Separate physical tests of lower extremities and postural control are associated with cognitive impairment. Results from the general population study Good Aging in Skåne (GÅS-SNAC)

Figures & data

Table 1 Characteristics of the participants (n = 2115)

	Cases n = 328	Intermediates n = 457	Controls n = 1330
Age, mean ± SD	75.8 ± 10.2	71.8 ± 9.5	69.0 ± 9.1
Male/female (%)	(50.9/49.1)	(50.1/49.9)	(43.5/56.5)
Age groups, n (%)
Males
60–69 years	64 (38.3)	129 (56.3)	398 (68.9)
70–79 years	46 (27.5)	51 (22.3)	92 (15.9)
≥80 years	57 (34.1)	49 (21.4)	88 (15.2)
Females
60–69 years	45 (28.0)	86 (37.7)	456 (60.6)
70–79 years	33 (20.5)	75 (32.9)	130 (17.3)
≥80 years	83 (51.6)	67 (29.4)	166 (22.1)
Marital status, n (%)
Married/cohabiting	155 (47.8)	269 (59.5)	810 (61.2)
Widow/widower	107 (33.0)	92 (20.4)	225 (17.0)
Divorced/not cohabiting	41 (12.7)	66 (14.6)	197 (14.9)
Unmarried	21 (6.5)	25 (5.5)	91 (6.9)
Place of residence, n (%)
Rural	30 (9.3)	44 (9.8)	132 (10.0)
Urban	294 (90.7)	407 (90.2)	1190 (90.0)
Walking ability, n (%)
Independent walking	271 (82.6)	414 (90.6)	1229 (92.4)
Dependent on walking aids/wheelchair	57 (17.4)	43 (9.4)	101 (7.6)
P-ADL, n (%)
Dependent in ≤1 activity	310 (98.7)	438 (99.1)	1304 (99.7)
I-ADL, n (%)
Dependent in ≤1 activity	293 (92.7)	410 (94.0)	1239 (95.6)

Abbreviations: SD, standard deviation; P-ADL, personal activities of daily living; I-ADL, instrumental activities of daily living.

Table 2 Comparisons of the covariates education, health indicators, and comorbidity between cases, intermediates, and controls (n = 2115)

	Cases n = 328	Intermediates n = 457	Controls n = 1330	P
Education				<0.001
Elementary school not completed	6 (1.9)	20 (4.4)	27 (2.0)	–
Elementary school completed	190 (58.6)	246 (54.5)	586 (44.4)	–
Secondary school completed	80 (24.7)	119 (26.4)	401 (30.4)	–
≥1 year extra study or university with/without degree	48 (14.8)	66 (14.6)	307 (23.2)	–
Smoking habits				ns
Current smoker	44 (13.6)	82 (18.2)	245 (18.5)	–
Stopped smoking	121 (37.3)	165 (36.7)	532 (40.2)	–
Never smoked	159 (49.1)	203 (45.1)	546 (41.3)	–
Drinking habits				<0.001
No alcohol/drank alcohol a few times during the past year but not during the past month	126 (39.1)	165 (36.9)	358 (27.2)	–
Drank alcohol during the past month	196 (60.9)	282 (63.1)	960 (72.8)	–
Physical activity during the past year				0.001
Hardly any, mostly sedentary	67 (20.7)	89 (19.8)	184 (13.9)	–
Light activity (2–4 hours/week)	168 (52.0)	217 (48.2)	652 (49.4)	–
Strenuous activity (1–2 hours several times per week)	88 (27.2)	144 (32.0)	483 (36.6)	–
Comorbidity
Pulmonary disease (asthma, chronic bronchitis, emphysema)	44 (13.5)	57 (12.5)	142 (10.7)	ns
Coronary heart disease (myocardial infarction, angina)	58 (17.7)	89 (19.5)	171 (12.9)	0.001
Diabetes	25 (7.6)	28 (6.1)	82 (6.2)	ns
Rheumatoid arthritis	22 (6.8)	19 (4.2)	62 (4.7)	ns
Neurological disease	1 (0.3)	9 (2.0)	22 (1.7)	ns
Osteoarthritis of knee/hip	76 (23.2)	88 (19.3)	215 (16.2)	0.009
Fractures of lower extremities	32 (9.8)	46 (10.1)	100 (7.5)	ns
Congestive heart failure with symptoms	34 (10.7)	39 (8.8)	51 (3.9)	<0.001
Anemia	32 (9.8)	35 (7.7)	63 (4.7)	0.001
BMI				ns
Normal weight, BMI ≤ 24.99	112 (34.5)	158 (34.8)	473 (35.6)	–
Overweight, BMI 25.0–29.99	144 (44.3)	197 (43.4)	598 (45.1)	–
Obese, BMI ≥ 30.0	69 (21.2)	99 (21.8)	256 (19.3)	–
Pain
Back	101 (30.8)	121 (26.5)	374 (28.1)	ns
Right leg	103 (31.4)	150 (32.8)	429 (32.3)	ns
Left leg	107 (32.6)	135 (29.5)	394 (29.6)	ns
Medication
Use of sedatives	47 (14.3)	59 (12.9)	184 (13.8)	ns

