Higher insulin infusion rate but not 24-h insulin consumption is associated with hypoglycemia in critically ill patients.

AIMS: To assess the association between insulin infusion rates, and 24-h insulin consumption on hypoglycemia in the intensive care unit (ICU). METHODS: This was a retrospective case-control study, conducted at an academic institution in the United States. Adult patients admitted to the ICU receiving intravenous insulin infusions for blood glucose control were included. Hypoglycemic (blood glucose <70 mg/dL) patients were matched 1:1 with non-hypoglycemic controls based on age, gender, and body mass index. Multivariable conditional logistic regression analyses were conducted to determine the effect of: (1) weight-adjusted insulin infusion rate (units/kg/h), (2) non-weight-adjusted insulin infusion rate (units/h), or (3) 24-h insulin consumption (units/day) on hypoglycemia. RESULTS: A total of 122 patients were included in the study (61 cases, 61 controls). Compared to those patients who received <0.05 units/kg/h, the odds of hypoglycemia was higher in those who received was ≥0.1 units/kg/h (OR 4.57, 95% CI 1.45-14.41, p=0.010). Compared to those patients who received <4 units/h, the odds of hypoglycemia was higher in those who received was ≥8 units/h (4.17, 95% CI 1.18-14.75, p=0.027). The risk of hypoglycemia did not increase with higher 24-h insulin consumption. CONCLUSIONS: Higher insulin infusion rates rather than 24-h insulin consumption may be associated with hypoglycemia in critically ill patients in the ICU.

The exposure-dependent effects of aged secondhand smoke on endothelial function.

OBJECTIVES: The aim of this study was to investigate whether exposure to a range of relatively low concentrations of aged secondhand smoke (SHS), similar to those encountered commonly in the community, would impair endothelial function in a concentration-dependent manner. BACKGROUND: Exposure to SHS impairs endothelial function in humans. The concentration-dependent relationship for aged SHS effects on endothelial function after an exposure of short duration is unknown. METHODS: Thirty-three healthy nonsmokers were exposed to 1 of 2 low levels of aged SHS or to conditioned filtered air for 30 min. The primary end point was change in maximal percent brachial artery flow-mediated dilation after exposure. RESULTS: In a linear regression model for each increase in SHS exposure by 100 µg/m(3) respirable suspended particles, the absolute maximal percent brachial artery flow-mediated dilation was reduced by 0.67%. We did not find evidence of a threshold for the effect of SHS on flow-mediated dilation. CONCLUSIONS: Short-term exposure to real-world levels of aged SHS for 30 min resulted in a concentration-dependent decrease in endothelial function as measured by flow-mediated dilation.

Tobacco smoke and cardiovascular risk: a call for continued efforts to reduce exposure.

PURPOSE OF REVIEW: This review will summarize contemporary data regarding the cardiovascular effects of tobacco exposure. In particular, this review will highlight recent data that focuses on the magnitude of continued exposure both in the United States and abroad, the cardiovascular risks of tobacco exposure despite improvements in medical therapy, and the important effects of low levels of exposure including secondhand smoke (SHS). RECENT FINDINGS: Recent data demonstrates that the current burden of tobacco exposure both in the United States and worldwide remains large. Despite improvements in medical therapy for cardiovascular disease the cardiovascular effects of tobacco exposure are substantial. Recent data also demonstrates that even intermittent smoking and exposure to SHS have important cardiovascular effects. SUMMARY: The cardiovascular effects of tobacco exposure, including even low levels from SHS, remain important. Continued efforts to reduce exposure to our patients are critical for improved cardiovascular health.

Impact of smoking on cardiovascular events in patients with coronary disease receiving contemporary medical therapy (from the Treating to New Targets [TNT] and the Incremental Decrease in End Points Through Aggressive Lipid Lowering [IDEAL] trials).

To define the incremental risk of cigarette smoking in patients with coronary disease receiving contemporary medical therapy, we performed a post hoc analysis of 18,885 patients by combining data from the Treating to New Targets (TNT) and the Incremental Decrease in End Points through Aggressive Lipid Lowering (IDEAL) trials. These studies compared high-dose treatment (atorvastatin 80 mg/day) to moderate-dose treatment (atorvastatin 10 mg/day in TNT and simvastatin 20 to 40 mg/day in IDEAL) in patients with established coronary heart disease. The primary end point of this pooled analysis was major cardiovascular events, a composite of cardiac death, myocardial infarction, stroke, or resuscitated cardiac arrest. At baseline 4,196 patients had never smoked, 11,513 were ex-smokers, and 3,176 were current smokers. The adjusted hazard ratio for current smokers compared to never smokers was 1.68 (95% confidence interval 1.46 to 1.94) and that for current smokers compared to ex-smokers was 1.57 (95% confidence interval 1.41 to 1.76). Event rates for current smokers compared to ex-smokers were similarly increased in each treatment group. The difference in absolute event rates between current and ex-smokers in this pooled analysis was 4.5%, which is >2 times as large as the decrease in absolute event rates between high-dose and moderate-dose statin therapy found in the IDEAL (1.7%) and TNT (2.2%) trials, respectively. In conclusion, in patients with coronary disease receiving modern medical therapy, smoking cessation is of substantial benefit with a number needed to treat of 22 to prevent a major cardiovascular event over 5 years. Smoking cessation deserves greater emphasis in secondary prevention.