Due to the COVID-19 pandemic, measures such as city lockdowns were imposed across the world. In Japan, people were mandated to refrain from going out unnecessarily and to work from home when possible, schools were closed. This has given people more time to spend at home and has associated physical, mental, and social stress. Many reports have been published on how these lockdowns affect lifestyle habits. An online survey of 1,033 Chinese people showed that 70% of participants increased their screen time, whereas 30% of participants increased in the frequency of their vegetable and fruit intake [9]. An analysis of 995 Indian people revealed that physical activity decreased, whereas sitting time and screen time increased. Improvement in dietary habits was seen in younger people. Body weights increased in one-third of participants. Quarantine-induced stress and anxiety increased in nearly one-fourth of the participants [10]. A study on young Saudi women (aged 19–30) showed that approximately half of the participants did not report a weight change, 30% reported weight loss, and 18% reported weight gain. The variables associated with increased weight gain were self-quarantine since COVID-19 started, age, and stress at baseline and during lockdown. The variables associated with reduced risk of weight gain were physical activity during lockdown, coffee consumption, and total sleep time [11]. According to a survey conducted at 35 research institutes in West Asia, North Africa, Europe, and the United States, which used the Internet to evaluate the psychological and lifestyle-related effects of home confinement due to COVID-19, the period of home confinement had a negative effect on mental health and emotions, and these were associated with unhealthy lifestyle (lack of physical activity + 15.2%; decreased social activity + 71.2%; deterioration of sleep quality + 12.8%; unhealthy eating habits + 10% compared with the period before confinement) [12]. In the general population, physical inactivity has been identified in many reports, although dietary habits varied. Many reports showed that increased stress leads to unhealthy eating habits. In a study on patients with diabetes in India, about 80% of people reported that their diet and physical activity remained unchanged. Body weight and HbA1c were unchanged, but mental stress and lack of sleep were associated with unhealthy eating habits, resulting in poor glycemic control in these populations. The importance of a mental stress approach was emphasized [7].
Four reports in Japan observed a relationship between lifestyle changes and glycemic control due to the COVID-19 pandemic. Munekawa et al. [3] investigated stress levels and lifestyle-related changes in 203 patients with type 2 diabetes using a questionnaire and found that 40% of the study population felt increased stress, and 50% had decreased physical activity. Increased stress was associated with decreased physical activity and increased dietary intake. Tanaka et al. [4] conducted a self-administered questionnaire survey of 463 patients with diabetes. They found an increase in snacking habits in 21%, a decrease in physical activity in 51.2%, and an increase in alcohol intake in 8.7%. People under the age of 65 years with increased snacking exhibited worsening HbA1c and weight gain, whereas in those over the age of 65 years, physical inactivity was a factor of weight gain. A difference depending on the age has been reported. Takahara et al. [5] observed the relationships among lifestyle-related changes, HbA1c, and body weight in 1402 patients with diabetes using an interview questionnaire. A decrease in leisure time exercise as associated with worsening HbA1c and weight gain, whereas an increase in dietary intake and snacking were each associated with weight gain. Differences in these relationships were found to vary with age and with exercise habits. Kishimoto et al. [6] surveyed 168 diabetic patients. Patients with reduced exercise due to teleworking or gym closure had worse glycemic control, but patients with improved diet, regardless of exercise, reported improved glycemic control. In this study, 32% showed increased snacking, whereas 47% showed decreased physical activity. In the overall analysis, the factor statistically associated with worsening glycemic control was increased snacking, indicating the importance of diet management during the COVID-19 pandemic, as demonstrated by Kishimoto et al.
In this study, we examined the factors that influence the deterioration of HbA1c during the COVID-19 pandemic according to sex to determine whether lifestyle changes differed according to sex. In the male population, many of the employed had worsened HbA1c, whereas no association between employment status and worsened HbA1c was observed. However, the unemployed subjects exhibited worsened HbA1c, and a sex difference was observed.
Sex differences were observed in the changes in the three lifestyle habits (physical activity, snacking habits, and drinking habits). Comparing the physical activity between the sexes especially indicated that it decreased among the women answered but increased among the men. Thus, women may be more likely to be less physically active than men during the pandemic.
Much research has been done on sex differences in normal conditions, but not during the COVID-19 pandemic. According to demographic and behavioral data from a cohort study in 20 countries, the “PURE-Saudi” study, women were more likely to experience some form of stress [13]. In real life, women may neglect their own health by prioritizing their household chores and family [8]. Since ancient times, men have been hunting, and women have been collecting to secure food. Men and women in that period were said to vary in their dietary behaviors. The Handza tribe of Tanzania still maintain these traditional, sex-based hunter-gatherer roles. Reports on the differences in dietary behaviors between the men and women of the Handza stated that males consumed a higher proportion of meat in total calories, whereas females consumed a higher proportion of tubers (plant roots). Women were also reported to eat more often than men [14].
In addition, while women are highly interested in healthy eating and form their own weight and eating habits, men tend to eat fatty foods because they prioritize the joy of eating [15]. These sex differences in eating behavior are influenced by sex hormones. Estrogen, a female hormone, is said to have anti-obesity and anti-feeding properties. Chronic increased stress is known to cause a bias toward a high-energy diet (rich in sugars and lipids), which is said to be more pronounced in men [16]. The cortisol-secreting response to stress may increase food intake and sweets [17]. Unproductive time or spells of boredom also affects eating behavior. Boredom is known to increase the desire for snacking, which is considered an avoidance behavior from self-loathing caused by boredom [18]. Chronic psychological stress and boredom as a result of lockdowns during the COVID-19 pandemic, therefore, increase the tendency for a high-energy dietary intake and snacking, and the effects can be significant, especially in men. The present study also indicates that snacking contributes to the deterioration of HbA1c in men. The effects of lifestyle-related changes on HbA1c were associated with an increase in snacking in the overall and male population analyses. Patients with diabetes need to maintain balanced diet and regular exercise during the COVID-19 pandemic period. Furthermore, this study emphasized the need for glycemic control in men with diabetes, whereas the need to engage in physical activity was identified in women.
The data obtained on the changes in lifestyle habits were not quantitative evaluations but were subjective responses of the subjects. No dietary intake or nutritional survey other than snacking was investigated. Patient information such as complications and duration of diabetes were not sufficiently investigated. In addition, because this study is a retrospective medical record survey, the medications were administered at the discretion of the attending physician and thus varied among the patients. These limitations must be thoroughly addressed in future studies to obtain more conclusive results.