Relationships between vascular resistance and energy deficiency, nutritional status and oxidative stress in oestrogen deficient physically active women.
OBJECTIVE
Oestrogen deficiency contributes to altered cardiovascular function in premenopausal amenorrheic physically active women. We investigated whether other energy deficiency-associated factors might also be associated with altered cardiovascular function in these women.


METHODS
A prospective observational study was completed at a research facility at the University of Toronto.


METHODS
Thirty-two healthy premenopausal women (18-35 years old) were studied; 9 sedentary and ovulatory; 14 physically active and ovulatory; and 8 physically active and amenorrheic.


METHODS
We measured calf vascular resistance, resting heart rate, dietary energy intake, resting energy expenditure and serum measures of homocysteine, high-sensitivity C-reactive protein, oxidized low-density lipoproteins, total T(3), ghrelin, leptin and insulin.


RESULTS
Groups were similar (P > 0.05) in age (25.1 +/- 0.8 years; mean +/- SEM), weight (57.3 +/- 1.1 kg), and BMI (21.4 +/- 0.3 kg/m(2)). Resting vascular resistance and ghrelin were highest (P < 0.05, main effect), and total T(3) and energy expenditure adjusted for fat free mass lowest (P < 0.05, main effect) in oestrogen deficient women. Using pooled data for stepwise multiple regression modelling: ghrelin and resting energy expenditure adjusted for fat free mass were associated with resting vascular resistance (R(2) = 0.398, P = 0.018); adjusted dietary energy intake was associated with peak-ischaemic vascular resistance (R(2) = 0.231, P = 0.015). Adjusted resting energy expenditure (r = 0.624, P < 0.001) and total T(3) correlated (r = 0.427, P = 0.019) with resting heart rate. Homocysteine, high-sensitivity C-reactive protein and oxidized low-density lipoproteins were similar (P > 0.05, main effect) among the groups, and were unrelated to cardiovascular measures.


CONCLUSIONS
Altered resting vascular resistance in premenopausal oestrogen deficient physically active amenorrheic women is not associated with vascular inflammation or oxidative stress, but rather with parameters that reflect metabolic allostasis and dietary intake, suggesting a potential role for chronic energy deficiency in vascular regulation.
O'Donnell
Emma
E
Cardiovascular Regulation Laboratory, Department of Exercise Sciences, University of Toronto, Toronto, Ontario, Canada.
Harvey
Paula J
PJ
De Souza
Mary Jane
MJ
D000293:Adolescent; D000328:Adult; D000568:Amenorrhea / Q000503:physiopathology; D002097:C-Reactive Protein / Q000378:metabolism; D002149:Energy Intake / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology*; D004967:Estrogens / Q000097:blood / Q000172:deficiency*; D005260:Female; D054439:Ghrelin / Q000097:blood; D006339:Heart Rate / Q000502:physiology; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000097:blood; D008077:Lipoproteins, LDL / Q000097:blood; D009043:Motor Activity / Q000502:physiology*; D009752:Nutritional Status / Q000502:physiology*; D010060:Ovulation / Q000502:physiology; D018384:Oxidative Stress / Q000502:physiology*; D011446:Prospective Studies; D014655:Vascular Resistance / Q000502:physiology*; D055815:Young Adult
D004967:Estrogens; D054439:Ghrelin; D007328:Insulin; D020738:Leptin; D008077:Lipoproteins, LDL; D006710:Homocysteine; D002097:C-Reactive Protein