Chronic kidney disease is a progressive and irreversible condition that contributes to physical and psychological burdens across the illness trajectory. Decline in renal function among patients exacerbates feelings of uncertainty about their future, restricted lifestyles and increasing treatment demands, which affect emotional well-being [1,2]. In advanced stages, a life-sustaining yet invasive treatment of Haemodialysis (HD) is required. At the same time, non-dialysis CKD patients opt to manage the disease with routine monitoring and pharmacological medical treatment [3]. Patients experiencing CKD in both the above groups report emotional stress, anxiety, lower quality of life and depression, which highlights the need for addressing challenges related to emotional processing within the CKD population [4].   Alexithymia is a psychosomatic construct characterised by difficulty in identifying and expressing emotions, limited imagination and a tendency toward externally oriented thinking rather than internal emotional awareness [5]. Individuals experiencing alexithymia display a lack of emotional awareness, diminished social relationships and maladaptive coping strategies, which may aggravate both psychological and physical symptoms. In CKD, the long-term health burden, repeated medical procedures and prolonged stress may increase alexithymia traits [6]. CKD patients undergoing HD are exposed to repetitive invasive vascular access, limitations in fluid and diet intake and pain associated with haemodialysis [7]. At the same time, CKD patients in the non-dialysis group, although not exposed to dialysis-related procedures, may still experience uncertainty regarding disease progression, which may lead to emotional dysregulation. These differences in illness experiences suggest that alexithymia may manifest differently across HD and ND groups.   Sociodemographic factors play a crucial role in shaping emotional functioning, disease perception and treatment adherence in chronic illness. Variables including age, gender, occupation, treatment duration, marital status and socioeconomic status influence treatment access, coping mechanisms and emotional expression, thereby increasing vulnerability to alexithymia [8]. These demographic differences may also be associated with the modality and stage of CKD, affecting emotional processing. Evaluating alexithymia in HD and non-dialysis groups through sociodemographic variables is therefore essential to identify high-risk subgroups and implement appropriate psychological interventions. A clearer understanding of these associations may help improve psychosocial care and support the development of holistic renal health programs for CKD patient.   Aim of the Study The purpose of this investigation is to assess the level of alexithymia in the HD and ND CKD groups and the effect of sociodemographic factors like gender, marital status, age, occupation, socioeconomic status and treatment duration on the alexithymia in both HD and ND groups. By exploring these differences in demographic variables, we sought to gain insights into alexithymia and its impact on patients' emotional outcomes.

The study started after receiving approval from Saveetha Medical College and Hospital's Institutional Human Ethics Committee (Approval No. 019/11/2023/IEC/SMCH, dated 22 November 2023). Further permission was secured from the authorities of the haemodialysis centre and the outpatient ward. The research data were collected at Saveetha Medical Hospital (Saveetha Institute of Technology and Sciences, Chennai, India). The quantitative comparison study included 300 patients with chronic kidney disease: 150 on maintenance dialysis and 150 in the non-dialysis group. For non-dialysis participants, information on CKD stage was retrieved from hospital medical records and determined based on estimated glomerular filtration rate (eGFR) according to KDIGO criteria (“Notice,” 2013). Subject participants were selected randomly using a simple randomisation method, according to the inclusion criteria. CKD patients aged 18-60 years with a treatment period of more than 3 months in the HD group and undergoing pharmacological treatment for 3 months or more were recruited for the non-dialysis group. CKD patients with vision loss, cognitive deficits and neurological disorders, psychiatric comorbidities, missed appointments, inability to provide informed consent and who are unable to complete the questionnaires were excluded. Neurological and psychiatric comorbidities or substance use were identified through medical records, with treatment adherence additionally verified through reports from clinical staff.   