Sociodemographic Characteristics and Comorbidities of Primary Fibromyalgia: A Cross-Sectional Study

Abstract

Introduction

Fibromyalgia (FM) is a chronic condition characterized by widespread musculoskeletal pain, fatigue, cognitive disturbances, and multiple somatic symptoms. However, data on primary fibromyalgia in the West Bank remain limited, particularly regarding clinical characteristics and associated comorbidities in clinic-based populations.

Methods

A cross-sectional observational study was conducted involving 301 patients diagnosed with primary fibromyalgia at the Al Ahli Outpatient Clinic. Data were collected from electronic health systems and paper-based medical records from January 2020 to January 2024. The analysis examined demographic characteristics, comorbidities, and occupational distribution using SPSS version 28.

Results

Among the 301 patients with primary fibromyalgia, a marked female predominance was observed (86%; female-to-male ratio 6:1), with a mean age of 38.28 ± 10.65 years. Most patients were older than 35 years (64.8%). Vitamin D deficiency was identified in 42.2% of patients, followed by irritable bowel syndrome (40.2%) and insomnia (35.5%). Hypothyroidism was present in 9% of patients, while cardiovascular and metabolic conditions were reported in 23.6% of the cohort. Correlation analysis demonstrated significant associations between occupation and sex (r = −0.664, p < 0.001) and between occupation and age (r = −0.250, p < 0.001).

Conclusion

Primary fibromyalgia in this clinic-based population was characterized by a high proportion of female patients and a notable burden of comorbid conditions. The observed occupation–gender associations and the high proportion of housewives may reflect sociocultural patterns within the study population. These findings provide baseline clinical data on primary fibromyalgia and may support improved clinical recognition and management strategies in similar healthcare settings.

Introduction

Fibromyalgia (FM) is a chronic condition characterized by widespread musculoskeletal pain and is frequently accompanied by fatigue, cognitive disturbances, psychiatric symptoms, and various somatic symptoms.^1,2 Its etiology remains poorly understood, and its pathophysiology has not been fully clarified. Muscle and joint stiffness, persistent tender points, cognitive dysfunction, sleep disturbance, anxiety, fatigue, generalized sensitivity, and depressive episodes are common symptoms of fibromyalgia.^2,3. This central sensitivity syndrome negatively affects quality of life and is more prevalent in women than in men. ²

In Europe and South America, prevalence estimates range from 3.3% to 8.3%, and are estimated at 4.9% for men and 7.7% for women in the United States. Current studies suggest that several workplace characteristics may contribute to the onset of fibromyalgia and increase symptom severity. ⁴ Fibromyalgia is considered the second most common condition observed by rheumatologists, with an estimated mean prevalence of approximately 2.7%. ⁵

For many years, diagnosing FM has been difficult for clinicians because of the unclear pathophysiology, frequent comorbidities, lack of specific laboratory investigations to confirm its presence, and symptoms that fluctuate over time and often overlap with other clinical conditions. Consequently, a considerable proportion of cases remain undiagnosed, overdiagnosed, or misdiagnosed. ⁵

Fibromyalgia can be broadly classified into two main subclasses: primary fibromyalgia and secondary fibromyalgia. Primary fibromyalgia is considered an idiopathic condition of unknown etiology, whereas secondary fibromyalgia occurs in association with other medical conditions, such as autoimmune diseases, infections, or physical trauma.^6-10 The pathophysiology of fibromyalgia is multifactorial and involves altered central pain processing mechanisms, including central sensitization.^5,6

The 2016 diagnostic criteria of the American College of Rheumatology (ACR) are currently the most widely accepted evidence-based recommendations.^8,9 A diagnosis is made when the following criteria are met: a Widespread Pain Index (WPI) ≥7 with a Symptom Severity Scale (SSS) score ≥5, or a WPI of 4–6 with an SSS score ≥9. Symptoms must be present for at least three months, and generalized pain must be present in at least four of the five body regions.

