Dietary Patterns and Prevalence of Post-bronchodilator Airway Obstruction in Dairy Farmers Exposed to Organic Dusts

Figures & data

Table 1. Main characteristics and pulmonary function of the study participants according to exposure to dairy-farming, number of smoked pack-years and presence of post-bronchodilator airway obstruction (defined by FEV1/FVC).

	Dairy farmers						Nondairy farmers
	≥ 10 pack-years			< 10 pack-years			≥ 10 pack-years
	Post-BD airway obstruction (n = 23)	Normal spirometry (n = 42)	p-value	Post-BD airway obstruction (n = 34)	Normal spirometry (n = 88)	p-value	Post-BD airway obstruction (n = 47)	Normal spirometry (n = 87)	p-value
Age (years)	62 ± 9	57 ± 10	0.08	61 ± 8	60 ± 9	0.52	62 ± 8	60 ± 7	0.34
Men, n (%)	21 (91)	39 (93)	1	26 (76)	75 (85)	0.29	37 (79)	65 (75)	0.67
Smoking status, n (%)			0.61			0.16
Non-smoker	–	–		28 (82)	69 (78)		–	–	0.01
Former smoker	12 (52)	25 (60)		4 (12)	18 (20)		15 (32)	48 (55)
Active smoker	11 (48)	17 (40)		2 (6)	1 (1)		32 (68)	39 (45)
Number of pack-years	30 ± 15	25 ± 11	0.18	1.0 ± 2.6	0.9 ± 2.1	0.85	42.0 ± 24.6#	30.3 ± 13.3	0.004
mMRC dyspnea > 0	11 (48)	13 (31)	0.19	10 (30)	16 (18)	0.09	22 (47)	26 (30)	0.06
Post-bronchodilator spirometry
FEV1, L	2.72 ± 0.67	3.31 ± 0.60	0.002	2.86 ± 0.90	3.24 ± 0.74	0.03	2.37 ± 0.70	3.27 ± 0.71	<0.001
z-score	–1.37 ± 0.84	0.07 ± 1.03	<0.001	–1.23 ± 0.98	0.10 ± 0.92	<0.001	–1.76 ± 0.87	0.20 ± 0.95	<0.001
FVC, L	4.58 ± 0.88	4.47 ± 0.87	0.63	4.72 ± 1.33	4.29 ± 0.91	0.09	4.13 ± 1.07	4.27 ± 0.95	0.46
z-score	0.32 ± 0.91	0.41 ± 1.05	0.70	0.51 ± 1.12	0.27 ± 0.87	0.28	–0.04 ± 1.07	0.26 ± 0.82	0.10
FEV1/FVC, %	59.1 ± 6.2	73.9 ± 5.8	<0.001	60.1 ± 7.4	75.6 ± 6.4	<0.001	57.1 ± 7.3	77.0 ± 6.5	<0.001
z-score	–2.41 ± 0.62	–0.55 ± 0.73	<0.001	–2.44 ± 0.70	−0.29 ± 0.87	<0.001	–2.61 ± 0.68	–0.12 ± 0.89	<0.001
Severity of airway obstruction, n (%)
Stage I	15 (65)	–		23 (70)	–		20 (43)*	–
Stage II+	8 (35)	–		10 (30)	–		27 (57)*	–

post-BD, post-bronchodilator; mMRC, modified medical research council; FEV₁, forced expiratory volume in 1 second; z-score, standardized residual; FVC, forced vital capacity. Stage I, FEV1 > 80% of the predicted value; Stage II+, FEV1 of less than ≤ 80% of the predicted value. Values are means ± SD.

^#: p < 0.05 vs. dairy farmers with post-BD airway obstruction who had smoked ≥ 10 pack-years; *: p < 0.05 vs. dairy farmers with post-BD airway obstruction < 10 pack-years

Figure 1. Flowchart of the population.

Table 2. Adapted Alternate Healthy Eating Index scores and subscores and nutritional intake ratios with the results of food-frequency questionnaires according to exposure to dairy farming, number of pack-years smoked and presence of post-bronchodilator airway obstruction (defined by FEV1/FVC).