Patients were initially provided with information about participation and informed consent and their data were kept confidential. Their demographic details, encompassing age, marital status, gender, occupational status, socioeconomic status and treatment duration (haemodialysis or medical management), were obtained. Subsequently, a face-to-face appraisal was held with each patient, briefing them on each question in English or Tamil, depending on their proficiency and authentic responses were recorded. Finally, these responses were entered into an Excel sheet and the total alexithymia scores were calculated using the scoring manual.   The present analysis used the Perth Alexithymia Questionnaire (PAQ) for measuring alexithymia in both groups. It is a 24-item self-evaluation tool in which each item is a statement designed to assess three significant alexithymia components: Difficulty in Finding Emotions (DIF), Difficulty in Describing Feelings (DDF) and Externally Oriented Thinking (EOT). Participants responded to each item on a 7-point Likert scale, with 1 representing "strongly disagree" and seven representing "strongly agree." The Perth Alexithymia Questionnaire does not specify clinical cut-off scores. Therefore, the subjects were categorised into higher, average and lower alexithymia subgroups using sample-based cut-off values derived from the mean±1 standard deviation of PAQ total scores, a method commonly adopted in psychological research for group comparisons. Higher values indicate greater alexithymia.   To achieve maximum reliability, the number of items per component was kept to a minimum. All statements in the DIF and DDF sections addressed both positive and negative emotions. For example, phrases beginning with “When I am feeling good…” and “When I am feeling bad…” were designed to understand how individuals with low consciousness experience pleasant or unpleasant emotions. The EOT aspect precisely gauges a patient’s inclination to avoid focusing on emotions. Therefore, statements such as “I prefer to let my emotions happen in the background, rather than focus on them” or “I do not pay attention to my emotions” were included (Chan et al., 2023). An investigation demonstrated, through confirmatory factor analysis, that the PAQ has a theoretically congruent structure and can competently assess its components across all emotions (Preece et al., 2020). Cronbach's alpha coefficient was employed to evaluate internal consistency reliability (Cronbach, 1951). In the current study, PAQ demonstrated excellent reliability, with a Cronbach’s α exceeding 0.997 and subscale coefficients of 0.99 for DIF, DDF and EOT.

The association between alexithymia in the haemodialysis and non-dialysis CKD groups and sociodemographic variables, including age, marital status, gender, occupational status, treatment duration and socioeconomic status, was analysed using Chi-square (χ²) tests. Two- way analysis of variance was used to calculate group differences (ANOVA). To identify specific differences between groups, minimise type I error and perform post hoc comparisons, the Bonferroni t-test was used. SigmaPlot version 14.5 (Systat Software Inc., San Jose, CA, USA) was employed for statistical analyses. p<0.05 or less was regarded as statistically significant.   Table 1 shows the association between alexithymia and both HD and ND in the CKD groups. The percentage scores of higher, average and lower alexithymia in both HD and ND groups were 20.7%, 10.7%, 68.7%, 5.3%, 10.7% and 84%, respectively. The p-value of 0.001 or less indicates a significant difference between the two groups. Patients on haemodialysis exhibited higher alexithymia than the non-dialysis group. Whereas both HD and ND patients experience similar levels of average alexithymia, the majority of non-dialysis CKD patients had lower alexithymia.   