Introduction

Type 2 diabetes mellitus (T2DM) is a widespread chronic disease that has escalated to pandemic proportions. The World Health Organization reports that approximately 422 million people globally are living with diabetes [1]. The International Diabetes Federation projects that by 2045, about 783 million people, or 1 in 8 adults, will have diabetes [2]. T2DM significantly impacts patients’ quality of life, leading researchers to investigate health-related quality of life (HRQOL) and its influencing factors [3]. Regular assessments of quality of life in clinical practice can enhance communication between patients and healthcare providers, uncover hidden issues, and assess the impact of treatments on individual patients [4].

Managing T2DM requires daily commitment to lifestyle changes, including a healthy diet, physical activity, smoking cessation, regular check-ups, blood glucose monitoring, and medication adherence if prescribed. This constant self-management can restrict patients’ lives, affecting their emotional and social well-being as well as their financial stability due to medication and frequent doctor visits, which can be costly and disruptive [5]. Each individual with diabetes faces unique challenges, and while many struggle with disease control, all experience significant life impacts. Patients often feel mentally burdened by the strict regimen their condition imposes. Additional challenges include microvascular and macrovascular complications associated with short- and long-term diabetes management [6].

Lower quality of life among diabetes patients is linked to factors such as older age, female gender, low economic status, limited education, inadequate physical activity, and chronic complications from the disease [7]. Effective management of diabetes involves a holistic approach that balances mental health, family support, and blood glucose control [8]. Current trends highlight the importance of primary prevention as a cost-effective strategy. Prevention efforts should concentrate on urban planning, food marketing policies, and fostering supportive environments in workplaces and schools to promote healthier lifestyles. Targeting these interventions towards children and families could significantly reduce the risk of T2DM in future generations [9].

This study aims to evaluate how T2DM affects the quality of life (QoL) of patients using the adapted Ferrans and Powers Quality of Life Index (QLI). Specifically, we seek to determine which aspects of QoL are most impacted by diabetes management and to assess the effectiveness of this tool in capturing the comprehensive effects of the disease on patients’ daily lives and well-being

Subjects and methods

The study was conducted as a cross-sectional analysis from October 23, 2023, to December 23, 2023, at the Internal Clinic and Polyclinic of the Clinical Center of Montenegro. It involved 151 patients diagnosed with type 2 diabetes mellitus (T2DM) receiving treatment at the same facility. Prior to participation, all subjects were thoroughly informed about the study’s objectives and procedures. They voluntarily consented to participate with written consent, understanding their right to withdraw at any time. To ensure confidentiality, the survey was conducted anonymously under conditions that safeguarded participants’ privacy.

Results

The initial section of the questionnaire focused on the demographic characteristics of the participants (refer to Supplementary file; S1 Table). Among the 151 individuals surveyed, 74 (49%) were male. The average age was 60.05 ±  11.63 years, ranging from 34 to 84 years. As for educational attainment, 45.7% had completed secondary school, 14.6% had only primary education, 12.6% held higher education qualifications, 11.3% possessed university degrees, and 4.0% had not completed elementary school. Regarding marital status, 54.7% were married, 16.7% were widowed, 13.3% lived alone, and 12.0% were divorced. Concerning the duration of diabetes, 42% had been diagnosed for over 10 years, 34% for less than 5 years, and 24% for between 5 and 10 years. Additionally, 64% reported no other diseases, while 36% indicated the presence of comorbidities.

The second section of the study assessed participants’ subjective life satisfaction across various domains of entire study population, using a scale from 1 (very dissatisfied) to 5 (very satisfied). Key findings include:

• Personal Health Satisfaction: 34.4% of participants were satisfied, while 20.5% expressed dissatisfaction, resulting in an average score of 3.14 ±  0.98.
• Healthcare Satisfaction: A majority of 51.3% were satisfied, with an average score of 3.56 ±  0.79.
• Energy Levels for Daily Activities: 33.8% reported satisfaction, whereas 24.5% were dissatisfied, leading to an average score of 3.28 ±  1.02.
• Self-Care Ability Without Assistance: 47.7% were satisfied, and 20.5% were very satisfied, averaging a score of 3.70 ±  1.03.
• Independent Glucose Monitoring at Home: 55.0% expressed satisfaction, with an average score of 3.81 ±  0.91.
• Satisfaction with Lifestyle Changes Due to Diabetes: 40.4% were satisfied, while 14.6% were dissatisfied, resulting in an average score of 3.52 ±  0.95.
• Control Over Personal Health: 49.7% felt satisfied, leading to an average score of 3.57 ±  0.96.
• Sexual Life Satisfaction: 32.6% were satisfied, whereas 17.4% were dissatisfied, with an average score of 3.04 ±  1.17.

Detailed findings for each domain are presented in Table 1.

