Coping styles associated with glucose control in individuals with type 2 diabetes mellitus.

AIMS/
OBJECTIVES: Glycemic control varies according to stress level and the efficacy of control measures, affecting the outcomes of diabetes. Although detailed coping styles have not been well studied in patients with type 2 diabetes mellitus, problem-focused coping strategies are believed to be related to better control of blood glucose. Associations between coping profiles/dimensions and blood glucose control were examined in individuals with type 2 diabetes.
MATERIALS AND METHODS: The participants included 503 Japanese patients (mean age 63.9 ± 12.6 years) with type 2 diabetes. The average glycated hemoglobin A1c (HbA1c) levels were calculated from HbA1c levels measured more than four times within the 12 months before the assessment. Coping profiles were assessed using the Brief Scale for Coping Profile. Lifestyle factors were also included in the analyses.
RESULTS: Factors other than age were not associated with HbA1c levels in patients who used insulin. Conversely, habitual alcohol consumption, single status, the adaptive emotion-focused coping dimension, and changing mood and changing one's point of view profiles were associated with HbA1c levels.
CONCLUSIONS: These findings suggest that adaptive emotion-focused coping supports glycemic control in type 2 diabetes patients who do not use insulin. Additional studies using a longitudinal design are required to further examine the relationships between psychological factors and glycemic control.

Introduction

Type 2 diabetes mellitus is a worldwide epidemic1. The high prevalence of type 2 diabetes, which is a lifestyle‐related disease, has resulted in a substantial socioeconomic burden, and type 2 diabetes can increase the risks of serious physical and mental health issues2. It has been shown that glycemic control improves the health of type 2 diabetes patients3, and associations between multiple factors, such as self‐efficacy or stress, and diabetes outcomes, such as body mass index and metabolic control, have been examined intensively4. Self‐management in patients with type 2 diabetes is known to be burdensome, because it requires self‐discipline and perseverance to adapt everyday activities (exercise, diet, rest) to the requirements of medication use and the control of glucose levels5. In particular, insulin therapy might be related to increased psychological distress6. Thus, the coping strategies used to manage diabetes play important roles in the maintenance and psychosocial adjustment to diabetes7, 8, 9.

Traditionally, two primary concepts of coping dimensions have been considered, including a problem‐focused coping dimension (making a plan of action) and an emotion‐focused coping dimension (seeking emotional support)10, 11. Problem‐focused coping is related to better metabolic control, emotional status and overall adjustment in patients with diabetes12, whereas emotion‐focused coping is related to poor adjustment and adherence to health regimens in chronically ill patients13.

In addition, emotion‐focused coping has recently been divided into two dimensions14. Approach‐oriented emotion‐focused coping might be considered as an attempt to strategize or energize oneself as a result of a stressful environment, whereas traditional emotion‐focused coping represents an attempt to ignore the problem altogether; the former consists of adaptive emotion‐focused coping strategies, and the latter of maladaptive emotion‐focused coping strategies. Both emotion‐focused coping approaches alleviate the negative effects of stressors, but only adaptive emotion‐focused coping techniques lead to better adjustment to the stressful situation. Thus, there are three types of coping strategies, namely, problem‐focused, adaptive emotion‐focused and maladaptive emotion‐focused coping strategies. In several studies of patients with diabetes, problem‐reducing actions have been shown to be positively associated with health‐related quality of life and metabolic control15. Indeed, this coping strategy is central to many diabetes self‐management programs16. The use of approach‐ and problem‐focused coping has been associated with better overall adjustment (effect size 0.13), although adjustment was found to not be associated with adaptive emotion‐focused (effect size 0.10) and maladaptive emotion‐focused (effect size −0.07) coping strategies15. Consistently, it is reported that glycated hemoglobin A1c (HbA1c) is not associated with problem‐focused (effect size 0.002), adaptive emotion‐focused (effect size 0.13) and maladaptive emotion‐focused (effect size 0.01) coping strategies15. Nevertheless, few studies have examined the potential links between the three coping dimensions and glycemic control among Japanese individuals with type 2 diabetes.

In the present study, we aimed to investigate the relationship between coping profiles and glycemic control among individuals with type 2 diabetes. We hypothesized that a problem‐focused and adaptive emotion‐focused coping strategy would be associated with better glycemic control.

