...Relation Between [FM] Severity and Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Mean Platelet Volume, 2022, Jayakrishnan et al

[Andy]

Abstract

Background: Fibromyalgia is characterized by chronic widespread pain, which has been linked to neuroinflammation. Hematological indices, i.e., neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and mean platelet volume (MPV) have been shown to be effective markers in neurological diseases like depression.

Aims: To study the association between fibromyalgia severity and the hematological indices (NLR, PLR, and MPV).

Subjects and Methods: This was a hospital-based cross-sectional study of fibromyalgia patients satisfying the 2016 modification of the 2010/11 ACR criteria. Demographic and clinical characteristics were recorded along with fibromyalgia outcomes and hematological indices. Statistical analysis was done using descriptive statistics, ROC analysis using the Youden index, and Pearson and Spearman correlations.

Results: A total of 266 patients were recruited. The (mean ± S.D) NLR, MPV, and PLR were 1.92 ± 1.26, 8.94 ± 1.25, and 119.48 ± 76.91, respectively. Patients with severe visual analog scale (VAS) pain scores had lower MPV (8.8 ± 1.3) than those with mild/moderate pain (9.2 ± 1.1, p = 0.016). MPV showed a mild negative correlation with the Fibromyalgia Impact Questionnaire-Revised (FIQR) score (R2 -0.31 p 0.004). MPV threshold of 8.95 was discriminated severely from mild/moderate VAS-pain score with a sensitivity of 52.3 % and specificity of 66.7%.

Conclusions: MPV can possibly be considered as a biomarker for predicting pain severity in fibromyalgia. Given its inexpensive nature, MPV can be used as a cost-effective method to assess fibromyalgia severity in rural India.

Open access, https://www.cureus.com/articles/864...-to-lymphocyte-ratio-and-mean-platelet-volume

 

[Hutan]

The correlation coefficient is -0.31. I'm assuming that's the slope of a regression line. That is, reported fibromyalgia impact is very slightly more likely to be higher with a lower mean platelet value. Yes, the p value is good at 0.004, BUT...

Seriously

Given its inexpensive nature, MPV can be used as a cost-effective method to assess fibromyalgia severity in rural India.

No, on the basis of this study, it absolutely cannot. Look at the range of platelet volumes in each quintile of FIQR.

A cost-effective method of assessing fibromyalgia severity in rural India remains asking the patient, perhaps using the FIQR, I don't know.

Mean platelet volume, normally measured using automated blood analysers, reflects the average size of platelets in circulation. It is meant to show the relationship between platelet synthesis in bone marrow and cell destruction. A normal MPV has a range of 7.5–11.5 fL.

Ninety-five percent of the individuals had a MPV between 7.2 and 11.7 fL.

Going by that, this sample looks to have mostly normal mean platelet volumes. There are slightly more women with abnormally low mean platelet volumes than abnormally high platelet volumes. Low platelet volumes can be caused by quite a lot of things including anaemia and cancer. I hope that the women with abnormal platelet volumes were properly assessed - perhaps they have a treatable condition that is causing the symptoms currently attributed to fibromyalgia.

I find this study concerning.