Is being breastfed as an infant associated with adult pulmonary function?

Association between History of Prolonged Exclusive Breast-Feeding and the Lung Function Indices in Childhood

Although the propitious effects of breastfeeding on children's health are indisputable, the impact of exclusive breastfeeding on the lung function later in life remains controversial. Our objective was to explore the possible associations between breastfeeding and the lung function of children who were exclusively breastfed for an extensive period of time. This was a cross-sectional study of children who were exclusively breastfed for more than 12 months. Demographics and anthropometric data were collected; the body mass index (BMI), % body fat, and % central obesity were calculated; and all the participants underwent standard spirometry with reversibility testing. The relationship between breastfeeding duration and spirometric parameters was assessed by Spearman's correlation and multivariable regression, after adjustment for other confounders. Forty-six children (21 boys), aged 9.2 ± 2.4 years, with a reported breastfeeding duration of 27.5 ± 12.5 months (range 12-60 months) were included; 13% were overweight (none were obese) and 21.7% had central obesity. The average FEV1 was 104.7 ± 10.4% and the average FEF25-75 was 107.9 ± 13.3%. The duration of exclusive breastfeeding was positively correlated with FEF25-75% (r = 0.422, p = 0.003). Multivariable linear regression analysis confirmed the above finding (beta coefficient 0.478, p = 0.002), independently of age, overweight, and central obesity. No correlation was noted between the duration of breastfeeding and other spirometric parameters. In addition to its favorable impact on the metabolic profile, prolonged exclusive breastfeeding seems to exert a propitious effect on the function of smaller airways throughout childhood.

Duration and exclusiveness of breastfeeding and school-age lung function and asthma

BACKGROUND

Breastfeeding reduces the risk of asthma in early childhood, but it is not clear whether its effect on respiratory morbidity is still present in later childhood.

OBJECTIVE

To examine the associations of any breastfeeding, breastfeeding duration, and breastfeeding exclusiveness with lung function and asthma in school-aged children and whether associations were influenced by respiratory tract infections and maternal or child's atopic status.

METHODS

This study of 4,464 children was embedded in a population-based prospective cohort study. Information on breastfeeding was obtained by multiple questionnaires from birth until 1 year of age. At 10 years of age, lung function was measured by spirometry, and information on asthma was obtained by questionnaire. Adjusted linear and logistic regression models were used to examine the associations.

RESULTS

Shorter duration of breastfeeding was associated with a lower forced expiratory volume in 1 second (FEV₁) only (z score change, -0.01; 95% confidence interval [CI], -0.02 to -0.00) per month shorter breastfeeding, but not asthma. When categorized, breastfeeding for 2 to 4 months was associated with a lower forced vital capacity (FVC) (z score change, -0.11; 95% CI, -0.20 to -0.03) compared with breastfeeding for 6 months or longer. Nonexclusive breastfeeding for 4 months was associated with a lower FVC (z score change, -0.08; 95% CI, -0.16 to -0.01) compared with exclusive breastfeeding for 4 months. Results did not materially change after additional adjustment for lower respiratory tract infections and were not modified by maternal history of asthma or atopy, child's eczema, or inhalant allergic sensitization.

CONCLUSION

Shorter duration and nonexclusivity of breastfeeding were associated with a lower FEV₁ and FVC but not asthma at school-age.

Breastfeeding and asthma outcomes at the age of 6 years: The Generation R Study

BACKGROUND

Breastfeeding is associated with a lower risk of asthma symptoms in early childhood, but its effect at older ages remains unclear. We examined the associations of duration and exclusiveness of breastfeeding with asthma outcomes in children aged 6 years, and whether these associations were explained by atopic or infectious mechanisms.

METHODS

We performed a population-based prospective cohort study among 5675 children. Information about breastfeeding was collected by questionnaires. At age 6 years, we measured interrupter resistance (Rint) and fractional exhaled nitric oxide (FeNO). Information about wheezing patterns (early (≤3 years only), late (>3 years only), persistent (≤3 and >3 years)), and current asthma at 6 years was derived from repeated questionnaires.

RESULTS

Compared to children who were ever breastfed, those who were never breastfed had lower FeNO levels (sympercent (95% CI): -16.0 (-24.5, -7.5)) and increased risks of late and persistent wheezing (OR(95% CI): 1.69 (1.06, 2.69) and 1.44 (1.00, 2.07), respectively). Shorter duration of breastfeeding was associated with early wheezing and current asthma (1.40 (1.14, 1.73) and 2.19 (1.29, 3.71), respectively). Less exclusive breastfeeding was associated with early wheezing (1.28 (1.08, 1.53)). Breastfeeding duration and exclusiveness were not associated with FeNO or Rint. The associations were not explained by inhalant allergies, partly by lower respiratory tract infections in early life, and to a lesser extent by lower respiratory tract infections in later life.

