Fibrinolytic response in subjects with hypertriglyceridemia and low HDL cholesterol

Central Obesity, the Metabolic Syndrome, and Plasminogen Activator Inhibitor-1 in Young Adults

PURPOSE

To determine the association of central obesity with the components of the metabolic syndrome (i.e., hyperinsulinemia, hypertension, hypertriglyceridemia, low levels of high-density lipoprotein cholesterol [HDL-C]) and plasma levels of plasminogen activator inhibitor-1 (PAI-1) in young adults. We hypothesized that central obesity as determined by waist circumference would be predictive of components of the metabolic syndrome and of PAI-1.

DATA SOURCES

Participants in this descriptive study consisted of 85 healthy young adults aged 19-22 years, 62% women who fasted for 12 h prior to data collection in the General Clinical Research Center at a major university hospital medical center in the southeastern United States.

CONCLUSIONS

The majority of the participants had one or more components of the metabolic syndrome (n= 43, 51%). Central obesity was present in 14.1% and was more common in women than men (chi(2)= 5.11; p= 0.021). Central obesity was significantly and positively correlated with elevated blood pressure (BP) and levels of insulin and PAI-1 while being negatively correlated with HDL-C. In multiple regression analyses, diastolic BP, insulin, and HDL-C were predictors of waist circumference (R(2)= 0.615). In a separate multiple regression, PAI-1 was predicted by waist circumference (R(2)= 0.331).

IMPLICATIONS FOR PRACTICE

Many otherwise healthy young adults have one or more components of the metabolic syndrome. Assessment and institution of preventative measures for obesity and the components of the metabolic syndrome should begin in childhood. Furthermore, determination of waist circumference especially in young women may aid the practitioner to identify those at risk for the metabolic syndrome earlier in their disease trajectory. Furthermore, insulin resistance is believed to occur initially in the trajectory of the metabolic syndrome, making it a principal contender for suitable interventions to reduce risk for both type 2 diabetes and cardiovascular disease (CVD). Homeostatic model assessment for insulin resistance was used to assess for insulin resistance among the euglycemic participants. Recording the presence of insulin resistance will aid the practitioner in determining if a low-risk patient is in peril for development of type 2 diabetes and/or CVD. Early cardiovascular risk recognition is vital to clinical practice as it allows more time for the practitioner to counsel patients for the essential planning needed to make lifestyle changes.

Structural and functional abnormality of systemic microvessels in cardiac syndrome X

BACKGROUND AND AIM

Microvascular damage of coronary bed has been considered the main pathogenetic factor of cardiac syndrome X (chest pain, exercise-induced ischemic ST-segment changes and angiographically normal coronary arteries). Previous studies have demonstrated that vascular abnormalities are not confined to the heart, suggesting a peripheral vascular dysfunction. On the hypothesis of a generalized microvascular disturbance in cardiac syndrome X, we performed a morphologic and functional study of systemic microcirculation in patients with syndrome X compared to normal subjects.

METHODS AND RESULTS

Microvessels were evaluated with intravital videocapillaroscopy (VCP) executed in peripheral and conjunctival observation sites which explore micro and paramicrocirculation; biohumoral study included markers of inflammation and of endothelial function, coagulative-fibrinolytic system and lipid metabolism. Videocapillaroscopy showed several morphologic changes (present in high percent of patients with syndrome X and not in controls) and significant quantitative alterations (capillary density, granular flow score, alterations of vessel profile, length of capillary loop branches and of arteriole/venule diameter) which indicated a severe alteration of whole vessel structure and an important rearrangement of microvascular disposition. In a similar way, the humoral study showed some significant changes of endothelial (vWF, ICAM-1, E-sel, PAI-1), inflammatory (C-reactive protein (CRP), fibrinogen) and metabolic factors (HDL-chol) which are commonly associated with inflammatory response.

CONCLUSIONS

We conclude that patients with cardiac syndrome X exhibited some structural and functional alterations of systemic microvasculature; the pattern is similar to that detected in systemic inflammatory diseases and suggests a vascular lesion of inflammatory type. The same changes could be operating also in coronary microvessels of patients with syndrome X.