Does low physical activity cause cognitive decline in elderly type 2 diabetes patients: A propensity score matching analysis

Table 1 Demographic characteristics and physical activity levels of elderly type 2 diabetes mellitus patients included in this study (n = 245), n (%)/mean ± SD

Characteristics	Overall (n = 245)
Age	70.9 ± 7.8
Male	152 (51.4)
Residence in urban area	194 (79.2)
Education	10.3 ± 4.3
Occupational category
Light physical work	46 (18.8)
Heavy physical work	36 (14.7)
Mental work	134 (54.7)
Other	29 (11.8)
Marital status
Married	177 (72.2)
Unmarried/divorced	68 (27.8)
Living condition
Building with elevator	126 (51.4)
Building without elevator	73 (29.8)
Bungalow	14 (5.7)
Low physical activity	126 (51.4)

Table 2 Comparison of demographic and clinical characteristics between the low physical activity and non-low physical activity groups of elderly type 2 diabetes mellitus patients before and after propensity score matching, n (%)/mean ± SD

Characteristic	Before PSM		t/χ2	P value	After PSM		t/χ2	P value
	Low physical activity group (n = 126)	Non-low physical activity group (n = 119)			Low physical activity group (n = 100)	Non-low physical activity group (n = 100)
Age (years)	72.1 ± 0.7	69.9 ± 0.7	-2.31	0.01	72.1 ± 8.1	70.2 ± 7.4	-0.8	0.42
Male	52 (41.3)	62 (52.1)	2.82	0.08	44 (44.0)	46 (46.1)	0.08	0.77
Smoking	50 (39.7)	49 (41.2)	0.05	0.81	36 (36)	33 (33)	0.19	0.65
Drinking	11 (15.2)	16 (21.0)	1.39	0.23	17 (17.2)	9 (9.0)	2.93	0.08
Hypertension	100 (79.4)	87 (73.7)	1.92	0.38	81 (81.0)	74 (74.0)	1.89	0.38
Cardiovascular disease	73 (57.9)	87 (73.7)	6.73	< 0.01	37 (37)	30 (30)	1.1	0.29
Stroke	105 (83.3)	105 (88.2)	1.20	0.27	15 (15.0)	13 (13.0)	0.16	0.68
Hearing impairment	9 (6.3%)	0 (0%)	9.931	< 0.01	4 (4.0)	0 (0.0)	4.08	0.04
Hyperlipidemia	60 (42.0%)	71 (46.4)	0.593	0.441	42 (42.0)	47 (47.0)	0.50	0.47
