Comparative study of physical activity status and food patterns in adolescents with and without polycystic ovary syndrome: an analytical approach

Introduction

One of the prevalent endocrine diseases in women during childbearing age is polycystic ovary syndrome (PCOS).1 This syndrome is a heterogeneous condition with variable phenotypic expressions that have significant differences in diagnostic criteria.2 Although the aetiology of this syndrome is not completely understood, factors such as genetic predisposition, increased insulin secretion, insulin resistance, obesity, environmental and chemical pollution, environmental factors, nutrition and physical activity are effective in its occurrence. The role of genetics and lifestyle is undeniable.3–6 Although PCOS can occur at any age, it mostly begins in the adolescent period.7 8 Adolescence is one of the most critical periods of life, and the occurrence of chronic disorders during this period can affect the future of adolescents’ health and well-being.9 The detection of PCOS during adolescence is challenging because of the overlap with the physiological events of puberty. The diagnosis of PCOS in adolescent girls should be based on the two main criteria of irregular menstrual cycles and hyperandrogenism (clinical and/or biochemical symptoms).10 Since adolescents with this syndrome may be exposed to disorders, such as obesity, metabolic syndrome, insulin resistance, type 2 diabetes, infertility, cancer, heart diseases and mental disorders, identifying the risk factors and managing this syndrome during this period is very important.11 12

Studies have shown that, compared with healthy people, women with PCOS consume foods with a high glycaemic index, high fat (saturated fat and polyunsaturated fat) and high total energy intake.13 14 In a study on obese or overweight women with PCOS in Iran, the authors found that these women consumed more fat, carbohydrates, caffeine and fewer vitamins and minerals than healthy people.14 Since no study has been conducted on the dietary patterns and lifestyle of adolescent girls with PCOS, this study is designed to compare the physical activity status and dietary patterns of adolescents with and without PCOS.

Materials and methods

This cross-sectional study was conducted in health centres affiliated with the Gorgan University of Medical Sciences in Iran between February 2021 and October 2021. This article was written in compliance with the Declaration of the World Medical Association of Helsinki on Ethical Research Conduct.

Overall, 400 adolescents, who had PCOS (n=200) and without PCOS (n=200), were referred to health centres affiliated with the Gorgan University of Medical Sciences in Iran between February 2021 and October 2021 and included in this study through a simple random sampling method.

The inclusion criteria for the study were adolescent girls aged between 12 and 24 who have health literacy, no history of chronic diseases that affect the regularity of the menstrual cycle, such as endocrine disorders and genetic problems, and have had at least 2 years since the start of their menstruation. The Rotterdam criteria were used to diagnose PCOS in this study.15 These criteria include anovulation, hyperandrogenism and polycystic ovaries. Polycystic ovaries are defined as having at least 12 follicles measuring 2–9 mm in diameter or an ovarian volume >10 mL in at least one ovary. The presence of at least two clinical-biochemical criteria was used to confirm the diagnosis. All girls were subjected to sonographic and laboratory examinations and the results were reviewed by gynaecologists. If the gynaecologist’s final diagnosis was confirmed, the teenagers were placed in the affected group, and if the diagnosis was not confirmed, they were placed in the non-affected group. Adolescents in both groups completed three questionnaires. The questionnaires were completed by the self-reporting method.

On the other hand, the exclusion criteria for the study were the unwillingness of participants to continue the study for any reason, failure to complete the questionnaire and lack of access to adolescent information after three follow-ups by phone.

Covariates

Age, weight, height, body mass index (BMI), menarche, interval between two mensurations, length of menstruation, education, family history of PCOS and smoking were obtained from self-administered questionnaires. The education level was defined as under-diploma, diploma and university. Family history of PCOS and smoking was defined as yes or no questions.

Results

The flow diagram of the study is shown in figure 1. 550 adolescents were assessed for eligibility, and finally, 400 teenagers were included in this study. The mean age of participants was 19.16±3.18. The demographic characteristics of participants are shown in table 1. The results of the independent t-test showed that the group with PCOS has significantly more weight, height and interval between two periods than the non-affected group (p<0.05), but their menstrual duration is significantly shorter than the other group (p<0.05), even after adjusting for other characteristic variables.

