J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://www.jocmr.org

Original Article

Volume 15, Number 3, March 2023, pages 148-160

Risk Factors Associated With Atrial Fibrillation in Elderly Patients

**Table 1.** Baseline Characteristics
Variable	Patients with atrial fibrillation (n = 418)	Patients without atrial fibrillation (n = 2,015)	P
SD: standard deviation; BP: blood pressure; BMI: body mass index; HbA1c: glycosylated hemoglobin A1c; LDL: low-density lipoprotein; HDL: high-density lipoprotein; TG: triglycerides; TSH: thyroid-stimulating hormone; hs-CRP: high-sensitivity C-reactive protein; WBC: white blood cell count; ESR: erythrocyte sedimentation rate; ANA: anti-nuclear antibody; CAD: coronary artery disease; DM: diabetes mellitus; CVA: cerebrovascular accident; CHF: congestive heart failure; PAD: peripheral arterial disease; OSA: obstructive sleep apnea; COPD: chronic obstructive pulmonary disease; CKD: chronic kidney disease; HIV: human immunodeficiency virus; NSAIDs: non-steroidal anti-inflammatory drugs; SSRIs: selective serotonin reuptake inhibitors; SNRIs: serotonin and norepinephrine reuptake inhibitors; CNS: central nervous system; NOACs: novel oral anticoagulants.
Age (years), mean (SD)	80.1 (7.8)	75.7 (7.3)	< 0.001
Sex
Male, n (%)	225 (53.8)	832 (41.3)	< 0.001
Female, n (%)	193 (46.2)	1,183 (58.7)
Race
White, n (%)	361 (86.3)	1,536 (76.2)	< 0.001
Black, n (%)	27 (6.5)	261 (13.0)
Other, n (%)	30 (7.2)	218 (10.8)
Social
Tobacco use, n (%)	177 (42.3)	852 (42.3)	0.990
Alcohol use, n (%)	209 (50.1)	1,078 (53.5)	0.204
Recreational drug use, n (%)	15 (3.6)	49 (2.4)	0.174
Vitals
Systolic BP (mm Hg), mean (SD)	126 (18)	129 (16)	0.002
Diastolic BP (mm Hg), mean (SD)	72 (11)	74 (9)	< 0.001
Weight
BMI (kg/m²), mean (SD)	29.8 (18.5)	28.2 (6.0)	0.095
Lab values
HbA1c (%), mean (SD)	6.9 (5.1)	6.9 (5.7)	0.996
Total cholesterol (mg/dL), mean (SD)	151.8 (39.6)	174.1 (42.9)	< 0.001
LDL (mg/dL), mean (SD)	80.3 (42.9)	96.4 (48.4)	< 0.001
HDL (mg/dL), mean (SD)	53.5 (16.9)	56.9 (25.8)	0.009
TG (mg/dL), mean (SD)	102.7 (54.1)	112.0 (64.2)	0.006
TSH (mIU/L), mean (SD)	2.8 (2.4)	2.3 (1.8)	< 0.001
hs-CRP (mg/L) (median, 25th - 75th)	0.60 (0.18 - 3.23)	0.80 (0.28 - 2.60)	0.434
WBC (× 10⁹/L) (median, 25th - 75th)	6.79 (5.50 - 8.08)	6.40 (5.40 - 7.86)	0.030
ESR (mm/h) (median, 25th - 75th)	18.50 (6.75 - 37.00)	16.00 (7.00 - 32.00)	0.105
