[Monitoring of glucose concentration in critical patients, comparing arterial blood glucose concentrations and interstitial glucose concentration measured by microdialysis technique]

INTRODUCTION

Recent studies have shown that normalization of blood glucose in critically ill patients by intensive insulin therapy significantly decreases their mortality and morbidity. The aim of our study was to compare interstitial glucose concentrations in subcutaneous adipose tissue (measured by microdialysis technique) and arterial blood glucose concentrations to test the suitability of subcutaneous adipose tissue for long-term placement of biosensors for glucose measurement in critically ill patients.

PATIENTS AND METHODS

20 patients (16 men and 4 women) after cardiac surgery hospitalized at postoperative intensive care unit were included into the study. Mean age was 68 +/- 10 years, BMI was 28.3 +/- 3.9 year. Only patients with glycemia higher than 6.7 mmol/l at a time of admission to the ICU were included. Samples for measurement of interstitial glucose concentrations were collected in 60 minutes intervals during 48 hours using microdialysis of the subcutaneous adipose tissue. Perfusion fluid was 5% mannitol, perfusion rate was 1 microl/min. Arterial blood glucose concentration was measured in 60 minutes intervals, absolute concentrations of interstitial glucose were calculated using ionic reference technique.

RESULTS

Mean arterial glucose concentration during the study was 6.7 +/- 0.56 mmol/l, absolute concentration of glucose in interstitial fluid was 3.55 +/- 0.58 mmol/l. Mean correlation coefficient between arterial and interstitial concentrations was 0.77 +/- 0.15.

CONCLUSION

Our study demonstrated good correlation between interstitial glucose concentrations in subcutaneous adipose tissue and arterial blood glucose concentrations in post-cardiac surgery patients. Further studies are needed to evaluate this relationship in patients with more severely disturbed perfusion of subcutaneous adipose tissue.

Homocysteine and risk of cardiovascular disease among postmenopausal women

CONTEXT

Individuals with elevated levels of homocysteine tend to have higher prevalence of cardiovascular disease. However, prospective studies of homocysteine are inconsistent and data among women are limited.

OBJECTIVE

To determine whether elevated homocysteine levels in healthy postmenopausal women predict risk of developing cardiovascular disease.

DESIGN

Prospective, nested case-control study with a mean 3-year follow-up.

SETTING

The Women's Health Study, an ongoing US primary prevention trial initiated in 1993.

PARTICIPANTS

From a total cohort of 28,263 postmenopausal women with no history of cardiovascular disease or cancer at baseline, 122 women who subsequently experienced cardiovascular events were defined as cases, and 244 age- and smoking status-matched women who remained free of disease during follow-up were defined as controls.

MAIN OUTCOME MEASURES

Incidence of death due to cardiovascular disease, nonfatal myocardial infarction (MI), stroke, percutaneous transluminal coronary angioplasty, or coronary artery bypass graft by baseline homocysteine level.

RESULTS

Of the 122 cases, there were 85 events of MI or stroke and 37 coronary revascularizations. Case subjects had significantly higher baseline homocysteine levels than controls (14.1 vs 12.4 micromol/L; P = .02). Subjects with homocysteine levels in the highest quartile had a 2-fold increase in risk of any cardiovascular event (relative risk [RR], 2.0; 95% confidence interval [CI], 1.1-3.8). This effect was largely due to an excess of cases with high levels of homocysteine; the RR for those with homocysteine levels at or higher than the 95th percentile (20.7 micromol/L) was 2.6 (95% CI, 1.1-5.7). Risk estimates were independent of traditional risk factors and were greatest for the end points of MI and stroke (RR for those with baseline homocysteine levels in the top quartile, 2.2; 95% CI, 1.1-4.6). Self-reported multivitamin supplement use at study entry was associated with significantly reduced levels of homocysteine (P<.001). However, the association between increasing quartile of homocysteine level and risk of MI or stroke remained significant in analyses controlling for baseline multivitamin supplement use (P = .003 for trend), and subgroup analyses limited to women who were (P = .02 for trend) or were not (P = .04 for trend) taking multivitamin supplements.

CONCLUSIONS

Among healthy postmenopausal US women, elevated levels of homocysteine moderately increased the risk of future cardiovascular disease. Whether lowering the homocysteine level reduces risk of cardiovascular events requires testing in randomized controlled trials.

[A hysteroscopic and anatomicopathological study in women with breast cancer]

OBJECTIVE

To study the uterine mucosa of women with breast cancer in order to evaluate the frequency of endometrial diseases.

EXPERIMENTAL DESIGN

Prospective, controlled study carried out from January to December 1996. SURROUNDINGS: Patients with breast cancer and normal controls from 4 out-patient university services in Porto Alegre, Brazil.

PATIENTS

Postmenopausal women without hormonal therapy were compared: 67 of them with breast cancer and 101 normal controls.

METHODS

Hysteroscopy followed by endometrial biopsy carried out in both groups as an out-patient procedure.

RESULTS

In patients with breast cancer, 29.85% abnormal biopsies were found as follows: 10 endometrial polyps (15.0%), 8 with proliferative changes (11.9%), 1 case of cancer (1.5%), and one case of hyperplasia (1.5%). In the control group 8% abnormal morphological findings were found, as follows: 4 (4%) with endometrial polyps and 4 (4%) with proliferative changes. The differences in abnormal biopsies were statistically significant, mainly in patients with corporal mass index above 27.3. The sensibility of hysteroscopy was 82.14%; its specificity 97.16%; its predictive positive value 85.18% and its predictive negative value 96.48% in detecting endometrial activity, for a prevalence of 16.7% of endometrial activity.

CONCLUSIONS

Endometrial evaluation must be included in the initial evaluation of patients with breast cancer, mainly if they were obese. Hysteroscopy, performed in out-patient basis, showed to be an adequate method to evaluate the uterine mucosa, helping to select the area of this cavity for biopsy.

Prospective study of C-reactive protein and the risk of future cardiovascular events among apparently healthy women

BACKGROUND

C-reactive protein (CRP) predicts risk of myocardial infarction (MI) and stroke among apparently healthy men, but in women, virtually no data are available.

METHODS AND RESULTS

CRP was measured in baseline blood samples from 122 apparently healthy participants in the Women's Health Study who subsequently suffered a first cardiovascular event and from 244 age- and smoking-matched control subjects who remained free of cardiovascular disease during a 3-year follow-up period. Women who developed cardiovascular events had higher baseline CRP levels than control subjects (P=0.0001), such that those with the highest levels at baseline had a 5-fold increase in risk of any vascular event (RR=4.8; 95% CI, 2.3 to 10.1; P=0.0001) and a 7-fold increase in risk of MI or stroke (RR=7.3; 95% CI, 2.7 to 19.9; P=0.0001). Risk estimates were independent of other risk factors, and prediction models that included CRP provided a better method to predict risk than models that excluded CRP (all P values <0.01). In stratified analyses, CRP was a predictor among subgroups of women with low as well as high risk as defined by other cardiovascular risk factors.

CONCLUSIONS

In these prospective data among women, CRP is a strong independent risk factor for cardiovascular disease that adds to the predictive value of risk models based on usual factors alone. (Circulation. 1998;98:731-733.)