Note: The values given are numbers of subjects, with percentages in parentheses.

Abbreviations: P, probability; BMI, body mass index; ns, not significant.

Table 3 Results of the physical performance tests for cases, intermediates, and controls stratified according to age

	Cases		Intermediates		Controls
	n	mean ± SD	n	mean ± SD	n	mean ± SD
Step test, right leg (n)
60–69	109	17.3 ± 5.21	214	17.3 ± 4.08	845	18.2 ± 4.37
70–79	74	13.8 ± 3.63	123	14.8 ± 4.28	219	15.8 ± 4.12
≥80	121	12.4 ± 3.94	107	12.4 ± 3.74	236	13.0 ± 4.07
Step test, left leg (n)
60–69	109	17.6 ± 5.20	212	17.3 ± 3.93	841	18.2 ± 4.20
70–79	75	13.8 ± 3.54	123	14.8 ± 4.16	218	15.8 ± 3.91
≥80	122	12.0 ± 3.65	106	12.5 ± 3.76	235	12.7 ± 3.96
Chair stands (s)
60–69	108	10.8 ± 5.04	214	10.4 ± 3.49	837	10.1 ± 2.81
70–79	72	12.7 ± 3.69	116	12.4 ± 3.74	218	11.2 ± 3.04
≥80	115	14.6 ± 5.70	100	14.0 ± 4.99	222	14.2 ± 5.47
TUG self-selected speeda (s)
60–69	109	8.9 ± 1.65	215	9.0 ± 1.92	849	8.8 ± 1.67
70–79	75	11.1 ± 2.35	123	10.7 ± 2.60	221	10.0 ± 2.14
≥80	120	13.1 ± 4.01	104	12.2 ± 3.42	223	12.7 ± 3.75
TUG fast speeda (s)
60–69	109	6.9 ± 1.44	215	6.8 ± 1.32	849	6.6 ± 1.27
70–79	75	8.3 ± 1.61	122	8.2 ± 1.76	220	7.7 ± 1.66
≥80	120	10.5 ± 3.78	104	9.4 ± 2.47	224	9.6 ± 2.51
Self-selected WSa (m/s)
60–69	109	1.5 ± 0.26	214	1.5 ± 0.21	846	1.5 ± 0.21
70–79	73	1.3 ± 0.20	120	1.3 ± 0.19	220	1.3 ± 0.21
≥80	105	1.1 ± 0.19	92	1.2 ± 0.18	186	1.1 ± 0.20
Fast WSa (m/s)
60–69	109	1.8 ± 0.34	214	1.8 ± 0.30	844	1.9 ± 0.30
70–79	73	1.5 ± 0.25	119	1.6 ± 0.26	219	1.6 ± 0.31
≥80	105	1.4 ± 0.26	92	1.4 ± 0.27	186	1.4 ± 0.26
Time 2 × 15 m, self-selected speeda (s)
60–69	109	22.2 ± 4.19	214	22.2 ± 3.42	847	22.1 ± 3.48
70–79	73	25.9 ± 4.07	120	25.7 ± 3.98	219	24.8 ± 4.65
≥80	104	28.8 ± 4.82	90	27.9 ± 4.46	186	28.7 ± 6.00
Time 2 × 15 m, fast speeda (s)
60–69	109	18.2 ± 3.80	214	18.2 ± 4.86	845	17.6 ± 3.23
70–79	73	21.6 ± 4.20	119	21.1 ± 3.69	219	20.1 ± 3.68
≥80	104	24.5 ± 5.59	92	23.3 ± 4.59	186	23.4 ± 4.40

Note:

a Only the results from subjects not needing walking aids to perform the test were included in the analysis.