Education level (years)	9.8 ± 0.4	10.3 ± 0.5	0.71	0.46	10.8 ± 3.9	10.3 ± 4.8	-0.18	0.85
Married status			1.28	0.25			0.23	0.63
Married/cohabitating	95 (75.4)	82 (68.9)			75 (75)	72 (72)
Divorced/single/widowed	31 (24.6)	37 (31.1)			25 (25)	28 (28)
Residential region			6.71	0.01			0.77	0.38
Urban	108 (85.7)	86 (72.3)			82 (82)	77 (77)
Rural	18 (14.3)	33 (27.7)			18 (18)	23 (23)
Night sleep time			1.31	0.25			0.07	0.78
≤ 6 h/day	43 (37.4)	29 (29.9)			30 (33.7)	27 (31.8)
> 6 h/day	72 (62.6)	68 (70.1)			59 (66.3)	58 (68.2)
BMI (kg/m2)	26.1 ± 0.3	25.4 ± 0.3	-1.43	0.15	26.8 ± 3.8	25.9 ± 3.4	-1.67	0.09
Mid-UAC (mm)	26.5 ± 3.9	27.8 ± 3.7	2.51	0.01	26.8 ± 3.4	27.2 ± 3.3	2.14	0.03
6MWT (m)	460.8 ± 40	540.5 ± 82	-6.63	< 0.01	482.3 ± 61	560.4 ± 80	-5.92	< 0.01
Grip strength (kg)	24.2 ± 11.8	29.3 ± 14.5	2.74	< 0.01	24.1 ± 12.9	27.3 ± 11.2	1.72	0.08
FBG (mmol/L)	8.2 ± 3.5	8.1 ± 3.1	-1.13	0.86	8.0 ± 3.1	7.9 ± 3.5	0.14	0.88
HbA1C (%)	8.4 ± 2.3	8.1 ± 2.2	-0.96	0.35	8.4 ± 2.1	8.2 ± 2.2	-0.82	0.41
hsCRP (mg/L)	6.8 ± 5.6	2.7 ± 5.5	-2.72	< 0.01	6.8 ± 5.5	4.5 ± 3.2	-2.44	0.01
β2-MG (mg/L)	3.7 ± 2.2	3.2 ± 1.4	-1.97	0.04	3.6 ± 2.2	3.2 ± 1.6	-1.60	0.11
IL-6 (pg/mL)	8.3 ± 5.9	5.3 ± 4.7	-2.22	0.02	5.08 ± 2.0	6.25 ± 3.1	-2.01	0.04
LDL-C (mmol/L)	2.2 ± 0.9	2.6 ± 1.0	2.14	0.03	2.2 ± 0.9	2.6 ± 0.9	1.22	0.22
TG (mmol/L)	1.9 ± 1.8	1.7 ± 1.2	-1.24	0.22	1.8 ± 1.6	1.7 ± 1.1	-1.19	0.23
TCH (mmol/L)	4.1 ± 1.1	4.3 ± 1.2	1.20	0.20	4.2 ± 1.1	4.3 ± 1.2	0.45	0.65
HDL-C (mmol/L)	1.2 ± 0.5	1.2 ± 0.3	0.44	0.65	1.2 ± 0.3	1.3 ± 0.4	0.26	0.78
MOCA-based cognitive impairment	32 (30.5)	25 (21.0)	2.63	0.03	25 (25.0)	22 (22.0)	1.44	0.22
MNA-SF-based malnutrition	21 (20.0)	12 (11.1)	5.93	0.04	6 (6.0)	10 (10.0)	1.09	0.58
IADL-based disability	62 (49.2)	35 (29.4)	10.02	< 0.01	48 (48.0)	32 (32.0)	5.33	0.02
FRAIL-based frailty phenotype	32 (31.1)	4 (3.4)	32.31	< 0.01	22 (22.0)	4 (4.0)	20.5	< 0.01

