We present the development of the first procedure for hair cortisol measurement through an automated method. Hair samples were obtained from 286 individuals. After cortisol extraction, samples were measured in a Siemens Immulite 2000 (Gwynedd, UK) automated chemoluminiscent immunoassay analyzer. Normal reference values were obtained from hair cortisol levels measured in 213 healthy individuals with low levels of stress. Hair cortisol concentration median was 55 pg/mg hair (2.5–97.5 percentile (40–128)) in healthy individuals with low levels of stress and 250 pg/mg hair (range 182–520) in stressed individuals. No significant differences were observed in hair cortisol levels between subjects with and without dye (40 (40–107) and 40 (40–155) pg/mg hair, respectively; p = 0.128). The novel procedure presented here shows an adequate analytical performance.

Psychological factors and stressful life events (LE) are considered to play a role in the onset of the metabolic syndrome (MS). We tested the association between LE and cortisol, a marker of chronic stress, with the risk of developing MS and their interaction. From a total number of 2906 men who completed a screening for the early detection of prostate cancer, 149 healthy men (mean ± SD age, 58.6 ± 7.7 years) were included in this study. Participants were assessed by the Holmes and Rahe questionnaire about their experience of LE during the previous 1-5 years. MS was diagnosed according to National Cholesterol Education Program-Adult Treatment Panel III (ATP-III) and International Diabetes Federation (IDF) criteria. Serum cortisol was measured at 08:00-09:00 h. Participants with MS (IDF criteria) reported significantly more past LE (p = 0.009) and greater summed weight of LE (p = 0.049) than those without MS. Furthermore, LE interacted with cortisol in relation to MS: in men with increased serum cortisol levels ( ≥ 13.7 μg/dl), number of LE significantly predicted MS-status (relative risk (RR) = 1.16, p = 0.03), whereas in men with low cortisol, LE were unrelated to MS (p = 0.52). We conclude that LE were significantly more prevalent in men with the MS than without the MS, according to IDF criteria, independent of the effects of age and body mass index, especially in men with increased serum cortisol levels.

Our finding of increased plasma activity of MMP-2 in overweight/obese women, associated with menopausal status, is important given that it fits in with an early stage of cardiovascular disease; the association of MMP-2 activity with obesity markers may be a link between adipose tissue and risk for cardiovascular disease.

This study adds weight to the idea that two psychosocial factors, namely hostility and social support, acting jointly, may affect MMP-2 activity. Moreover, in hostile patients, there is a link between IL-1β and MMP-9. These findings support the role of psychosocial factors in plaque destabilization and in the inflammatory process in AMI.