Incidence and risk factors for infantile colic in Iranian infants

AIM: To assess the incidence of infantile colic and its association with variable predictors in infants born in a community maternity hospital, Tehran, Iran. METHODS: In this prospective cohort study, mothers who gave birth to live newborns between February 21 and March 20, 2003 at the hospital were invited to join to the study. For every infant-mother dyad data were collected on infant gender, type of delivery, gestational age at birth, birth weight, birth order, and mother's reproductive history. Then mothers were given a diary to document the duration of crying/fussiness behav-iors of their infants for the next 12 wk. We scheduled home visits at the time the infants were 3 mo of age to collect the completed diaries and obtain additional information on infants' nutritional sources and identify if medications were used for colic relief. Cases of colic were identifi ed by applying Wessel criteria to recorded data. Chi-square and Mann-whitney U tests were used to compare proportions for non-parametric and para-metric variables, respectively. RESULTS: From 413 infants, follow-up was completed for 321 infants. In total, 65 infants (20.24%) satisfi ed the Wessel criteria for infantile colic. No statistical sig-nifi cance was found between colicky and non-colicky infants according to gender, gestational age at birth, birth weight, type of delivery, and, infant's feeding pattern. However, fi rstborn infants had higher rate for developing colic (P = 0.03). CONCLUSION: Colic incidence was 20% in this popu-lation of Iranian infants. Except for birth order status, no other variable was signifi cantly associated with in-fantile colic.

The role of melatonin and cortisol circadian rhythms in the pathogenesis of infantile colic

Background Despite the high prevalence of infantile colic, the pathogenesis remains incompletely understood. Cortisol and melatonin hormones affect gastrointestinal system development in several ways, and interestingly, both cortisol and mela-tonin's circadian rhythms begin around the 3rd month in which infantile colic symptoms start to decrease. We hypothesized that infantile colic might associate with desynchronization of normal circadian rhythms of these hormones. In this study, we aimed to investigate the role of melatonin and cortisol in the pathogenesis of infantile colic. Methods Patients who were diagnosed as infantile colic according to Wessel's 'rule of three' were enrolled in the colic group. We measured the saliva melatonin and cortisol levels of colic group and control group infants. In both groups, the saliva samples were taken in mornings and at evenings, at the time of diagnosis and 6th month. Results Fifty-five infants finished the study. Melatonin circadian rhythm developed earlier in the control group than the infantile colic group in our study. We found no significant difference between the daily mean cortisol levels. However, infants with colic had flatter daily cortisol slope than controls which pointed out the probability that they had a less clearly defined cortisol rhythm than infants without colic. Conclusions We found an association between melatonin levels and infantile colic. However, more research is needed to fully understand the role of hypothalamic–pituitary–adrenal axis and hormone's role on infantile colic physiopathology.