PSM: Propensity score matching; BMI: Body mass index; UAC: Upper arm circumference; 6MWT: 6-minute walk test; FBG: Fasting blood glucose; hsCRP: High-sensitivity C-reactive protein; β2-MG: β2-microglobulin; IL: Interleukin; LDL-C: Low-density lipoprotein cholesterol; TG: Triglycerides; TCH: Total cholesterol; HDL-C: High-density lipoprotein cholesterol; MOCA: Montreal Cognitive Assessment; MNA-SF: Mini Nutritional Assessment-Short Form; FRAIL: Fatigue, resistance, ambulation, illness, and loss of weight.

Table 3 Models 1 and 2 for risk of cognitive decline in elderly type 2 diabetes mellitus patients

Variable	Model 1						Model 2
	Univariate analysis			Multivariate analysis			Univariate analysis			Multivariate analysis
	β	OR (95%CI)	P value	β	OR (95%CI)	P value	β	OR (95%CI)	P value	β	OR (95%CI)	P value
Age	0.066	1.068 (1.036-1.102)	< 0.01				0.068	1.081 (1.032-1.131)	< 0.01	0.075	1.079 (1.028-1.132)	0.02
Male	-0.643	0.526 (0.299 -0.923)	0.02				0.227	1.255 (0.786-1.987)	0.51
Education level	-0.08	0.923 (0.862-0.987)	0.02				0.043	1.004 (0.449-1.760)	0.285
Mental work	-0.572	0.564 (0.223-0.812)	0.178				-0.909	0.403 (0.197-0.824)	0.01	-1.248	0.287 (0.127-0.651)	< 0.01
Residential region (urban)	-0.122	0.886 (0.734-0.992)	0.70				0.381	1.464 (1.098-1.803)	0.34
Smoking	-0.57	1.99 (0.013-3.211)	0.05				-0.366	0.693 (0.228-1.091)	0.31
Drinking	0.075	1.078 (0.978-1.232)	0.56				0.075	1.078 (0.332-2.597)	0.87
Hypertension	0.457	1.579 (1.343-1.923)	0.18				0.282	1.326 (1.021-1.643)	0.486
Cardiovascular disease	0.489	1.631 (0.983-2.922)	0.10				0.657	1.932 (0.332-3.594)	0.06
Hearing impairment	2.378	10.78 (2.10-54.8)	< 0.01				2.227	9.273 (0.940-91.436)	0.04
Stroke	1.068	2.91 (1.251-6.770)	0.01	1.415	4.118 (1.40, 12.109)	0.01	1.130	3.096 (1.220-7.858)	0.02	1.527	4.604 (1.506-14.076)	< 0.01
Hyperlipidemia	-0.048	0.954 (0.322-1.940)	0.86				0.122	1.129 (0.756-1.911)	0.72
BMI	0.001	1.001 (0.921-1.344)	0.97				0.046	1.047 (0.334-2.019)	0.29
Mid-UAC	-0.029	0.972 (0.187-3.009)	0.54				-0.007	0.993 (0.033-2.870)	0.9
6MWT	0.269	1.308 (1.131-1.513)	< 0.01	0.175	1.191 (1.024, 1.385)	0.02	0.26	1.297 (1.084-1.553)	< 0.01
Grip strength	-0.063	0.93 (0.90-0.987)	< 0.01	-0.055	0.947 (0.911, 0.984)	< 0.01	-0.053	0.948 (0.911-0.988)	0.01
FBG	-0.04	0.996 (0.541-1.982)	0.935				-0.023	0.977 (0.334-2.081)	0.67
HbA1C	0.106	1.12 (0.711-1.593)	0.09				0.098	1.103 (0.321-3.017)	0.199
hsCRP	0.07	1.007 (0.448-1.831)	0.61				0.07	1.007 (0.409-1.910)	0.646
β2-MG	0.24	1.273 (1.051-1.542)	0.013				0.285	1.330 (1.036-1.714)	0.028
IL-6	0.02	1.02 (0.772-1.406)	0.21				0.014	1.014 (0.119-4.557)	0.508
TCH	-0.309	0.734 (0.569-0.948)	0.012				-0.206	0.814 (0.286-1.337)	0.173
TG	0.073	1.076 (0.471-2.696)	0.44				0.012	1.012 (0.553-3.469)	0.902
LDL-C	-0.263	0.77 (0.224-1.927)	0.07				-0.267	0.766 (0.468-1.370)	0.126
HDL-C	0.068	1.071 (0.443-3.042)	0.82				0.056	1.057 (0.427-3.285)	0.871
MNA-SF-based malnutrition	1.063	2.895 (1.438-5.830)	< 0.01	1.075	2.930 (1.218, 7.046)	0.02	0.902	2.465 (1.040-5.839)	0.04	0.912	2.908 (1.01-4.913)	0.044
IADL-based disability	1.333	3.793 (2.117-6.796)	< 0.01	0.896	2.449 (1.160, 5.172)	0.01	1.171	3.226 (1.624-6.405)	< 0.01	0.856	2.354 (1.062-5.215)	0.035
FRAIL-based frailty phenotype	-0.380	1.463 (0.563-1.980)	0.42				0.914	2.493 (0.462-5.707)	0.157
Low physical activity	0.621	1.860 (1.053-3.285)	0.03				0.407	1.502 (0.978-3.750)	0.23

BMI: Body mass index; UAC: Upper arm circumference; 6MWT: 6-minute walk test; FBG: Fasting blood glucose; hsCRP: High-sensitivity C-reactive protein; β2-MG: β2-microglobulin; IL: Interleukin; LDL-C: Low-density lipoprotein cholesterol; TG: Triglycerides; TCH: Total cholesterol; HDL-C: High-density lipoprotein cholesterol; MOCA: Montreal Cognitive Assessment; MNA-SF: Mini Nutritional Assessment-Short Form; FRAIL: Fatigue, resistance, ambulation, illness, and loss of weight.

Table 4 Baseline characteristics of the training set and test set, n (%)/mean ± SD

