Divergent relationships among soluble tumor necrosis factor-alpha receptors 1 and 2, insulin resistance, and endothelial function

Impact of obesity and diabetes on postoperative outcomes following surgical treatment of nontraumatic subarachnoid hemorrhage: Analysis of the ACS-NSQIP Database

BACKGROUND

Nontraumatic subarachnoid hemorrhage (SAH) refers to high pressure extravasation of blood into the subarachnoid space that typically occurs spontaneously from rupture of cerebral aneurysm. The purpose of this study was to identify postoperative complications requiring increased surveillance in obese, diabetic, and hypertensive patients.

METHODS

Patients who underwent surgical treatment for nontraumatic SAH were queried in the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database from the years 2012-2018. Cases were identified using ICD codes and then classified independently by three dichotomous diagnoses: obesity, diabetes, and hypertension.

RESULTS

Among 1,002 patients meeting inclusion criteria, 311 (31%) were obese (BMI >30), 86 (9%) had diabetes treated with insulin or non-insulin agents and 409 (41%) required medication for hypertension. There was a statistically significant association between diabetes and post-operative pneumonia (OR = 1.694; 95% CI 0.995 - 2.883; p = 0.050), prolonged ventilator dependence (OR = 1.700; 95% CI 1.087 - 2.661; p = 0.019), and death (OR = 1.846; 95% CI 1.071 - 3.179; p = 0.025). Medicationdependent hypertension was statistically associated with incidence of stroke/CVA (OR = 1.763; 95% CI 1.056 - 2.943; p = 0.023). Obesity was not associated with adverse outcomes in this population.

CONCLUSIONS

In patients undergoing surgical management of SAH, hypertensive and diabetic patients had poorer outcomes, including prolonged ventilator dependence, pneumonia, stroke/CVA, and death. Surprisingly, preexisting obesity was not associated with poor outcomes. In fact, overweight BMI, Class I, and Class II obesity had decreased need for transfusion in the 30-day postoperative period.

Paradoxical preservation of vascular function in severe obesity

BACKGROUND

Obesity is associated with a high risk of coronary artery disease morbidity and mortality. Yet, postmortem studies have shown that severely obese subjects exhibit smooth coronary arteries, thus suggesting that they may be protected from atherosclerosis. We assessed vascular function and its possible determinants in a cohort of normal-weight to severely obese insulin-sensitive subjects (body mass index [BMI] 23.2-49 kg/m(2)).

METHODS

Seventy-one healthy, insulin-sensitive subjects (Homeostasis Model Assessment of Insulin Resistance index <2.5), divided into normal-weight (n = 13; BMI = 23.2 +/- 1.6), obese (n = 35; BMI=32.6+/-2.5), and severely obese (n=23; BMI=49.0+/-7.9) groups, were enrolled. Vascular function was evaluated by flow-mediated dilation and carotid intima-media thickness. High-sensitivity C-reactive protein, leptin, adiponectin, vascular growth factors, and CD34+KDR+/CD133+ endothelial progenitor cells, known markers of vascular health/protection, also were measured.

RESULTS

Flow-mediated dilation was higher in severely obese than in obese and normal-weight individuals (P=.019 and P=.011 respectively). Intima-media thickness was consistently lower in severely obese than in obese individuals (P=.040) and similar in severely obese and normal-weight individuals (P >.99). Levels of high-sensitivity C-reactive protein and leptin were higher in severely obese than in obese and normal-weight individuals (high-sensitivity C-reactive protein: P=.018 and P=.05, respectively; leptin: P <.001 for both comparisons). CD34+KDR+ endothelial progenitor cells were significantly higher in severely obese versus obese individuals (P=.039).

CONCLUSION

Our study demonstrates that vascular function is paradoxically better in severely obese than in obese subjects and similar to that found in normal-weight subjects. Despite higher levels of high-sensitivity C-reactive protein and leptin, severely obese individuals may be partially protected from atherosclerosis, possibly by a greater mobilization of endothelial progenitor cells.