (4.2)	45 (20.5)
Ex smoker, n (%)	71 (35.9)	75 (45.7)		122 (51.0)	116 (53.5)
Non smoker, n (%)	110 (55.6)	60 (36.6)	<0.001	107 (44.8)	56 (25.8)	<0.001
Height, mean (SD)	160.3 (6.7)	159.8 (6.6)	0.460	173.8 (7.1)	174.3 (6.7)	0.425
BMI, kg/m2, mean (SD)	27.8 (4.7)	26.6 (4.6)	0.015	27.4 (3.73)	26.9 (4.0)	0.111
FEV1% pred, mean (SD)	99.4 (14.0)	81.2 (15.9)	<0.001	95.1 (13.4)	76.5 (17.5)	<0.001
Any respiratory symptoms, n(%)	77 (38.9)	97 (59.1)	<0.001	105 (44.9)	147 (67.7)	<0.001
Heart disease, n (%)	18 (9.1)	21 (12.8)	0.225	46 (19.2)	51 (23.5)	0.296
HGS, mean (SD)	24.6 (6.8)	22.8 (5.5)	0.008	43.3 (9.6)	41.1 (9.5)	0.013

Notes: ^aIndividuals with complete data on HGS; ^bComparing non-COPD and COPD, p-values < 0.05 in bold

Abbreviations: BMI, Body mass index; HGS, Hand grip strength; FEV₁% pred, Forced expiratory volume in one second percent of predicted; SD, Standard deviation

Table 2. Comparing A) fatigue assessed by the FACIT-fatigue questionnaire, and B) physical activity assessed by the IPAQ questionnaire, between individuals with and without COPD, among women and men, respectively.

	Women			Men
Variables	Non-COPD	COPD	p-value^a	Non-COPD	COPD	p-value^a
	Fatigue
A	n = 195^b	n = 155^b		n = 233^b	n = 212^b
FACIT-Fatigue, median (IQR)	48 (43–51)	47 (39–50)	0.098	48 (43–51)	46 (39–50)	0.002
CRF, n (%)	54 (27.7)	55 (35.5)	0.118	64 (27.5)	81 (38.2)	0.016
	IPAQ
B	n = 164^c	n = 134^c		n = 206^c	n = 178^c
IPAQ category Low, n (%)	17 (10.4)	19 (14.2)		28 (13.6)	33 (18.5)
IPAQ Moderate	52 (31.7)	64 (47.8)		55 (26.7)	48 (26.8)
IPAQ High	95 (57.9)	51 (38.1)	0.003^b	122 (59.2)	97 (54.5)	0.382^b
METmin/w, median (IQR)	3 649 (1 926–5 358)	2 428 (1 358–4 638)	0.002	3746 (1 773–6 635)	3 356 (1 145–5 999)	0.315

Notes: ^aComparing non-COPD and COPD, p-values<0.05 in bold; ^bIndividuals with complete data on FACIT-Fatigue; ^cIndividuals with complete data on IPAQ; ^dComparing the proportions of all three IPAQ categories between non-COPD and COPD.

Abbreviations: CRF, Clinically relevant fatigue; IPAQ, International Physical Activity Questionnaire; MET, Metabolic equivalent of task; IQR, Interquartile range

Table 3. Comparing mean HGS (SD) among those with and without clinically relevant fatigue (CRF) in COPD and non-COPD, among women and men, respectively.

	Women
	Non-COPD n = 194^a	COPD n = 152^a
Categories	Mean HGS (SD)	Mean HGS (SD)	p-value^b
Non-CRF	25.1 (6.5)	23.7 (5.0)	0.054
CRF	23.2 (7.2)	21.9 (5.9)	0.323
p-value	0.069^c	0.051^d
	Men
	n = 230^a	n = 209^a
	Mean HGS (SD)	Mean HGS (SD)
Non-CRF	44.2 (9.5)	43.1 (8.7)	0.313
CRF	42.0 (9.2)	38.6 (9.7)	0.035
p-value	0.114^c	0.001^d

Notes: ^aIndividuals with complete data on HGS and FACIT-Fatigue; ^bComparing mean HGS between non-COPD and COPD; ^cComparing mean HGS between non-CRF and CRF in non-COPD; ^dComparing mean HGS between non-CRF and CRF in COPD. CRF is defined as a FACIT-Fatigue score of ≤ 43.

Abbreviations: HGS, Hand grip strength; CRF, Clinically relevant fatigue; SD, standard deviation

Table 4. Comparing mean HGS (SD) between those with a category of low and moderate/high physical activity level according to IPAQ, among women and men, respectively.

	Women a
	Non-COPD n = 164^a	COPD n = 132^a
Categories	Mean HGS (SD)	Mean HGS (SD)	p-value^b
IPAQ Low	25.5 (9.0)	23.8 (4.5)	0.506
IPAQ Moderate-High	25.2 (6.7)	22.8 (5.4)	0.002
p-value	0.875^c	0.459^d
	Men
	n = 203	n = 175
	Mean HGS (SD)	Mean HGS (SD)
IPAQ Low	45.7 (10.3)	39.6 (9.7)	0.022
IPAQ Moderate-High	43.6 (9.1)	42.6 (9.1)	0.318
p-value	0.103^c	0.121^d

Notes: ^aIndividuals with complete data on HGS and IPAQ; ^bComparing mean HGS between non-COPD and COPD; ^cComparing mean HGS between IPAQ low and IPAQ moderate-high in non-COPD; ^dComparing of mean HGS between IPAQ low and IPAQ moderate-high in COPD.

Abbreviations: HGS, Hand grip strength; IPAQ, International Physical Activity Questionnaire; SD, standard deviation

Table 5. Multiple linear regression models analyzing the association between HGS, fatigue and low physical activity among A) women and B) men.

A	Non-COPD									COPD
Women	Model I n = 194^a			Model II n = 164^a			Model III n = 162^a			Model I n = 152^a			Model II n = 132^a			Model III n = 130^a
Variables	B	95% CI		B	95% CI		B	95% CI		B	95% CI		B	95% CI		B	95% CI
FACIT-Fatigue score	0.062	−0.048	0.172				0.038	−0.102	0.179	0.085	−0.001	0.171				0.048	−0.056	0.152
IPAQ Low				0.802	−2.213	3.817	1.101	−2.059	4.261				1.900	−0.670	4.470	2.145	−0.449	4.740
B	Non-COPD									COPD
Men	Model I n = 230^a			Model II n = 203^a			Model III n = 200^a			Model I n = 209^a			Model II n = 175^a			Model III n = 174^a
Variables	B	95% CI		B	95% CI		B	95% CI		B	95% CI		B	95% CI		B	95% CI
FACIT-Fatigue score	0.115	−0.019	0.250				0.134	−0.010	0.278	0.249	0.131	0.367				0.190	0.061	0.319
IPAQ Low				2.202	−0.590	4.994	2.536	−0.269	5.340				−0.380	−2.916	2.157	0.507	−2.058	3.073

Notes: All models are adjusted for age, smoking habits and height. Model I includes FACIT-Fatigue score (continuous); Model II includes IPAQ low (categorical); Model III includes both Fatigue & IPAQ low. ^aIndividuals with complete data on HGS, FACIT-Fatigue and IPAQ.

Abbreviations: HGS, Hand Grip Strength; IPAQ Low, those in low category of IPAQ