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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 3, May/June 2017
176
AFRICA
Effects of Ramadan intermittent fasting on North African
children’s heart rate and oxy-haemoglobin saturation at
rest and during sub-maximal exercise
Mohamed Amine Fenneni, Imed Latiri, Asma Aloui, Sonia Rouatbi, Karim Chamari, Helmi Ben Saad
Abstract
Aim:
To examine the effects of Ramadan intermittent fasting
(RIF) on the heart rate (HR) and oxyhaemoglobin saturation
levels (oxy-sat) of boys at rest and during a six-minute walk-
ing test (6MWT).
Methods:
Eighteen boys (age: 11.9
±
0.8 years, height: 153.00
±
8.93 cm, body mass: 55.4
±
18.2 kg), who fasted the entire
month of Ramadan in 2012 for the first time in their lives,
were included. The experimental protocol comprised four
testing phases: two weeks before Ramadan (pre-R), the
end of the second week of Ramadan (R-2), the end of the
fourth week of Ramadan (R-4), and 10 to 12 days after the
end of Ramadan (post-R). During each phase, participants
performed the 6MWT at approximately 15:00. HR (expressed
as percentage of maximal predicted HR) and oxy-sat (%)
were determined at rest and in each minute of the 6MWT.
Results:
R-4 HR values were lower than those of (1) pre-R (in
the second minute), (2) R-2 (in the first and second minutes),
and (3) post-R (in the first, second, fourth, fifth and sixth
minutes). R-2 oxy-sat values were higher than those of pre-R
(in the third minute) and those of post-R (in the fifth minute).
Post-R oxy-sat values were lower than those of pre-R and R-4
in the fifth minute. These oxy-sat changes were not clinically
significant since the difference was less than five points.
Conclusion:
In non-athletic children, their first RIF influenced
their heart rate data but had a minimal effect on oxy-sat values.
Keywords:
Tunisia, Ramadan fasting, heart rate, oxyhaemoglo-
bin saturation, walking test, child
Submitted 28/2/16, accepted 22/7/16
Published online 21/10/16
Cardiovasc J Afr
2017; 28: 176–181
www.cvja.co.zaDOI: 10.5830/CVJA-2016-078
Ramadan intermittent fasting (RIF) is the fourth pillar of Islam
and, according to most religious scholars, it concerns every
healthy Muslim after puberty.
1
It is important to know the effects
of RIF on human physiology, not only for Muslim-majority
countries but also for many countries where Muslims are in
the minority.
2
In a globalised society, physicians have to deal
with issues such as Muslim patients who desire to fast during
Ramadan, regardless of whether they are in good health or not.
3
Several studies have assessed the effects of RIF on variables
such as body mass, biological data or markers, and sleep patterns
in healthy adult subjects.
2,4-10
However, only a few studies have
been performed on healthy children.
11-14
This lack of information
on the effects of RIF on the health and physical performance
of healthy children could lead to confusion worldwide. For
example, on 10 June, one week before the start of Ramadan in
2015, the Barclay Primary School in east London, UK, sent a
letter to the parents of its students
(http://www.telegraph.co.uk/news/religion/11669767/Primary-schools-ban-children-from-
fasting-during-Ramadan.html; visited 8 May 2016): ‘The policy
of both Barclay Primary School and all schools within the Lion
Academy Trust does not allow any children (aged 6 to 12 years)
attending the schools to fast’, suggesting that fasting would
endanger the health and education of students.
In children, the evaluation of heart rate (HR) and/or
oxyhaemoglobin saturation (oxy-sat) dynamics during exercise
provides valuable information for making management decisions,
resulting in improved quality of life and functional capacity.
15,16
During exercise, HR responses reflect subjects’ physical level
and aerobic fitness.
17,18
To the best of our knowledge, to date, all
studies interested in the effects of RIF on HR changes concern
adults
19-25
and none has been performed in children.
26
In addition,
conclusions concerning the effect of fasting on healthy adults’
HR changes during exercise were controversial,
19-25
with modified
(lower
19,24
or higher
25
) or unchanged values reported.
20-23
Oxygen desaturation provides information regarding exercise-
induced desaturation.
17
However studies on the RIF effects on
oxyhaemoglobin saturation seem non-existent. AMedline search
(performed on 28 January 2015) using as keywords ‘fasting’ and
‘oximetry or oxyhemoglobin saturation’ and ‘exercise’ found no
articles.
Laboratory of Physiology, Faculty of Medicine, University
of Sousse, Tunisia
Mohamed Amine Fenneni, MSc
Imed Latiri, PhD
Sonia Rouatbi, MD, PhD
Helmi Ben Saad, MD, PhD,
helmi.bensaad@rns.tnFaculty of Sciences, Bizerte, Carthage University, Tunisia
Mohamed Amine Fenneni, MSc
High Institute of Sport and Physical Education, University
of Gafsa, Gafsa, Tunisia
Asma Aloui, PhD
Department of Physiology and Functional Exploration,
Farhat Hached University Hospital of Sousse, Tunisia
Sonia Rouatbi, MD, PhD
Helmi Ben Saad, MD, PhD
Athlete Health and Performance Research Center, ASPETAR,
Qatar Orthopedic and Sports Medicine Hospital, Qatar
Karim Chamari, PhD
Research Laboratory LR14ES05, Faculty of Medicine,
University of Sousse, Tunisia
Helmi Ben Saad, MD, PhD