Clustering of Lifestyle Factors and Its Association with Low Back Pain: A Cross-Sectional Study of Over 400,000 Japanese Adults

Figures & data

Table 1 Characteristics of the Study Participants by Low Back Pain in Men

	Low Back Pain (+)	Low Back Pain (−)	p-value^a
	(n = 5486)	(n = 275,622)
Age, years
Median (25th, 75th percentiles)	51 (41, 61)	45 (36, 55)	<0.001
Mean (standard deviation)	50.9 (12.5)	45.5 (12.5)
Body mass index, kg/m^2
Median (25th, 75th percentiles)	23.7 (21.6, 26.0)	23.2 (21.1, 25.6)	<0.001
Mean (standard deviation)	24.1 (3.7)	23.7 (3.7)
Current smoker, n (%)	2431 (44.3)	129,977 (47.2)	<0.001
Daily drinker, n (%)	2257 (41.1)	99,315 (36.0)	<0.001
Weight gain (≥10 kg since age 20 years), n (%)	2474 (45.1)	106,931 (38.8)	<0.001
Exercise (≥30 min/day, ≥ twice/week), n (%)	1320 (24.1)	64,772 (23.5)	0.332
Physical activity (≥1 hr/day), n (%)	2066 (37.7)	108,597 (39.4)	0.009
Walking faster, n (%)	2289 (41.7)	125,111 (45.4)	<0.001
Body weight change (≥3 kg/year), n (%)	2102 (38.3)	93,583 (34.0)	<0.001
Eating fast, n (%)	1773 (32.3)	83,972 (30.5)	0.003
Eating dinner within 2 hours before bedtime (≥3 times/week), n (%)	2294 (41.8)	117,739 (42.7)	0.181
Having a snack after dinner (≥3 times/week), n (%)	857 (15.6)	42,229 (15.3)	0.541
Skipping breakfast (≥3 times/week), n (%)	1215 (22.2)	79,135 (28.7)	< 0.001
Adequate sleep, n (%)	2850 (52.0)	169,996 (61.7)	< 0.001
Hypertension, n (%)	1892 (34.5)	88,180 (32.0)	< 0.001
Diabetes, n (%)	488 (8.9)	18,511 (6.7)	< 0.001
Dyslipidemia, n (%)	2790 (50.9)	136,124 (49.4)	0.031

Note: ^ap-value based on a chi-squared test or Wilcoxon rank-sum test.

Table 2 Characteristics of the Study Participants by Low Back Pain in Women

	Low Back Pain (+)	Low Back Pain (−)	p-value^a
	(n = 2575)	(n = 135,320)
Age, years
Median (25th, 75th percentiles)	54 (44, 61)	46 (36, 55)	<0.001
Mean (standard deviation)	52.3 (12.2)	45.6 (12.5)
Body mass index, kg/m^2
Median (25th, 75th percentiles)	22.6 (20.4, 25.4)	21.5 (19.5, 24.1)	<0.001
Mean (standard deviation)	23.3 (4.2)	22.2 (3.9)
Current smoker, n (%)	552 (21.4)	26,429 (19.5)	0.016
Daily drinker, n (%)	384 (14.9)	18,211 (13.5)	0.032
Weight gain (≥10 kg since age 20 years), n (%)	880 (34.2)	32,141 (23.8)	<0.001
Exercise (≥30 min/day, ≥ twice/week), n (%)	494 (19.2)	20,391 (15.1)	<0.001
Physical activity (≥1 hr/day), n (%)	928 (36.0)	44,201 (32.7)	<0.001
Walking faster, n (%)	926 (36.0)	52,711 (39.0)	0.002
Body weight change (≥3 kg/year), n (%)	907 (35.2)	39,699 (29.3)	<0.001
Eating fast, n (%)	687 (26.7)	30,257 (22.4)	<0.001
Eating dinner within 2 hours before bedtime (≥3 times/week), n (%)	690 (26.8)	33,694 (24.9)	0.028
Having a snack after dinner (≥3 times/week), n (%)	511 (19.8)	25,981 (19.2)	0.411
Skipping breakfast (≥3 times/week), n (%)	464 (18.0)	25,878 (19.1)	0.158
Adequate sleep, n (%)	1191 (46.3)	80,161 (59.2)	<0.001
Hypertension, n (%)	689 (26.8)	29,679 (21.9)	<0.001
Diabetes, n (%)	134 (5.2)	4453 (3.3)	<0.001
Dyslipidemia, n (%)	1027 (39.9)	45,872 (33.9)	<0.001

Note: ^ap-value based on a chi-squared test or Wilcoxon rank-sum test.