Table 1: Association of Alexithymia in HD and Non-Dialysis Groups Psychological Factor Categories Dialysis (HD) Non-Dialysis (ND) Alexithymia High 20.7% (31) 5.3% (8) Average 10.7% (16) 10.7% (16) Low 68.7% (103) 84% (126) χ2: 15.874, p<0.001, Haemodialysis: 150, Non-Dialysis: 150. The figures in the parentheses are the count of high, average and low alexithymia within haemodialysis (HD) and Non-Dialysis (ND)   As demonstrated in Table 2, there was a significant difference among age, employment status and alexithymia (p-value=0.001). Post hoc t-tests reveal a considerable difference between CKD patients aged 40-60 in both groups. The mean score of 66.8 indicates that a higher proportion of middle-aged patients in the haemodialysis group experienced higher alexithymia. A higher rate of patients who are unemployed in the HD group experienced greater alexithymia. No significant difference was found in sociodemographic factors or treatment duration between the dialysis and alexithymia groups.   Table 2: Association of the Dialysis (HD) group with the distribution of Alexithymia with demographic variables Demographic Variable Demographic Category Higher Alexithymia Average Alexithymia Lower Alexithymia χ2 p-value Age <39 years 9.7% (3) - 21.6% (22) 20.429 <0.001 40 - 59 years 74.2% (23) 10% (16) 47% (48) > 60 years 16% (5) - 32% (33) Gender Male 80.6% (25) 62.5% (10) 71% (73) 1.930 0.981 Female 19% (6) 37.5% (6) 29% (30) Marital Status Married 90% (28) 87.5% (14) 86% (89) 0.331 0.848 Unmarried 9.7% (3) 12.5% (2) 13.6% (14) Employment Status Employed 13% (4) 6% (1) 91% (94) 93.694 <0.001 Unemployed 87% (27) 94% (15) 9% (9) Socioeconomic status Lower 71% (22) 44% (7) 68% (70) 8.314 0.081 Middle 26% (8) 56% (9) 32% (33) Upper 3% (1) - - Treatment duration (Years) <1 26% (8) 25% (4) 14% (14) 3.942 0.414 1-5 64.5% (20) 56.3% (9) 72% (74) > 5 9.7% (3) 18.6% (3) 14.6% (15) Haemodialysis: 150. The numbers in parentheses indicate the counts of patients with higher, average and lower alexithymia in the dialysis group (HD). The χ2 and ‘P’ values were obtained using the chi-square test.   According to Table 3, no significant differences among the groups or the demographic variables in the ND group.   Table 3: Association of Non-Dialysis (ND) group on the distribution of alexithymia with demographic variables Demographic Variable Demographic Category Higher Alexithymia Average Alexithymia Lower Alexithymia χ2 p-value Age <39 years 12.5% (1) 31% (5) 25% (32) 3.931 0.415 40 - 59 years 37.5% (3) 25% (4) 45% (57) > 60 years 50% (4) 44% (7) 29% (37) Gender Male 87.5% (7) 62.5% (10) 50% (63) 4.855 0.088 Female 12.5% (1) 37.5% (6) 50% (63) Marital Status Married 62.5% (5) 56% (9) 73% (92) 2.197 0.333 Unmarried 37.5% (3) 44% (7) 27% (34) Employment Status Employed 25% (2) 19% (3) 45% (57) 5.038 0.081 Unemployed 75% (6) 81% (13) 55% (69) Socio-economic status Lower 87.5% (7) 62.5% (10) 66% (83) 3.251 0.517 Middle 12.5% (1) 31% (5) 32.5% (41) Upper - 6.3% (1) 1.6% (2) Treatment duration (Years) <1 50% (4) 25% (4) 44% (55) 2.653 0.617 1-5 50% (4) 69% (11) 53% (67) > 5 - 6.3% (1) 3.2% (4) Non-Dialysis: 150, The numbers in parentheses indicate the counts of patients with higher, average and lower alexithymia in the non-dialysis group (ND). The χ2 and ‘P’ values were obtained using the chi-square test.   Table 4 demonstrates the influence of age on alexithymia in both groups. Post hoc t-tests show a significant difference between middle-aged patients in both groups (p<0.001). The mean score of 66.8 shows that the majority of HD patients aged between 40 and 60 exhibit higher alexithymia than those in the ND group.   Table 4: Influence of Age on Alexithymia in HD and ND groups S. No. Groups Age Alexithymia 1 Dialysis <40 years 47.6 + 7.8 2 Dialysis 40 - 60 years 66.8 + 4.2 3 Dialysis ≥ 60 years 51.9 + 6.3 4 Non-Dialysis <40 years 35.4 + 6.3 5 Non-Dialysis 40 - 60 years 37.3 + 4.9 6 Non-Dialysis ≥ 60 years 44.8 + 5.6 7 Comparison of groups (Dialysis/Non-Dialysis) F = 11.099 p <0.001 8 Comparison of age (<39/40-60≥ 60) F = 1.567 p = 0.210 9 Interaction (group X age) F = 2.531 p = 0.081 10 Comparison within Dialysis (<39/40-60) t = 2.162 p = 0.094 11 Comparison within Dialysis (<39/≥ 60) t = 0.424 p = 1.0 12 Comparison within Dialysis (40-60≥ 60) t = 1.962 p = 0.152 13 Comparison of non-dialysis (<39/40-60) t = 0.239 p = 1.0 14 Comparison of non-dialysis (<39/>60) t = 1.105 p = 0.811 15 Comparison of non-dialysis (40-59/>60) t = 1.000 p = 0.954 16 Comparison between <40 (HD/Non-Dialysis) t = 1.214 p = 0.226 17 Comparison between 40 - 60 (HD/Non-Dialysis) t = 4.581 p <0.001 18 Comparison between ≥60 (HD/Non-Dialysis) t = 0.838 p = 0.403 The values are mean+standard error (HD: 150, non-dialysis: 150). The ‘F’, ‘t’ and ‘P’ values are by two-way ANOVA with Bonferroni ‘t’ test for multiple comparisons   There is a significant difference between male CKD patients in the HD and ND groups. The mean value of 68.8 shows that male CKD patients in the HD group had higher alexithymia than those in the non-dialysis group.    