The Predictive Value of Morning Stiffness Save

A prospective study evaluated the value and associations with morning stiffness (MS) in patients with clinically suspect arthralgia (CSA), and found that the presence of MS increases the odds of inflammation (as detected by CRP and MRI synovitis).

Patients with clinically suspect arthralgia (n=575) were investigated with laboratory assessments and contrast-enhanced 1.5 T-MRI of hand and forefoot (looking for subclinical joint-inflammation - synovitis, tenosynovitis or osteitis). An increased CRP was defined as ≥ 5 mg/l. MS duration was quantified (≥30, ≥60, ≥120 min).

Only one-third (n=195; 34%) of CSA-patients had MS ≥60 min. Those with MS were more likely to have:

• Subclinical (MRI) synovitis (34% vs 21%, OR 1.95 (95%CI 1.32–2.87)) 
• Subclinical (MRI) tenosynovitis (36% vs 26%, OR 1.59 (1.10–2.31))
• Increased-CRP (31% vs 19%, OR 1.93 (1.30–2.88))

In multivariable analyses, MS was independently associated with subclinical synovitis (OR 1.77 (1.16–2.69)) and CRP (OR 1.78 (1.17–2.69)).  These associations were stronger in those who later developed RA (‘pre-RA’) -  subclinical synovitis (OR 2.56 (1.04–6.52)) and CRP (OR 3.86 (1.45–10.24)). 

MS increases the odds of inflammation. Despite the significant associations the predictive value of MS is low.