Abbreviations: SD, standard deviation; TUG, Timed Up and Go; WS, walking speed.

Table 4 Multiple ordinal regression of cognitive impairment, with controls, intermediates, and cases as the dependent variable, and separate physical performance testsa, adjusted for confounders

Physical performance testb	n	Estimate	P	OR	95% CI
Step test, right leg (n)	1970	−0.049	<0.001	0.95	0.93–0.98
Step test, left leg (n)	1964	−0.046	<0.001	0.96	0.93–0.98
Chair stands (s)	1931	0.033	0.009	1.03	1.01–1.06
TUG self-selected speedc (s)	1960	0.024	0.216	1.02	0.99–1.06
TUG fast speedc (s)	1958	0.102	<0.001	1.11	1.05–1.17
Self-selected WSc (m/s)	1891	−0.204	0.416	0.82	0.50–1.33
Fast WSc (m/s)	1887	−0.678	<0.001	0.51	0.35–0.73
Time, 2 × 15 m, self-selected speedc (s)	1888	0.006	0.621	1.01	0.98–1.03
Time, 2 × 15 m, fast speedc (s)	1887	0.051	<0.001	1.05	1.03–1.08
OLS <10s, right leg	1877	0.376	0.006	1.46	1.11–1.91
OLS <20s, right leg	–	0.487	0.002	1.63	1.20–2.21
OLS <30s, right leg	–	0.192	0.321	1.21	0.83–1.77
OLS <10s, left leg	1874	0.578	<0.001	1.78	1.34–2.37
OLS <20s, left leg	–	0.295	0.060	1.34	0.99–1.82
OLS <30s, left leg	–	0.409	0.031	1.51	1.04–2.19

Notes:

a Multiple ordinal regression with controls, intermediates, and cases (highest category) as dependent variable;

b adjusted for age, sex, education, drinking habits, physical activity during the past year, anemia, coronary heart disease, congestive heart failure with symptoms, and osteoarthritis of the hip/knee;

c only the results from subjects not needing walking aids to perform the test were included in the analysis.

Abbreviations: P, probability; OR, odds ratio; CI, 95% confidence interval; TUG, Timed Up and Go; WS, walking speed; OLS, one-leg standing, eyes open.

Table 5 An adjusted general linear modelb between separate performance tests and cognitive impairment for cases, controls, and intermediates

Physical performance testa	Controls/intermediates vs cases			Intermediates vs controls
	B	P	95% CI	P^d 95% CI
Step test, right leg (n)
Controls	0.794	0.002	0.28–1.31	0.006
Intermediates	0.183	0.541	−0.40–0.77	−1.05 to −0.18
Step test, left leg (n)
Controls	0.721	0.005	0.22–1.22	0.023
Intermediates	0.228	0.433	−0.34–0.80	−0.92 to −0.07
Chair stands (s)
Controls	−0.614	0.013	−1.10 to −0.13	0.195
Intermediates	−0.344	0.222	−0.90–0.21	−0.14–0.68
TUG fast speedc (s)
Controls	−0.454	<0.001	−0.67 to −0.24	0.360
Intermediates	−0.367	0.004	−0.62 to −0.12	−0.10–0.27
Fast WSc (m/s)
Controls	0.055	0.002	0.02–0.09	0.036
Intermediates	0.023	0.266	−0.02–0.06	−0.06 to −0.00
Time, 2 × 15 m, fast speedc (s)
Controls	−0.931	<0.001	−1.41 to −0.45	0.047
Intermediates	−0.519	0.063	−1.07–0.03	0.01–0.82

Notes:

a Adjusted for age, sex, education, drinking habits, physical activity during the past year, anemia, coronary heart disease, congestive heart failure with symptoms, and osteoarthritis of the hip/knee;

b the case group was the reference;

c only the results from subjects not needing walking aids to perform the test were included in the analysis.

Abbreviations: B, estimate; P, probability; P^d, P-value for comparison between intermediates and controls; OR, odds ratio; CI, 95% confidence interval; TUG, timed up and go; WS, walking speed; OLS, one-leg standing, eyes open.