Methods

Participants

The protocol of this study was approved by the ethics committee of the Graduate School of Medicine, Hirosaki University, and we obtained written informed consent from all participants before entering the present study. This study included 728 of 945 individuals with type 2 diabetes who received treatment for at least 1 year at the Department of Endocrinology and Metabolism at the Hirosaki University Hospital and agreed to participate in the survey. The remaining 217 patients were excluded due to moderate‐to‐severe dementia (85 patients), blindness (23 patients), severe mental illness (such as bipolar disorder and schizophrenia [68 patients]) and withdrawal (41 patients). The severity of dementia was assessed by the doctors overseeing each patient.

In total, 611 of the 728 patients returned the questionnaires, and 503 (67.4%) had complete questionnaires. Blood samples were collected routinely from these patients four times per year and were analyzed for the HbA1c level. A total of 408 patients were taking oral hypoglycemic drugs, and 267 were using insulin; both oral hypoglycemic drugs and insulin were used by 211 patients. A total of 39 patients did use not any medication. We obtained demographic data, such as age, sex, smoking, alcohol consumption, exercise habits, marital status, solitary living and medical histories, of the patients using questionnaires and medical records (Table 1).

Table 1

Participant characteristics

Variables
Sex
Male, n (%)	304 (60)
Female, n (%)	209 (40)
Age (years)	63.9 ± 12.5
Body mass index (kg/m2)	25.1 ± 4.2
HbA1c (%)	7.1 ± 0.9
Smoking habit
Yes, n (%)	79 (15.7)
No, n (%)	425 (84.3)
Habitual alcohol consumption
Yes, n (%)	160 (32)
No, n (%)	343 (68)
Exercise frequency
None, n (%)	253 (50)
Once a week, n (%)	30 (6)
2–3 times a week, n (%)	79 (16)
4–5 times a week, n (%)	45 (9)
Almost every day, n (%)	95 (19)
Single
Yes, n (%)	149 (30)
No, n (%)	354 (70)
Living alone
Yes, n (%)	64 (13)
No, n (%)	439 (87)
Insulin use (n = 504)
Yes, n (%)	267 (53)
No, n (%)	236 (47)
CES‐D	13.3 ± 7.6
Coping dimensions
Problem‐focused	14.4 ± 4.8
Adaptive emotion‐focused	15.8 ± 4.4
Maladaptive emotion‐focused	20.6 ± 3.1
Coping profiles
Active solution	6.3 ± 2.6
Seeking help for a solution	8.1 ± 2.8
Changing mood	8.1 ± 2.6
Emotional expression involving others	11.1 ± 1.6
Avoidance and suppression	9.5 ± 2.1
Changing one’s point of view	7.6 ± 2.4

Values show the mean ± standard deviation. CES‐D, Center for Epidemiologic Studies Depression Scale; HbA1c, glycated hemoglobin A1c.

We used the Japanese version of the Center for Epidemiologic Studies Depression Scale to evaluate the severity of depressive symptoms in all patients17, 18. The Center for Epidemiologic Studies Depression Scale is a 20‐item self‐reported measure that focuses on the depressive symptoms the patient experienced during the week before completing the questionnaire. The maximum score is 60, with higher scores indicating more severe depressive symptoms.

We evaluated coping behaviors using The Brief Scale for Coping Profile (BSCP). The BSCP consists of 18 items rated on a 4‐point Likert scale19, 20, 21, 22. We asked patients to check a box indicating the frequency with which they used the strategy in an item in stressful situations using a scale from 1 (almost never) to 4 (very often). The original study validated the BSCP and determined that the Cronbach’s reliability coefficients in workers ranged from 0.66 to 0.7519. We confirmed that the Cronbach’s reliability coefficient for our participants was 0.835, suggesting sufficiently high internal consistency. The scale evaluates the ability to cope with stressful daily environments using six subscales: “Active solution,” “Seeking help for a solution,” “Changing mood,” “Changing one’s point of view,” “Avoidance and suppression” and “Emotional expression involving others.” These six subscales reflect three coping dimensions: problem‐focused coping dimensions (“Active solution” and “Seeking help for a solution”), adaptive emotion‐focused coping dimensions (“Changing mood” and “Changing one’s point of view”) and maladaptive emotion‐focused (“Avoidance and suppression” and “Emotional expression involving others”) coping dimensions. A high score on a certain subscale indicates that the respondent frequently selected that coping method.