ANA (median, 25th - 75th)	0.00 (0.00 - 0.09)	0.00 (0.00 - 1.70)	0.414
Rheumatoid factor (IU/mL) (median, 25th - 75th)	0.00 (0.00 - 7.70)	4.00 (0.00 - 10.00)	0.009
Family history
Atrial fibrillation, n (%)	6 (1.5)	10 (0.5)	0.038
CAD, n (%)	131 (31.3)	507 (25.2)	0.011
Comorbidities
Hypertension, n (%)	359 (85.9)	1,381 (68.5)	< 0.001
Hyperlipidemia, n (%)	307 (73.4)	1,300 (64.5)	0.021
DM, n (%)	136 (32.5)	543 (27.0)	< 0.001
CAD, n (%)	156 (37.3)	340 (16.9)	< 0.001
CVA, n (%)	59 (14.1)	88 (4.4)	0.015
CHF, n (%)	73 (17.5)	56 (2.8)	< 0.001
Carotid stenosis, n (%)	30 (7.2)	88 (4.4)	< 0.001
Aortic aneurysm, n (%)	25 (5.4)	5 (2.0)	0.019
PAD, n (%)	43 (10.3)	64 (3.2)	< 0.001
Hypothyroidism, n (%)	91 (21.8)	375 (18.6)	0.135
Hyperthyroidism, n (%)	8 (1.9)	26 (1.3)	0.321
Other endocrine disorders, n (%)	37 (8.9)	131 (6.5)	0.085
Long QTc, n (%)	1 (0.2)	5 (0.2)	1.000
Other arrhythmias, n (%)	153 (36.6)	304 (15.1)	0.001
OSA, n (%)	71 (17.0)	206 (10.2)	0.001
Depression, n (%)	84 (20.1)	326 (18.7)	0.052
Bipolar disorder, n (%)	4 (1.0)	19 (0.09)	1.000
Anxiety disorder, n (%)	85 (20.3)	326 (18.7)	0.426
Schizophrenia, n (%)	1 (0.2)	3 (0.1)	0.529
COPD, n (%)	48 (11.5)	1,113 (5.6)	< 0.001
Asthma, n (%)	47 (11.2)	203 (10.1)	0.474
Osteoarthritis, n (%)	216 (51.7)	540 (26.8)	< 0.001
Other rheumatological disorders, n (%)	4 (1.0)	607 (30.1)	< 0.001
CKD, n (%)	106 (25.4)	221 (11.0)	< 0.001
Liver disease, n (%)	39 (9.3)	111 (5.5)	0.005
Colorectal disease, n (%)	111 (26.6)	403 (20.0)	0.003
Frail, n (%)	21 (5.1)	108 (5.4)	0.694
HIV infection, n (%)	1 (0.2)	3 (0.1)	0.530
Other immunodeficiency disorders, n (%)	6 (1.4)	26 (1.3)	0.813
Post-immunosuppressant treatment, n (%)	2 (0.5)	23 (1.1)	0.293
Monoclonal antibody therapies, n (%)	0 (0.0)	36 (1.8)	0.005
Cancer, n (%)	153 (36.6)	535 (26.6)	< 0.001
Medications
Aspirin, n (%)	183 (43.9)	856 (42.5)	0.598
Antihypertensive medication, n (%)	359 (85.9)	1,362 (67.5)	< 0.001
NSAIDs, n (%)	50 (12.0)	628 (31.2)	< 0.001
Statin, n (%)	307 (73.4)	1,253 (62.2)	< 0.001
Steroid, n (%)	113 (27.1)	690 (34.2)	0.005
Levothyroxine, n (%)	83 (19.9)	365 (18.1)	0.396
Digoxin, n (%)	6 (1.4)	22 (1.1)	1.000
SSRIs, n (%)	70 (16.8)	293 (14.5)	0.241
SNRIs, n (%)	18 (4.3)	99 (4.9)	0.604
CNS stimulants, n (%)	0 (0.0)	14 (0.7)	0.147
Benzodiazepines, n (%)	69 (16.5)	324 (16.1)	0.813
Warfarin, n (%)	52 (12.5)	40 (2.0)	< 0.001
NOACs, n (%)	219 (52.5)	52 (2.6)	< 0.001

