Comparison of Knowledge of Lactose Intolerance and Cow’s Milk Allergy Among the Medical Students at Two Universities in Saudi Arabia

Lactose intolerance is a condition causing an inability to absorb and digest lactose leading to gastrointestinal symptoms such as abdominal pain, diarrhea, and flatulence. Because of the similarities between lactose intolerance and cow’s milk allergy, it is becoming necessary to increase physicians’ understanding of these two diseases. Consequently, we aimed to determine the level of knowledge of lactose intolerance and cow’s milk allergy among medical students. An electronic survey was distributed to 399 medical students at two universities in Saudi Arabia from October to November 2022. The majority of the respondents had an inadequate knowledge of both lactose intolerance and cow’s milk allergy (99.75% and 97.99%, respectively). According to the study’s results that showed a lack of awareness among health-related students, further studies and awareness programs are highly recommended.


Introduction
About 70% of the world's population has lactose intolerance (LI), which is caused by the inability to digest and absorb lactose (the sugar found in milk and other dairy products) [1,2].Lactose has to be broken down by lactase enzyme into D-glucose and D-galactose before it can be absorbed into the bloodstream [1,2].After weaning, the expression of the lactase enzyme gradually decreases in most of the world's population, known as lactase non-persistence [2,3].Population genomics research suggests that lactase persistence, or the capacity to digest lactose after infancy, first appeared during the Eurasian Bronze Age (3000-1000 BC) [1,4].The regular consumption of milk and fermented milk products may have improved people's nutritional condition [1,2].LI is characterized by mild gastrointestinal symptoms such as diarrhea, flatulence, and abdominal pain [5].Individuals under five can usually tolerate lactose well since primary LI occurs in people over five [5].LI and cow's milk allergy (CMA) symptoms in the gastrointestinal tract are so similar that many parents and physicians conflate them [1].
Owing to the similarities of LI and CMA, it is crucial to increase physicians' awareness and knowledge of both diseases.Limited investigation shows physicians' inadequate understanding of LI and CMA [6][7][8].A recent study reveals that nutritionists have limited knowledge of the nutritional management of LI [9].By contrast, another study shows that the leading suggestions given by pediatricians and nutritionists for treating CMA are conceptually incorrect [10].Consequently, this study aims to investigate the level of knowledge of LI and CMA among the medical students at both Umm Al-Qura University and King Abdulaziz University.

Study design and participants
In this cross-sectional study, we targeted the medical students of both Umm Al-Qura University and King Abdulaziz University to compare their respective levels of knowledge of LI and CMA from October 10 to November 10, 2022, and we excluded those who refused to participate in the study.

Sample size and ethical consideration
We calculated the sample size using the software of Open Epi [11].To obtain 95% confidence and a 5% acceptable error margin, we collected the data from 399 medical students using the convenience sampling method.
We obtained ethical approval from the biomedical ethics committee of the College of Medicine at Umm Al-Qura University, Makkah, Saudi Arabia (approval number HAPO-02-K-012-2022-09-1203).

Study procedure and questionnaire design
The study questionnaire was adopted and modified from previously published studies [10,12].The survey was electronically designed using Google Forms and distributed on social media platforms (Telegram and WhatsApp).
It was divided into three parts.The first part was designed to collect the participants' demographic data, the second part included questions to assess their knowledge of CMA, and the third part aimed to assess their knowledge of LI.The questionnaire was accompanied by a consent form to be signed by all the respondents before they moved on to the main survey and the email of the corresponding author for any inquiries.

Statistical analysis
The final data were stored in Microsoft Excel spreadsheets to check their completeness and eliminate typographical errors.The descriptive statistics were represented by percentages for the categorical variables and mean and standard deviation for the continuous variables, using a Statistical Package for the Social Studies 23 spreadsheet (IBM, Armonk, NY).Finally, the categorical variables were computed using the independent chi-square test to determine all the knowledge-related factors.A p-value less than or equal to 5% was considered significant.

Results
This survey-based study targeted medical students at two universities in Saudi Arabia.We enrolled 399 students with a mean age of 21.38 (SD=1.89).Most of the students were men (n=224, 56.1%).Most of the responses were from the students at Umm Al-Qura University (n=308, 77.2%), with fewer responses from the students from King Abdulaziz University (n=91, 22.8%).Furthermore, most of the responses were from third-year medical students (n=111, 27.8%), followed by sixth-year students (n=108, 27.1%) (

Discussion
To our knowledge, this is the first study that estimates the level of understanding of LI and CMA among medical students.Most studies have been conducted among physicians, and the level of knowledge about each disease was investigated separately [9,12].

Knowledge of LI
LI is a gastrointestinal disorder encountered among more than 65% of the human population [13,14].LI is characterized by the incapability to absorb the lactose sugar in dairy products and milk, which leads to stomach pain or discomfort [13,14].So, it is vital to improve public awareness of LI with the main knowledge about symptoms and the use of a lactose-free diet with which LI can be significantly decreased.
LI is not life-threatening, but it does affect patients' quality of life and well-being, and they may experience extreme discomfort caused by ineffective treatment [12,15].Thus, medical students must recognize its diagnosis workup and management.
According to our findings, most participants had poor knowledge of LI.Similarly, two different studies conducted in Saudi Arabia among nutritionists and the general population showed a limited level of knowledge regarding LI [9,13].However, these disagree with a study conducted among clinicians, which found that they understood the general aspects of LI but not the diagnostic aspects [12].

Knowledge of CMA
Owing to the early representation of CMA symptoms during childhood, a study has suggested that it is essential for primary care physicians to be aware of the circumstances and prepared to make a correct diagnosis and use current treatment and management approaches [16].
Our study reports that most students have poor knowledge of CMA.Another study of food allergies that involved 407 pediatricians and primary care doctors demonstrated that the basic knowledge of clinicians was only average; however, they were comfortable following up with children who had a food allergy [17].
Another study showed that pediatricians receive insufficient training in diagnosing, treating, and managing anaphylaxis caused by food allergies [18].Furthermore, the availability of insufficient information on the

TABLE 1 : Participants' demography
Most of the students had a negative past history of both CMA and LI (94.5% and 87%, respectively).By contrast, 5.5% of the students had a history of CMA, while 13% had a history of LI.Moreover, 6.5% had a positive family history of CMA compared with 18% for LI (Table1).