CONCLUSIONS

Breastfeeding patterns may influence wheezing and asthma in childhood, which seems to be partly explained by infectious mechanisms.

The effect of breastfeeding on lung function at 12 and 18 years: a prospective cohort study

The objective was to assess associations between duration of total and exclusive breastfeeding and lung function up to adolescence.A birth cohort (Melbourne Atopy Cohort Study) of 620 infants with a family history of allergic disease was recruited. Mothers were encouraged to breastfeed exclusively for 6 months. Lung function was assessed at 12 and 18 years of age. Associations between breastfeeding and lung function were investigated using multivariable linear regression and path analysis was used to assess the potential mediating factors.Duration of breastfeeding (total and exclusive) was not associated with most assessed lung function outcomes. However, there was a trend for increased pre-bronchodilator mid-expiratory flow (MEF) at both 12 (adjusted mean difference (95% CI) per week of breastfeeding of 10 (-1-20) mL·s(-1)) and 18 years (11 (-1-22) mL·s(-1)) (p-values of 0.07 and 0.08, respectively). There was a strong indirect effect of height on these observed associations.Duration of breastfeeding does not appear to greatly influence lung function outcomes in children with a family history of allergic diseases. Longer duration of exclusive breastfeeding may be associated with an increase in MEF, partly due to greater attained height of the child.

The impact of breastfeeding on lung development and function: a systematic review

With the global trend of increasing asthma and allergic disorders there is strong interest regarding early life nutrition as a potentially modifiable risk factor for lung disease. This systematic review includes 10 studies that assessed the effect of breastfeeding on lung growth and function. The review found breastfeeding to be beneficial for lung function, with the most consistent effect on increased forced vital capacity. There was no clear evidence that the relationship between breastfeeding and lung function was mediated through other factors. Furthermore, the findings from the few studies that investigated if maternal asthma modified the effect of breastfeeding on lung function were inconsistent. Further research is needed to determine the specific details such as duration and type (exclusive vs partial) of breastfeeding that leads to improved lung function.

The effect of breastfeeding on cardiorespiratory risk factors in adult life

OBJECTIVE

Nutrition in the first weeks of life may program disease risk in adulthood. We examined the influence of initial infant feeding on cardiorespiratory risk factors in adulthood.

PATIENTS AND METHODS

A total of 9377 persons born during 1 week in 1958 in England, Scotland, and Wales were followed-up periodically from birth into adulthood. Infant feeding was recorded from a parental questionnaire at 7 years old as never breastfed, breastfed partially or wholly for <1 month, or breastfed for >1 month. Height; waist circumference; hip circumference; waist/hip ratio; body mass index; blood pressure; forced expiratory volume; total, high-density, and low-density lipoprotein cholesterol; triglycerides; hemoglobin A1c; fibrinogen; fibrin D-dimer; C-reactive protein; von Willebrand factor; and tissue plasminogen activator antigen were measured at 44 to 45 years of age.

RESULTS

Breastfeeding for >1 month was associated with reduced waist circumference, waist/hip ratio, von Willebrand factor, and lower odds of obesity compared with formula feeding after adjustment for birth weight, prepregnancy maternal weight, maternal smoking during pregnancy, socioeconomic position in childhood and adulthood, region of birth, gender, and current smoking status. Infant feeding status was not associated with other cardiorespiratory risk factors after adjustment, except for lower fibrinogen and C-reactive protein levels in women.

CONCLUSIONS

The inverse associations of breastfeeding for >1 month with measures of central obesity and inflammatory markers in the current study are small and of little public health importance. Although there was no substantial long-term protective effect of breastfeeding for >1 month on other cardiorespiratory risk factors in adult life, further studies with contemporaneous data on exclusive breastfeeding are needed to confirm these findings.

Breast feeding and future health

PURPOSE OF REVIEW

This review discusses the long-term health effects of breast feeding, based on the most relevant publications from the second half of 2004 and 2005.

RECENT FINDINGS

The positive effect of breast feeding on later cognitive function continues to be the most consistent and important effect. Also, breast feeding is likely to protect against some immune-related diseases later in life, such as type 1 diabetes, coeliac disease, inflammatory bowel diseases and perhaps cancer. The evidence for an effect on allergic disease continues to be inconclusive. Furthermore, breast feeding seems to be associated with a lower blood pressure and serum cholesterol, but there is no clear association with cardiovascular disease or death. Most new studies and meta-analyses show a protective effect against later obesity, but this seems to be small. A new hypothesis suggests that breast feeding programmes the insulin-like growth factor axis and results in higher growth velocity later in childhood.

SUMMARY

Evidence is increasing that breast feeding, beyond its well-established beneficial effects during the breast-feeding period, also confers long-term benefits. These effects are not strong at the individual level, but are likely to be of importance at the population level. Since the majority of the studies are observational, however, it is difficult to prove causality.