Table 1. Baseline Characteristics

Variable

Patients with atrial fibrillation (n = 418)

Patients without atrial fibrillation (n = 2,015)

SD: standard deviation; BP: blood pressure; BMI: body mass index; HbA1c: glycosylated hemoglobin A1c; LDL: low-density lipoprotein; HDL: high-density lipoprotein; TG: triglycerides; TSH: thyroid-stimulating hormone; hs-CRP: high-sensitivity C-reactive protein; WBC: white blood cell count; ESR: erythrocyte sedimentation rate; ANA: anti-nuclear antibody; CAD: coronary artery disease; DM: diabetes mellitus; CVA: cerebrovascular accident; CHF: congestive heart failure; PAD: peripheral arterial disease; OSA: obstructive sleep apnea; COPD: chronic obstructive pulmonary disease; CKD: chronic kidney disease; HIV: human immunodeficiency virus; NSAIDs: non-steroidal anti-inflammatory drugs; SSRIs: selective serotonin reuptake inhibitors; SNRIs: serotonin and norepinephrine reuptake inhibitors; CNS: central nervous system; NOACs: novel oral anticoagulants.

Age (years), mean (SD)

80.1 (7.8)

75.7 (7.3)

< 0.001

Sex

Male, n (%)

225 (53.8)

832 (41.3)

< 0.001

Female, n (%)

193 (46.2)

1,183 (58.7)

Race

White, n (%)

361 (86.3)

1,536 (76.2)

< 0.001

Black, n (%)

27 (6.5)

261 (13.0)

Other, n (%)

30 (7.2)

218 (10.8)

Social

Tobacco use, n (%)

177 (42.3)

852 (42.3)

0.990

Alcohol use, n (%)

209 (50.1)

1,078 (53.5)

0.204

Recreational drug use, n (%)

15 (3.6)

49 (2.4)

0.174

Vitals

Systolic BP (mm Hg), mean (SD)

126 (18)

129 (16)

0.002

Diastolic BP (mm Hg), mean (SD)

72 (11)

74 (9)

< 0.001

Weight

BMI (kg/m²), mean (SD)

29.8 (18.5)

28.2 (6.0)

0.095

Lab values

HbA1c (%), mean (SD)

6.9 (5.1)

6.9 (5.7)

0.996

Total cholesterol (mg/dL), mean (SD)

151.8 (39.6)

174.1 (42.9)

< 0.001

LDL (mg/dL), mean (SD)

80.3 (42.9)

96.4 (48.4)

< 0.001

HDL (mg/dL), mean (SD)

53.5 (16.9)

56.9 (25.8)

0.009

TG (mg/dL), mean (SD)

102.7 (54.1)

112.0 (64.2)

0.006

TSH (mIU/L), mean (SD)

2.8 (2.4)

2.3 (1.8)

< 0.001

hs-CRP (mg/L) (median, 25th - 75th)

0.60 (0.18 - 3.23)

0.80 (0.28 - 2.60)

0.434

WBC (× 10⁹/L) (median, 25th - 75th)

6.79 (5.50 - 8.08)

6.40 (5.40 - 7.86)

0.030

ESR (mm/h) (median, 25th - 75th)

18.50 (6.75 - 37.00)

16.00 (7.00 - 32.00)

0.105

ANA (median, 25th - 75th)

0.00 (0.00 - 0.09)

0.00 (0.00 - 1.70)

0.414

Rheumatoid factor (IU/mL) (median, 25th - 75th)

0.00 (0.00 - 7.70)

4.00 (0.00 - 10.00)

0.009

Family history

Atrial fibrillation, n (%)

6 (1.5)

10 (0.5)

0.038

CAD, n (%)

131 (31.3)

507 (25.2)

0.011

Comorbidities

Hypertension, n (%)

359 (85.9)

1,381 (68.5)

< 0.001

Hyperlipidemia, n (%)

307 (73.4)

1,300 (64.5)

0.021

DM, n (%)

136 (32.5)

543 (27.0)

< 0.001

CAD, n (%)

156 (37.3)

340 (16.9)

< 0.001

CVA, n (%)

59 (14.1)

88 (4.4)

0.015

CHF, n (%)

73 (17.5)

56 (2.8)

< 0.001

Carotid stenosis, n (%)

30 (7.2)

88 (4.4)

< 0.001

Aortic aneurysm, n (%)

25 (5.4)

5 (2.0)

0.019

PAD, n (%)

43 (10.3)

64 (3.2)

< 0.001

Hypothyroidism, n (%)

91 (21.8)

375 (18.6)

0.135

Hyperthyroidism, n (%)

8 (1.9)

26 (1.3)

0.321

Other endocrine disorders, n (%)

37 (8.9)

131 (6.5)

0.085

Long QTc, n (%)

1 (0.2)

5 (0.2)

1.000

Other arrhythmias, n (%)

153 (36.6)

304 (15.1)

0.001

OSA, n (%)

71 (17.0)

206 (10.2)

0.001

Depression, n (%)

84 (20.1)

326 (18.7)

0.052

Bipolar disorder, n (%)

4 (1.0)

19 (0.09)

1.000

Anxiety disorder, n (%)

85 (20.3)

326 (18.7)

0.426

Schizophrenia, n (%)

1 (0.2)

3 (0.1)