Fibromyalgia (FM) is not a diagnosis of exclusion and may coexist with other diseases, such as rheumatoid arthritis, systemic lupus erythematosus, or ankylosing spondylitis. Although there are no specific laboratory diagnostic tests for fibromyalgia, other treatable conditions should be considered during evaluation.^9,11

The management of fibromyalgia includes both pharmacologic and nonpharmacologic approaches. Drug therapy is not always required, and patient education, aerobic exercise, and cognitive–behavioral therapy are considered key components of management. ¹²

Fibromyalgia presents particular challenges in Palestine due to occupation-related stressors, economic constraints, and limitations within the healthcare system. These factors may contribute to delayed diagnosis, limited access to specialized care, and suboptimal disease management.^5,12

The Palestinian healthcare system faces several structural barriers, including limited availability of specialized rheumatology services, shortages of trained mental health professionals, and restricted access to advanced diagnostic resources. ¹³ These barriers may hinder appropriate assessment, follow-up, and long-term multidisciplinary care for patients with fibromyalgia.^13,14

International research has provided valuable insights into fibromyalgia; however, comprehensive studies examining its clinical features and comorbidities within the Palestinian population remain limited.^15,16 Previous studies have suggested potential associations between fibromyalgia symptoms and factors such as chronic stress, vitamin D deficiency, and limited healthcare access. ¹⁵ Nevertheless, the extent to which these factors are associated with symptom burden in Palestinian patients has not been adequately explored. Therefore, this study aimed to evaluate the clinical characteristics and comorbidities associated with primary fibromyalgia among patients in the West Bank.

Therefore, this study aimed to evaluate the clinical characteristics and comorbidities associated with primary fibromyalgia among patients in the West Bank, Palestine, to improve understanding of the disease profile in this population and to provide insights relevant to other resource-limited or conflict-affected healthcare settings.

Methodology

Sample Size

The required le size was calculated using the Raosoft online sample size calculator. Assuming a 95% confidence level, a 5% margin of error, and a response distribution of 50% (used in the absence of reliable regional prevalence data), the minimum recommended sample size was determined. The final study sample included 301 participants, meeting the required minimum and ensuring adequate precision of the study estimates.

Study Design

A cross-sectional observational study was conducted among Palestinian citizens of the West Bank, and this design could effectively address current prevalence rates, demographic trends, and comorbidity associations at a lower cost and with greater operational flexibility, given the study’s constrained funding. This approach enabled the concurrent capture of sociodemographic data, medical conditions, and occupational information in the medical record archives.

Although this design falls short in distinguishing between association and causation and may have seasonal fluctuations, it was useful for creating a baseline for the Palestinian population and generating hypotheses for future research. Given that the research was exploratory and constrained by practical healthcare settings, we believe this method is more appropriate.

Study Setting

This survey was conducted at the Al Ahli Outpatient Clinic from January 2020 to January 2024, targeting Palestinian patients in the West Bank, Palestine. Selecting the Al Ahli Outpatient Clinic in the West Bank as the study setting was strategic for several reasons. As these healthcare facilities are major regional centers, they have easy access to a wide variety of fibromyalgia patients.

Electronic Health Record (EHR) systems are used by clinics and both electronic and paper recording systems, allowing convenient data capture and analysis. The West Bank site was particularly germane to the study, which helped us understand the effect of fibromyalgia on Palestinian society, with all its specific sociopolitical, cultural, and physical features.

This study was conducted in accordance with the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for cross-sectional studies. ¹⁷

Inclusion and Exclusion Criteria

The study included adult patients (≥18 years) diagnosed with primary fibromyalgia according to the 2016 American College of Rheumatology (ACR) criteria. Diagnosis was confirmed either through documented Widespread Pain Index (WPI) and Symptom Severity Scale (SSS) scores in the medical records or based on physician clinical assessment consistent with the ACR 2016 criteria at the Al Ahli Outpatient Clinic in 2024.The exclusion criteria were as follows: patients with secondary fibromyalgia (i.e., symptoms attributable to autoimmune diseases, infections, or trauma), those with incomplete medical records, and individuals unable to provide informed consent. Participants with comorbid rheumatologic conditions, such as rheumatoid arthritis or systemic lupus erythematosus, were also excluded.