Statistical analysis

In the present study, comparisons of several factors among three groups based on HbA1c levels were carried out using anova and χ2‐tests. The data are presented as the mean ± standard deviation. Univariate linear regression analyses with forced entry were carried out to examine the correlations between glycemic control (average HbA1c level) and several factors, such as age, sex, body mass index, smoking habits, alcohol consumption habits, presence of other people in the household, exercise habits and scores for the six coping profiles or three coping dimensions.

We used the following dummy variables: male = 0, female = 1; absence of spouse = 0, presence of spouse = 1; living alone = 0, living with family = 1; absence of smoking = 0, presence of smoking = 1; absence of alcohol consumption = 0, presence of alcohol consumption = 1; no exercise = 1, exercise once a week = 2, exercise 2–3 days per week = 3, exercise 4–5 days per week = 4, and exercise almost every day = 5; and insulin non‐use = 0, insulin use = 1. A P‐value < 0.05 indicated statistical significance. SPSS software for Windows, version 25.0 (IBM Corporation, Armonk, NY, USA), was used for all analyses. A P‐value <0.05 was regarded as significant. Bonferroni’s corrections were applied for multiple testing for the six coping profiles or three coping dimensions. A P‐value <0.0167 and <0.0083 was regarded as significant for the six coping profiles and three coping dimensions, respectively.

Results

The HbA1c level was correlated with age, body mass index, habitual alcohol consumption and insulin use in univariate linear regression analyses (Table 2). Because insulin use had strong effects on this association, we stratified the data based on insulin use or non‐use. There were no differences in factors other than HbA1c between patients who used insulin and those who did not use insulin (Table 3). Factors other than age were not associated with HbA1c levels in patients who used insulin. In contrast, habitual alcohol consumption, single status, the adaptive emotion‐focused coping dimension, and changing mood and changing one’s point of view profiles were associated with HbA1c levels (Table 4).

Table 2

Univariate linear regression results for factors including coping dimensions and profiles associated with glycemic control among type 2 diabetes patients

	r	Significance
Sex	0.034	0.450
Age	−0.134	0.002*
BMI	0.090	0.042*
Smoking	−0.007	0.876
Alcohol	0.106	0.018*
Exercise frequency	−0.056	0.212
Single	0.052	0.244
Living alone	−0.004	0.924
CES‐D	−0.001	0.976
Insulin use	0.329	<0.000*
Coping dimensions
Problem‐focused	−0.027	0.550
Adaptive emotion‐focused	−0.083	0.062
Maladaptive emotion‐focused	−0.025	0.572
Coping profiles
Active solution	0.018	0.684
Seeking help for a solution	−0.062	0.164
Changing mood	−0.044	0.330
Emotional expression involving others	−0.016	0.726
Avoidance and suppression	−0.026	0.566
Changing one’s point of view	−0.085	0.058

*Statistically significant. BMI, body mass index; CES‐D, Center for Epidemiologic Studies Depression Scale.

