Effect of long-term high-fat diet intake on peripheral insulin sensibility, blood pressure, and renal
function in female rats
Sammanfattning
Background: This study determines whether 8-week high-fat diet (HFD) consumption alters
insulin sensitivity, kidney function, and blood pressure (BP) in female rats when compared with
standard rodent diet (ND) intake in gender- and age-matched rats.
Methods: The present study investigates, in female Wistar HanUnib rats, the effect of long-term high-
fat fed group (HFD) compared with standard chow on BP by an indirect tail-cuff method using an
electrosphygmomanometer, insulin and glucose function, and kidney function by creatinine and
lithium clearances.
Results: The current study shows glucose tolerance impairment, as demonstrated by increased
fasting blood glucose (ND: 78±2.8 vs. HFD: 87±3.8 mg/dL) associated with reduced insulin secretion
(ND: 0.58±0.07 vs. HFD: 0.40±0.03 ng/mL) in 8-week female HFD-treated rats. The incremental area
under the curve (AUC, ND: 1,4558.0±536.0 vs. HFD: 1,6507.8±661.9), homeostasis model
assessment of insulin resistance (HOMA-IR) index, and the first-order rate constant for the
disappearance of glucose (Kitt) were significantly enhanced in 8-week HFD-treated rats compared
with age-matched ND group (respectively, P=0.03, P=0.002, and P<0.0001). The current study also
shows a significantly higher systolic BP measured in 5 and 8 weeks posttreatment in HFD (5-week
HFD-treated: 155.25±10.54 mmHg and 8-week HFD-treated: 165±5.8 mmHg) (P=0.0001), when
compared to BP values in 5-week ND, 137±4.24 mmHg and 8-week ND, 131.75±5.8 mmHg age-
matched group. Otherwise, the glomerular filtration rate and renal sodium handling evaluated by
FENa, FEPNa and FEPPNa, were unchanged in both groups.
Conclusion: We may conclude that 8-week female HFD-fed rats compared with ND group stimulate
harmful effects, such as BP rise and peripheral glucose intolerance. The increased BP occurs
through insulin resistance and supposedly decreased vasodilatation response without any change
on renal function.