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Open access

Irina Bancos, Jon Hazeldine, Vasileios Chortis, Peter Hampson, Angela E Taylor, Janet M Lord and Wiebke Arlt

Open access

Irina Bancos, Jon Hazeldine, Vasileios Chortis, Peter Hampson, Angela E Taylor, Janet M Lord and Wiebke Arlt

Objective

Mortality in patients with primary adrenal insufficiency (PAI) is significantly increased, with respiratory infections as a major cause of death. Moreover, patients with PAI report an increased rate of non-fatal infections. Neutrophils and natural killer (NK) cells are innate immune cells that provide frontline protection against invading pathogens. Thus, we compared the function and phenotype of NK cells and neutrophils isolated from PAI patients and healthy controls to ascertain whether altered innate immune responses could be a contributory factor for the increased susceptibility of PAI patients to infection.

Design and methods

We undertook a cross-sectional study of 42 patients with PAI due to autoimmune adrenalitis (n = 37) or bilateral adrenalectomy (n = 5) and 58 sex- and age-matched controls. A comprehensive screen of innate immune function, consisting of measurements of neutrophil phagocytosis, reactive oxygen species production, NK cell cytotoxicity (NKCC) and NK cell surface receptor expression, was performed on all subjects.

Results

Neutrophil function did not differ between PAI and controls. However, NKCC was significantly reduced in PAI (12.0 ± 1.5% vs 21.1 ± 2.6%, P < 0.0001). Phenotypically, the percentage of NK cells expressing the activating receptors NKG2D and NKp46 was significantly lower in PAI, as was the surface density of NKG2D (all P < 0.0001). Intracellular granzyme B expression was significantly increased in NK cells from PAI patients (P < 0.01).

Conclusions

Adrenal insufficiency is associated with significantly decreased NKCC, thereby potentially compromising early recognition and elimination of virally infected cells. This potential impairment in anti-viral immune defense may contribute to the increased rate of respiratory infections and ultimately mortality in PAI.

Free access

Anna C Phillips, Douglas Carroll, Catharine R Gale, Janet M Lord, Wiebke Arlt and G David Batty

Objectives

The aim of the present analyses was to examine the association between cortisol, DHEA sulphate (DHEAS) and the cortisol:DHEAS ratio and mortality.

Design

This was a prospective cohort analysis.

Methods

Participants were 4255 Vietnam-era US army veterans. From military service files, telephone interviews and a medical examination, occupational, socio-demographic and health data were collected. Contemporary morning fasted cortisol and DHEAS concentrations were determined. Mortality was tracked over the subsequent 15 years. The outcomes were all-cause, cardiovascular disease, cancer, other medical mortality and external causes of death. Cox proportional hazard models were tested, initially with adjustment for age, and then with adjustment for a range of candidate confounders.

Results

In general, cortisol concentrations did not show an association with all-cause or cause-specific mortality. However, in age-adjusted and fully adjusted analyses, DHEAS was negatively related to all-cause, all cancers and other medical mortality; high DHEAS concentrations were protective. The cortisol:DHEAS ratio was also associated with these outcomes in both age-adjusted and fully adjusted models; the higher the ratio, the greater the risk of death.

Conclusions

DHEAS was negatively associated, and the ratio of cortisol to DHEAS was positively associated with all-cause, cancer and other medical cause mortality. Further experimental study is needed to elucidate the mechanisms involved in these relationships.

Free access

Anna C Phillips, Douglas Carroll, Catharine R Gale, Janet M Lord, Wiebke Arlt and G David Batty

Objectives

The aim of these analyses was to examine the association of cortisol, DHEAS and the cortisol:DHEAS ratio with the metabolic syndrome (MetS) and its components.

Design

The analyses were cross-sectional.

Methods

Participants were 4255 Vietnam era US army veterans. From military service files, telephone interviews and a medical examination, occupational, socio-demographic and health data were collected. MetS was ascertained from data on body mass index; fasting blood glucose or a diagnosis of diabetes; blood pressure or a diagnosis of hypertension; high-density lipoprotein cholesterol; and triglyceride levels. Contemporary morning fasted cortisol and DHEAS concentrations were determined. The outcomes were MetS and its components. Analysis was by logistic regression, first adjusting for age and then additionally for an array of candidate confounders.

Results

Cortisol, although not in the fully adjusted analysis, and DHEAS were both related to MetS. Whereas high cortisol concentrations were associated with an increased risk of MetS, high DHEAS concentrations appeared protective. By far, the strongest associations with MetS were observed for the cortisol:DHEAS ratio; the higher the ratio, the greater the risk of having MetS. The ratio was also significantly related to four of the five MetS components.

Conclusions

The cortisol:DHEAS ratio is positively associated with MetS. Prospective analyses are needed to help untangle direction of causality, but this study suggests that the cortisol:DHEAS ratio is worthy of further study in this and other health contexts.