Association of Menstrual Disorders with Body Mass Index in Undergraduate Medical Students

330 Abstract: Objective: Menstrual disorders constitute one of the major problems faced by medical students globally. Amongst the various factors attributed as causative factors in menstrual cycle variations, include body mass index [BMI] is the most easily modifiable factor. As we still do not have clear answers, this study was planned to study the association of menstrual disorders with BMI. Methodology: This is a cross sectional study, done in undergraduate female medical students in the age group of 18 to 30 years. Exclusion criteria included pregnancy, breast feeding, <12 months post-partum, <6 months post abortion/miscarriage, concomitant medical disorders and intake of hormonal medication. Data was collected for socio-demographic variables, detailed menstrual history, obstetric and medical history. Examination recorded anthropometric details, hirsutism, acne, any signs of virilization. Menstrual cycle variables were studied for their association with BMI. Results: A total of 254 students participated in the study with an average age of 23.9 years. Dysmenorrhea was globally found. Majority of cases were mild dysmenorrhea. Premenstrual syndrome [PMS] was seen commonly, commonest symptoms being mood swings and abdominal cramps. There was no association between mean menstrual blood loss [MBL], PMS and BMI and poor association with dysmenorrhea. Conclusion: Dysmenorrhea and PMS were very commonly seen and were not related to BMI. The mean MBL was independent of BMI. A rise in BMI had a positive association with cycle irregularity.


Introduction:
Menstrual disorders constitute one of the major problems faced by medical students globally with an estimated prevalence of 87-91%. 1 The disorders range from amenorrhea, cycle irregularity, abnormal flow, dysmenorrhea and premenstrual syndrome [PMS]. It is hypothesized that due to disproportionate degree of stress in medical education, the trainees are vulnerable to menstrual abnormalities. The stress includes both physical and psychological factors such as irregular and long working hours, insufficient sleep, irregular food and exercise habits. 2,3 Important factors responsible for variations in menstrual cycle include genetic and racial characteristics, hormonal changes, associated medical disorders and body mass index [BMI]. Amongst these, BMI is the most easily modifiable factor which has been seen to affect the patterns of menstrual cycle in many studies. However, we still do not have clear answers and need to study the effect of BMI on menstrual patterns in greater detail.
This study was therefore planned to observe the association of variations in menstrual patterns with body mass index [BMI].

Methodology:
This is a cross-sectional study done in a medical college from October to November 2020. It was approved by the institutional committee. Subjects were recruited on the basis of inclusion and exclusion criteria, after xplaining the purpose and components of the planned study. Anonymity and confidentiality were ensured, and those willing to participate were asked to sign a consent form before inclusion in study.

Inclusion and Exclusion Criteria:
All undergraduate female medical students in the age group of 18 to 30 years who consented to be part of the study were included. Exclusion criteria included pregnancy, breast feeding, <12 months post-partum, <6 months post abortion/ miscarriage, concomitant medical disorders and intake of hormonal medication. A p-value of <0.05 was considered statistically significant.

Observations:
A total of 254 students were included for the study. Table 1 gives socio-demographic variables of the subjects. The average age of students in the present study was 23.9 years and the mean age of menarche was 13 +/-1 years.

Discussion:
Previous studies have noted that the prevalence of menstrual problems in medical students has risen and BMI seems to be an important contributory factor. Dysmenorrhea and PMS are important contributors to absence from classes, leading to significant loss in terms of academics as well as clinical work. 5 MBL and cycle irregularity has also been observed to have a direct association with BMI. However, the findings are controversial, and many investigators have found contrary results. This study was thus planned to study the menstrual cycle variations in medical students and find out the variables that change with BMI.

Dysmenorrhea:
In the present study, we found that dysmenorrhea was universally present to varying degrees in the subjects. Similar high prevalence of pain during periods has been observed in Indians. Kural et al [2015] 6 found a prevalence of 84.2% in college going girls. We observed a negative association of mild dysmenorrhea and BMI. Subjects with lower BMI had a higher incidence of pain (  8 found that a rise in BMI above 23 is highly associated with higher pain scores. However, in the present study, we did not find any significant association of BMI with moderate or severe dysmenorrhea. Therefore, the association with mild dysmenorrhea is at the most, probably weak. This effect theoretically should be found more in obesity and morbid obesity. However, we did not have the sufficient numbers of subjects in this range, therefore, it is difficult to comment on this finding. We feel that larger studies are required before any conclusion can be drawn on the subject.

Cycle regularity:
We observed a significant association between cycle regularity with BMI ( There is a strong association with BMI, prevalence of PCOS and anovulatory cycles. We think that many subjects with higher BMI may be having anovulatory cycles, hence more prevalence of irregular cycles.

Conclusion:
• Dysmenorrhea and premenstrual syndrome were very common among undergraduate medical students, and not related to body mass index. • Mean menstrual blood loss was independent of body mass index. • A rise in body mass index had a positive association with cycle irregularity.

Limitations of the study:
We anticipated that medical undergraduates have higher menstrual cycle abnormalities as compared to general age matched population, due to lifestyle patterns. However, we did not study the menstrual cycle abnormalities in controls. Besides, we did not examine the psychological factors and their association with menstrual cycle, which may be strong confounders. As the study is recall based, the subjects may not be able to give accurate answers to changes in menstrual cycle pattern during periods of stress such as examination.

Recommendations:
Prospective studies with long term follow up are needed to find out how BMI affects menstrual cycle patterns, with sufficient numbers to exclude common confounders.