Association of Ferritin Levels With Clinical Parameters in Patients With Fibromyalgia Syndrome
Conditions: Fibromyalgia
Sponsor: Tokat State Hospital

Association of Ferritin Levels with Clinical Parameters in Patients with Fibromyalgia Syndrome  
NCT03825393  01,03,2016 
This sectional study included 200 female individuals (control:100, FMS:100) older than 18 years of 
age who presented to Physical Treatment and Rehabilitation polyclinic in 2016-17 period. The patient 
group included 100 patients who were selected by simple random sampling among 137 non-anemic 
FMS patients who had their diagnoses based on 2011 FMS diagnosis criteria of American 
Rheumatology College and whose ferritin levels were measured in the last four weeks. The control 
group, on the other hand, consisted of 100 individuals without a FMS diagnosis selected by simple 
random sampling among 153 individuals, who were non-anemic, who met exclusion criteria and 
whose ferritin levels were measured in the last four weeks. Individuals who used parenteral or enteral 
iron in last four weeks, whose hemoglobin level was less than 12 g/dl, who had infection, malignity, 
active inflammatory arthritis, serious skin variations, serious peripheral vascular disease, iron storing 
disorder and pregnant or lactating patients were excluded. The study was approved by local ethic 
committee (17-KAEK-093) and informed consent was taken from all participants. Serum ferritin 
levels of all participants measured within the last four weeks were obtained from hospital information 
system records. All FMS patients filled a questionnaire form which included questions about 
descriptive characteristics, Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), 
Fibromyalgia Impact Questionnaire (FIQ) and Pittsburg Sleep Quality Index (PSQI). Questionnaires 
were applied only to FMS patient group. 
 
Fibromyalgia Impact Questionnaire (FIQ) is a 10-item evaluation tool developed to measure status, 
prognosis and outcomes of FMS patients. Total points vary from 0 to 100. Higher points show the 
effect of FMS on functionality. Validity and reliability of FIQ in Turkish population were shown by 
Sarmer et al. (13). 
Beck Depression Inventory (BDI) is a 21-item questionnaire evaluating the presence and severity of 
depression. Higher points mean heavier depression (0-9 points: minimum depression; 10-18 points: 

slight depression; 19-29 points: moderate depression; 30-63 points: severe depression). Hisli et al. 
(14) showed validity and reliability of BDI in Turkish population. 
Beck Anxiety Inventory is a short, easily applied and graded, 21-item questionnaire to evaluate the 
severity of patients’ anxiety. Total points vary from 0 to 63 (0-9 points: normal; 10-18 points: slight 
to moderate anxiety; 19-29 points: moderate to severe anxiety and 30-63 points: very severe 
anxiety). Validity and reliability of BAI in Turkish population were shown by Ulusoy et al. (15). 
Pittsburgh Sleep Quality Index (PSQI) is an 18-item questionnaire measuring sleep quality and 
disorders in a time period of one month. PSQI measures subjective sleep quality, duration and 
latency of sleep, sleep disorders, habitual sleep efficiency, daytime dysfunction and use of 
medication for sleeping. PSQI distinguishes “poor” sleep from “good” sleep. Five or higher total 
points in PSQI mean “poor” sleep. Ağargün et al. (16) showed the validity and reliability of PSQI 
for Turkish population. 
Serum ferritin level was measured in a Roche Cobas e801 autoanalyzer (Roche Diagnostics, 
Mannheim, Germany) in our hospital laboratory using electrochemiluminescence immunoassay 
(ECLIA) method. Serum ferritin level less than 30 ng/mL was considered iron deficiency. 
Statistical Analyses 
Descriptive analyses were carried out to obtain information about general characteristics of study 
groups. Data from various variables were given as mean ± standard deviation, while data from 
categorical ones were expressed as n (%). Shapiro-Wilk’s test was used to assess the normality of the 
data. Group means were compared using independent samples t test for normally distributed 
quantitative variables. Mann Whitney U test was used for quantitative variables with non-normal 
distribution. Relationships between quantitative variables were evaluated with Pearson correlation 
coefficient. p levels <0.05 was considered statistically significant. Statistical analyses were carried out 
using SPSS software (ver. 19.0.0; IBM Corp, Somers, NY).