Variables	Total (n = 200)	Training set (n = 140)	Test set (n = 60)	Statistic	P value
Age (years)	70.87 ± 7.77	70.93 ± 7.84	70.73 ± 7.66	t = -0.16	0.871
Male	90 (45.00)	65 (46.43)	25 (41.67)	χ² = 0.38	0.535
Smoking	69 (34.50)	46 (32.86)	23 (38.33)	χ² = 0.56	0.455
Drinking	26 (13.07)	20 (14.29)	6 (10.17)	χ² = 0.62	0.431
Hypertension	155 (77.89)	112 (80.58)	43 (71.67)	χ² = 0.32	0.141
Cardiovascular disease	67 (33.50)	51 (36.43)	16 (26.67)	χ² = 1.80	0.180
Stroke	28 (14.00)	21 (15.00)	7 (11.67)	χ² = 0.39	0.534
Hearing impairment	4 (2.00)	4 (2.86)	0 (0.00)	χ² = 0.60	0.440
Hyperlipidemia	89 (44.50)	65 (46.43)	24 (40.00)	χ² = 0.70	0.402
Hypertension	155 (77.89)	112 (80.58)	43 (71.67)	χ²= 0.32	0.141
Education level (years)	10.02 ± 4.39	10.09 ± 4.35	9.85 ± 4.50	t = -0.33	0.740
BMI (kg/m2)	25.83 ± 3.66	25.85 ± 3.84	25.77 ± 3.22	t = -0.24	0.513
Mid-UAC (mm)	27.20 ± 3.73	26.73 ± 3.73	28.26 ± 3.53	t = 2.50	0.113
6MWT (m)	6.45 ± 2.43	6.57 ± 2.35	6.18 ± 2.60	t = -0.97	0.335
Grip strength (kg)	26.53 ± 13.73	26.44 ± 13.91	26.75 ± 13.44	t = 0.13	0.893
FBG (mmol/L)	7.99 ± 3.29	7.85 ± 3.26	8.31 ± 3.37	t = 0.90	0.368
HbA1C (%)	8.19 ± 2.30	8.21 ± 2.34	8.17 ± 2.23	t =-0.11	0.914
hsCRP (mg/L)	4.78 ± 11.62	5.21 ± 12.89	3.72 ± 7.60	t = -0.76	0.451
β2-MG (mg/L)	3.42 ± 1.63	3.48 ± 1.72	3.27 ± 1.37	t = -0.77	0.440
IL-6 (pg/mL)	6.59 ± 10.32	6.06 ± 9.51	7.93 ± 12.12	t = 1.06	0.291
TCH (mmol/L)	4.24 ± 1.20	4.26 ± 1.30	4.21 ± 0.93	t = -0.34	0.738
TG (mmol/L)	1.80 ± 1.67	1.86 ± 1.69	1.65 ± 1.63	t = -0.84	0.403
LDL-C (mmol/L)	2.35 ± 1.03	2.37 ± 1.07	2.30 ± 0.93	t = -0.45	0.654
HDL-C (mmol/L)	1.28 ± 0.48	1.27 ± 0.50	1.32 ± 0.41	t = 0.64	0.524
Mental work	109 (60.56)	76 (60.80)	33 (60.00)	χ² = 0.01	0.919
Residential region, urban	159 (79.50)	109 (77.86)	50 (83.33)	χ² = 0.77	0.379
MOCA-based cognitive impairment	47 (23.50)	32 (22.90)	15 (25.00)	χ² = 0.61	0.413
MNA-SF-based malnutrition	26 (14.21)	18 (14.29)	8 (14.04)	χ2 = 0.00	0.964
IADL-based disability	80 (40.00)	62 (44.29)	18 (30.00)	χ² = 3.57	0.059
FRAIL-based frailty phenotype	26 (14.29)	17 (13.71)	9 (15.52)	χ² = 0.31	0.858

BMI: Body mass index; UAC: Upper arm circumference; 6MWT: 6-minute walk test; FBG: Fasting blood glucose; hsCRP: High-sensitivity C-reactive protein; β2-MG: β2-microglobulin; IL: Interleukin; LDL-C: Low-density lipoprotein cholesterol; TG: Triglycerides; TCH: Total cholesterol; HDL-C: High-density lipoprotein cholesterol; MOCA: Montreal Cognitive Assessment; MNA-SF: Mini Nutritional Assessment-Short Form; FRAIL: Fatigue, resistance, ambulation, illness, and loss of weight.

