Abstract
Dear Editor:
I read with great interest the article titled, “Pulmonary Function of Young Muslim Males During the Month of Ramadan” (Roy & Bandyopadhyay, 2016). Four points, qualified as sources of confusion, should be highlighted.
Point 1. Lack of information about the season and/or about temperature and humidity during their study period. In fact, only the following vague sentence was cited in the discussion section: “Environmental temperature and relative humidity varied within a very narrow span during the course of the present study.” Ramadan can happen at any season (Fenneni et al., 2014; Fenneni et al., 2015). Consequently, the effects of daytime fasting are strongly influenced by climatic circumstances, as Ramadan during the winter at lower latitudes presents very different features compared to Ramadan in the summer at high latitudes (Fenneni et al., 2014; Fenneni et al., 2015). If Ramadan occurs during summer, fasting hours are longer than in winter, possibly causing more fatigue and dehydration, and therefore, spirometric data change is much more probable. This has been highlighted in several studies on the effects of high temperature and/or climatic heat stress on lung function (Schmidt & Bundgaard, 1986). The Indian study was performed during Ramadan 2014 from June 29 to July 27 (Roy & Bandyopadhyay, 2016). Therefore, it was most likely performed in summer, when the weather was hot and humid (average temperature and humidity were, respectively, 30°C and 84% (www.timeanddate.com/weather/india/kolkata/historic?month=8&year=2014; accessed June 9, 2016). At higher temperatures, fatigue can set in, which may result in a decrease in submaximal effort, which can decrease some spirometric data such as peak expiratory flow (Pedersen, 1997).
Point 2. Lack of information about the elapsed time between the last meal taken and the spirometry test, especially during the pre- and postexperimental trial sessions. The time of the last meal can influence spirometric data, and in practice, “eating a large meal within 2 hours pretesting” is among the activities that should be avoided prior to spirometry (Miller et al., 2005).
Point 3. Lack of information about the participants’ earlier experience with Ramadan fasting. As seen in studies evaluating the effects of Ramadan fasting on exercise performance (Chtourou, Hammouda, Chaouachi, Chamari, & Souissi, 2012), it is possible that the subjects’ Ramadan-fasting history could influence their respiratory adaptations (Fenneni et al., 2015).
Point 4. Lack of information about participant position during spirometry. It has been shown that on average all the spirometric indices of healthy nonobese adult subjects, except the peak expiratory flow, were higher in the standing position compared to the sitting position (American Thoracic Society, 1987).
The evaluation of the effects of Ramadan fasting on human physiology has clinically applicable implications (Bragazzi, 2015). For that reason, future studies aiming to evaluate the effects of Ramadan fasting on lung function should be conducted and reported more rigorously by taking into account the various factors discussed above and in the well-done Indian study (Roy & Bandyopadhyay, 2016).