Fibromyalgia (FM) is a complex syndrome characterized by widespread chronic pain, which lacks observable abnormalities on laboratory and imaging tests. In addition to musculoskeletal pain, people with FM often experience somatosensory complaints that significantly impact their quality of life. This syndrome can also manifest in mood abnormalities and cognitive and personality traits, such as neocriticism and alexithymia. Although central pain sensitization plays a role in the development of FM, it does not fully explain patients' psychosocial and mood changes. In particular, previous social and physical experiences can also contribute to the genesis of FM. Furthermore, the gender prevalence of FM may suggest hormonal contributions, as well as hierarchical and social factors in society.

Given the widespread determinant factors associated with FM, the demographic profiles of patients can exhibit significant regional variation. Due to the traditional family and social structure of the Indian population, the clinical characteristics and patient profiles of Indian patients may differ from those of patients from other countries. Understanding these differences is crucial to better managing FM in the Indian setting. Factors such as social status, occupational profile, and family background can all affect the prevalence of FM and its clinical manifestations. Furthermore, the current diagnostic criteria for FM do not adequately account for the psychological, environmental, and socio-cultural factors that contribute to the onset, maintenance, diagnosis, and treatment of the syndrome. We conducted this study to better understand the socio-cultural factors, lifestyle, and psychological disorders associated with FM in an Indian setting.

A total of 121 patients were included for analysis. The baseline characteristics of the patients are mentioned in Table 1.

The present study aimed to investigate the characteristics of patients with FM in the Indian population. We recruited 121 patients over a fixed period in an outpatient rheumatology-based setting. Our results indicate that FM affects females (93%), with an average age of approximately 45 years, consistent with the FM national epidemiology of the condition as established by previous research [5, 6]. Female preponderance in FM is believed to be due to hormonal, genetic, or socio-cultural factors. However, recent unbiased, community-based studies have challenged the notion of a marked female predominance [7].

Interestingly, we observed that individuals with a better educational status (66.6%) had a higher prevalence of FM than those with a lower educational level, in contrast to the results reported in the literature [8-10]. We suggest two potential explanations for this discrepancy. First, according to the literature, lower educational status may be related to lower income, leading to increased social stress and poorer access to healthcare. However, in the Indian social support model, lower education status may be associated with a more traditional joint family living arrangement, resulting in better social support and pain-coping mechanisms. Second, our study was hospital-based, which may be biased toward patients with lower educational status who have poorer access to healthcare facilities. Additionally, lower levels of education in Indian patients may be associated with poorer healthcare literacy, leading to less awareness of symptoms and reduced utilization of healthcare.

In addition to examining the symptoms of patients with FM, we also investigated other lifestyle factors such as diet, exercise, and television habits. In particular, most of the participants in the study were vegetarians. Our findings suggest that participants generally had low levels of physical activity, with only a minority reporting regular exercise.

Previous studies have shown that social support plays a crucial role in the genesis and treatment of FM by facilitating coping mechanisms. Low socioeconomic status and divorce have been associated with a higher prevalence of FM [11]. However, we found that most of the patients in our study were married and homemakers who remained in nuclear families, highlighting the importance of conducting culturally specific research to better understand the socio-cultural determinants of FM. However, there is limited research exploring the impact of socio-cultural factors on FM, particularly in India, where social structures and marriage patterns differ from other regions.

The literature indicates that people with a lower socioeconomic status can experience a higher prevalence and severity of symptoms related to FM due to limited access to medical care, poor health literacy, low adherence to management recommendations and financial restrictions [12, 13]. However, we had a relatively even distribution across the three middle social status categories, with few individuals at the extremes of the upper or lower status. This may be due to the variable socioeconomic status structures of Indian society.

All our patients have reported widespread body pain, specific tender points, and other accompanying symptoms such as cognitive dysfunction, mood disturbances (such as depression and anxiety), and gastrointestinal issues. These symptoms varied in frequency, intensity, and distribution, meaning that each patient with FM may have a similar profile but with different intensity and functional outcomes. Although there is no universal agreement on a quantitative measurement for the severity of fibromyalgia, we utilized the Fibromyalgia Score as a measure of severity and investigated the association between the severity of FM and associated factors. Our findings revealed that depression was the only factor significantly associated with severity. This finding is consistent with findings from other authors and may warrant a psychiatric consultation for every patient with FM to improve their management [14].

