Abstract
Hypothalamus-pituitary-adrenal-axis activity is suggested to be involved in the pathophysiology
of the metabolic syndrome. In diet-induced obesity mouse models, features of the metabolic
syndrome are induced by feeding high fat diet. However, the models reveal conflicting
results with respect to the hypothalamus-pituitary-adrenal-axis activation. The aim
of this review was to assess the effects of high fat feeding on the activity of the
hypothalamus-pituitary-adrenal-axis in mice. PubMed, EMBASE, Web of Science, the Cochrane
database, and Science Direct were electronically searched and reviewed by 2 individual
researchers. We included only original mouse studies reporting parameters of the hypothalamus-pituitary-adrenal-axis
after high fat feeding, and at least 1 basal corticosterone level with a proper control
group. Studies with adrenalectomized mice, transgenic animals only, high fat diet
for less than 2 weeks, or other interventions besides high fat diet, were excluded.
20 studies were included. The hypothalamus-pituitary-adrenal-axis evaluation was the
primary research question in only 5 studies. Plasma corticosterone levels were unchanged
in 40%, elevated in 30%, and decreased in 20% of the studies. The effects in the peripheral
tissues and the central nervous system were also inconsistent. However, major differences
were found between mouse strains, experimental conditions, and the content and duration
of the diets. This systematic review demonstrates that the effects of high fat feeding
on the basal activity of the hypothalamus-pituitary-adrenal-axis in mice are limited
and inconclusive. Differences in experimental conditions hamper comparisons and accentuate
the need for standardized evaluations to discern the effects of diet-induced obesity
on the hypothalamus-pituitary-adrenal-axis.
Key words
corticosterone - diet-induced obesity - metabolic syndrome
