According to the WHO report, obesity is the most common but neglected disease and is a global phenomenon to the extent that it is called ‘Globesity’ [1,2]. In Korea, according to the National Statistical Office’s ‘National Quality of Life 2023’ report, the obesity rate among adults aged 19 and older in 2022 is 37.2%, which is still higher than before COVID-19. The obesity rate among women is 25.7%, which is decreasing to a level similar to before COVID-19, but the obesity rate among men is still reported to be high at 47.7% [3]. To prevent obesity, which can be associated with cardiovascular disease, type 2 diabetes, and cancer, it is necessary to manage eating habits and physical activity [1]. Lack of physical activity is a major risk factor for chronic diseases and is known to be associated with the development of diabetes and high blood pressure, among diseases that affect dental care. Unlike middle and high school students, college students have free class hours and different meal and rest times, so individuals can adjust their eating habits and physical activities [4,5]. Healthy lifestyle habits during this period are very important as they can have an impact throughout adulthood. However, domestic female college students’ beauty values ​​are focused on weight and they prefer a thin body, so they sometimes diet through diet rather than exercise. This can have a negative impact on health by causing nutritional deficiencies or decreased immunity due to weight loss due to excessive diet control without exercise. Compared to male students, female students have lower physical strength due to their biological characteristics, but their body fat percentage is higher, so physical activity is essential for health [6,7]. A decrease in muscle strength is also related to the risk of cardiovascular disease and diabetes. Recently, grip strength is a representative indicator of muscle quality and quantity, and data on the relationship between grip strength and diabetes is increasing. Grip strength measurement is easier and more economical to measure than cardiorespiratory fitness, so it is considered a good biomarker in several studies on the relationship between physical strength and health [8-11]. The lower the grip strength, the higher the blood sugar level, and research results have been published on the relationship between grip strength and the prevalence of diabetes. In Korea, it was reported in the National Health and Nutrition Examination Survey that there is an independent relationship between grip strength and type 2 diabetes [12-14]. The age of your 20s is the early stages of adulthood and is a time when you are physically healthy, but it is also a time when you can reduce the risk of chronic diseases that can affect health after middle age and improve the quality of life through health promotion. Health-related behaviors and oral health-related behaviors formed during this period are very important, but adults exposed to new environments such as college life or employment may have poor health or physical strength due to irregular living environments, smoking, drinking, and low physical activity. However, it is a period in which correction is possible because lifestyle habits have not yet been firmly formed [15-17]. It has been reported that oral health is related to relative health and is only related to increasing the prevalence and risk of progression of periodontal disease, although it is closely related to major disability symptoms below general health [18,19]. Although body composition, grip strength, and muscle strength are being studied in other fields, research on these in the oral cavity is still insufficient. Accordingly, this study identified the correlation between oral health management behaviors, such as the use of oral hygiene products related to the health of the oral area. This study was conducted to use it as basic data when developing a program for the continuous practice of oral health management behavior along with health-related behavior in the future.

1. Subject

1) Number of study subjects

The target population of this study was college students attending the Department of Dental Hygiene at A University in Andong. Among these, students who agreed after hearing the researcher’s explanation of the research purpose and method were selected as research subjects. The sample size was determined using the G*Power version 3.1.9 program. The significance level (a) was 0.05, the effect size was 0.3, and the power (1-b) was 0.80. As a result, the number of samples was 82, but considering the dropout rate, the study was conducted with 100 people. Among them, 85 people who had no problems with both the Inbody test results and the questionnaire were selected as the final research subjects.

2) Study instruments

(1) Participants’ general characteristics

The general characteristics of the study subjects consisted of four health-related behaviors, satisfaction with life (Satisfaction With Life Scale, K-SWLS), and depression level (Patient Health questionnaire-9, PHQ-9). Health-related behaviors were investigated whether smoking, drinking, exercising, and taking vitamins. The results of K-SWLS are 7 questions on a 5-point Likert scale [13]. A total score of 9 or less is very dissatisfied, 10-14 points are quite satisfied, 15-19 points are slightly dissatisfied, 20 points are neutral, and 21-14 points are very satisfied. A score of 25 was classified as slightly satisfied, 26-30 as quite satisfied, and 31-35 as very satisfied. The PHQ-9 is a questionnaire consisting of 9 questions. The more severe the depressive symptoms, the higher the number. It is scored from 0 to 3, with a maximum total score of 27. Based on the total score, a score of 9 or less was classified as moderate depression, a score of 10-14 as mild depression, a score of 15-19 as severe depression, and a score of 20 or more as severe depression.

