Dietary Patterns and Chronic Obstructive Pulmonary Disease: A Meta-analysis

Figures & data

Table 1. Characteristics of 13 studies included in the meta-analysis (1990–2015).

Author Publication Year	Location	Study design	Total number of subjects	Age	Diet-assessment method	Factors adjusted for in analysis	Dietary patterns Identified
Varraso et al (n = 2)2007[9)	United States	Cohort	72043 women	30-55y	FFQ	Age, smoking status, pack-years, exposure to secondhand tobacco smoke, menopausal status, race/ethnicity, spouse's educational attainment, physician visits, U.S. region, physical activity, multivitamin use, and energy intake.	Prudent; western
Shaheen et al 2010 [10)	United Kingdom	Cohort	Male:1551; Female:1391	Male:65.7 Female:66.6y	FFQ	Age, height, smoking status, pack-years, smoke in home, age left education, home ownership status, number of rooms, cars, social class, fat mass, activity score, energy intake, alcohol dietary supplement use, birth weight, father's social class at birth, inhale or oral steroids use, paracetamol use	Prudent
Varraso et al (n = 3) 2007[11)	United States	Cohort	42917 men	40-75y	FFQ	Age, energy intake, smoking status, pack-years, race/ethnicity, physician visits, U.S. region, body mass index, physical activity and multivitamin use	Prudent; western
McKeever et al 2010[12)	Netherlands	Cross-sectional	12648	20-59y	FFQ	Age, sex, age squared, height, age*height, smoking status, pack-years of smoking, BMI, and educational level	Cosmopolitan diet; traditional diet; refined-foods diet
Waston et al 2002 [16)	Ireland	Case-control	115 cases 115 controls	> 45y	FFQ	Age, body mass index and total energy.	Total vegetables and fruit
Varraso et al 2015 [17)	United States	Cohort	73228 female 47026 male	Female 30-55y Male 40-75y	FFQ	Age,physical activity, body mass index, total energy intake, smoking status, pack years of smoking, secondhand tobacco exposure, race/ethnicity, physician visits, U.S. region, spouse, Highest education attainment, and menopausal status	Alternate healthy eating index
Yin et al 2011 [18)	China	Cohort	48974	15-69y	FFQ	Age, sex, region, smoking, history of COPD	Vegetables and fruit consumption
Hirayama et al 2009[19]	Japan	Case-control	278 cases 340 controls	50-75y	FFQ	Age, gender, BMI, education level, alcohol drinking, cigarette smoking, smoking pack-years, lifelong physical activity involvement, and daily intake of red meat, chicken and fresh fish.	Total vegetables and fruits
Jiang et al 2007[20]	United States	Cross-sectional	7352	>45y	FFQ	Age, sex, race/ethnicity, smoking variables, smoking status, pack-years of smoking, serum cotinine concentration, household environmental tobacco smoking, education, family income, BMI	Cured meat consumption
Kan et al 2007 [21]	United States	Cross-sectional	15792	44-66y	FFQ	Age, sex, study center, ethnicity, smoking status, pack-years of smoking, body mass index, occupation, education, diabetes status, traffic density, total energy intake, glycemic index, micronutrients	Total fiber
Varraso et al 2007[22]	United States	Cohort	51529	40-75y	FFQ	Age, energy intake, smoking status, pack-years, pack-years squared, race/ethnicity, U.S. region, body mass index, and physical activity	Cured meats consumption
Varraso et al 2010[23]	United States	Cohort	121700 female 51529 male	Female: 30-55y Male: 40-75y	FFQ	Age, sex, smoking status, pack-years, energy intake, U.S. region, physician visits, BMI, physical activity, diabetes, omega-3 polyunsaturated fatty acid intake, cured meat intake, and other sources of fiber	Total fiber intake
Yang et al 2015[24]	China	Case-control	1025 cases 1061 controls	—	Questionnaire	Age, sex, BMI, educational experience, and center	Cured meat consumption; Vegetables/fruits consumption

FFQ: Food frequency questionnaire; BMI: Body mass index.

Figure 1. Flow chart of article screening and selection process.

Figure 2. Funnel plots for COPD in the highest compared with the lowest category of intake of the healthy/ prudent dietary pattern in all studies.

Figure 3. Funnel plots for COPD in the highest compared with the lowest category of intake of the unhealthy/western-style dietary pattern in all studies.

Appendix 1

Dietary patterns and chronic obstructive pulmonary disease: Assessment of Study Quality

	Selection				Comparability		Outcome
Studies	1	2	3	4	5A	5B	6	7	8	Score
Cohort
Varraso et al. (n = 2) (2007)	*	*	*	*	*	*	*	*	*	*********
Shaheen et al. (2010)		*	*	*	*		*	*		******
Varraso et al. (n = 3) (2007)	*	*	*	*	*	*	*	*	*	*********
Varraso et al. (2015)	*	*	*	*	*		*	*	*	********
Yin et al. (2011)	*		*	*	*		*	*		******
Varraso et al. (2007)	*		*	*	*		*	*	*	*******
Varraso et al. (2010)	*	*	*	*	*	*	*	*	*	*********
Case-control
Waston et al. (2002)			*	*	*		*	*		*****
Hirayama et al. (2009)	*			*	*		*	*		*****
Yang et al. (2015)	*		*	*	*		*	*		******
Cross-sectional
McKeever et al. (2010)	*		*	*	*		*	*		******
Jiang et al. (2007)	*		*	*	*		*	*		*******
Kan et al. (2007)	*	*	*	*	*		*	*		*******

FFQ: Food frequency questionnaire; BMI: Body mass index.

Appendix 2

Forest plot for ORs of the highest compared with the lowest category of intake of the healthy/prudent dietary pattern and COPD.

Forest plot for ORs of the highest compared with the lowest category of intake of the unhealthy/western-style dietary pattern and COPD.