Endogenous melatonin levels and therapeutic use of exogenous melatonin in tension type headache: A systematic review

BACKGROUND-PURPOSE

A bidirectional relationship appears to connect tension-type headache (TTH) and circadian dysregulation. The present systematic review examined the published evidence for melatonin (MT) supplementation in the prophylaxis of TTH. Initially, we reviewed case-control studies investigating nocturnal MT or 6-sulphatoxymelatonin (aMT6s, a urine-discarded metabolite) in TTH individuals and healthy controls (HC). Secondly, we reviewed studies appraising the use of MT in the prevention of TTH.

METHODS

The search strategy involved MEDLINE EMBASE, CENTRAL, PsycINFO, trial registries, Google Scholar and OpenGrey. Case-control studies were appraised according to the Newcastle-Ottawa-Scale, whereas randomised controlled trials were assessed based on the risk-of-bias Cochrane tool. Infrequent, as well as frequent, episodic, and chronic TTH patients were evaluated separately in children and adults.

RESULTS

Our search strategy yielded two case-control studies. One (high-quality) did not reveal any difference in morning salivary MT concentration between children with frequent episodic TTH and HC. The second (moderate-quality) was indicative of a disturbed nocturnal secretion pattern in adults with chronic TTH. For the second part, five uncontrolled studies were retrieved. In total, 94 adults with chronic TTH were assessed and results were suggestive of a beneficial effect of MT on headache frequency, intensity, induced disability, and induced analgesic consumption. However, the uncontrolled-unblinded designs may have induced an important placebo effect. Non-adult populations and frequent TTH were substantially understudied.

CONCLUSIONS

There are not enough studies to designate the role of MT in the prevention of TTH. Given the disease's background, additional relevant research is warranted for chronic TTH.

Anti-C1q autoantibodies are frequently detected in patients with systemic sclerosis associated with pulmonary fibrosis

BACKGROUND

Anti-C1q autoantibodies (autoAbs) are associated with systemic lupus erythematosus (SLE), but their presence in other rheumatic diseases has not been adequately investigated.

OBJECTIVES

We aimed to assess anti-C1q autoAbs and circulating immune complexes (CICs) in systemic sclerosis (SSc).

METHODS

In total 124 patients with SSc were studied; 106 were female and the median age was 59·4 years (range 25-81·4). Overall 75 (60·5%) had limited cutaneous SSc and 49 (39·5%) had diffuse cutaneous SSc. Also included were 25 patients with Sjögren syndrome (SjS), 29 with rheumatoid arthritis (RA), 38 with SLE and 53 healthy controls. Enzyme-linked immunosorbent assays with high- and low-salt buffers were used to measure anti-C1q antibodies and CICs. The former allows only anti-C1q antibody binding to C1q and the latter also allows IgG Fc to bind to C1q.

RESULTS

Anti-C1q antibodies were present in 20 of 124 (16·1%) patients with SSc: five had high levels (> 80 RU mL^-1 ) and 10 (50%) had moderate levels (40-80 RU mL^-1 ). Anti-C1q antibodies were also present in one of 25 (4%) patients with SjS, one of 29 (3%) with RA (P < 0·05 for both) and three of 53 (6%) healthy controls (P < 0·01). Anti-C1q antibodies were detected in 13 of 38 (34%) patients with SLEs. Anti-C1q antibodies were more frequent in male than female patients with SSc (P = 0·005); this association remained after multivariate regression analysis. Anti-C1q antibody level was the most important factor in predicting the presence of pulmonary fibrosis, and the second most important in predicting pulmonary arterial hypertension. Fourteen patients with SSc (11·3%) had CICs.

CONCLUSIONS

Anti-C1q autoAbs were frequently detected in patients with SSc, and their high levels predict the co-occurrence of pulmonary fibrosis or pulmonary arterial hypertension.