	Dairy farmers						Nondairy farmers
	≥ 10 pack-years			< 10 pack-years			≥ 10 pack-years
	Post-bronchodilator airway obstruction	Normal spirometry	p-value	Post-bronchodilator airway obstruction	Normal spirometry	p-value	Post-bronchodilator airway obstruction	Normal spirometry	p-value
	(n = 23)	(n = 42)		(n = 34)	(n = 88)		(n = 47)	(n = 87)
Total AHEI score	37 ± 7	36 ± 8	0.88	38 ± 7	37 ± 7	0.90	36 ± 7	36 ± 7	0.87
AHEI subscores
Vegetables	5.9 ± 2.0	5.1 ± 1.7	0.07	5.5 ± 1.5	5.6 ± 1.7	0.91	5.7 ± 1.7	5.6 ± 1.8	0.86
Fruits	4.1 ± 3.4	4.1 ± 3.5	0.93	4.9 ± 3.2	5.1 ± 3.2	0.68	4.6 ± 3.4	5.0 ± 3.5	0.45
Nuts and soy proteins	3.3 ± 1.1	3.2 ± 1.2	0.86	3.1 ± 1.1	3.0 ± 1.1	0.42	2.9 ± 1.0	2.9 ± 1.3	0.96
Ratio of white to red meat	3.3 ± 1.1	3.8 ± 1.3	0.43	3.6 ± 1.4	3.6 ± 1.2	0.84	4.2 ± 1.3^#	4.2 ± 1.3	0.78
Cereal fiber	5.4 ± 1.1	4.7 ± 1.5	0.08	4.9 ± 1.2	4.9 ± 1.3	0.88	4.2 ± 1.7^#	4.5 ± 1.7	0.37
Long-chain omega 3 fatty acids	3.9 ± 1.9	3.8 ± 2.2	0.57	3.3 ± 198	3.2 ± 1.9	0.73	3.8 ± 2.8	2.8 ± 2.7	0.05
Polyunsaturated fatty acids	4.6 ± 1.4	4.3 ± 1.6	0.22	4.6 ± 1.6	4.5 ± 1.7	0.71	4.4 ± 197	4.0 ± 1.4	0.27
Alcohol	6.6 ± 3.4	7.3 ± 3.1	0.39	7.8 ± 2.8	7.6 ± 2.5	0.80	6.5 ± 2.9	7.0 ± 2.5	0.34
Nutritional intake ratios
Lipids (%)	19.7 ± 2.5	19.9 ± 2.2	0.87	19.5 ± 2.4	19.5 ± 2.7	0.93	21.3 ± 3.7	19.3 ± 2.9	0.001
Proteins (%)	21.0 ± 1.6	20.9 ± 2.0	0.92	21.2 ± 1.8	20.8 ± 1.9	0.24	21.2 ± 2.3	21.0 ± 2.1	0.63
Carbohydrates (%)	59.3 ± 3.4	59.2 ± 3.1	0.75	59.4 ± 3.4	59.6 ± 3.6	0.73	57.5 ± 4.6	59.6 ± 3.7	0.009

post-BD, post-bronchodilator; AHEI, Alternate Healthy Eating Index. Values are means ± SD.

#: p < 0.05 vs. dairy farmers with post-bronchodilator airway obstruction who had smoked ≥ 10 pack-years.

Table 3. Morphometric characteristics and body composition evaluated by bioelectrical impedance analysis according to exposure to dairy-farming, number of smoked pack-years and presence of post-bronchodilator airway obstruction (defined by FEV1/FVC).

	Dairy farmers						Nondairy farmers
	≥ 10 pack-years			< 10 pack-years			≥ 10 pack-years
	Post-bronchodilator airway obstruction	Normal spirometry	p-value	Post-bronchodilator airway obstruction	Normal spirometry	p-value	Post-bronchodilator airway obstruction	Normal spirometry	p-value
	(n = 23)	(n = 42)		(n = 34)	(n = 88)		(n = 47)	(n = 87)
Weight (kg)	78 ± 15	79 ± 13	0.88	80 ± 16	79 ± 14	0.82	76 ± 16	78 ± 13	0.54
Height (cm)	170 ± 7	174 ± 8	0.04	173 ± 11	171 ± 7	0.38	172 ± 8	171 ± 8	0.85
BMI (kg/m²)	25.6 ± 3.3	27.2 ± 4.4	0.32	26.1 ± 4.1	26.9 ± 3.9	0.34	25.7 ± 3.9	27.3 ± 4.0	0.02
FFMI (kg/m²)	21.4 ± 4.1	20.3 ± 2.9	0.06	20.6 ± 4.2	20.5 ± 3.6	0.92	19.8 ± 3.8^#	20.0 ± 3.7	0.82
Fat mass (% body weight)	22.5 ± 10.9	21.6 ± 5.5	0.53	22.2 ± 8.5	23.5 ± 8.5	0.45	23.2 ± 6.7	24.9 ± 8.4	0.21
Total body water (L)	43.3 ± 7.9	44.0 ± 8.0	0.68	42.7 ± 9.1	44.6 ± 8.0	0.30	41.1 ± 7.3	41.9 ± 7.0	0.57
Extra-cellular water (%)	37.6 ± 2.3	37.5 ± 2.4	0.81	37.9 ± 5.4	38.3 ± 2.9	0.68	39.4 ± 5.1^#	38.5 ± 2.6	0.24
Intra-cellular water (%)	72.9 ± 6.0	73.3 ± 7.1	0.92	69.7 ± 11.3	71.7 ± 7.4	0.34	69.6 ± 8.0	70.6 ± 6.8	0.49

post-BD post-bronchodilator; BMI body mass index; FFMI fat-free mass index. Values are means ± SD.