Insulin sensitivity in young women with vasovagal syncope

Ruiz, Graciela Aurora; Calvar, Cecilia; Hermes, Ricardo; Rivadeneira, Daniel; Bengolea, Viviana; Chirife, Raúl; Tentori, María Cristina; Gelpi, Ricardo J.

doi:10.1016/s0002-8703(02)94707-1

Cited by 11 publications

(16 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Insulin hypersensitivity has been linked with vasovagal syncope (Ruiz et al . ). In the present study, blood glucose was measured only in a subgroup of consecutive women ( n = 12), and although we did not see any trend towards a difference in blood glucose between OI and OT women, we cannot rule out minor group differences in insulin hypersensitivity or blood glucose level.…”

Section: Discussionmentioning

confidence: 97%

Slower lower limb blood pooling in young women with orthostatic intolerance

Lindenberger

Länne

2014

Experimental Physiology

View full text Add to dashboard Cite

New Findings r What is the central question of this study?Orthostatic stress is mostly caused by venous blood pooling in the lower limbs. Venous distension elicits sympathetic responses, and increased distension speed enhances the cardiovascular response. We examine whether lower limb blood pooling rate during lower body negative pressure is linked to orthostatic intolerance. r What is the main finding and its importance?A similar amount of blood was pooled in the lower limb, but at a slower rate in women who developed signs of orthostatic intolerance. The difference in blood pooling rate increased with orthostatic stress and was most prominent at a presyncope-inducing level of lower body negative pressure. The findings have implications for the pathophysiology as well as treatment of orthostatic intolerance.Vasovagal syncope is common in young women, but its aetiology remains elusive. Orthostatic stress-induced lower limb blood pooling is linked with central hypovolaemia and baroreceptor unloading. Venous distension in the arm elicits a sympathetic response, which is enhanced with more rapid distension. Our aim was to study both the amount and the speed of lower limb pooling during orthostatic stress and its effects on compensatory mechanisms to maintain cardiovascular homeostasis in women with orthostatic intolerance. Twenty-seven healthy women, aged 20-27 years, were subjected to a lower body negative pressure (LBNP) of 11-44 mmHg. Five women developed symptoms of vasovagal syncope (orthostatic intolerant) and were compared with the remaining women, who tolerated LBNP well (orthostatic tolerant). Lower limb blood pooling, blood flow and compensatory mobilization of venous capacitance blood were measured. Lower body negative pressure induced equal lower limb blood pooling in both groups, but at a slower rate in orthostatic intolerant women (e.g. time to 50% of total blood pooling, orthostatic intolerant 44 ± 7 s and orthostatic tolerant 26 ± 2 s; P < 0.001). At presyncope-inducing LBNP, the mobilization of venous capacitance blood was both reduced (P < 0.05) and much slower in orthostatic intolerant women (P = 0.0007). Orthostatic intolerant women elicited blunted arterial vasoconstriction at low-grade LBNP, activating only cardiopulmonary baroreceptors, while orthostatic tolerant women responded with apparent vasoconstriction (P < 0.0001). In conclusion, slower lower limb blood pooling could contribute to orthostatic intolerance in women. Mobilization of venous capacitance blood from the peripheral to the central circulation was both slower and decreased; furthermore, reduced cardiopulmonary baroreceptor sensitivity

show abstract

Section: Discussionmentioning

confidence: 97%

Slower lower limb blood pooling in young women with orthostatic intolerance

Lindenberger

Länne

2014

Experimental Physiology

View full text Add to dashboard Cite

show abstract

“…Oral glucose tolerance tests are not without complications, however, since they induce supine fainting in about 60% of young women with vasovagal syncope (Ruiz et al 2003). In the older adult population, it has long been recognized that supine blood pressure falls after a meal (Jansen and Hoefnagels 1990;Lipsitz et al 1983).…”

Section: Introductionmentioning

confidence: 99%

Oral glucose tolerance test reduces arterial baroreflex sensitivity in older adults

Madden

Tedder

Lockhart

et al. 2008

Can. J. Physiol. Pharmacol.

View full text Add to dashboard Cite

Although postprandial decreases in blood pressure are a common cause of syncope in the older adult population, the postprandial effects of the oral glucose tolerance test on blood pressure and the arterial baroreflex remain poorly characterized in older adults. Therefore, arterial blood pressure and the arterial baroreflex were studied in 19 healthy older adults (mean age 71.7 +/- 1.1 years) who were given a standardized oral glucose load (75 g) or an isovolumetric sham drink during 2 separate sessions. All measures were taken for 120 min after treatment. Baroreflex function was assessed by using the spontaneous baroreflex method (baroreflex sensitivity, BRS). Subjects demonstrated a decrease in BRS after oral glucose that was not seen in the placebo session (two-way analysis of variance, p = 0.04). There was no significant change in systolic, mean, or diastolic blood pressure; together with a drop in BRS, this resulted in a significant tachycardia post glucose (two-way analysis of variance, p < 0.001). We conclude that healthy older adults can successfully maintain blood pressure during an oral glucose tolerance test despite a decrease in arterial BRS. Decreased BRS resulted in a tachycardic response to glucose.

show abstract

“…In contrast to individuals who are overweight or obese, thin individuals do not have insulin resistance. In fact, a recent study showed that women with a positive HUT response had an increased sensitivity to insulin compared with those with a negative HUT or normal weight controls without syncope . This phenomenon can be directly related to the complex mechanism of the triggering of VVS episodes.…”

Section: Discussionmentioning

confidence: 98%

“…8,9 Young women with VVS and a positive HUT have a higher incidence of hypersensitivity to insulin. 10 In contrast, the intracellular deposition of fat (as seen in obesity) increases insulin resistance, 11 and this is often associated with increased peripheral vascular resistance. [12][13][14][15] Based on these observations, we performed an observational study to test the hypothesis that obesity (high body mass index [BMI]) is protective against a positive HUT result in patients referred for the investigation of syncope.…”

Section: Introductionmentioning

confidence: 99%