One of the key strengths of our study was the use of the ACR 2016 criteria, which enabled us to include patients with other primary rheumatological and pain disorders in the classification of FM. Our study identified the coexistence of other autoimmune diseases, such as rheumatoid arthritis in 10% of patients and ankylosing spondylitis in 7.5%. The relationship between FM and autoimmune diseases remains complex and is not fully elucidated. While some evidence suggests an autoimmune pathogenesis for FM, further investigation is required to confirm this hypothesis [15]. The literature also suggests a higher incidence of FM in patients with other autoimmune diseases, along with a higher severity of FM in these individuals [16, 17]. These findings highlight the need for more research to understand FM's underlying mechanisms and potential therapeutic targets of FM and its relationship with autoimmune disorders.

We also found that a significant number of patients had comorbid conditions, which can be grouped into three main categories: physical comorbidities, psychological comorbidities, and other chronic pain syndromes. These comorbidities included conditions such as FM-associated headaches and chronic low back pain. Especially, headache was a common symptom among our patients, with a higher incidence of migrainous-type headaches than chronic tension headaches. These findings align with other studies exploring the association between FM and headache [18-20]. The precise mechanisms underlying this relationship are not yet fully understood. However, it is postulated that central sensitization, a process in which the central nervous system becomes hyperresponsive to stimuli, may play a role in the development of both conditions [21]. This finding is significant because it highlights the complexity of FM and its association with other chronic conditions. By recognizing and understanding these comorbidities, healthcare professionals can provide more comprehensive and targeted care to patients with FM.

Our findings suggest that sleep disturbances are common in individuals with FM; many experience snoring, awakening at night, daytime sleepiness, and taking daytime naps.

The findings are consistent with the existing literature on the subject. For example, a systematic review and meta-analysis of sleep in FM found that individuals with FM had reduced sleep duration and efficiency, increased sleep latency, and more awakenings compared to healthy controls [22-25]. Other studies found that individuals with FM reported more snoring and sleep apnoea compared to healthy controls [26, 27]. This highlights the importance of addressing sleep disturbances in the treatment of FM.

To determine the prevalence of depression among patients with FM, we used the Hamilton scoring criteria. Our findings revealed that most (82.5%) of FM patients had symptoms of depression, with a significant proportion (31.6%) exhibiting moderate to severe depression. This is consistent with previous research in the literature that consistently reports depression as a common comorbidity among people with FM. In a systematic review of 32 studies, the current and lifetime prevalence rates of depression were reported to be 63% and 43%, respectively [28]. Furthermore, our study highlights the high prevalence of comorbidities such as obsessive-compulsive behaviour in patients with FM.

Although our study aimed primarily to investigate the prevalence and associations of these factors, it is imperative to recognise that the relationships among them are often multifaceted and can exert mutual influences. For example, the high prevalence of psychological comorbidities such as depression and anxiety may contribute to sleep disturbances and exacerbate the perception of pain among FM patients. On the contrary, the chronic pain and sleep disturbances inherent in FM could potentially contribute to the development or intensification of psychological conditions. This bidirectional relationship between FM and other psychological and chronic pain syndromes may be due to shared predisposing and trigger factors, such as central sensitisation and initiation, involvement of brain areas that regulate pain and mood, and changes in the hypothalamic-pituitary-adrenal axis (HPA axis) [14].

Most of the patients in our study had a vitamin D deficiency, which aligns with previous research. Although there is no consensus on the relationship between vitamin D and FM, a recent meta-analysis has shown that serum levels of vitamin D in patients with FM are significantly lower than in control groups [29]. Additionally, some studies have found that vitamin D supplementation may alleviate pain and other symptoms in people with FM, which could have therapeutic implications.

Our study is limited by its modest sample size and the fact that it was conducted in a tertiary hospital, which can introduce some degree of bias in estimating the actual distribution of our findings. Future research may benefit from larger community-based observations to confirm our results. A notable strength of our study is the use of the ACR 2016 criteria, which considers other primary disorders that can cause pain. This comprehensive approach enables a more accurate assessment of FM, particularly in cases where other comorbidities can contribute to pain symptoms. By incorporating these criteria, our study provides a more pragmatic approach to evaluating FM in a clinical setting [30].

Our study suggests that the typical profile of a patient with FM in India is that of a middle-aged married homemaker living in a nuclear family within a middle to upper-middle-class society and with a satisfactory educational status. Although this demographic profile is similar to that reported in the literature, we observed varied socio-cultural profiles, which may require further community-based prevalence studies to delineate the profile of FM patients in the Indian population. Our study highlights the high prevalence of sleep disorders and other chronic psychological comorbidities, including depression and obsessive compulsive behaviour, among Indian patients with FM. Presence of moderate to severe depression was associated with the severity of FM.Future research exploring these associations may provide valuable insights into the pathogenetic mechanisms of FM. Overall, our study contributes to the growing body of knowledge on the epidemiology and management of FM worldwide, providing valuable information on the clinical features of FM in India.