Central obesity, depression and the hypothalamo-pituitary-adrenal axis in men and postmenopausal women.

OBJECTIVE

We examined the relationship of adiposity to pituitary-adrenal responses to corticotrophin-releasing hormone (CRH) in men and postmenopausal women, controlling for the influence of depression.

DESIGN

Studies of CRH responses, cortisol metabolite levels and depression scores in relation to adiposity in men and postmenopausal women.

SUBJECTS

Thirteen men: age (median, interquartile range) 62 y (52-63), body mass index (BMI) 29.0 kg/m2 (26.3-33.1), waist circumference (waist) 105 cm (97-111), waist:hip ratio (WHR) 1.03 (0.98-1.07), subscapular to triceps skinfold thickness ratio (STR) 2.0 (1.2-2.4), total body fat (TBF) 25.4 kg (19.8-28.8); and eight women: age 54 y (53-62), BMI 30 kg/m2 (23-41), waist 86 cm (79-117), WHR 0.94 (0.87-1.10), STR 1.0 (0.85-1.07), TBF 35.0 kg (18.7-48.8).

MEASUREMENTS

A standard CRH test was conducted with additional basal samples taken for leptin and interleukin 6 (IL-6). Total urine cortisol metabolites (TCM) and the ratio of urinary cortisol:cortisone (Fm/Em) metabolites were measured. Depression scores were measured by the General Health Questionnaire (GHQ-30) and Hospital Anxiety and Depression Scale (HAD) questionnaire. All subjects completed an overnight dexamethasone suppression test.

RESULTS

The basal to peak percentage increments (%inc.) in adrenocorticotrophic hormone (ACTH) and cortisol in men correlated directly with STR (ACTH %inc. r=0.70, P<0.01; cortisol %inc. r=0.55, P=0.05); this relationship was independent of depression scores. In women, the ACTH area under incremental curve (AUIC) correlated negatively with STR (r=-0.81, P<0.05). In men, but not in women, there was a significant correlation between GHQ-30 score and ACTH AUIC (r=0.62, P<0.05) and cortisol AUIC (r=0.72, P<0.01). Depression scores were consistently and directly related to indices of obesity and central obesity. There were no significant relationships in either sex between urinary TCM or Fm/Em ratio and BMI, waist, WHR, TBF, STR or CRH responses. The urinary Fm/Em ratio was higher in men than in women (median 0.74 vs 0.66, P<0.05). In men, but not in women, GHQ-30 scores correlated positively with urinary TCM (r=0.57, P=0.05) and HAD-depression scores were inversely related to the urine Fm/Em ratio (r=-0.65, P<0.05). All subjects suppressed normally with dexamethasone.

CONCLUSIONS

Cortisol metabolite levels were increased in depression in men, but were not related to adiposity in either sex. We demonstrate that central obesity in men, but not postmenopausal women, is associated with an enhanced pituitary-adrenal response to CRH and that this relationship is independent of depression score. International Journal of Obesity (2000) 24, 246-251