Maternal reports of sleep in 6-18 month-old infants from Nepal and Zanzibar: association with iron deficiency anemia and stunting.
BACKGROUND
Infants with iron deficiency anemia (IDA) and stunting explore and interact less with their environment. They may also be fatigued more often, suggesting their sleep may be affected. It is unclear whether fatigue in these infants is due to poor nighttime sleep or if it is compensated for with frequent naps or longer sleep.


OBJECTIVE
In 2 studies from Pemba Island, Zanzibar and 1 from Nepal we investigated the relationship between IDA, stunting, and maternal reports of sleep in 6-18 mo old infants.


METHODS
Parents reported on the number and duration of naps, hours of nighttime sleep, and frequency of night waking. Anemia was defined as Hb<10 g/dL, iron deficiency as zinc protoporphyrin (ZPP > or = 90 micromol/mol heme), stunting as HAZ<-2 SD, and IDA as Hb<10 g/dL and ZPP > or = 90 micromol/mol heme.


RESULTS
The prevalence of IDA and stunting was 34-84% and 22-37%, respectively. Most infants napped during the day and took approximately 1.5 naps (mean nap duration 1.4-1.7 h). Mean nighttime sleep duration was 8.3-9.7 h and infants awoke 2.1-2.5 times per night. Both IDA and stunting were associated with differences in reported sleep characterized by shorter night sleep duration and higher frequency of night waking; stunting was also related to shorter nap duration.


CONCLUSIONS
We found reduced sleep duration and increased night waking among infants with IDA and stunting. Because sleep plays an essential role in infant development, our findings indicate a clear need for further research into these relationships.
Kordas
Katarzyna
K
Department of Environmental Health, Harvard School of Public Health, Boston, MA 02215, United States. kkordas@hsph.harvard.edu
Siegel
Emily H
EH
Olney
Deanna K
DK
Katz
Joanne
J
Tielsch
James M
JM
Chwaya
Hababu M
HM
Kariger
Patricia K
PK
Leclerq
Steven C
SC
Khatry
Subarna K
SK
Stoltzfus
Rebecca J
RJ
D018798:Anemia, Iron-Deficiency / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D002675:Child, Preschool; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005221:Fatigue / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D006130:Growth Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D008297:Male; D009035:Mothers; D009390:Nepal / Q000453:epidemiology; D009752:Nutritional Status; D015995:Prevalence; D012893:Sleep Wake Disorders / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D013636:Tanzania / Q000453:epidemiology