Kenneth Maleta1, Yue-Mei Fan2, Juho Luoma2, Ulla Ashorn2, Jaden Bendabenda1, Kathryn G Dewey3, Heikki Hyöty4,5, Mikael Knip2,6,7,8, Emma Kortekangas2, Kirsi-Maarit Lehto2, Andrew Matchado1, Minyanga Nkhoma2, Noora Nurminen4, Seppo Parkkila5,9, Sami Purmonen9, Riitta Veijola10, Sami Oikarinen4, Per Ashorn2,11. 1. School of Public Health and Family Medicine, College of Medicine, University of Malawi, Blantyre, Malawi. 2. Center for Child Health Research, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland. 3. Institute for Global Nutrition and Department of Nutrition, University of California, Davis, CA, USA. 4. Department of Virology, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland. 5. Fimlab Ltd, Tampere University Hospital, Tampere, Finland. 6. Paediatric Research Center, Children's Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland. 7. Research Programs for Clinical and Molecular Metabolism, Faculty of Medicine, University of Helsinki, Helsinki, Finland. 8. Folkhälsan Research Centre, Helsinki, Finland. 9. Clinical Medicine, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland. 10. Department of Paediatrics, PEDEGO Research Unit, Medical Research Centre, Oulu University Hospital and University of Oulu, Oulu, Finland. 11. Department of Paediatrics, Tampere University Hospital, Tampere, Finland.
Abstract
BACKGROUND: Insulin-like growth factor I (IGF-I) is the most important hormonal promoter of linear growth in infants and young children. OBJECTIVES: The objectives of this study were to compare plasma IGF-I concentration in a low- compared with a high-income country and characterize biological pathways leading to reduced IGF-I concentration in children in a low-income setting. METHODS: We analyzed plasma IGF-I concentration from 716 Malawian and 80 Finnish children at 6-36 mo of age. In the Malawian children, we studied the association between IGF-I concentration and their environmental exposures; nutritional status; systemic and intestinal inflammation; malaria parasitemia and viral, bacterial, and parasitic enteric infections; as well as growth at 18 mo of age. We then conducted a pathway analysis to identify direct and indirect associations between these predictors and IGF-I concentration. RESULTS: The mean IGF-I concentrations were similar in Malawi and Finland among 6-mo-old infants. At age 18 mo, the mean ± SD concentration was almost double among the Finns compared with the Malawians [24.2 ± 11.3 compared with 12.5 ± 7.7 ng/mL, age- and sex-adjusted difference in mean (95% CI): 11.8 (9.9, 13.7) ng/mL; P < 0.01]. Among 18-mo-old Malawians, plasma IGF-I concentration was inversely associated with systemic inflammation, malaria parasitemia, and intestinal Shigella, Campylobacter, and enterovirus infection and positively associated with the children's weight-for-length z score (WLZ), female sex, maternal height, mother's education, and dry season. Seasonally, mean plasma IGF-I concentration was highest in June and July and lowest in December and January, coinciding with changes in children's length gain and preceded by ∼2 mo by the changes in their WLZ. CONCLUSIONS: The mean plasma IGF-I concentrations are similar in Malawi and Finland among 6-mo-old infants. Thereafter, mean concentrations rise markedly in Finland but not in Malawi. Systemic inflammation and clinically nonapparent infections are strongly associated with lower plasma IGF-I concentrations in Malawi through direct and indirect pathways.
BACKGROUND:Insulin-like growth factor I (IGF-I) is the most important hormonal promoter of linear growth in infants and young children. OBJECTIVES: The objectives of this study were to compare plasma IGF-I concentration in a low- compared with a high-income country and characterize biological pathways leading to reduced IGF-I concentration in children in a low-income setting. METHODS: We analyzed plasma IGF-I concentration from 716 Malawian and 80 Finnish children at 6-36 mo of age. In the Malawian children, we studied the association between IGF-I concentration and their environmental exposures; nutritional status; systemic and intestinal inflammation; malaria parasitemia and viral, bacterial, and parasitic enteric infections; as well as growth at 18 mo of age. We then conducted a pathway analysis to identify direct and indirect associations between these predictors and IGF-I concentration. RESULTS: The mean IGF-I concentrations were similar in Malawi and Finland among 6-mo-old infants. At age 18 mo, the mean ± SD concentration was almost double among the Finns compared with the Malawians [24.2 ± 11.3 compared with 12.5 ± 7.7 ng/mL, age- and sex-adjusted difference in mean (95% CI): 11.8 (9.9, 13.7) ng/mL; P < 0.01]. Among 18-mo-old Malawians, plasma IGF-I concentration was inversely associated with systemic inflammation, malaria parasitemia, and intestinal Shigella, Campylobacter, and enterovirus infection and positively associated with the children's weight-for-length z score (WLZ), female sex, maternal height, mother's education, and dry season. Seasonally, mean plasma IGF-I concentration was highest in June and July and lowest in December and January, coinciding with changes in children's length gain and preceded by ∼2 mo by the changes in their WLZ. CONCLUSIONS: The mean plasma IGF-I concentrations are similar in Malawi and Finland among 6-mo-old infants. Thereafter, mean concentrations rise markedly in Finland but not in Malawi. Systemic inflammation and clinically nonapparent infections are strongly associated with lower plasma IGF-I concentrations in Malawi through direct and indirect pathways.
Authors: Mandy B Belfort; Sara E Ramel; Camilia R Martin; Raina Fichorova; Karl C K Kuban; Timothy Heeren; Rebecca C Fry; T Michael O'Shea Journal: J Pediatr Date: 2021-09-08 Impact factor: 4.406