0.529

COPD, n (%)

48 (11.5)

1,113 (5.6)

< 0.001

Asthma, n (%)

47 (11.2)

203 (10.1)

0.474

Osteoarthritis, n (%)

216 (51.7)

540 (26.8)

< 0.001

Other rheumatological disorders, n (%)

4 (1.0)

607 (30.1)

< 0.001

CKD, n (%)

106 (25.4)

221 (11.0)

< 0.001

Liver disease, n (%)

39 (9.3)

111 (5.5)

0.005

Colorectal disease, n (%)

111 (26.6)

403 (20.0)

0.003

Frail, n (%)

21 (5.1)

108 (5.4)

0.694

HIV infection, n (%)

1 (0.2)

3 (0.1)

0.530

Other immunodeficiency disorders, n (%)

6 (1.4)

26 (1.3)

0.813

Post-immunosuppressant treatment, n (%)

2 (0.5)

23 (1.1)

0.293

Monoclonal antibody therapies, n (%)

0 (0.0)

36 (1.8)

0.005

Cancer, n (%)

153 (36.6)

535 (26.6)

< 0.001

Medications

Aspirin, n (%)

183 (43.9)

856 (42.5)

0.598

Antihypertensive medication, n (%)

359 (85.9)

1,362 (67.5)

< 0.001

NSAIDs, n (%)

50 (12.0)

628 (31.2)

< 0.001

Statin, n (%)

307 (73.4)

1,253 (62.2)

< 0.001

Steroid, n (%)

113 (27.1)

690 (34.2)

0.005

Levothyroxine, n (%)

83 (19.9)

365 (18.1)

0.396

Digoxin, n (%)

6 (1.4)

22 (1.1)

1.000

SSRIs, n (%)

70 (16.8)

293 (14.5)

0.241

SNRIs, n (%)

18 (4.3)

99 (4.9)

0.604

CNS stimulants, n (%)

0 (0.0)

14 (0.7)

0.147

Benzodiazepines, n (%)

69 (16.5)

324 (16.1)

0.813

Warfarin, n (%)

52 (12.5)

40 (2.0)

< 0.001

NOACs, n (%)

219 (52.5)

52 (2.6)

< 0.001

**Table 2.** Influence of Risk Factors on Atrial Fibrillation
Risk factor	B	P	Exp(B)	95% CI for Exp(B)
B: beta coefficient; CI: confidence interval; P: probability significance; Exp(B): odds ratio; SBP: systolic blood pressure; DBP: diastolic blood pressure; TSH: thyroid-stimulating hormone; LDL-C: low-density lipoprotein cholesterol; HDL-C: high-density lipoprotein cholesterol; WBC: white blood cell count; CAD: coronary artery disease; CVA: cerebrovascular accident; PAD: peripheral arterial disease; COPD: chronic obstructive pulmonary disease; CHF: congestive heart failure; CKD: chronic kidney disease; NSAIDs: non-steroidal anti-inflammatory drugs; NOACs: novel oral anticoagulants.
Age (years)	0.044	< 0.001	1.045	1.022	1.069
Sex, male	0.178	0.330	1.195	0.835	1.712
Black vs. White	-1.294	< 0.001	0.274	0.141	0.531
Other races vs. White	-0.287	0.338	0.750	0.417	1.350
SBP	-0.009	0.107	0.991	0.980	1.002
DBP	0.015	0.105	1.015	0.997	1.034
TSH	0.074	0.029	1.077	1.007	1.151
LDL-C	-0.004	0.086	0.996	0.991	1.001
HDL-C	0.002	0.442	1.002	0.997	1.008
Triglyceride	-0.002	0.182	0.998	0.994	1.001
WBC	0.002	0.801	1.002	0.984	1.021
Family history of CAD	0.244	0.199	1.276	0.880	1.850
Hypertension	0.807	0.001	2.241	1.421	3.534
Hyperlipidemia	-0.093	0.651	0.911	0.609	1.363
Diabetes mellitus	0.061	0.764	1.063	0.714	1.583
CAD	0.316	0.136	1.372	0.906	2.077
CVA	0.313	0.284	1.367	0.772	2.423
Carotid artery stenosis	-0.494	0.206	0.610	0.283	1.313
PAD	0.600	0.093	1.822	0.904	3.672
Other cardiac arrhythmias	0.926	< 0.001	2.523	1.720	3.702
Obstructive sleep apnea	0.142	0.590	1.152	0.688	1.930
COPD	0.016	0.961	1.016	0.537	1.920
CHF	1.135	< 0.001	3.111	1.674	5.784
Osteoarthritis	1.103	< 0.001	3.014	2.138	4.247
Other rheumatological disorders	-1.935	< 0.001	0.144	0.086	0.243
CKD	0.230	0.306	1.258	0.810	1.953
Liver disease	0.756	0.014	2.129	1.164	3.893
Colorectal disease	0.405	0.048	1.500	1.003	2.243
Cancer	0.212	0.238	1.237	0.869	1.760
NSAIDs	-1.580	< 0.001	0.206	0.125	0.338
Antihypertensive medication	0.716	0.003	2.256	1.534	3.452
Statin	-0.233	0.263	0.792	0.526	1.191
Corticosteroid	-0.592	0.003	0.553	0.374	0.819
Warfarin	2.591	< 0.001	13.346	6.962	25.585
NOACs	3.786	< 0.001	44.097	28.275	68.773