Table 5 Comparison of risk in the training and test sets for cognitive decline

Variable	Training						Test
	Univariate analysis			Multivariate analysis			Univariate analysis			Multivariate analysis
	β	OR (95%CI)	P value	β	OR (95%CI)	P value	β	OR (95%CI)	P value	β	OR (95%CI)	P value
Age	0.062	1.063 (1.011-1.124)	0.01	1.612	1.083 (1.012- 1.151)	0.01	0.077	1.080 (0.990-1.167)	0.05	0.161	1.175 (1.039-1.330)	0.01
Male	0.169	1.245 (0.883-1.862)	0.06				0.233	1.258 (0.901-1.983)	0.23
Education level	-0.042	0.959 (0.872-1.055)	0.39				-0.114	0.814 (0.449-0.760)	0.28
Mental work	-0.062	0.640 (0.013-0.739)	0.01	-0.066	0.610 (0.47-1.22)	0.03	-0.893	0.509 (0.097-0.894)	0.02	-1.303	0.233 (0.065-0.794)	< 0.01
Residential region (urban)	-0.122	0.886 (0.734-0.992)	0.70				0.41	1.575 (0.961-1.912)	0.51
Smoking	0.301	1.704 (1.311-2.163)	0.48				0.496	1.132 (0.908-1.801)	0.69
Drinking	0.127	1.308 (0.293-2.643)	0.82				0.087	1.181 (0.764-1.597)	0.74
Hypertension	0.068	1.071 (0.391-2.934)	0.19				0.522	1.347 (0.990-1.814)	0.41
Cardiovascular disease	0.721	2.057 (0.922-4.588)	0.06				0.471	1.843 (0.891-2.914)	0.09
Hearing impairment	2.395	10.31 (3.10-46.8)	0.04				2.124	5.173 (1.302-13.232)	0.04
Stroke	1.561	4.762 (1.573-14.419)	< 0.01	1.611	5.010 (1.27-12.908)	0.02	0.984	1.292 (0.213-4.858)	0.02	1.134	1.456 (0.831-4.762)	0.02
Hyperlipidemia	0.043	1.044 (0.473-2.305)	0.81				0.312	1.541 (0.451-2.211)	0.73
BMI	0.037	1.038 (0.940-1.146)	0.46				0.031	1.542 (0.411-2.897)	0.21
Mid-UAC	0.012	1.012 (0.894-1.145)	0.84				-0.014	0.323 (0.033-2.870)	0.87
6MWT	0.149	1.161 (0.971-1.389)	0.10				0.213	1.245 (1.084-1.913)	0.08
Grip strength	-0.033	0.967 (0.928-1.008)	0.11				-0.413	0.899 (0.414-1.184)	0.11
FBG	-0.032	0.969 (0.852-1.101)	0.62				-0.051	0.914 (0.245-2.181)	0.82
HbA1C	0.008	1.035 (0.873-1.227)	0.38				0.144	1.243 (0.324-3.197)	0.43
hsCRP	0.07	1.008 (0.979-1.039)	0.59				0.114	1.303 (0.441-1.910)	0.65
β2-MG	0.094	1.099 (0.869-1.389)	0.43				0.34	1.311 (1.046-2.09)	0.51
IL-6	-0.013	0.987 (0.927-1.052)	0.69				0.011	1.017 (0.213-3.511)	0.81
TCH	-0.259	0.772 (0.553-1.076)	0.12				-0.099	0.974 (0.423-1.037)	0.17
TG	0.003	1.097 (0.886-1.264)	0.97				0.013	1.041 (0.351-2.916)	0.78
LDL-C	-0.293	0.746 (0.502-1.109)	0.14				0.012	1.016 (0.688-1.349)	0.31
HDL-C	0.193	1.213 (0.572-2.570)	0.61				0.091	1.133 (0.387-3.465)	0.83
MNA-SF-based malnutrition	1.063	2.895 (1.438-5.830)	< 0.01	0.75	1.680 (1.01-2.146)	0.04	0.931	3.465 (1.34-8.331)	0.02	1.021	3.193 (0.944-5.523)	0.04
IADL-based disability	0.987	2.683 (1.188-6.061)	0.02	1.170	3.203 (1.189-6.06)	0.02	0.606	1.833 (0.539-6.294)	< 0.01	0.833	2.104 (1.187-6.051)	0.03
FRAIL-based frailty phenotype	1.110	3.033 (0.622-14.785)	0.17				0.911	2.933 (0.462-5.097)	0.22
Low physical activity	0.371	1.57 (1.290-2.987)	0.41				0.432	1.033 (0.478-3.250)	0.51

BMI: Body mass index; UAC: Upper arm circumference; 6MWT: 6-minute walk test; FBG: Fasting blood glucose; hsCRP: High-sensitivity C-reactive protein; β2-MG: β2-microglobulin; IL: Interleukin; LDL-C: Low-density lipoprotein cholesterol; TG: Triglycerides; TCH: Total cholesterol; HDL-C: High-density lipoprotein cholesterol; MOCA: Montreal Cognitive Assessment; MNA-SF: Mini Nutritional Assessment-Short Form; FRAIL: Fatigue, resistance, ambulation, illness, and loss of weight.