Table 3

Characteristics of participants who used insulin and did not use insulin

Variables	Insulin users	Insulin non‐users	Significance
Sex
Male, n (%)	150 (56)	144 (61)	0.261
Female, n (%)	117 (44)	92 (39)
Age (years)	63.9 ± 12.1	63.8 ± 13.0	0.98
Body mass index (kg/m2)	24.9 ± 4.0	25.3 ± 4.5	0.236
HbA1c (%)	7.3 ± 0.9	6.8 ± 0.7	0.000*
Smoking habit
Yes, n (%)	35 (13)	44 (19)	0.085
No, n (%)	232 (87)	192 (81)
Habitual alcohol consumption
Yes, n (%)	78 (29)	82 (35)	0.218
No, n (%)	189 (71)	154 (65)
Exercise frequency
None, n (%)	139 (52)	114 (48)	0.056
Once a week, n (%)	18 (7)	12 (6)
2–3 times a week, n (%)	39 (15)	40 (17)
4–5 times a week, n (%)	25 (9)	20 (8)
Almost every day, n (%)	46 (17)	49 (21)
Single
Yes, n (%)	77 (29)	72 (31)	0.730
No, n (%)	190 (71)	164 (69)
Living alone
Yes, n (%)	34 (13)	30 (13)	0.938
No, n (%)	233 (87)	206 (87)
CES‐D	13.3 ± 7.0	13.2 ± 8.3	0.897
Coping dimensions
Problem‐focused	14.6 ± 5.0	14.1 ± 4.6	0.209
Adaptive emotion‐focused	15.7 ± 4.2	15.9 ± 4.6	0.800
Maladaptive emotion‐focused	20.5 ± 3.0	20.7 ± 3.1	0.663
Coping profiles
Active solution	6.4 ± 2.7	6.1 ± 2.4	0.065
Seeking help for a solution	8.1 ± 2.9	8.0 ± 2.7	0.830
Changing mood	8.1 ± 2.7	8.0 ± 2.5	0.621
Emotional expression involving others	11.1 ± 1.6	11.2 ± 1.5	0.396
Avoidance and suppression	9.4 ± 2.1	9.5 ± 2.1	0.611
Changing one's point of view	7.6 ± 2.4	7.7 ± 2.4	0.589

Values show the mean ± standard deviation.

*Statistically significant. CES‐D, Center for Epidemiologic Studies Depression Scale; HbA1c, glycated hemoglobin A1c.

Table 4

Univariate linear regression results for factors including coping dimensions and profiles associated with glycemic control among type 2 diabetes patients who did not use insulin and who used insulin

	Insulin non‐users (n = 236)		Insulin users (n = 267)
	r	Significance	r	Significance
Sex	0.047	0.472	0.000	1.000
Age	−0.112	0.088	−0.169	0.006*
BMI	0.140	0.032	0.099	0.106
Smoking	0.010	0.878	−0.071	0.244
Alcohol	0.208	0.002***	0.012	0.846
Exercise frequency	0.016	0.806	−0.063	0.308
Single	0.172	0.008***	−0.015	0.812
Living alone	−0.010	0.878	−0.002	0.970
CES‐D	0.001	0.982	−0.008	0.894
Coping dimensions
Problem‐focused*	−0.142	0.030	0.014	0.822
Adaptive emotion‐focused*	−0.216	0.000***	0.018	0.774
Maladaptive emotion‐focused*	−0.083	0.202	0.033	0.596
Coping profiles
Active solution**	−0.085	0.192	0.035	0.564
Seeking help for a solution**	−0.161	0.014	−0.010	0.872
Changing mood**	−0.202	0.002***	0.041	0.508
Emotional expression involving others**	−0.053	0.414	0.029	0.640
Avoidance and suppression**	−0.086	0.188	0.025	0.676
Changing one’s point of view**	−0.181	0.006***	−0.015	0.812

P < 0.0167 is regarded as significant due to three multiple tests.

P < 0.0083 is regarded as significant due to six multiple tests.

Statistically significant. BMI, body mass index; CES‐D, Center for Epidemiologic Studies Depression Scale.

Discussion

The results of the present study show for the first time that the adaptive emotion‐focused coping dimension is inversely associated with HbA1c levels in type 2 diabetes patients, but only in those who did not use insulin. Therefore, psychological therapy focusing on stress management using adaptive emotion‐focused coping, such as cognitive‐behavioral therapy, might improve glycemic control.

Problem‐reducing actions have been shown to be positively related to health‐related quality of life and metabolic control in several studies of diabetes patients15. Problem‐focused coping is associated with adjustment, anxiety and depression, but not with glycemic control15. This coping strategy is central to many diabetes self‐management programs.16 We failed to find a strong association between the problem‐focused coping dimension and glycemic control. Univariate linear regression showed a significant correlation between the problem‐focused coping dimension and glycemic control in patients who did not use insulin, but not in insulin users, although Bonferroni’s correction showed no correlation between the problem‐focused coping dimension and glycemic control regardless of insulin use. In addition, the seeking help for a solution profile correlated positively with glycemic control, which is opposite to the direction shown in a previous study23, 24. We have no clear explanation for this discrepancy. First, the sample size might not have been large enough to allow detection of the association. Second, the mentality of the participants might have been different between former studies and this study, because Japanese people traditionally do not prefer active coping strategies.

