Morning cortisol and fasting glucose are elevated in women with chronic widespread pain independent of comorbid restless legs syndrome.
BACKGROUND AND AIMS
Chronic widespread pain (CWP) is associated with poor quality of sleep, but the detailed underlying mechanisms are still not fully understood. In this study we investigated the influence of CWP on morning cortisol and fasting glucose concentrations as well as sleep disordered breathing.


METHODS
In this case-control study, subjects with CWP (n=31) and a control group without CWP (n=23) were randomly selected from a population-based cohort of women. Current pain intensity, sleep quality, excessive daytime sleepiness [Epworth sleepiness scale (ESS)], psychiatric comorbidity and occurrence of restless legs syndrome (RLS) were assessed. Overnight polygraphy was applied to quantify sleep apnoea, airflow limitation and attenuations of finger pulse wave amplitude (>50%) as a surrogate marker for increased skin sympathetic activity. Morning cortisol and fasting glucose concentrations were determined. Generalised linear models were used for multivariate analyses.


RESULTS
CWP was associated with higher cortisol (464±141 vs. 366±111 nmol/L, p=0.011) and fasting glucose (6.0±0.8 vs. 5.4±0.7 mmol/L, p=0.007) compared with controls. The significance remained after adjustment for age, body mass index, RLS and anxiety status (β=122±47 nmol/L and 0.89±0.28 mmol/L, p=0.009 and 0.001, respectively). The duration of flow limitation in sleep was longer (35±22 vs. 21±34 min, p=0.022), and pulse wave attenuation was more frequent (11±8 vs. 6±2 events/h, p=0.048) in CWP subjects compared with controls. RLS was associated with higher ESS independent of CWP (β=3.1±1.3, p=0.018).


CONCLUSIONS
Elevated morning cortisol, impaired fasting glucose concentration and increased skin sympathetic activity during sleep suggested an activated adrenal medullary system in subjects with CWP, which was not influenced by comorbid RLS.


IMPLICATIONS
CWP is associated with activated stress markers that may deteriorate sleep.
['Stehlik|Romana|R|', 'Ulfberg|Jan|J|', 'Zou|Ding|D|', 'Hedner|Jan|J|', 'Grote|Ludger|L|']
D000293:Adolescent D000328:Adult D000368:Aged D015415:Biomarkers D001786:Blood Glucose D015992:Body Mass Index D059350:Chronic Pain D015331:Cohort Studies D015897:Comorbidity D005215:Fasting D005260:Female D006801:Humans D006854:Hydrocortisone D001523:Mental Disorders D008875:Middle Aged D017440:Photoperiod D063177:Pulse Wave Analysis D012148:Restless Legs Syndrome D012890:Sleep D012891:Sleep Apnea Syndromes D013564:Sympathetic Nervous System D055815:Young Adult
cortisol glucose restless legs syndrome finger pulse wave skin sympathetic activation multi-site pain