Download:

• PNG
  larger image
• TIFF
  original image

Table 1. Subjective satisfaction levels of the study participants.

https://doi.org/10.1371/journal.pone.0319369.t001

In the third domain of the questionnaire, respondents assessed their satisfaction with various aspects of their environment and daily activities. Notably, 82.4% of respondents expressed satisfaction with the emotional support received from family, with an average score of 4.07 ±  0.89. Similarly, 83.1% were satisfied with their living arrangements, resulting in an average score of 3.99 ±  0.78. In contrast, satisfaction with spouses or partners was comparatively lower, with only 60.5% reporting contentment and an average score of 3.04 ±  1.17. Overall, the mean satisfaction score across all evaluated aspects was 3.68 ±  0.72, indicating a trend toward neutrality or slight satisfaction among respondents. Detailed percentages and mean scores for each aspect are presented in Table 2.

Download:

• PNG
  larger image
• TIFF
  original image

Table 2. Satisfaction with environment and daily activities.

https://doi.org/10.1371/journal.pone.0319369.t002

The Mann-Whitney U test demonstrated a significant effect of comorbidities on quality of life, with a Z value of 2.84 and a p-value of less than 0.001. Participants without comorbidities reported higher satisfaction (Median =  85.52) compared to those with comorbidities (Median = 75.20). Additionally, no significant associations were found between quality of life and either gender or the duration of the disease (refer to Supplementary file; S2 Table).

Pearson’s linear correlation coefficient was calculated to assess the relationship between age and quality of life among the respondents, revealing a robust negative correlation, r=−0.263, with a p-value of less than 0.001. This indicates that satisfaction with quality of life decreases as age increases (refer to Supplementary file; S3 Table).

The fourth section of our questionnaire evaluated respondents’ perceptions of various aspects of their daily lives. Table 3 summarizes the average ratings for the entire study population across various categories, including personal health, healthcare, energy levels for daily activities, independent self-care, self-monitoring of blood glucose, lifestyle changes due to diabetes, sexual life, the role of a spouse or partner, emotional support from family, the importance of friends, and emotional support from non-family members. The data reveal that respondents prioritize personal health (Mean =  4.32, SD =  0.76) and emotional support from family (Mean =  4.20, SD =  0.84) the highest. Conversely, aspects such as sexual life (Mean =  3.27, SD =  1.27) and emotional support from non-family members (Mean =  3.58, SD =  0.94) are deemed less important.

Download:

• PNG
  larger image
• TIFF
  original image

Table 3. Respondents’ subjective perceptions of the importance of various aspects of their daily lives.

https://doi.org/10.1371/journal.pone.0319369.t003

The fifth section of our questionnaire assessed respondents’ perceptions of the importance of various aspects of their environment and daily activities. Table 4 summarizes the average ratings for the following elements: being useful to others, absence of worries, neighborhood, home or residence, job, ability to manage financial needs, engaging in enjoyable activities, peace of mind, achievement of personal goals, physical appearance, and overall happiness. The analysis of the entire study population reveals that respondents place the highest importance on overall happiness (Mean =  4.30, SD =  0.75) and peace of mind (Mean =  4.22, SD =  0.79). In contrast, aspects such as satisfaction with their neighborhood (Mean =  3.34, SD =  0.70) and engagement in enjoyable activities (Mean =  3.68, SD =  0.91) are considered less significant.

Download:

• PNG
  larger image
• TIFF
  original image

Table 4. Respondents’ perceived importance of environmental factors and daily activities.

https://doi.org/10.1371/journal.pone.0319369.t004

Discussion

Diabetes is a chronic illness, necessitating regular assessments of patients’ quality of life. Complications from diabetes impact multiple organ systems, contributing significantly to the disease’s associated morbidity and mortality [11]. Quality of life is typically diminished among individuals with diabetes, irrespective of gender. Studies on quality-of-life aid in evaluating psychological functioning, identifying patients’ specific needs and deficits at different stages of T2DM, and comparing the effects of various treatment regimens on well-being and satisfaction [12]. In our study, most respondents were female (51%), with an average age of 60.05 ±  11.63 years, a finding consistent with Ali et al., who reported a mean age of 59.65 ±  12.3 years in their research [13]. Wild et al. noted that, in developing countries, the highest prevalence of diabetes is among individuals aged 45 to 65 years [14]. Younger patients, despite high glucose and HbA1c levels, tend to experience a better quality of life, likely due to a shorter disease duration and fewer complications. This age group also benefits from better healthcare access and stronger family support, which fosters a more optimistic outlook. Several studies have observed that young individuals with diabetes enjoy a quality of life comparable to their non-diabetic peers [15]. Our findings indicate that 64% of respondents do not have other illnesses, while over one-third report having at least one comorbidity.

These findings align with studies indicating an aging population, which correlates with increased rates of chronic illness and higher medication usage [16]. The reduced quality of life observed in individuals with diabetes is partly due to the fact that elderly patients often have multiple chronic conditions, leading to polypharmacy and an elevated risk of cognitive complications [17].