(2) BMI (Body Mass Indux)

A body composition analyzer (Accuniq, Korea, Inbody IOI353) using touch-type electrical stimulation was used to determine body mass index, including weight and muscle mass, and a stadiometer (Pocheon, Korea, HIE-401) was used to measure height. BMI applies Asia-Pacific standards: less than 18.5 kg/m² is underweight, 18.5 kg/m² to 22.9 kg/m² is normal, 23.0 kg/m² to 24.9 kg/m² is overweight, and 25.0 kg/m² to 29.9 kg/m² is. Mild obesity, 30.0 kg/m² to 34.9 kg/m² was classified as moderate obesity, and 35.0 kg/m² or more was classified as severe obesity. The normal range for WHR (Waist Hip Ratio, abdominal fat percentage) was set at 0.75 to 0.90, and the normal range for body water content was set at 45% to 65% of body weight.

(3) Muscle mass

Limb muscle mass index was measured using a body composition analyzer (Inbody IOI353, Accuniq, Korea). In addition, calf and abdominal circumferences were measured, and muscle strength was measured using a grip dynamometer (TKK5401, JAPAN).

(4) Oral health care behavior

The items on oral health management behavior consisted of three upper-level items on whether or not to brush teeth after lunch, whether or not to brush teeth before bed, and whether or not to use oral hygiene products, and a lower-level item on whether or not to use different types of oral hygiene products [14].

2. Analysis method

1) IRB approval

This study was initiated after receiving approval from the Institutional Review Board (IRB) 70365-202307-002-04 and was conducted until December 31, 2023. The questionnaire was self-administered, and the health-related variables were measured by a pre-trained researcher.

2) Statistics processing

Data analysis was two-sided using IBM SPSS Statistics version 27.0 at a statistical significance level of p<0.05. Frequency analysis and descriptive statistics were performed on all basic variables related to the study content, and Pearson’s correlation was used to verify the relationship between oral health care behavior and other variables.

1. General characteristics

The general characteristics of the study subjects were 42.4% smoked, 85.9% drank alcohol, and 78.8% exercised. Those who did not take vitamins were even higher at 64.7%. The highest level of depression was found to be moderate at 91.8%, and there were no study subjects with severe depression. The highest level of satisfaction with life was quite satisfied at 27.1%, and slightly satisfied at 18.8%, with a total of 49.4% of respondents saying they were satisfied (Table 1).

Table 1 . General characteristics

Characteristics	Details classification	N	%
Smoking	Yes	36	42.4
	No	49	57.6
Drinking	Yes	73	85.9
	No	12	14.1
Exercise	Yes	67	78.8
	No	18	21.2
Taking vitamins	Yes	30	35.5
	No	55	64.7
The degree of depression	In general	78	91.8
	A mild depression	5	5.9
	Moderate depression	2	2.4
	A severe depression	0	0.0
	A great dissatisfaction	4	4.7
	A great deal of dissatisfaction	7	8.2
	A little dissatisfied	18	21.2
Satisfaction with life scale	Neutrality	14	16.5
	Little satisfied	16	18.8
	Quite satisfactory	23	27.1
	Very satisfied	3	3.5
Total		85	100

2. Body composition

The body water content of the study subjects was 34.85, body fat mass was 28.41, and relative grip strength was 42.29 (Table 2). The number of study subjects with walking muscle loss was only 3.5%, and the study subject with grip strength loss was only 1.2%. In BMI classification, normal was the highest at 40.4%, and level 1 obesity was also high at 22.4%. Stage 3 obesity was the lowest at 3.5%. As a result of WHR measurement, normal was the highest at 70.6%, and abdominal obesity was the lowest at 4.7% (Table 3).

Table 2 . Body composition

Characteristics	M±SD
Body water content	34.85±7.96
Body fat mass	28.41±6.07
Arm and leg muscle mass	44.53±10.13
The perimeter of oneʼs thighs	35.92±3.96
Waist circumference	77.40±13.77
Relative grip strength	42.29±11.08
N	85

Table 3 . Muscle loss and obesity rates

Characteristics	Details classification	N	%
Walking muscle loss	Yes	3	3.5
	No	82	96.5
A decrease in grip strength	Yes	1	1.2
	No	84	98.8
BMI	Underweight	4	4.7
	Normal	34	40.0
	Overweight	12	14.1
WHR	Level 1 Obesity	19	22.4
	Level 2 Obesity	13	15.3
	Level 3 Obesity	3	3.5
	Not abdominal obesity	21	24.7
	In general	60	70.6
	Abdominal obesity	4	4.7
Total		85	100

3. Oral care

While only 27.1% responded that they brush their teeth after lunch, 91.8% responded that they brush their teeth before going to bed. The response that they used oral hygiene products was 91.8%. Multiple responses from users showed that 44.8% used dental floss, 34.6% used tongue cleaners, 14.1% used interdental brushes, and 3.8% used waterpiks (Table 4).