A consecutive sampling approach was used, whereby data were collected from a secondary data source in tertiary healthcare settings in the West Bank, Palestine. The data were extracted from the clinics' electronic health systems and paper-based medical records. These methods allowed for the analysis of a defined dataset, including the study variables, and the data were exported to Microsoft Excel for further analysis using SPSS version 28.

Data Analysis

Data analysis was conducted using the Statistical Package for Social Sciences (SPSS) version 28. Descriptive statistics, including frequencies, percentages, means, and standard deviations, were used to summarize the sociodemographic and clinical characteristics of the study participants. To evaluate the associations between categorical variables (e.g., sex, occupation, and comorbidities), the chi-square test was utilized, with p < 0.05 indicating statistical significance. Correlation analyses were performed to assess the relationships between continuous variables (e.g., age) and categorical factors (e.g., occupation and sex). These statistical approaches enabled the identification of patterns, associations, and demographic trends within the primary fibromyalgia patient cohort, ensuring a robust exploration of the research objectives.

Results

A total of 301 patients diagnosed with primary fibromyalgia were included in the analysis. The mean age of the participants was 38.28 ± 10.65 years. The majority of participants were female (86%), whereas 14% were male, corresponding to a female-to-male ratio of approximately 6:1. The sociodemographic characteristics of the study population are summarized in Table 1.

Table 1.

Socio-Demographics: Primary Fibromyalgia Patients’ Profile (N=301)

Socio-demographics	n	%
Age
(M ± SD)	(38.28 ± 10.652)
Less than 20 years	12	4.0
20 – 35 years	94	31.2
Over 35 years	195	64.8
Gender
Male	42	14.0
Female	259	86.0
Occupation
Housewife	202	67.1
Student	16	5.3
Teacher	23	7.6
Healthcare professionals	8	2.7
Business and manual service professionals	52	17.3
Medical conditions
Free history	223	74.1
Hypertension	29	9.7
Diabetes Mellitus	20	6.6
Other medical conditions	29	9.6

Regarding age distribution, 4% of the participants were younger than 20 years, 31.2% were between 20 and 35 years, and the majority (64.8%) were older than 35 years, as presented in Table 2.

Table 2.

Prevalence of Primary Fibromyalgia According to Age

Variables			Fibromyalgia
Age categories	Young (less than 20 years)	Count	12
		% within fibromyalgia	4.0%
	Adult (20 – 35 years)	Count	94
		% within fibromyalgia	31.2%
	Older (over 35 years)	Count	195
		% within fibromyalgia	64.8%

Among the study participants, 34.9% reported at least one diagnosed medical condition, whereas 65.1% had no significant prior medical history. Cardiovascular and metabolic conditions were observed in 23.6% of the study population. Hypertension was the most frequently reported condition, affecting 16.3% of patients, including 10.3% with isolated hypertension and 6.0% with coexisting hypertension and diabetes mellitus. Diabetes mellitus alone was reported in 4.7% of participants. Other cardiovascular and metabolic conditions, including prediabetes, dyslipidemia, ischemic heart disease, supraventricular tachycardia, and transient ischemic attack, were less common, each occurring in less than 1% of cases, as shown in Table 3.

Table 3.

Prevalence of Medical Conditions With Primary Fibromyalgia

Medical conditions	Prevalence
Cardiovascular and Metabolic	23.6%
Musculoskeletal	3.7%
Other Conditions	4.3%
Free Medical history	68.4%
For patients with at least one medical condition	34.9%

Additional comorbid conditions were also identified in the study population. Hypothyroidism was present in 9% of the patients, whereas 91% did not have hypothyroidism. Insomnia was reported by 35.5% of participants, while 64.5% reported no insomnia symptoms. Vitamin D deficiency was observed in 42.2% of patients, whereas 57.8% had normal vitamin D levels. Furthermore, irritable bowel syndrome (IBS) was reported in 40.2% of the participants, while 59.8% did not report IBS symptoms, as summarized in Table 4.

