Effects of prematurity and intrauterine growth on respiratory health and lung function in childhood.

OBJECTIVE--To determine whether birth weight and gestational age are associated with respiratory illness and lung function in children aged 5-11 years. DESIGN--Cross sectional analysis of parent reported birth weight, gestational age, and respiratory symptoms; parental smoking and social conditions; forced vital capacity (FVC), forced expiratory volume in one second (FEV1), forced expiratory rates between 25% and 75% and 75% and 85% (FEF25-75 and FEF75-85), and height. SETTING--Primary schools in England and Scotland in 1990. SUBJECTS--5573 children aged 5-11 (63.3% of eligible children) had respiratory symptoms analysed and 2036 children (67.1% of eligible children) had lung function measured. MAIN OUTCOME MEASURES--Symptoms of asthma, bronchitis, occasional and frequent wheeze, cough first thing in the morning, and cough at any other time and lung function. RESULTS--Birth weight adjusted for gestational age was significantly associated with all lung function measurements, except FEF25-75. The association remained for FVC (b = 0.475, 95% confidence interval 0.181 to 0.769) and FEV1 (b = 0.502, 0.204 to 0.800) after adjustment for gestational age, parental smoking, and social factors. FEF75-85 was the only lung function related to gestational age. Respiratory symptoms, especially wheeze most days (adjusted odds ratio 0.9, 0.84 to 0.97) were significantly associated with prematurity. Every extra week of gestation reduced the risk of severe wheeze by about 10%. CONCLUSIONS--Lung function is affected mainly by intrauterine environment while respiratory illness, especially wheezing, in childhood is related to prematurity.     

Adult feeding and host type modulate the life history traits of the capital breeder Zabrotes subfasciatus

Income breeding animals support reproduction by the intake of energy and molecular building blocks during adulthood. Capital breeders, in contrast, fuel reproduction by the intake of materials during the larval stage. There exists, however, some controversy as to whether adult feeding in capital breeders actually increases fitness. We tested whether individuals feed as adults in the weevil Zabrotes subfasciatus Boheman, whether they equally accept carbohydrate- or nitrogen-rich food (sugar or yeast), whether food ingestion varies with the available host type and whether feeding as adults alters life history traits. The hosts tested were three varieties of Phaseolus vulgaris, Carioca, Jalo, and Preto; Vigna unguiculata Frade; and Vicia faba. We also tested whether sugar ingestion affects life history traits differently in the presence of different host types. We found that Z. subfasciatus feed as adults and equally accept sugar and yeast, and food ingestion depends on host type. Sugar and yeast significantly promote oviposition of larger eggs on Carioca seeds and enhance adult emergence, and sugar ingestion increases longevity. Moreover, the insects avoid feeding when on V. faba seeds, on which they did not oviposit. Mean fitness values showed the following hierarchy: Carioca = Jalo > Frade > Preto > V. faba. These results show that the capital breeder Z. subfasciatus feed as adults, which increases life history traits and suggests the existence of a hierarchy of performance on different hosts, with the P. vulgaris varieties Carioca and Jalo offering the best conditions.