We failed to find an association between the maladaptive emotion‐focused coping dimension and poor glycemic control. One possible explanation for this discrepancy is that the present study included participants who were older, and had more severe type 2 diabetes and longer illness durations. Some studies have suggested that avoidant coping strategies are related to perceived well‐being in situations that are difficult to control25, and that avoidance is positively related to adjustment in the short‐term (i.e., immediately after diagnosis)26. In addition, the discrepancy might be attributable to cultural differences. In the Aomori region of Japan, where the present study was carried out, there are shaman called kamisama or itako who make predictions, tell fortunes and provide medical care through their spiritual or religious power27. Several studies with various patient groups suggested that an increase in spiritual or religious coping in type 2 diabetes patients decreases anxiety, hopelessness or depression, and stimulates psychological functions or quality of life28, 29, 30.

The present study had several notable limitations. First, the assessment of coping profiles was based on the BSCP, which includes just 18 items, and was developed for Japanese workers and not for people with chronic diseases, such as type 2 diabetes. Several studies have tested different dimensions7, 8, 9, 10, 11, 12, 13, 14, 15, 31, 32, 33, 34, 35, 36. Even for three dimensions, the detailed factors have not yet been integrated. We have shown that: (i) task‐oriented coping (problem‐focused coping); (ii) emotion‐oriented coping (adaptive emotion‐focused coping); and (iii) avoidance‐oriented coping (maladaptive emotion‐focused coping) dimensions are useful based on our clinical experience and previous Japanese research37. In addition, there are several questionnaires that have a validated Japanese version, such as the BSCP and the Coping Inventory for Stressful Situations‐2nd Edition34, 35, both of which include the three dimensions mentioned above. Because the BSCP was developed in Japan, it was available in Japan, whereas the Japanese version of the Coping Inventory for Stressful Situations‐2nd Edition has only recently been validated38. At the time our research plan was formulated, only the BSCP was available for the assessment of these three dimensions in Japan. Therefore, we could not compare the results between previous studies and the present study. The second limitation of this study was the recruitment strategy, which involved the recruitment of individuals with type 2 diabetes from the clinical setting of only one institution and excluded patients with severe mental illness, including major depressive disorders. Third, some patients with anemia were included in the study. Because HbA1c is influenced by iron‐deficiency anemia39 or renal anemia40, HbA1c cannot be regarded as an accurate biomarker for glucose control in the present study. Further studies with several biomarkers of glucose control in addition to HbA1c, such as fasting blood levels, are required. Finally, the present study design was cross‐sectional; thus, we could not determine a causal relationship between coping behaviors and glucose control among the patients in our study population. A follow‐up survey is required to investigate these associations.

In conclusion, the findings of the present study suggest that an adaptive emotion‐focused coping profile is a supportive factor for successful glycemic control in type 2 diabetes patients who do not use insulin. Other coping profiles did not have a major impact on glycemic control. Psychological therapy focusing on the coping profile might improve glycemic control. Additional studies using a longitudinal study design are required to examine the relationships between psychological factors and glycemic control.

Disclosure

Norio Yasui‐Furukori has been a speaker for Otsuka Pharmaceutical Co., Ltd., Mochida Pharmaceutical Co., Ltd., Dainippon‐Sumitomo Pharmaceutical Co. and MSD Co. Kazutaka Shimoda has received research support from Novartis Pharma K.K., Dainippon Sumitomo Pharma Co., Astellas Pharma Inc., Meiji Seika Pharma Co., Ltd., Eisai Co., Ltd., Pfizer Inc., Otsuka Pharmaceutical Co., Ltd., Daiichi Sankyo Co. and Takeda Pharmaceutical Co., Ltd., and honoraria from Eisai Co., Ltd., Mitsubishi Tanabe Pharma Corporation, Takeda Pharmaceutical Co., Ltd., Meiji Seika Pharma Co., Ltd., Janssen Pharmaceutical K.K., Shionogi & Co., Ltd., Dainippon Sumitomo Pharma Co., Daiichi Sankyo Co. and Pfizer Inc. The other authors declare no conflict of interest.