Diet-induced weight loss has chronic tissue-specific effects on glucocorticoid metabolism in overweight postmenopausal women.

BACKGROUND/OBJECTIVES: Tissue-specific glucocorticoid metabolism is altered in obesity, and may increase cardiovascular risk. This dysregulation is normalized by short-term calorie restriction and weight loss, an effect that varies with dietary macronutrient composition. However, tissue-specific glucocorticoid metabolism has not been studied during long-term (>6 months) dietary interventions. Therefore our aim was to test whether long-term dietary interventions, either a paleolithic-type diet (PD) or a diet according to Nordic nutrition recommendations (NNR) could normalize tissue-specific glucocorticoid metabolism in overweight and obese women. SUBJECTS/METHODS: Forty-nine overweight/obese postmenopausal women were randomized to a paleolithic diet or a diet according to NNR for 24 months. At baseline, 6 and 24 months anthropometric measurements, insulin sensitivity, excretion of urinary glucocorticoid metabolites in 24-hour collections, conversion of orally administered cortisone to plasma cortisol and transcript levels of 11ß hydroxysteroid dehydrogenase type 1 (11ßHSD1) in subcutaneous adipose tissue were studied. RESULTS: Both diet groups achieved significant and sustained weight loss. Weight loss with the PD was greater than on NNR diet after 6 months (P<0.001) but similar at 24 months. Urinary measurement of 5α-reductase activity was increased after 24 months in both groups compared with baseline (P<0.001). Subcutaneous adipose tissue 11ßHSD1 gene expression decreased at 6 and 24 months in both diet groups (P=0.036). Consistent with increased liver 11ßHSD1, conversion of oral cortisone to cortisol increased at 6 months (P=0.023) but was unchanged compared with baseline by 24 months. CONCLUSIONS: Long-term weight loss in postmenopausal women has tissue-specific and time-dependent effects on glucocorticoid metabolism. This may alter local-tissue cortisol exposure contributing to improved metabolic function during weight loss.

Cortisol metabolism after weight loss: associations with 11 ß-HSD type 1 and markers of obesity in women.

OBJECTIVE: Increased glucocorticoid metabolite excretion and enhanced expression and activity of 11ß-hydroxysteroid dehydrogenase type 1 in adipose tissue are closely correlated with obesity and its detrimental consequences. Weight loss ameliorates the latter. The aim of this study was to explore whether increased glucocorticoid exposure in obesity is improved with substantial weight loss and thus is a consequence rather than a cause of obesity. DESIGN AND PATIENTS: A prospective cohort study in 31 women. MEASUREMENTS: 11ß-HSD type 1 expression and activity, urinary glucocorticoid metabolite excretion, body composition including regional adipose tissue depots and insulin resistance by HOMA-IR before and 2 years after gastric bypass surgery. RESULTS: After weight loss, excretion of cortisol and cortisone metabolites decreased. Both cortisol and cortisone metabolite excretion correlated with central obesity, where the intraabdominal fat depot showed the strongest association. Cortisol metabolites correlated with 11ß-HSD type 1 activity in abdominal subcutaneous adipose tissue. The ratio of cortisol to cortisone metabolites [(5α-tetrahydrocortisol (5αTHF) + tetrahydrocortisol (THF) + α-cortol)/(tetrahydrocortisone (THE) + α-cortolone)] and the ratio of 5α-THF/THF both decreased after stable weight loss, reflecting a downregulation of the net activities of 11ß-HSD type 1 and 5α-reductase. CONCLUSION: Long-term weight loss in women is not only followed by reduced glucocorticoid production, but also favourably decreases the global and tissue-specific activity of the cortisol-activating enzyme 11 ß-HSD type 1, possibly contributing to the health benefits of bariatric surgery.