Table 4.

Multiple Diseases Prevalence With Primary Fibromyalgia

​		Hypothyroidism	insomnia	Vitamin D deficiency	irritable bowel syndrome
no	% within fibromyalgia	91.0%	64.5%	57.8%	59.8%
yes	% within fibromyalgia	9.0%	35.5%	42.2%	40.2%

The occupational distribution of fibromyalgia patients showed notable variation across occupational categories. Housewives constituted the majority of cases (67.1%, n = 202), followed by manual or service workers (11.3%, n = 34) and teachers (7.6%, n = 23). Lower proportions were observed among business or professional workers (6.0%, n = 18), students (5.3%, n = 16), and healthcare workers (2.7%, n = 8), as presented in Table 5.

Table 5.

Prevalence of Primary Fibromyalgia Across Occupation

Occupation	Prevalence
Housewife	67.1
Student	5.3
Teacher	7.6
Healthcare professional	2.7
Manual/service worker	11.3
Business/Professional	6.0
Total	100.0

Correlation analyses were performed to assess the relationships between continuous variables (e.g., age) and categorical factors (e.g., occupation and sex). Categorical variables were numerically coded prior to analysis (e.g., sex: male, female; occupation was converted into dummy variables). A strong negative correlation was observed between occupation and sex (r = −0.664, p < 0.001). A moderate negative correlation was found between occupation and age (r = −0.250, p < 0.001). In addition, a weak positive correlation was identified between age and sex (r = 0.145, p = 0.012). These correlations are presented in Table 6.

Table 6.

Correlation Matrix of Occupation, Gender, and Age Across Primary Fibromyalgia

Variables	Occupation	Age	Gender	​
Occupation	Pearson Correlation	1	-.250**	-.664**
	Sig. (2-tailed)	​	.000	.000
	N	301	301	301
Age	Pearson Correlation	-.250**	1	.145*
	Sig. (2-tailed)	.000	​	.012
	N	301	301	301
Gender	Pearson Correlation	-.664**	.145*	1
	Sig. (2-tailed)	.000	.012	​
	N	301	301	301

**Correlation is significant at the 0.01 level (2-tailed).

*Correlation is significant at the 0.05 level (2-tailed).

Discussion

This study provides important epidemiological insights into the demographic and clinical characteristics of patients diagnosed with primary fibromyalgia in the West Bank. The findings demonstrate a marked gender disparity, with women representing the majority of the study population, corresponding to a female-to-male ratio of approximately 6:1, as presented in Table 1. This observation is consistent with global epidemiological patterns indicating that fibromyalgia occurs more frequently in women than in men. Hormonal influences, genetic susceptibility, and neurobiological differences in pain perception have been proposed as potential contributors to this disparity. Similar findings have been reported in regional studies conducted in Palestinian populations.^14,18 However, the ratio observed in this study differs from global estimates reported in previous international studies, which identified ratios ranging from approximately 2–3:1 to as high as 13:1.^15,19

Age distribution analysis revealed that fibromyalgia prevalence was highest among individuals older than 35 years, as shown in Table 2. This pattern suggests that fibromyalgia may become more clinically apparent during midlife, potentially reflecting cumulative exposure to psychological stressors, age-related physiological changes, and the increasing burden of chronic comorbid conditions. These findings are consistent with those reported in previous studies that also observed peak prevalence in middle-aged populations. ¹⁹ However, they differ from findings reporting peak prevalence between 50 and 60 years of age and from studies describing earlier onset in certain populations.^15,20 Regional evidence supports the present findings, as similar age distributions have been reported among Palestinian patients with chronic rheumatologic conditions. ¹³