Table 3 Association Between Lifestyle Risk Score and Low Back Pain by Sex

		Total	LBP	Model 1	Model 2	Model 3
		N	n (%)	OR (95% CI)	OR (95% CI)	OR (95% CI)
Men
Lifestyle risk score	Low (0–3)	63,022	986 (1.56)	1.00	1.00	1.00
	Moderate (4–5)	105,120	2080 (1.98)	1.27 (1.18–1.37)	1.32 (1.22–1.43)	1.33 (1.23–1.44)
	High (6–12)	112,966	2420 (2.14)	1.38 (1.28–1.48)	1.53 (1.42–1.65)	1.54 (1.43–1.67)
	p for trend			<0.001	<0.001	<0.001
Women
Lifestyle risk score	Low (0–3)	49,179	735 (1.49)	1.00	1.00	1.00
	Moderate (4–5)	55,757	1054 (1.89)	1.27 (1.15–1.40)	1.39 (1.27–1.54)	1.40 (1.27–1.54)
	High (6–12)	32,959	786 (2.38)	1.61 (1.45–1.78)	1.81 (1.63–2.02)	1.83 (1.64–2.03)
	p for trend			<0.001	<0.001	<0.001

Notes: Model 1: Crude model. Model 2: Adjusted for age and body mass index. Model 3: Adjusted for age, body mass index, hypertension, diabetes, and dyslipidemia.

Abbreviations: OR, odds ratio; CI, confidence interval; LBP, low back pain.

Table 4 Association Between Lifestyle Risk Score and Low Back Pain Stratified by Age Group

	Age: 20–39 Years			Age: 40–59 Years			Age: ≥ 60 Years
	Total	LBP	Adjusted	Total	LBP	Adjusted	Total	LBP	Adjusted
	N	n (%)	OR (95% CI)	N	n (%)	OR (95% CI)	N	n (%)	OR (95% CI)
Men
Lifestyle risk score
Low (0–3)	20,831	166 (0.80)	1.00	27,222	406 (1.49)	1.00	14,969	414 (2.76)	1.00
Moderate (4–5)	33,946	383 (1.13)	1.33 (1.11–1.60)	52,474	1043 (1.99)	1.33 (1.19–1.50)	18,700	654 (3.50)	1.36 (1.20–1.54)
High (6–12)	39,307	558 (1.42)	1.56 (1.30–1.86)	61,866	1348 (2.18)	1.47 (1.31–1.65)	11,793	514 (4.36)	1.79 (1.56–2.05)
p for trend			<0.001			<0.001			<0.001
Women
Lifestyle risk score
Low (0–3)	13,652	87 (0.64)	1.00	25,086	346 (1.38)	1.00	10,441	302 (2.89)	1.00
Moderate (4–5)	18,182	158 (0.87)	1.31 (1.01–1.71)	29,938	573 (1.91)	1.37 (1.20–1.57)	7637	323 (4.23)	1.54 (1.31–1.82)
High (6–12)	11,475	155 (1.35)	1.89 (1.44–2.48)	18,404	481 (2.61)	1.84 (1.59–2.13)	3080	150 (4.87)	1.79 (1.45–2.21)
p for trend			<0.001			<0.001			<0.001

Note: Adjusted for age, body mass index, hypertension, diabetes, and dyslipidemia.

Abbreviations: OR, odds ratio; CI, confidence interval; LBP, low back pain.

Table 5 Association Between Lifestyle Risk Score and Low Back Pain Stratified by BMI Status

	Underweight (BMI < 18.5 kg/m^2)			Normal (18.5–24.9 kg/m^2)			Overweight/Obese (BMI ≥ 25 kg/m^2)
	Total	LBP	Adjusted	Total	LBP	Adjusted	Total	LBP	Adjusted
	N	n (%)	OR (95% CI)	N	n (%)	OR (95% CI)	N	n (%)	OR (95% CI)
Men
Lifestyle risk score
Low (0–3)	3833	49 (1.28)	1.00	47,712	728 (1.53)	1.00	11,477	209 (1.82)	1.00
Moderate (4–5)	5470	74 (1.35)	1.07 (0.75–1.55)	71,131	1336 (1.88)	1.32 (1.21–1.45)	28,519	670 (2.35)	1.37 (1.17–1.60)
High (6–12)	3824	78 (2.04)	1.66 (1.15–2.38)	63,763	1311 (2.06)	1.60 (1.45–1.75)	45,379	1031 (2.27)	1.46 (1.25–1.70)
p for trend			0.004			<0.001			<0.001
Women
Lifestyle risk score
Low (0–3)	7561	77 (1.02)	1.00	36,415	559 (1.54)	1.00	5203	99 (1.90)	1.00
Moderate (4–5)	7391	90 (1.22)	1.43 (1.05–1.95)	37,478	635 (1.69)	1.28 (1.14–1.44)	10,888	329 (3.02)	1.75 (1.39–2.20)
High (6–12)	2939	38 (1.29)	1.68 (1.13–2.50)	19,357	449 (2.32)	1.95 (1.71–2.22)	10,663	299 (2.80)	1.80 (1.42–2.27)
p for trend			0.005			<0.001			<0.001

Note: Adjusted for age, body mass index, hypertension, diabetes, and dyslipidemia.

Abbreviations: OR, odds ratio; CI, confidence interval; LBP, low back pain; BMI, body mass index.