Table 2. Influence of Risk Factors on Atrial Fibrillation

Risk factor

Exp(B)

95% CI for Exp(B)

Lower

Upper

B: beta coefficient; CI: confidence interval; P: probability significance; Exp(B): odds ratio; SBP: systolic blood pressure; DBP: diastolic blood pressure; TSH: thyroid-stimulating hormone; LDL-C: low-density lipoprotein cholesterol; HDL-C: high-density lipoprotein cholesterol; WBC: white blood cell count; CAD: coronary artery disease; CVA: cerebrovascular accident; PAD: peripheral arterial disease; COPD: chronic obstructive pulmonary disease; CHF: congestive heart failure; CKD: chronic kidney disease; NSAIDs: non-steroidal anti-inflammatory drugs; NOACs: novel oral anticoagulants.

Age (years)

0.044

< 0.001

1.045

1.022

1.069

Sex, male

0.178

0.330

1.195

0.835

1.712

Black vs. White

-1.294

< 0.001

0.274

0.141

0.531

Other races vs. White

-0.287

0.338

0.750

0.417

1.350

SBP

-0.009

0.107

0.991

0.980

1.002

DBP

0.015

0.105

1.015

0.997

1.034

TSH

0.074

0.029

1.077

1.007

1.151

LDL-C

-0.004

0.086

0.996

0.991

1.001

HDL-C

0.002

0.442

1.002

0.997

1.008

Triglyceride

-0.002

0.182

0.998

0.994

1.001

WBC

0.002

0.801

1.002

0.984

1.021

Family history of CAD

0.244

0.199

1.276

0.880

1.850

Hypertension

0.807

0.001

2.241

1.421

3.534

Hyperlipidemia

-0.093

0.651

0.911

0.609

1.363

Diabetes mellitus

0.061

0.764

1.063

0.714

1.583

CAD

0.316

0.136

1.372

0.906

2.077

CVA

0.313

0.284

1.367

0.772

2.423

Carotid artery stenosis

-0.494

0.206

0.610

0.283

1.313

PAD

0.600

0.093

1.822

0.904

3.672

Other cardiac arrhythmias

0.926

< 0.001

2.523

1.720

3.702

Obstructive sleep apnea

0.142

0.590

1.152

0.688

1.930

COPD

0.016

0.961

1.016

0.537

1.920

CHF

1.135

< 0.001

3.111

1.674

5.784

Osteoarthritis

1.103

< 0.001

3.014

2.138

4.247

Other rheumatological disorders

-1.935

< 0.001

0.144

0.086

0.243

CKD

0.230

0.306

1.258

0.810

1.953

Liver disease

0.756

0.014

2.129

1.164

3.893

Colorectal disease

0.405

0.048

1.500

1.003

2.243

Cancer

0.212

0.238

1.237

0.869

1.760

NSAIDs

-1.580

< 0.001

0.206

0.125

0.338

Antihypertensive medication

0.716

0.003

2.256

1.534

3.452

Statin

-0.233

0.263

0.792

0.526

1.191

Corticosteroid

-0.592

0.003

0.553

0.374

0.819

Warfarin

2.591

< 0.001

13.346

6.962

25.585

NOACs

3.786

< 0.001

44.097

28.275

68.773