Table 5: Influence of Gender on Alexithymia in Dialysis (HD) and Non-dialysis (ND) groups S. No. Groups Gender Alexithymia 1 Dialysis Male 63.3 + 3.8 2 Dialysis Female 51.0 + 6.1 3 Non-Dialysis Male 43.3 + 4.4 4 Non-Dialysis Female 34.4 + 4.7 5 Comparison of groups (HD /Non-Dialysis) F = 14.438 p <0.001 6 Comparison of gender (male/female) F = 4.871 p = 0.028 7 Interaction (group X gender) F = 0.124 p = 0.725 8 Comparison within Dialysis (male/female) t = 1.722 p = 0.086 9 Comparison of non-dialysis (male/female) t = 1.386 p = 0.167 10 Comparison between Male (HD /Non-Dialysis) t = 3.443 p <0.001 11 Comparison between Female (HD /Non-Dialysis) t = 2.161 p = 0.032 The values are mean+standard error (haemodialysis: 150, non-dialysis: 150). ‘F’, ‘t’ and ‘p’ values are by two-way ANOVA with Bonferroni ‘t’ test for multiple comparisons   The influence of married status on the alexithymia in both groups is represented in Table 6. In the married category, the two groups differed significantly from one another. The mean value of 60.3 reveals that a higher proportion of CKD patients in the HD group who are married have higher alexithymia.   Table 6: Influence of Marital Status on Alexithymia in HD and Non-dialysis (ND) groups S. No. Groups Marital Status Alexithymia 1 Dialysis Married 60.3 ± 3.3 2 Dialysis Unmarried 50.0 ± 15.0 3 Non-Dialysis Married 39.4 ± 3.5 4 Non-Dialysis Unmarried 38.0 ± 9.0 5 Comparison of groups (Haemodialysis /Non-Dialysis) F = 3.348 p = 0.068 6 Comparison of marital status (married/unmarried) F = 0.433 p = 0.511 7 Interaction (group X marital status) F = 0.260 p = 0.611 8 Comparison within Dialysis (married/unmarried) t = 0.683 p = 0.495 9 Comparison of Non-Dialysis (married/unmarried) t = 0.143 p = 0.887 10 Comparison between Married (HD /Non-Dialysis) t = 4.364 p <0.001 11 Comparison between Unmarried (HD /Non-Dialysis) t = 0.685 p = 0.494 The values are mean+standard error (haemodialysis: 150, non-dialysis: 150). ‘F’, ‘t’ and ‘p’ values are by two-way ANOVA with Bonferroni ‘t’ test for multiple comparisons   Table 7 demonstrates the association between occupational status and alexithymia in the HD and ND groups. A significant difference in the unemployed category between the two groups (p<0.001). The mean value of 68.3 represents that a higher proportion of unemployed HD patients have higher levels of alexithymia.   Table 7: Influence of Employment Status on Alexithymia in Dialysis (HD) and Non-dialysis (ND) groups S.No Groups Employment Status Alexithymia 1 Dialysis Employed 48.5 ± 7.2 2 Dialysis Unemployed 63.6 ± 3.6 3 Non-Dialysis Employed 35.7 ± 5.0 4 Non-Dialysis Unemployed 41.6 ± 4.2 5 Comparison of groups (HD /Non-Dialysis) F = 10.707 p = 0.001 6 Comparison of employment status (employed/unemployed) F = 3.766 p = 0.053 7 Interaction (group X employment status) F = 0.637 p = 0.425 8 Comparison within Dialysis (employed/unemployed) t = 1.764 p = 0.079 9 Comparison of Non-Dialysis (employed/unemployed) t = 0.906 p = 0.366 10 Comparison between employed (HD /ND) t = 1.463 p = 0.145 11 Comparison between the unemployed (HD /ND) t = 3.814 p <0.001 The values are mean+standard error (haemodialysis: 150, non-dialysis: 150). ‘F’, ‘t’ and ‘p’ values are by two-way ANOVA with Bonferroni ‘t’ test for multiple comparisons

The present study examined the differences in alexithymia between haemodialysis (HD) and non-dialysis (ND) groups and the influence of sociodemographic variables. The results reveal that HD patients experience higher alexithymia, suggesting that treatment modality and disease burden significantly influence emotional processing in the CKD population. This finding aligns with theoretical frameworks indicating that repetitive exposure to invasive procedures and prolonged medical distress often lead to emotional suppression and difficulty identifying emotions [9,10]. Higher levels of alexithymia among maintenance dialysis patients may reflect their inability to experience and express emotions both outwardly and internally. This response may arise due to persistent stressors such as frequent cannulation, dependency on treatment and reduced independence.   