Table 4 . Oral care

Characteristics	Details classification	N	%
Brushing after lunch	Yes	23	27.1
	No	62	72.9
Brushing before bed	Yes	78	91.8
	No	7	8.2
Oral hygiene products	Yes	78	91.8
	No	7	8.2
	Dental floss	35	44.8
	Interdental brush	11	14.1
	Water pick	3	3.8
N		85	100

4. Correlation between general characteristics and oral health care behaviors

There was a positive correlation between brushing teeth before bed and drinking alcohol (p<0.05), and a positive correlation was also seen between the use of oral hygiene products and taking vitamins (p<0.05). There was a negative correlation between satisfaction with life and level of depression (p<0.01) (Table 5).

Table 5 . Correlation between general characteristics and oral health management behaviors

	1	2	3	4	5	6	7
1. Smoking	1
2. Drinking	0.142	1
3. Taking vitamins	−0.085	0.158	1
4. The degree of depression	0.075	−0.065	0.077	1
5. Satisfaction with life scale	−0.037	0.039	0.227*	−0.316**	1
6. Brushing before bed	0.084	0.247*	0.132	0.084	0.088	1
7. Oral hygiene products	0.052	0.097	0.223*	0.119	0.086	0.173	1

*p<0.05, **p<0.01 by pearson’s correlation analysis

5. Correlation between body composition and oral health care behavior

Among body compositions, there was a negative correlation between body water and body fat mass (p<0.01), and a positive correlation between limb muscle mass and body mass ejection fraction (p<0.01). There was a positive correlation between relative grip strength and body water content (p<0.01), and a negative correlation with body fat percentage. Toothbrushing before bed was found to have a positive correlation with body fat mass (p<0.01) and a negative correlation with relative grip strength (p<0.01). There were no variables that showed a statistically significant correlation with oral hygiene products (Table 6).

Table 6 . Correlation between body composition and oral health management behavior

	1	2	3	4	5	6	7	8
1. Body water content	1
2. Body fat mass	−0.476**	1
3. Arm and leg muscle mass	−0.169	0.273*	1
4. Relative grip strength	0.297**	−0.615**	−0.125	1
5. BMI	−0.377*	0.679**	0.778**	−0.388**	1
6. WHR	−0.201	0.581**	0.616**	−0.271*	−0.669**	1
7. Brushing before bed	−0.090	0.256*	−0.013	−0.256*	0.063	0.136	1
8. Oral hygiene products	0.080	−0.200	0.089	0.105	−0.082	−0.013	0.173	1

*p<0.05, **p<0.01 by pearson’s correlation analysis

One of the concerns worldwide, including Korea, is obesity [1,2]. Reflecting the obese population that is increasing every year, research related to this is actively underway in various fields, and Korea is not far away from obesity to the extent that the obesity standard is designated separately for Asia-Pacific [6]. In the case of obesity, it is receiving more social attention as many cases are reported to be related to life satisfaction and depression. In addition, interest in muscle loss has recently been increasing. Aside from the natural muscle loss in the elderly due to aging, symptoms of muscle loss in young people and adolescents are also being discussed [20]. Obesity or muscle loss during college years requires attention as it can affect not only smooth academic life and academic achievement, but also oral health and eating habits that affect overall health. The results of this study showed that among general characteristics, 57.6% responded that they do not smoke and 85.9% responded that they drink alcohol. This is higher than the report of 49.9% for non-smokers in Song and Jeong’s [21] study, but lower than the report for 90.2% for drinking. The majority of respondents said they exercised, but I think there should have been more research on the types and times of exercise. The answer that they exercised was high at 78.8%, and only 3.5% of the study subjects showed symptoms of muscle loss in the muscle loss test using walking speed, so this study did not classify them into a separate group. The BMI standard was applied according to the Asia-Pacific standard proposed by the World Obesity Society. As a result, normal was the highest at 40.0%, followed by stage 1 obesity at 22.4%, stage 2 obesity at 15.3%, overweight at 14.1%, underweight at 4.7%, and stage 3 severe obesity at 3.5%. W.H.R (abdominal obesity rate) is a method of indirectly assessing abdominal obesity and is one of the measures to know in advance the increased risk of diseases related to metabolic syndrome caused by obesity. The study results showed that normal obesity was the highest at 70.6%, and abdominal obesity was the lowest at 4.7%. This was a very high result compared to the study by Park [22], which found that 17.2% of female students were obese, and the survey by Kim [23] of 316 college students in the Seoul area, where 12% were overweight and obese. Since the sample for this study is small, it is believed that more accurate data can be collected in future studies by considering the similarity of the living environments of the sample groups.