Comorbid medical conditions were commonly observed among patients in this study. Cardiovascular and metabolic disorders were present in nearly one-quarter of the participants, suggesting that these conditions may contribute to the overall clinical burden of fibromyalgia. Hypertension was the most frequently reported cardiovascular condition. Chronic stress, autonomic nervous system dysregulation, and inflammatory processes have been suggested as potential mechanisms linking fibromyalgia with cardiovascular risk factors.^6,15

Endocrine and sleep-related disorders were also observed. Hypothyroidism was present in 9% of patients, consistent with previous studies that suggest a possible link between thyroid dysfunction and fibromyalgia. ⁶ Both conditions share similar clinical features, including fatigue, musculoskeletal pain, and cognitive impairment, which can complicate diagnosis and management. Thyroid hormone imbalances may contribute to neuromuscular dysfunction and inflammation that could worsen fibromyalgia symptoms through mechanisms associated with central sensitization. ⁶

Sleep disturbances were reported by more than one-third of the patients, with insomnia affecting 35.5% of the study population. Sleep dysfunction is widely recognized as both a symptom and a contributing factor in fibromyalgia. Poor sleep quality may disrupt the body’s restorative processes, leading to increased pain sensitivity, fatigue, and cognitive dysfunction, often referred to as “fibro fog.” In addition, sleep disruption may activate physiological stress responses, including elevated cortisol levels, which can further exacerbate fibromyalgia symptoms. ¹⁵

Vitamin D deficiency was also highly prevalent in this population, affecting 42.2% of patients. Vitamin D plays an essential role in musculoskeletal health, immune regulation, and pain modulation. Deficiency has been associated with increased pain perception, reduced muscle strength, and fatigue, which are key features of fibromyalgia. ¹² The relatively high prevalence observed in this study may be influenced by regional lifestyle factors, including limited sun exposure and cultural clothing practices.

Irritable bowel syndrome (IBS) was present in 40.2% of patients, exceeding the prevalence commonly reported in international studies. The coexistence of fibromyalgia and IBS has been widely documented and is believed to involve shared pathophysiological mechanisms, including central sensitization, dysregulation of the autonomic nervous system, and disturbances in the gut–brain axis.^6,15 Psychological comorbidities such as anxiety and depression may further contribute to symptom amplification in both conditions.

The coexistence of multiple comorbid conditions highlights the complex and multifactorial nature of fibromyalgia. These conditions may interact in a bidirectional manner, contributing to symptom amplification and greater disease burden. For example, sleep disturbances may worsen pain perception and fatigue, while vitamin D deficiency may contribute to musculoskeletal discomfort and systemic inflammation. Similarly, endocrine and gastrointestinal disorders may interact through neuroendocrine and autonomic pathways, further intensifying fibromyalgia symptoms.^6,15 These findings emphasize the importance of a comprehensive and multidisciplinary approach when managing patients with fibromyalgia.

Occupational distribution analysis revealed that housewives constituted the largest proportion of patients in the study population (67.1%). This finding may reflect sociocultural dynamics within the Palestinian context, where women often assume significant domestic and caregiving responsibilities. These roles may involve substantial physical and psychological stress, potentially influencing symptom severity and healthcare-seeking behavior. Similar occupational patterns have been reported in regional studies. ¹⁸ In contrast, studies conducted in Western populations often emphasize workplace physical demands and occupational stress as potential contributing factors. ¹⁵ The strong inverse correlation observed between occupation and gender likely reflects broader gender roles and occupational structures within Palestinian society.

Overall, this study provides valuable baseline epidemiological data on primary fibromyalgia in the West Bank, contributing to the limited body of literature on fibromyalgia in Palestinian and Middle Eastern populations. The findings highlight notable clinical patterns, including female predominance, high prevalence of comorbid conditions, and the potential influence of sociocultural factors on disease presentation and healthcare utilization.