Initially, suppressing emotions may function as a coping mechanism for patients. However, over time these responses may manifest as an inability to define, identify and express emotions, which are central characteristics of alexithymia [11]. Similar patterns have been observed across chronic illness populations, where higher alexithymia is associated with increased disease burden and emotional vulnerability [12,13]. Age emerged as a significant determinant, with middle-aged haemodialysis patients demonstrating higher alexithymia compared with those in the ND and other age groups [14]. Individuals in midlife often experience peak occupational, familial and financial responsibilities. The interference of chronic illness during this period may result in emotional distress, leading individuals to adopt maladaptive coping strategies such as emotional denial. This finding suggests that middle-aged HD patients may be particularly vulnerable to difficulties in emotional processing.   Gender differences indicated higher alexithymia among male haemodialysis patients compared with those in the non-dialysis group. Previous studies suggest that men tend to restrict emotional expression, especially under chronic health conditions, which may predispose them to alexithymia [15,16]. A significant association was also observed with marital status, as married CKD patients undergoing haemodialysis demonstrated higher alexithymia. Although marital relationships can provide support, chronic illness may alter relationship dynamics, increasing perceptions of caregiver burden and dependency [17-19]. These experiences may encourage patients to conceal rather than express emotions, thereby contributing to alexithymic tendencies.   Employment status was also associated with alexithymia, with unemployed HD patients demonstrating higher scores. Occupation is closely related to psychological well-being, social interaction and emotional competence. CKD patients may lose employment due to functional limitations and treatment burden, which may contribute to diminished self-identity and emotional withdrawal, thereby intensifying alexithymia [20-23].   In the non-dialysis group, no significant associations with demographic variables were observed. This suggests that emotional functioning may not yet be severely impaired in the earlier stages of CKD. These findings indicate that disease progression intensifies psychological burden and emotional inhibition among CKD patients [24]. From a clinical perspective, these findings highlight the importance of psychological screening for alexithymia among HD patients, particularly those who are middle-aged, unemployed, male and married. Alexithymia has been associated with reduced treatment adherence, underreporting of symptoms and poorer quality of life, emphasizing the need for psychosocial interventions within renal care settings [25].

This study substantiates that the psychological vulnerability in the haemodialysis patients is greater when compared to CKD patients in the non-dialysis group. Alexithymia has emerged as a distinguishing psychological factor in haemodialysis patients with higher scores, specifically in the middle-aged, male, married and unemployed categories. CKD patients in the non-dialysis group showed lower alexithymia levels. The influence of sociodemographic variables was significant in the haemodialysis group, while the ND patients showed consistent psychological profiles. These findings posit that the demands and prolonged burdens associated with chronic kidney disease in the long term may impair emotional awareness and regulation. The results also pinpoint the need for timely and appropriate psychological interventions for haemodialysis patients at a higher sociodemographic risk. Determining the symptoms of alexithymia at the early stage may help improve the emotional functioning of the HD patients, reduce their emotional distress and support their adherence to the treatment regimens. Integrating mental health professionals into haemodialysis care may enhance both psychological and overall well-being of the CKD patients and treatment outcomes.   Ethical Statement Institutional Review Board Statement The study commenced after receiving approval from Saveetha Medical College and Hospital's Institutional Human Ethics Committee (Approval No. 019/11/2023/IEC/SMCH, dated 22 November 2023).