In our study, quality of life was assessed in two domains, each consisting of 11 questions. The first domain focused on satisfaction with health, while the second assessed satisfaction with environment and socio-economic conditions. In the health and functioning domain, respondents expressed the greatest dissatisfaction with their sexual life, which aligns with the known impact of diabetes on sexual function. Hyperglycemia, a key factor in diabetic macrovascular and microvascular complications, contributes to the mechanisms of sexual dysfunction. Additionally, diabetes-related conditions such as hypertension, dyslipidemia, obesity, metabolic syndrome, and smoking are risk factors for sexual dysfunction in both genders [18].

Respondents reported the highest satisfaction with their ability to care for themselves independently and manage their blood glucose levels. In contrast, they expressed the most dissatisfaction in the socio-economic domain, particularly with their ability to meet financial needs. One study highlights the broader impact of diabetes on patients, employers, and society, noting not only higher unemployment rates but also health-related work limitations for those who remain employed [19]. The greatest sources of satisfaction were emotional support from family, their living environment, and friendships, reflecting a positive assessment of their social domain. The psychological outlook of individuals with diabetes plays a crucial role in their engagement with disease management [20]. These results underscore the importance of family support, aligning with previous findings that strong family relationships positively influence metabolic control [21].

Analyzing the average scores of the two questionnaire domains, respondents indicated slightly higher satisfaction with their environment and socio-economic conditions (3.68 ±  0.72) than with their health (3.45 ±  0.73). The overall quality of life was rated at an average of 3.65, suggesting that most respondents are generally satisfied. However, as most participants are elderly, the lower scores in quality of life could be attributed to age-related challenges and the prevalence of diabetes with comorbidities in older populations. Similar findings were noted by Ali et al. and Glasgow et al., who observed that aging negatively impacts quality of life in diabetes patients; our study also found a weak negative correlation between age and quality of life (p = 0.00) [13,22], indicating that satisfaction tends to decrease with age. For accurate assessments, the effect of age must be considered when analyzing diabetes and quality of life. Additionally, our research found no significant differences in quality of life based on gender, nor was the duration of diabetes significantly linked to quality of life, consistent with findings in other studies [23,24].

Our study enhances the current research on the quality of life (QoL) in individuals with Type 2 diabetes mellitus (T2DM) by utilizing the adapted Ferrans and Powers Quality of Life Index (QLI). This adaptation allows us to explore a broad array of life domains impacted by diabetes management, such as personal health and emotional support, affirming many earlier findings about diabetes’ impact on QoL.

In contrast to other QoL instruments used in diabetes research like the World Health Organization Quality of Life (WHOQOL) instruments, EQ-5D, SF-36 Health Survey, and the Diabetes Quality of Life (DQOL) measure, the QLI offers unique insights. For example, WHOQOL facilitates broad cultural comparisons, EQ-5D supports economic evaluations, and SF-36 provides detailed health status assessments. Meanwhile, the DQOL, tailored specifically for diabetes, focuses on disease-specific lifestyle impacts and treatment satisfaction.

Our results particularly align with those from the DQOL, highlighting significant areas like self-care and glucose management as crucial for life satisfaction. However, the QLI’s integration of personal value weightings adds a nuanced layer to the QoL assessment, emphasizing patient-centered factors such as emotional and familial support. This is a dimension often corroborated by studies using the SF-36, which notes the importance of social functioning and emotional roles.

Looking forward, conducting cross-instrument comparisons could offer deeper insights into how various cultural and healthcare contexts influence the prioritization of different QoL dimensions, potentially broadening our understanding of effective diabetes management worldwide.

To gain a more comprehensive understanding of the quality of life in patients with T2DM, future research should aim to compare these findings with those from individuals without diabetes.

These insights underscore the importance of addressing both medical and socio-economic factors in diabetes management, particularly as the aging population grows. Future research should include comparisons with non-diabetic populations to gain a broader understanding of how T2DM uniquely impacts quality of life.

Conclusion

In conclusion, this study reveals that the overall quality of life in individuals with type 2 diabetes mellitus (T2DM) is generally satisfactory, with notable variations across different life domains. In the health-related domain, participants reported the highest satisfaction with their independence in self-care and blood glucose management, while expressing the most dissatisfaction with their sexual life. In the socio-economic domain, emotional support from family, living environment, and friendships were key sources of satisfaction. However, financial difficulties and job dissatisfaction were prominent areas of concern.

Our findings show that quality of life in T2DM patients declines with age, indicating that older individuals experience greater challenges, likely due to age-related health issues and comorbidities. Importantly, the study found no significant difference in quality of life based on gender or diabetes duration. However, the presence of comorbidities significantly impacted quality of life, with individuals without additional health conditions reporting higher satisfaction.

Supporting information