This study has several strengths. The relatively large sample size enhances the statistical reliability of the findings, and the inclusion of multiple demographic and clinical variables provides a comprehensive overview of fibromyalgia characteristics in this population. Additionally, the use of standardized clinical records from multiple clinics improves the validity of the collected data.

Several limitations should be considered when interpreting these findings. First, the cross-sectional design inherently limits causal inference, preventing the determination of whether observed associations between fibromyalgia and demographic or clinical factors represent causal relationships or simple correlations. Second, geographic constraints limited data collection to clinics in the West Bank, excluding other Palestinian regions, such as Gaza and areas beyond the Green Line, which may restrict the generalizability of the findings. Third, reliance on retrospective medical records may have introduced information bias due to incomplete documentation or variation in diagnostic practices across clinics. Financial constraints also limited the availability of certain laboratory investigations, including inflammatory markers and thyroid function tests, in some cases, and seasonal symptom variations were not evaluated. Future research should therefore incorporate prospective study designs, larger multicenter samples, and multivariate statistical models to control for potential confounding factors, such as age, socioeconomic status, education level, and comorbidity burden.

Despite these limitations, this study provides valuable preliminary insights into the characteristics of fibromyalgia in an underrepresented population and highlights important areas for future research. Improving fibromyalgia care in Palestine requires coordinated efforts across clinical practice, research, and healthcare policy. In primary care settings, standardized screening tools for fibromyalgia symptoms and associated comorbidities, such as hypothyroidism, vitamin D deficiency, insomnia, and irritable bowel syndrome, may facilitate earlier diagnoses and more comprehensive management. Training programs for healthcare providers may further improve disease recognition and management strategies, particularly in settings with limited access to rheumatology specialists.

Future research should focus on longitudinal study designs to better understand the causal links between psychosocial stressors, occupational demands, and the progression of fibromyalgia. Collaboration across disciplines, including rheumatologists, psychologists, and public health professionals, can facilitate the development of culturally sensitive interventions, such as trauma-informed cognitive-behavioral therapy and community-based rehabilitation programs. From a healthcare policy standpoint, incorporating fibromyalgia management guidelines into primary care, expanding access to diagnostic services, and enhancing physician education through ongoing medical training can improve disease recognition and treatment. Additionally, implementing vitamin D screening and supplementation programs may help reduce the high prevalence of deficiency observed in this population.

Conclusion

Primary fibromyalgia in this clinic-based cohort was characterized by a marked female predominance and was most frequently observed among individuals older than 35 years, particularly housewives. A substantial proportion of patients presented with comorbid conditions, including cardiovascular and metabolic disorders, insomnia, vitamin D deficiency, and irritable bowel syndrome.

These findings highlight the importance of comprehensive clinical assessment in patients with fibromyalgia, including evaluation for commonly reported comorbid conditions. Improved recognition of these patterns may support more comprehensive clinical management and multidisciplinary care approaches.

Overall, this study provides baseline clinical and demographic data on primary fibromyalgia among patients attending outpatient clinics in the West Bank. The findings may contribute to improved awareness and future research on fibromyalgia in similar healthcare contexts.

ORCID iDs

Shahd Alosta https://orcid.org/0009-0007-3123-7093

Nisma Fataftah https://orcid.org/0009-0001-6928-1475

Islam Abu shaker https://orcid.org/0009-0008-1181-6204

Raghad Al-Amoudi https://orcid.org/0009-0009-5408-8259

Yazan F. khdour https://orcid.org/0000-0003-2450-7773

Ethical Considerations

This study was conducted in accordance with the principles of the Declaration of Helsinki. Ethical approval was obtained from the Institutional Review Board (IRB) of the College of Medicine, Hebron University, Palestine (Ref: HC CM MEC March 23 2024; approval date: 22 April 2024).

Consent to Participate

Verbal informed consent was obtained from all participants prior to their inclusion in the study.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.*