Vol. 283, Issue 2, H562-H567, August 2002
Relationship among hyperinsulinemia, insulin resistance, and
hypertension is dependent on sex
Denise M.
Galipeau,
Linfu
Yao, and
John H.
McNeill
Division of Pharmacology and Toxicology, Faculty of
Pharmaceutical Sciences, University of British Columbia, Vancouver,
British Columbia, Canada V6T 1Z3
Hyperinsulinemia and insulin
resistance have been linked to hypertension; however, the influence of
sex on this relationship has not been well studied. The purpose of this
experiment was to compare the effects of chronic insulin treatment on
insulin sensitivity and blood pressure in male and female rats. Male
and female Wistar rats were treated with insulin (2 U/day) via
subcutaneous sustained release implants for 5 wk. Systolic blood
pressure was measured via the tail-cuff method before and after
treatment, and insulin sensitivity was assessed with an oral glucose
tolerance test. The insulin sensitivity of female rats was 4.5-fold
greater than male rats. Chronic insulin treatment impaired insulin
sensitivity in both sexes; however, this occurred to a greater degree
in male rats. Blood pressure increased in male rats treated with
insulin only. The results demonstrate that hyperinsulinemia and insulin resistance are associated with hypertension in male rats only. Therefore, the link between these conditions appears to depend on sex.
blood pressure; insulin sensitivity; male; female; vasculature
