Background Asthma is a growing public health problem in developing countries. However, few studies have studied the role of urbanisation in this phenomenon. It was hypothesised that children living in a peri-urban setting in Peru have higher rates of asthma and allergy than rural counterparts. Methods 1441 adolescents aged 13–15 years were enrolled from two settings: a peri-urban shanty town in Lima (n=725) and 23 rural villages in Tumbes (n=716). Participants filled in questionnaires on asthma and allergy symptoms, environmental exposures and sociodemographics, and underwent spirometry, and exhaled nitric oxide (eNO) and allergy skin testing. Indoor particulate matter (PM) concentrations were measured in 170 households. Results Lima adolescents had higher rates of lifetime wheezing (22% vs 10%), current asthma symptoms (12% vs 3%) and physician-diagnosed asthma (13% vs 2%; all p <0.001). Current rhinitis (23% vs 12%), eczema (12% vs 0.4%), atopy (56% vs 38%), personal history of cigarette smoking (7.4% vs 1.3%) and mean indoor PM (31 vs 13 μg/m3) were also higher in Lima (all p <0.001). The peri-urban environment of Lima was associated with a 2.6-fold greater odds (95% CI 1.3 to 5.3) of asthma in multivariable regression. Forced expiratory volumes were higher and FEV1/FVC (forced expiratory volume in 1 s/forced vital capacity) ratios were lower in Lima (all p <0.001). Higher eNO values in Lima (p <0.001) were attributable to higher rates of asthma and atopy. Conclusions Peri-urban adolescents had more asthma, atopy and airways inflammation and were exposed to more indoor pollution. The findings provide evidence of the risks posed to lung health by peri-urban environments in developing countries.

PurposeAdherence to a Mediterranean diet pattern may be associated with lower asthma prevalence in children. We sought to corroborate these findings in Peruvian children.MethodsThis case–control study included children of ages 9–19 years living in Lima, Peru. A food frequency questionnaire (FFQ) was completed and diet pattern was analyzed using a modified Mediterranean diet score (MDS). Primary analysis investigated the relationship between MDS and asthma status. Maternal education, age, sex, and body mass index category were included in multivariate model. Secondary outcomes included asthma control, forced expiratory volume in 1 s (FEV1), allergic rhinitis, and atopic status.Results287 participants with asthma and 96 controls without asthma completed a FFQ. Mean age was 13.5 years. According to the asthma control test (ACT), 86 % of those with asthma were controlled (score >19). MDS scores ranged 6–18 (median 15). In adjusted analysis, being above the median MDS scores was associated with decreased odds of asthma [OR = 0.55, 95 % CI (0.33, 0.92), p = 0.02]. Among children whose mothers completed secondary education, being above the median MDS significantly decreased the odds of asthma [OR = 0.31, 95 % CI (0.14, 0.71), p < 0.01], whereas among those whose mothers did not complete secondary education there was no protective effect [OR = 0.86, 95 % CI (0.43, 1.7), p = 0.66]. There was no association between MDS scores and asthma control, FEV1, allergic rhinitis, or atopic status.ConclusionAdherence to the Mediterranean diet was inversely associated with having asthma among children in Lima, Peru. This effect was strongest among children with better educated mothers.

Background Vitamin D deficiency may be associated with an increased risk of asthma. Objective We studied the association between 25-hydroxy (25-OH) vitamin D deficiency and asthma prevalence in two Peruvian populations close to the equator but with disparate degrees of urbanization. Methods We conducted a population-based study in 1441 children in two communities in Peru, of which 1134 (79%) provided a blood sample for 25-OH vitamin D analysis. Results In these 1134 children, mean age was 14.8 years; 52% were boys; asthma and atopy prevalence were 12% in Lima vs. 3% in Tumbes (p<0.001) and 59% in Lima vs. 41% in Tumbes (p<0.001), respectively; and, mean 25-OH vitamin D was 20.8 ng/mL in Lima vs. 30.1 ng/mL in Tumbes (p<0.001). Prevalence of 25-OH vitamin D deficiency (<20 ng/mL) was 47% in Lima vs. 7% in Tumbes (p<0.001). In multivariable logistic regression, we found that lower 25-OH vitamin D levels were associated with an increased odds of asthma (OR = 1.7 per each 10 ng/mL decrease in 25-OH vitamin D levels, 95% CI 1.2 to 2.6; p<0.01). In stratified analyses, the association between lower 25-OH vitamin D levels and asthma was limited to children with atopy (OR=2.2, 95% CI 1.3 to 3.6) and not in those without atopy (OR=0.9, 95% CI 0.5 to 2.0). We did not find associations between 25-OH vitamin D levels and other clinical biomarkers for asthma, including exhaled nitric oxide, total serum IgE and pulmonary function. Conclusion and Clinical Relevance Both asthma and 25-OH vitamin D deficiency were common among children living in Lima (latitude=12.0°S) but not among those in Tumbes (3.6°S). The relationship between 25-OH vitamin D deficiency and asthma was similar in both sites and was limited among children with atopy. Future supplementation trials may need to consider stratification by atopy at the time of design.

Household air pollution from biomass fuel use affects three billion people worldwide; however, few studies have examined the relationship between biomass fuel use and blood pressure. We sought to determine if daily biomass fuel use was associated with elevated blood pressure in high altitude Peru and if this relationship was affected by lung function. We analyzed baseline information from a population-based cohort study of adults aged ≥35 years in Puno, Peru. Daily biomass fuel use was self-reported. We used multivariable regression models to examine the relationship between daily exposure to biomass fuel smoke and blood pressure outcomes. Interactions with sex and quartiles of forced vital capacity (FVC) were conducted to evaluate for effect modification. Data from 1004 individuals (mean age 55.3 years, 51.7% female) were included. We found an association between biomass fuel use with both prehypertension (adjusted relative risk ratio 5.0, 95% CI 2.6 to 9.9) and hypertension (adjusted relative risk ratio 3.5, 95% CI 1.7 to 7.0). Biomass fuel users had a higher SBP (7.01 mmHg, 95% CI 4.4 to 9.6) and a higher DBP (5.9 mmHg, 95% CI 4.2 to 7.6) when compared to nonusers. We did not find interaction effects between daily biomass fuel use and sex or percent predicted FVC for either SBP or DBP. Biomass fuel use was associated with an increased risk of hypertension and higher blood pressure in Peru. Reducing exposure to household air pollution from biomass fuel use represents an opportunity for cardiovascular prevention.