**3.6 Polymyalgia rheumatica**

We found two studies of polymyalgia rheumatica based on the same groups of subjects (Kreiner & Galbo, 2011; Kreiner et al., 2010) (**Table 6**). These two studies reported marked

Potential Muscle Biomarkers of Chronic Myalgia in Humans –

Substances investigated Flow rate

Lactate Pyruvate Glutamate 5-HT BKN PGE2 K+ ATP 3µl/min

IL-1α/β IL-1 receptor antagonist (IL-1Ra) IL-6 IL-8 TNF-α Monocyte chemoattract

ant protein 1(MCP-1) 3µl/min

Study Condition

Kreiner & Galbo (Kreiner & Galbo, 2011)

Kreiner et al. (Kreiner et al., 2010)

 Number of Subjects, % women(W) Muscles

Polymyalgia rheumatica (PMR)(n=20), 60%W Healthy controls (HC) (n=20), 65%W Trapezius Vastus lateralis

Polymyalgia rheumatica (PMR)(n=20), 60%W Healthy controls (HC) (n=20), 65% W Trapezius Vastus lateralis

A Systematic Review of Microdialysis Studies 117

Results

P=0.05

P=0.05

P=0.001

P=0.01

P=0.01

P=0.01

P=0.05

P=0.05

P=0.05

P=0.05

P=0.05

Table 6. Studies of Polymyalgia rheumatica. The results of the different substances are

\*Low flow rate associated with 100% relative recovery was defined as 0.3µl/min.

baseline data. Healthy controls are abbreviated as HC.

BKN–vastus: ns

K+–vastus: ns ATP–vastus: ns

>HC; P=0.05 5-HT–trapezius: ns BKN–trapezius: ns PGE2–trapezius: ns K+–trapezius: ns ATP–trapezius: ns Lactate–vastus: ns Pyruvate–vastus: ns

(comparisons between patients

Lactate –trapezius: PMR >HC;

Glutamate–vastus: PMR >HC;

5-HT–vastus: PMR >HC; P=0.05

PGE2–vastus: PMR >HC; P=0.05

IL-1α–trapezius: PMR >HC;

IL-1β–trapezius: PMR >HC;

IL-1Ra–trapezius: PMR >HC;

IL-6–trapezius: PMR >HC;

IL-8–trapezius: PMR >HC;

TNF-α–trapezius: PMR >HC;

MCP-1–trapezius: PMR >HC;

IL-1α–vastus: PMR >HC; P=0.01 IL-1β–vastus: PMR >HC; P=0.05 IL-1Ra–vastus: PMR >HC;

IL-6–vastus: PMR >HC; P=0.05 IL-8–vastus: PMR >HC; P=0.05 TNF-α–vastus: PMR >HC; P=ns MCP-1–vastus: PMR >HC;

Pyruvate –trapezius: ns Glutamate–trapezius: PMR Comments (Compensated for RR (Y/N) or low flow rate\* (NA or Y/N)

Compensated for RR: Y Low flow: NA

Compensated for RR: Y Low flow: NA

and HC; p-values)

alterations in cytokines but also to some extent in algesic substances such as glutamate in two muscles. These two studies also reported 5-HT in one muscle and in BKN in one muscle. Interestingly, all alterations were normalized after prednisolone treatment.


\*Low flow rate associated with 100% relative recovery was defined as 0.3µl/min.

Table 5. Studies of chronic tension type headaches. The results of the different substances are baseline data. Healthy controls are abbreviated as HC.