The average calorie intake and physical activity in the two groups are shown in table 2. Based on the independent t-test, the calorie intake in the PCOS group was significantly higher, and the daily physical activity was lower than the control group (p=0.001). After adjusting for various characteristics of teenagers (age, weight, height, BMI, menarche, group (PCOS/control), interval between two mensurations and length of menstruation), multivariate analysis revealed that the OR for calorie intake and daily physical activity in the two groups was 3.54 (95% CI 1.98 to 3.82) and 2.61 (95% CI 1.31 to 3.76), respectively.

The distribution of eating habits and patterns among teenagers with and without PCOS based on the Adami and Quadra questionnaires is shown in table 3. Based on the findings of this table, among teenagers with PCOS compared with non-sufferers, unhealthy eating habits are more frequent, like skipping one of the daily meals to lose weight, the tendency to eat snacks in the evening, the tendency to consume more food at lunch than dinner and the tendency to watch TV while eating.

Discussion

The present study was conducted to compare the nutritional status and physical activity among adolescents with and without PCOS. The findings of this study showed that there is a statistically significant difference in terms of average height, weight and menstrual status between the two groups. The findings of this study in this section were consistent with the findings of Hashimpour et al,22 Kaewnin et al,23 Desai et al,24 and Pourhosseini et al,25. Among these, there were two studies whose results in the menstrual status section were different from the results of the present study. The groups with PCOS had menstrual intervals and durations within the normal range and did not differ from non-sufferers,26 27 which of course may be due to the difference in the frequency of participants (early adolescence and less diagnosis of this disorder) and the racial differences between the participants of the two studies.

Also, the results of the present study showed that the amount of physical activity in the group of PCOS was unfavourable, and it was significantly different from the non-affected group. In line with the results of the present study, the study of Shayan et al reported a direct relationship between regular daily exercise and the reduction of symptoms of this syndrome. So aerobic and regular daily exercise for 36 min was associated with a decrease in the incidence of this syndrome.28

The results of the present study were consistent with the results of the study by Huang et al and Saremi et al regarding the effect of physical activity on PCOS.29 30 The systematic study by Patten et al emphasised the importance of exercise for patients with PCOS.31 Therefore, exercise is probably effective in regulating sex hormones (follicle-stimulating hormone and free testosterone) and improving the complications of PCOS.32 By reducing body fat and increasing the secretion of a beta-endorphin hormone, exercise reduces the level of LH and, as a result, decreases testosterone.33 The protective effect of regular exercise against diseases such as cardiovascular diseases, type 2 diabetes and breast and colon cancers is well established.34 The anti-inflammatory effect of regular exercise may mediate the beneficial effect of exercise on health in individuals,35 thus improving PCOS. But unlike the results of the present study, the results of Lin et al’s study showed that there is no relationship between physical activity and PCOS.36 Among the reasons for the difference between the results of the studies, we can mention the difference in the sample size, the difference in the tools used and the difference in the threshold of exercise to produce an effect on PCOS.

According to the results of the present study, there is a significant difference in the calories consumed by the two groups. The average calorie intake in the PCOS group is higher than that of healthy teenagers. However, Kulshreshtha et al showed that the intake of calories in women with PCOS does not differ from that of healthy women if their weight is adjusted, and the difference between the two groups is in the consumption of junk and low-fibre foods in the affected group.37 Also, the results of Panjeshahin et al’s study showed that high fat intake from total calories (especially saturated fat and cholesterol) could increase the occurrence of this syndrome.38

The present study also examined the eating patterns of adolescents with and without PCOS. Our study showed that abnormal eating patterns are more common in adolescents with PCOS than in healthy adolescents. In line with the present study, Hajivandi et al showed in their qualitative study that Iranian adolescents with PCOS have a greater tendency to consume high-fat, salty, sweet foods and unhealthy snacks.39

According to the result of Jakubowicz et al’s study, getting high calories at breakfast along with reducing dinner helps improve insulin resistance and reduce the activity of inflammatory factors, which improves hyperandrogenism and speeds ovulation40, which is in line with our study. A systematic review reported that women with PCOS had lower adherence to appropriate dietary patterns and lower consumption of major food groups (grains, fruits, vegetables, proteins, seeds, nuts and dairy).41

Conclusion

The results of the present study showed that physical activity status, nutritional patterns and the number of calories consumed are different between adolescents with PCOS and those without. The results of this study revealed that unhealthy eating patterns and insufficient physical activity are more common among adolescents with this syndrome. It is suggested that by improving the level of awareness of teenagers in this field and providing the necessary training, we take steps for the prevention and treatment of the complications caused by this syndrome in teenagers.