In the grip strength test conducted to determine the state of muscle strength, both hands were tested twice, and the strongest one was evaluated as relative grip strength compared to body weight. As a result of this study, the average relative grip strength was 42.3 kg, which was much higher than the average relative grip strength of 25.01 kg among adult women in Baek and Shin [1]. This is believed to be due to the fact that the age of the subjects of this study was limited to female college students in their early to mid-20s, while the previous study targeted people from 19 to 64 years old. Subjective satisfaction with oral condition was 68.2% for average, 25.9% for poor, and 5.9% for good, showing that the study subjects did not respond with confidence about their oral condition. While the response of not brushing their teeth after lunch was high at 72.9%, the response of brushing their teeth before going to bed was high at 91.8%. As a result of correlation analysis, BMI showed a negative correlation with body water content (p<0.01) and life satisfaction (p<0.05), but a positive correlation with W.H.R, limb muscle mass, body fat mass, calf circumference, and waist circumference. A relationship (p<0.01) was shown. It is thought that the more obese people are, the higher their abdominal obesity rate and body fat mass, the thicker their calves and waist circumferences become, and the lower their confidence in their appearance, which reduces their satisfaction with life. There was no significant relationship with oral health management behavior.

Relative grip strength showed a positive correlation with body water content (p<0.01), but a negative correlation with body fat percentage (p<0.01), so it can be thought that the higher the obesity level, the weaker the relative grip strength. This is consistent with the results showing a negative correlation with BMI (p<0.01), WHP (p<0.05), calf circumference (p<0.01), and waist circumference (p<0.01). Toothbrushing before bed showed a positive correlation with drinking status and body fat percentage (p<0.05). This appears to be due to frequent exposure to environments that require oral care due to drinking late at night or eating late at night, and this is supported by the above results showing a positive correlation between body fat percentage and BMI.

The use of vitamins was found to have a positive correlation with the use of vitamins (p<0.05), and although vitamins are inconvenient to take separately from meals, it is one of the health behaviors performed with health in mind. The use of oral hygiene products is also used for oral health, overcoming the inconvenience of using them separately, so it is a natural result that a positive correlation appears between the two. As a result of the lecture study, it was reported that grip strength did not show a significant correlation with the use of dental floss, but showed a significant correlation with the use of interdental brushes or electric toothbrushes [24]. This is the same as the results of this study.

Limitations of this study include that it only targeted female college students in some regions and that it was difficult to generalize because the actual oral condition could not be examined. Taking this into consideration, if research subjects from various age groups and regions are selected and studied in follow-up studies, it will be possible to uncover more diverse body composition and health behaviors that can influence section health [management behavior. Nevertheless, it is believed that this study can be used as basic data for follow-up research by attempting to study areas that are deeply related to the oral cavity but were not well covered in research.

This study conducted surveys and measurements on 85 students at A University located in Andong City to determine the extent to which adult women’s body composition and health-related behavior are related to oral health care behavior. The results were as follows.

1.Muscle loss occurred in less than 3.5% of the study subjects in each question, so there was no statistically significant effect.

2.BMI showed a negative correlation with body water (p<0.01) and life satisfaction (p<0.05), but a positive correlation with W.H.R, limb muscle mass, body fat mass, calf circumference, and waist circumference (p<0.01).

3.Relative grip strength was found to have a positive correlation with body water content (p<0.01) and a negative correlation with body fat percentage (p<0.01). There was also a negative correlation with BMI (p<0.01), WHP (p<0.05), calf circumference (p<0.01), and waist circumference (p<0.01).

4.Toothbrushing before bed showed a positive correlation with drinking status and body fat percentage (p<0.05), but a negative correlation with relative grip strength (p<0.01). The use of oral products appeared to have a positive correlation with the use of vitamins (p<0.05).

Considering the above results, it is believed that it can be concluded that there is a correlation between adult body composition and health behavior and oral health care behavior. Accordingly, if research on this area is conducted more actively in follow-up studies and related factors are identified, we hope to use it as basic data that can provide an environment that can achieve a synergistic effect between oral health and systemic health.

No potential conflict of interest relevant to this article was reported.